Clinical Judgment: How to Do Less

It was around 11:00 AM when we were called to a local skilled nursing facility for a hip fracture. The patient was a 61-year-old male with mild mental retardation and several other issues, who’d fallen last night while walking to the bathroom. He was helped back to bed with moderate hip pain, and the staff physician stopped by to check him out. A portable X-ray was performed, which the physician interpreted as showing a proximal femur fracture as well as an associated pelvic fracture. This was communicated to us via a scrawled note and a cursory report.

The patient was found resting comfortably in bed, semi-Fowler’s and alert. He had no complaints at rest, although his pelvis and left femoral region were mildly tender and quite painful upon movement. No deformity was notable and there was no obvious instability. His vitals were stable and he was generally well-appearing, in no apparent distress. He denied bumping his head and had no pain or tenderness in the head or neck.

We gently insinuated a scoop stretcher underneath him, filled the nearby voids with towels and other linen, and bundled him into a snug, easily-movable package. Then we gave him the slow ride to his requested emergency department, a teaching hospital in town just a few minutes away.

We rolled into the ED and were lifting him into bed on the scoop when a young man entered the room, bescrubbed and serious-looking. I gave a brief report. As the words “pelvic fracture” left my lips, his mental alarms started visibly beeping and flashing, and he hurriedly asked, “What kind of pelvic fracture?”

“We don’t know. All we’ve got is the radiology note, which doesn’t say much.”

“Okay, but pelvic fractures can be a big deal. It could be … ” he sucked in air, “… open-book. There could be a lot of bleeding.”

I stared at him. “Well, sure. But he’s been stable since last night, and has a basically normal physical with no complaints at rest. He’s not exactly circling the drain.”

He didn’t seem to hear me as he briskly approached the patient and began poking him and asking questions. While we pulled our stretcher out of the room, he asked, “Does your neck hurt at all?”

Now that the patient had been stuck on a scoop stretcher for over twenty minutes, he thought for a moment and then shrugged. “Sure.” The doctor immediately ordered the placement of a cervical collar.

As we escaped, he was on the phone to the SNF, and the last thing I heard was him berating them with his urgent need to know exactly what type of pelvic calamity the patient had suffered.

What was the failure here? It was a failure of clinical judgment.

Clinical judgment is a phrase which means different things to different people, and often its meaning is so nebulous (much like “patient advocacy“) that it sounds good while saying nothing. But most would agree that it means something like this: the ability to combine textbook knowledge and personal experience, applying them intelligently to the current patient’s situation to yield an accurate sense of the possible diagnoses and the costs vs. benefits of possible treatments. In other words, it means knowing what the patient’s probably got and what to do about it, which is the heart of medicine anyway. So what’s all the fuss about?

In reality, when clinical judgment is mentioned, what’s often meant is something specific: the wisdom to know when something’s not wrong. Much of medicine is about planning for the worst, ruling out the badness, and looking for the unlikely-but-possible occult killer that nobody wants to miss. As a result, we often act as if nearly everybody is seriously ill, even when they probably aren’t.

On a practical level, most complaints — from chest pain to the itchy toe — could conceivably represent a disaster. Anything’s possible. So if we want to truly adopt perfectly mindless caution, we should be intubating every patient and admitting them directly to the ICU so that we’re ready when their skin melts off and their eyes turn backwards.

But we can’t do that, and we shouldn’t. So how do we know when to do a little less? Clinical judgment.

Clinical judgment is the acumen to assess a patient and say, “I think we’re okay here. Let’s hold off on that.” It’s what you develop when you have both the knowledge and experience to understand that a person is low-risk, and that certain tests or treatments are more likely to harm than to hurt them. That doesn’t mean that nothing will be done, or that more definitive rule-out tests will not occur, but it means you’re not freaking out in the meanwhile. It’s a triage thing.

Put another way, imagine the patient who you’re placing in spinal immobilization, or providing with supplemental oxygen, or to whom you’re securing a splint. They ask, “Look, I don’t much like this; do I really need it?” Well, I don’t know, rockstar — does he? If you’re simply acting on algorithms, reflexively doing x because you found y, then you really don’t know. How important is that oxygen? To answer that, you’d need to truly understand the benefits versus the potential harms, which means having a strong grasp of the mechanism of action, familiarity with the relevant literature (including the pertinent odds ratios, NNT and so forth), prior experience with similar patients, et cetera… only with that kind of knowledge do you really understand what’s happening. In essence, the patient is asking for the informed element of informed consent, something he’s entitled to, and you can’t provide it if you don’t have it yourself.

But when you do develop that depth and breadth of knowledge, you gain a special ability. It’s the ability to do less. When you truly understand what you’re dealing with, and more importantly, what you’re not dealing with, you can titrate medicine to what’s actually needed and stop there. Along with the knowledge comes the confidence, because you don’t merely know, you know that you know; in other words, you don’t need to take precautionary steps merely because you’re worried there might be considerations you don’t understand.

When it comes to withholding anything, even the kitchen sink, you might ask, “isn’t there risk here?” And strictly speaking, there is risk. But you can set that bar wherever you want. The important thing to grasp is that “doing everything for everyone” is not the “safe” approach; overtriage and overtreatment are not benign. All those things you’re doing have a cost. They may cause real harm. Even at best, they cost time and money, and subject the patient to unnecessary discomfort and inconvenience. We’d like to minimize all that whenever possible.

So, we return to the gentleman with the pelvic fracture. Strictly speaking, fracture of the pelvis has the potential to be life-threatening; certain types of unstable fracture can cause massive bleeding, along with damage to nervous, urinary, and other structures. So a textbook response to “pelvic fracture?” might be to treat it as a high-risk trauma.

But a patient with an unstable, severely hemorrhaging open-book pelvic fracture probably wouldn’t look like that. It would be evident; it would cause a number of apparent effects, such as pain and distress, shock signs, altered vitals, deformity or palpable instability. Except in bizarre cases or in patients who are clinically difficult to evaluate, big problems create big changes. While it’s true that we don’t know exactly what the X-ray showed, so one could theoretically argue for any conceivable pathology, there’s no question that the patient appeared stable, had remained unchanged for many hours, and had apparently been judged low-acuity after evaluation and imaging by his own doctor. In other words, let’s take it easy.

The question of spinal immobilization is another example. Strictly speaking, could we rule out the possibility of a cervical spine fracture? Well, no. Not without CT and MRI and even then who knows. But the fall was many hours ago, the patient was freely mobile and turning his head throughout that period, had no peripheral neurological deficits, denied striking his head or loss of consciousness, and quite frankly, had no pain until he spent twenty minutes with his head against a metal board.

It’s not often that you find a doctor more concerned about C-spine than an EMT. How did it happen here?

Despite the fact that we delivered the patient to a major tertiary center, it was nevertheless a teaching hospital, and the new interns had just hit the wards. While this particular clinician was undoubtedly smart and well-educated, at this stage he had about two weeks of experience behind him, and that is not conducive to providing judicious (rather than applied-by-spatula) care. He had neither the experience to know when to take it easy, nor the confidence in that experience to stand by such a decision.

We don’t want to take this concept to its extreme, which would involve doing very little for most of our patients. In the end, this is still emergency medicine, and emergency care will always involve screening for the deadly needle in the benign haystack. There’s also danger in simply becoming lazy and burned-out, and using Procrustean application of cynical “street smarts” to justify never bothering with anything. The real goal is to do the right things for the right reasons, no more, no less. And to get to that point, you have to put in some time.

Live from Prospect St: The Big Crunch (conclusion)

Continued from part 1 and part 2

In the end, all three patients receive spinal immobilization. You transport both pediatric patients to Bullitt Medical Center; the P12 assumes care of the mother and transports her to the same destination. No significant injuries are found upon follow-up assessments; however, when the P12 checks Samantha’s blood glucose, they find it to be 32 mg/dL. They administer D50, normalizing her sugar, which improves her level of consciousness; however, she remains confused and becomes somewhat combative. She does endorse substantial alcohol ingestion, is somewhat unclear on drug use, and continues to deny a history of diabetes.

After transferring care, both crews fill out state-mandated documentation to report child abuse, with regard to the mother driving two young children while under the influence and without appropriate car seats or other restraints. You write your documentation with extra caution, aware that it may eventually be used in a court of law.

Discussion

This was a case where no patient was highly acute, but operational issues required some attention and medical confounders obscured the assessment.

General considerations for MVAs

With any significant MVA (or MVC for “motor vehicle collision,” since the DoT takes the position that nothing is truly accidental), there are several factors we should consider:

Scene safety. Wherever the scene may be, it’s generally at or near a roadway, and it’s a location that’s already proven itself accident-prone. In this case, we were situated in a truck yard somewhat off the main road. If it were a busier area, and we were first to arrive, we would want to park the ambulance to shield the scene from traffic, and request fire apparatus (for more blocking) and police (for traffic control). We should also consider the presence of chemicals or other hazardous material in an industrial area, which was not a problem here.
Extrication. The time to request additional resources is early. Heavy extrication, where vehicle frames need to be bent or cut, is usually performed by fire department ladder trucks or dedicated rescue apparatus; in this case, the driver’s door was dented and needed to be popped open (technically “confinement” rather than “entrapment”), and it was handled prior to our arrival.
Cause. Some accidents happen for obvious reasons, such as inattention. Sometimes they’re due to conditions, such as weather or visibility, which is a good clue that such conditions probably persist and might endanger you as well; protect the scene and be cautious during extrication and transport. Sometimes, accidents have a medical cause, which was the case here.
Damage. We are clinicians, not mechanics, but vehicle damage can provide clues to injury type and severity. Modern vehicles often develop horrific-looking body damage while yielding minor personal injury; automotive safety science has become quite advanced, and a large part of a car’s protection comes from intentionally crumpling to absorb impact. If occupants are restrained, the vehicle can easily eat up a large amount of shock without anyone suffering significant harm. In this case, we saw a front-left impact at seemingly moderate speed, so we anticipate a head-on type injury pattern with some lateral energy. Damage to the driver’s-side lower dashboard area, plus minor knee injury, suggested a “down and under” rather than “up and over” direction of movement, which is typical for a restrained driver; the windshield was also missing any apparent point-of-impact, which supports this. With the seatbelt and airbag, we were not too suspicious of frontal head injury, but we did look for evidence of lateral head impact against the window or side-wall; we found no obvious head trauma or internal vehicle damage. There was likewise no signs of internal impact from the children in the rear, although we remain suspicious of pelvic or abdominal trauma, since they were wearing lap belts without any torso restraints.
Number of patients. Life was made easier by the truck driver, who was obviously unharmed and decided to elope from the scene prior to our arrival. Samantha was making vague reference to her brother, but it seemed that he was coming to meet her and was not an occupant. It is somewhat bad form to forget about people, so it’s good to try and confirm these things, and the first-in responders (the fire department in this case) can help.

Assessment

Just like in most cases, the majority of essential information was communicated in the first few seconds on scene.

Our eyeball exam from twenty feet was enough for an initial assessment on the kids. The Pediatric Assessment Triangle is a model for identifying pediatric life threats that focuses on obvious, big-payoff findings rather than details (like specific vital signs) which can be tough to measure. The three components are:

General appearance. This is overall impression and rough neurological status. Are they conscious? If so, sluggish, alert, groggy, engaged with their surroundings, tracking with their eyes? Is there any muscle tone or are they limp? Are they crying? If so, are they consolable? Do they look sick or well?
Work of breathing. This is respiratory assessment. Is the child struggling to breathe? Are they tripoding or assuming a sniffing position to maintain an airway? Is there accessory muscle use, pursed-lip breathing, nasal flaring, chest retractions? Are grossly adventitious breath sounds audible (i.e. wheezing, stridor, grunting, snoring)?
Circulation. This is general circulatory status. Is skin pink and warm? Is there clear cyanosis, pallor, mottling? Obvious bleeding?

From the first moments on scene, we were able to observe that the pediatric patients were: conscious, crying loudly (therefore with a patent airway and adequate breathing), generally unhappy but not acutely distressed, without obvious bleeding or other trauma, and with normal skin signs. That’s plenty for the initial triage — a more full assessment will come later, but it’s unlikely that we’ll uncover any true life threats.

How about mom? We initially notice no obvious issues except for an altered mental status, which may be masking other problems (such as pain or neurological deficits). We also don’t know the cause of the AMS. Is there alcohol involved? Probably: she directly endorsed this. Drugs? Perhaps: vehemently denying drug use is not uncommon in drug users, and there were purpura consistent with needle “track marks” on her arm. But even if present, neither of those precludes a concomitant traumatic head injury; drunk and high people can bump their head too. And we were reminded of the first rule of EMS: everybody is diabetic. Although the circumstances didn’t necessarily suggest hypoglycemia as the most likely cause, it fit the presentation, and all drunk patients are somewhat at risk for this complication. If she’d stayed in our care, glucometry would have been wise during transport.

Is spinal immobilization needed? Local protocol comes into play. The children are probably low risk. The mechanism as a whole is potentially risky, due to the possibility of side-on energy transfer and head injury, but generally is not too alarming and the assessment findings are fairly reassuring. In the case of the mother, she is the classic example of a poor reporter who cannot reliably describe neck or back pain or participate in a neurological exam; most selective immobilization protocols (such as NEXUS or the Canadian C-spine rule) would advise immobilization in such cases. In this instance, due to equipment shortcomings, one child was immobilized via KED and the other two patients immobilized to long boards, with towel rolls used liberally. The children were liberated almost immediately after arrival at the ED, after a clinical exam by the pediatric emergency physician. The mother began fighting her board after she was roused with D50.

Transport and documentation

This case highlighted the need for intelligent patient assessment to guide transport destinations. Although low-acuity pediatric patients can sometimes be assessed in an adult ED, it depends on the receiving physician’s level of comfort, so in many cases they’ll prefer to transfer them to a specialty center (and any time a patient has to be transferred from where we brought them, we’ve failed them somewhat).

In a similar vein, acute patients needing surgical intervention should always be delivered to trauma centers. Does mom need a trauma center? Since we’re unable to rule out a traumatic cause for her mental status, it’s probably wise, although perhaps not essential. Do the kids need a pediatric trauma center? Probably not; they are, by all appearances, doing fine. Finally, although we could transport parent and kids to different hospitals, it would be distressing to everyone and create logistical headaches (involving consent, billing, and other concerns), so Bullitt Medical Center (an adult trauma center as well as a pediatric ED, although not a pediatric trauma center) is a sensible destination. (Since it’s a larger hospital, it’s also more capable of sustaining the “hit” of receiving three patients simultaneously than a small community ED.) Since the mother is a more challenging patient, it makes sense for the paramedics to take her while our BLS unit acts as a bus for the kids.

As for documentation, depending on state law we may be required to report all instances of child abuse to protective agencies. (In this particular region, reporting is mandated for any child or elder abuse.) If so, local procedures should be followed; although the hospital will most likely perform such reporting as well, in many states this does not absolve EMS of its own responsibilities.

When documenting the call, be aware that charges may be pursued against the mother for neglect, driving under the influence, or other offenses. These may hinge upon your documented findings, such as altered mental status, lack of appropriate child restraints, or statements about substance use. Depending on local laws for mandated reporters, you may be required to report these findings directly to police, or you may actually be prohibited from doing so by HIPAA laws; in either case, however, they should be noted in your report.

Live from Prospect St: The Big Crunch (part 2)

Continued from Part 1

Since the two children appear generally intact, you ask your partner to evaluate them more fully while you head for the sedan to find the driver. Anticipating three transports, two stable and one potentially critical, you ask your dispatch to continue the P12, and also to ensure that police are en route (they are).

Arriving at the sedan, you find a middle-aged woman in the driver’s seat, alert. She is pink and warm, perhaps more diaphoretic than you’d expect for the ambient temperature, and does not initially notice as you kneel beside her. A firefighter is holding C-spine immobilization from the back seat.

When you greet her and pat her on the shoulder, she gives no response, but with more vigorous stimulation she looks over and acknowledges you distractedly. With multiple attempts and some yelling, you’re able to get answers to a few questions, but she is slow, tangential, and often ignores you outright. She gives her name as Samantha, but cannot or will not provide her last name; she is unable to describe the events that led to the collision; and she gives no medical history or current medications. She does state several times that she’s fine and would like to leave. When asked about her passengers, she mumbles “my kids” and mentions her brother several times. She endorses pain when asked explicitly, but does not specify where. She agrees that she drank “a little” alcohol; when asked about any drug use, she denies it vehemently.

Physically, she appears generally unremarkable. She is breathing somewhat shallowly but effectively, and her radial pulse is around 100 and slightly weak. Her seatbelt is not in place, but it’s unclear whether it was removed at some point. No gross trauma is apparent upon her head, face, or neck, and she does not complain or grimace upon palpation. She is uncooperative with a neurological exam, but demonstrates spontaneous movement of all four extremities. Her pupils are equal and seem appropriately small on this moderately bright day. Chest rise is generally equal and her abdomen is supple; no bruising consistent with seatbelt injury is visible. Her left knee is abraded and somewhat swollen. A sprinkling of dark blotches and streaks are noted on her left ventral arm in the antecubital region. Both frontal airbags are deployed; the windshield is cracked, but lacks a “starred” point of impact; and the plastic dashboard in the driver’s knee area is damaged and cracked. No blood or other damage is visible in the interior compartment. There are no child seats.

Your partner comes over. “The kids seem fine, just upset. One’s complaining of some abdominal pain, but it looks okay. They’re little troopers. Fire says they were wearing regular lap belts with the shoulder strap tucked behind them.”

When you wonder aloud whether there are more patients, he says, “There was nobody else in the car when fire arrived. The truck driver gave a statement to the police about how she was swerving across the road and plowed into him, but then he eloped.” He looks over your shoulder. “Oh, and the P12 is pulling up now.”

What is your treatment plan for these three patients? What are their respective priorities, any points of concern, and how could you shed additional light on their status?

Who will transport which patient, and to which destinations?

What special considerations should be made during documentation?

The conclusion is here

Live from Prospect St: The Big Crunch (part 1)

It’s 4:00 PM on a gloomy Friday in Chandlerville, and you’re the technician for the A2, a dual-EMT, transporting BLS unit dedicated to the city. Chandlerville is a small town, but densely populated, and its numerous industrial districts are frequent sources of work. 911 dispatch is directly through the fire department, which also sends a BLS fire apparatus to assist on all medical calls; your company’s ALS is also available by request. You are equipped with finger-stick glucometry, glucose, aspirin, and epinephrine.

After a “man down” call that ended in a patient refusal, you’re now returning to quarters. Just as you’re beginning to back into the garage, a tone sounds.

“Engine 3 and Ambulance 2, respond to 2108 Coastal Rd, the Empire Shipping Company, for an MVA. That’s two-one-oh-eight Coastal Road, in front of Empire Shipping, for an MVA. Engine 3?”

“Engine 3 is responding.”

“Ambulance 2?”

As your partner flips on the lights and pulls out to the street, he speaks into the radio: “Ambulance 2 has 2108 Coastal Rd.”

“Time out 16:01.”

Coastal Road is a long connector that wraps around the edge of town, and you glance at the map book to confirm that the 2000 block will be near the very end, about as far away as you can get in Chandlerville. Engine 3 is stationed in that district, however, so they arrive within minutes.

“Engine 3 to Firecom.”

“Firecom answering.”

“We’re off at 2108 Coastal Road. Two-car MVA, car versus truck. Multiple injured parties and entrapment. Start an ALS unit and a ladder for extrication.”

“Engine 3, you have a car versus truck, multiple injuries with entrapment. Break. Ladder 3, respond to 2108 Coastal Rd for the MVA; Engine 3 is on scene and A2 is responding. Time out 16:04.”

A few seconds later, your company radio dispatches Paramedic 12 to the same address, after Chandlerville Firecom contacts them via landline. The P12 starts responding, but they’re coming from two towns away, with an ETA of 10+ minutes. The field supervisor also starts rolling from an unknown location to assist. 30 seconds later, Engine 3 updates that they have an injured adult and several children.

Now very awake, you reflect that the nearest hospital will be Chandlerville Memorial, a 3–5 minute emergent transport (10 minutes otherwise). The nearest large tertiary center, Bullitt Medical Center — a Level I adult trauma center and a designated pediatric ED — is 15 minutes emergently (25 otherwise). The nearest Level I pediatric trauma center, however, is the Children’s Hospital, which is also 15 minutes but in the opposite direction; they do not receive adult patients.

Ladder 3 arrives on scene momentarily, and you pull up a few minutes later. As you park and call yourself out, you observe a Ford sedan with its front left corner smashed in, two feet of its fender and frame crumpled. This is evidently the result of driving almost headlong into the side of an 18-wheeler. It appears that the driver swerved right to avoid the truck, undercutting its rear wheels and “submarining” itself; the damage reaches the passenger compartment, but there does not appear to be significant intrusion. The truck itself seems minimally damaged.

As you jump out, a firefighter waves you down. “We’ve got three!” he announces. “Mom’s in the driver’s seat; she seems really loopy, probably drunk. Her door is just dented, we popped it open. But her kids are over there.”

Twenty feet away, you see two young girls, around 4 years old, each in the arms of a firefighter. They are crying loudly and clearly upset, with no visible injuries. The mother is hidden from sight in the sedan. The driver of the truck is nowhere to be seen.

What are your initial steps for addressing this scene?

Who appears to be the first priority for care?

What resources will you need? Which, if any, should you cancel?

Continued in part 2 and the conclusion

Mastering BLS Ventilation: Algorithms

Continued from Mastering BLS Ventilation: Introduction, then Mastering BLS Ventilation: Hardware, then Mastering BLS Ventilation: Core Techniques, and finally Mastering BLS Ventilation: Supplemental Methods

Over the past few weeks, we’ve explored a large number of BLS tools for maintaining a patent airway and pushing oxygen through it. This is good, because the only reliable way to address this dilemma is by having a large toolbox. Nobody can oxygenate every patient with just one trick, no matter how skilled they are.

But a box of tools isn’t an approach to the airway, no matter how big it is. It’s just a box. You need more than that — you need a plan. If I toss you an apneic person, what are you going to do? What if that fails? What’s plan B? And plan C? Then what happens?

The only way to answer these questions is by creating your own scheme, a roadmap to fall back upon. I can’t give it to you, because I don’t know your variables. I don’t know your specific skillsets, what you’re comfortable with, what you’ve practiced and in what situations, versus what you’ve never done in your life. I don’t know what your local protocols are, and what equipment you have available (including extra toys like supraglottic airways or Narcan/naloxone), your typical transport times, or the general availability of ALS. I don’t know what type of patients you usually encounter, how many personnel you have on hand to manage them, and what sort of extrications are involved.

But you know those things. Roll it all into a ball so you understand your resources and challenges, consider the various tools we’ve discussed, and make a plan.

Click here for a PDF version (recommended if printing)

Here’s an example I concocted. This is a flowchart patterned after the airway algorithms commonly used in the ED or the ICU, and it incorporates most of the ideas we’ve talked about. It assumes certain things, so I’m not putting it forward as something to follow religiously. Rather, it’s meant as an example: this is the type of thinking you need to be doing. You probably won’t take the time to chart it out, but you should at least be thinking about it now, because figuring it out on scene with the sick person is too late. Mentally walk through what you’d do at each juncture, imagining yourself treating a real patient in your real ambulance using your real gear. Think about your responses to each dilemma, and if you discover you’re unsure about any details, seek out additional training or practice to patch those holes; for instance, spending some time with a (high quality) mannequin and a BVM can be beneficial. Even just a few minutes playing with the BVM (try bagging yourself until you really understand how the pressures and airflows work), the non-rebreather, your various airways, and so forth can help develop familiarity with little-used tools, so you truly understand how all the valves function, how to size and adjust everything, even where it can be found in your bags. This is particularly important if you rarely use these tools, because infrequent or not, you still need to exhibit mastery when the time comes.

Questions, comments, or remarks on our proposed model are welcome.

Thanks for sticking with us through this exploration of the art and science of BLS ventilation.

Mastering BLS Ventilation: Supplemental Methods

Continued from Mastering BLS Ventilation: Introduction, then Mastering BLS Ventilation: Hardware, and finally Mastering BLS Ventilation: Core Techniques

We said before that robust management of the “A’s and B’s” requires having a wide range of options and tools available to you. At the BLS level, we don’t have many, but we do have a few. Now that we’ve explored the most important methods, let’s look at a few supplemental tricks and points to ponder.

Sellick’s Maneuver

Once again, remember our upper airway anatomy: the larynx and trachea, through which air flows to the lungs, are positioned anterior to the esophagus, through which we’d prefer air did not flow. What’s more, these twin tubes are different types of structures. The trachea is built largely of cartilaginous rings, the same semi-rigid material that makes up the wobbly front of your nose; it’s not as stiff as bone, but it holds its shape well (go ahead, give your Adam’s apple a squeeze). The esophagus, on the other hand, is a fairly soft tube made of mostly muscle, and can easily be compressed flat.

This suggests a potentially useful trick. If we press upon the front of the larynx, it will retain its shape and move posteriorly, compressing the esophagus. In other words, although you’re pushing on the airway, it’ll remain open, while the esophagus behind it narrows and flattens. It’s like squishing a cardboard toilet paper roll with a metal pipe; they’re both tubes, but one is thin and easily distensible while the other is stiff and strong.

Since one of our challenges in BVM ventilation is getting air to go down the right tube, it makes intuitive sense that flattening the esophagus (the wrong tube) will help us push air into the trachea (the right tube). If we’re not successful with that, it may at least help prevent regurgitation from coming back out from the esophagus. This is particularly important because maneuvers like the sniffing position help straighten both of those tubes, so although they do open the airway, they also tend to increase the risk of gastric inflation. Worse, overly-aggressive bagging — from a first responder, for instance — can wedge open the LES guarding the stomach, and it can remain this way after you take over. Once someone’s forced it open, even gentle ventilations can enter the stomach.

This is called Sellick’s maneuver, or simply cricoid pressure. It’s properly applied by pressing gently upon the cricoid cartilage, which is a good spot because the cartilaginous ring there creates a full circle (most of the other cartilages are C-shaped). It’s helpful during intubation, since it tends to move the glottic opening into the line of sight, but has also traditionally been used to assist with bagging.

To find the cricoid cartilage, palpate the most prominent bulge of the trachea, the “Adam’s apple” or laryngeal prominence. Move your finger downward over a small indentation (the cricothyroid ligament or membrane, where emergency cricothyrotomy would be performed) until you find another, smaller bulge. This is the cricoid cartilage.

Here’s the problem: theory aside, it often doesn’t work very well. A substantial body of evidence has shown that it often doesn’t do much to reduce gastric inflation, nor to impair regurgitation, and can even partially occlude the airway. This led the AHA to state that “. . . the routine use of cricoid pressure in adult cardiac arrest is not recommended” in the 2010 update to their BLS recommendations.

That doesn’t mean it’s useless, but it certainly suggests it shouldn’t be one of our first moves. It’ll help if we take care to do it correctly: pressure should generally be gentle (too hard and you’ll compress the semi-rigid larynx itself), straight back (it’s easy to “roll” to one side and fail to transmit the pressure to the esophagus), and applied nowhere but the cricoid cartilage. I also find that using your index and middle fingers, as in the illustration above, better facilitates this type of pressure than a thumb-and-forefinger grip. Use it as a last resort after other methods to minimize gastric inflation have failed — particularly the simplest and most effective, which is simply bagging with less force (ease the air in, don’t shoot it in) — titrate the amount of pressure to the desired effect, and in the end, don’t be surprised if it fails.

Pocket Masks

People may look at you like you’ve got six heads if you suggest it, but using a “pocket mask” is still a valid and indeed a recommended method for ventilation. Many BLS units carry the devices, which are essentially the same type of mask you see on the BVM, plus a port for supplemental O2 and a one-way or filtered valve to prevent cootie exchange. (If you don’t have such a device, you could simply detach the mask from your BVM and breathe into the hole, removing your mouth between breaths to let the patient exhale. This won’t be as effective of a barrier to infection, since there’s no one-way port, so it’s your call — but the risks are probably minor. You might even be able to increase FiO2 by leaving a cannula on the patient… or wearing one yourself.)

The advantages of this method are numerous. First of all, because you have two hands available to hold the mask, you’ll rarely have difficulty making a seal. Second, it’s extremely easy to titrate the volume and pressure of the breaths you give; unlike with the BVM, where you’re brusquely squeezing a rubber sac, with the pocket mask you’re using your pulmonary apparatus (your lungs) to assist the patient’s pulmonary apparatus, and it’s very easy to maintain tight control over the variables. Simply breathe in normally (not a deep breath) and exhale into the mask with gentle force, stopping when you see the chest rise. You should be able to do this with almost infinitely gentle pressure, making gastric inflation very unlikely.

The disadvantages: you can’t provide 100% oxygen, although if you attach the tubing and crank up a high flow, you can probably provide ample FiO2 for anybody without significant V/Q problems. But the bigger problem is the “ick” factor. Although research has shown that the risk of contracting an infectious disease during mouth-to-mask ventilation is very small, many providers still aren’t comfortable getting that close, preferring to literally stay at arm’s length. But remember: if you’re unable to effectively ventilate an apneic patient and you’ve exhausted all other options, this is a life-or-death situation, and ickiness should not be a key concern.

Mouth to Mouth

What if even the pocket mask fails, or for some reason you have no equipment of any kind available?

There’s always direct mouth-to-mouth ventilation. Nobody will fault you for opting out of this, because of the aforementioned ick factor and the theoretical chance of disease transmission, although again, research has suggested the risk is small. But if all else fails, it should be considered an option, and whether you’ll attempt it is solely up to you. Sheet-type barrier devices, which some people carry on their keychains, may reduce either ick factor or real risk, although you’re probably unlikely to find one around unless you carry your own. Remember that you’ll need to pinch or otherwise seal the nose; if your hands are busy maintaining an airway, you may be able to accomplish this by pressing your cheek against the nares.

If the mouth is obstructed or otherwise non-patent, mouth-to-nose ventilation is a viable alternative; simply ensure their mouth is shut and breathe into the nares. If a stoma is present in the neck, mouth-to-stoma or mask-to-stoma (an infant-size mask may yield the best seal) ventilation can be an option, although depending on how it’s constructed you may need to seal both the nose and mouth to make it work.

Just options, folks. Airways need options.

Jaw Thrusts

Along with manipulating the head, we know that shifting the jaw forward is essential for opening the upper airway. In fact, when we walked the Halls of the Student EMT, the wise men told us that for patients in spinal immobilization, it’s all we’re allowed to do. (A little later they usually said “. . . however, a patent airway takes priority over spinal precautions,” but most of us had already dozed off at that point.)

In any case, translating the jaw forward as far as possible, no matter how you do it, can open the airway substantially.

Along with the classic jaw thrust, there’s another method that’s rarely seen anymore. It’s real easy: with one hand, grab their mandible by the chin and lower teeth and pull up. It works. Could you get bitten? Yes. You also can’t bag them while you’re holding their jaw in your hand like Hamlet. So it’s more of a first aid tactic, but it’s very idiot-proof, so it’s nice to know about. You can see it working in this video.

Risk Factors for Difficult BVM Ventilation

It’s one thing to have a wide range of options for dealing with difficult-to-bag patients, but it’s also helpful to know before you dive in when a patient is likely to become difficult. It can help inform your decisions about priorities and flow of care, as well as the need for ALS and transport destinations.

Patients who are often challenging to bag include:

The obese. Ample soft tissue tends to occlude the upper airway (this is why they often suffer from sleep apnea), adipose tissue bears down on their chest and diaphragm, and they’re generally difficult to position how you’d like. Ramp them and get a good sniffing position ahead of time (don’t try to dynamically head-tilt them while you apply the mask — situate them beforehand, so all you’ll need to do while you bag is maintain the jaw thrust), use airway adjuncts liberally, and plan ahead — don’t ever assume it’ll go smoothly, or you’ll find yourself in over your head without backup plans.
Bearded patients. Thick beards and other facial hair make obtaining a mask seal difficult. It can help if you smear it down with some water-based lubricant (such as your NPA lube), but it can also make a mess of everything until you’re slip-sliding away like Paul Simon. You could also shave them a bit if you have a razor (with your AED gear, for instance), although they probably won’t thank you later unless it’s quite necessary.
Sleep apnea. If you happen to know (via history) that the patient suffers from sleep apnea — or to a lesser extent, even that they snore at night — this indicates an existing predisposition toward upper airway occlusion when their level of consciousness is mildly depressed, so you can expect it to be that much worse when they’re entirely comatose.
The elderly. Everything is harder with old people, including bag-mask ventilation, for numerous reasons.
Anyone with a difficult-to-protract mandible. You probably won’t know this by looking, but if you go to initially address the airway and find that you’re unable to lift the jaw until the lower teeth are at least aligned with the upper teeth (preferably until they’re anterior), you’re probably going to have a hard time, and will need to compensate by achieving optimal extension and a sniffing position.
Anyone with gross trauma to the face or neck, which may create airway occlusion, hinder your ability to make a mask seal, or generate substantial blood and other fluids requiring aggressive suctioning.
Edentulous (toothless) patients. Aside from the fact that they’re usually elderly, patients without teeth have minimal structure to the oral cavity, giving you little to press against with the mask and obtain a seal. If dentures are present, it will help to leave them in; if not, make sure to place an OPA, which provides a little support at least. Make an effort to outwardly “spread” the air-filled skirt of the mask before applying it, which helps ensure that its maximum surface area remains in contact rather than curled uselessly underneath. Also consider this alternate mask placement, which may be more successful: the mask is shifted upward, so the lower edge meets the lower lip directly.

The End-Expiratory Pop

This is an interesting, unusual, and advanced technique which I’ve only ever seen advocated by the Department of Critical Care at the University of Pittsburgh. Briefly, it consists of the following: you bag with a two-person technique if at all possible, ensuring an excellent seal (which is mandatory) and letting you focus solely on the bag. You inflate as normal, release the bag and let the patient exhale, and then near the end of the expiratory phase, you “catch” them with a small squeeze to the bag, preventing their lungs from fully deflating. This may not seem possible, because there’s a valve present that allows exhaled air to vent, but that valve’s position is determined by the relative pressures on each side, so if you insufflate gas at a higher pressure than the patient’s exhaled gas, it’ll open in rather than out. This creates a sealed, temporarily closed system supported by the pressure you’ve created in the bag. If you don’t believe it, try bagging with the mask sealed against a table, or even upon your own face using clean gear.

View an example of the technique in this video clip, from :25 to :55. Here they’re simulating assisting with spontaneous respirations, probably one of the best applications for this method.

This yields two advantages: first, it gives you an excellent “feel” for pulmonary compliance. With a leak-free seal and balanced inspiration/expiration, compliance should remain consistent. If the resistance you feel suddenly decreases, you most likely have a leak. If it increases, you likely have either an obstruction or are “breath stacking,” failing to fully allow for expiration before beginning the next breath. With practice you can develop an excellent tactile sense of the bag-lung interface… as long as your mask seal remains flawless.

Second, and more profoundly, this actually creates positive end-expiratory pressure, or PEEP. In other words, you’re maintaining positive pressure in the lungs even after exhalation, where the alveoli ordinarily might collapse. By never quite “touching ground,” pressure-wise, you keep alveoli partially distended and portions of the bronchial tree “splinted” open that otherwise might have collapsed, particularly in disorders like COPD or CHF. This is the same principle used by CPAP or BiPAP devices, and it’s a wonderful boon that’s often the only way to effectively oxygenate patients with significant atelactasis (collapsed alveoli) and shunt (portions of the lungs that air is unable to reach). If you have a patent airway and are introducing adequate amounts of 100% oxygen, yet the patient remains hypoxic (according to skin signs or pulse oximetry), it’s almost certainly because of a V/Q mismatch like this, and that situation cannot be solved without PEEP or radically more aggressive measures.

The reason this trick is so cool is because it’s probably the only way to apply PEEP at the BLS level, since in most areas we do not carry CPAP devices, or even PEEP valves for the BVM. It’s theoretically possible to tape over or otherwise partially occlude the exhalation port of the BVM, narrowing the space for expiration and therefore providing some back-pressure, but this is totally unmeasurable, not easily titrated, and interferes with the entire phase of expiration. Although trickier, the “Pittsburgh PEEP pop” is better.

Why squeeze at the end of expiration? If you squeeze earlier, you’ll interfere with exhalation of gas, which needs to happen if we’re going to adequately blow off CO2 and avoid “stacking” breaths. If you squeeze later, you missed your chance to prevent a “zero pressure” state in the lungs, so you’re starting from zero again.

Key Points

Sellick’s maneuver (i.e. cricoid pressure) can be helpful for reducing gastric inflation, but is often ineffective or even counterproductive. Use it as a last resort, applying only gentle and direct pressure, and if it’s not working, stop.
Mouth-to-mask, mouth-to-mouth, mouth-to-nose, or mouth-to-stoma can all be effective backups to BVM ventilation, particularly when unable to achieve a mask seal or unable to ventilate without inflating the stomach.
Expect obese, bearded, elderly, toothless, or traumatic patients to be difficult to bag.
A small amount of PEEP can be created with a normal BVM using a small end-expiratory squeeze; this also helps confirm the ongoing integrity of the mask seal.

Next time we’ll give a method for combining all of these concepts into a cohesive approach to the BLS airway.

Continued at Mastering BLS Ventilation: Algorithms

Mastering BLS Ventilation: Core Techniques

Continued from Mastering BLS Ventilation: Introduction and Mastering BLS Ventilation: Hardware

Now that we understand the goals and the basic tools, let’s talk about the most important techniques for optimizing airway management and providing BLS ventilation to apneic patients.

Hand Technique

How do you hold a BVM to the patient’s face?

As a rule, we’re taught something called the “EC clamp.” It looks like this:

In theory, this lets us press the mask against the patient’s face (using the “C” of our thumb and forefinger) while pulling the jaw forward (using the “E” of our other fingers behind the mandible), and still leaves one hand free to squeeze the bag.

In theory.

In reality, this is tricky at best. Partly it’s because we’re trying to seal the edges of a circle by pressing on only one side, which usually results in a leak from the other side. Partly it’s because pulling the jaw forward like this — a highly necessary action — takes a fair amount of force, and we’re in a poor position to grip from. It also doesn’t help that, if no OPA is present, this method usually squeezes the mouth shut, leaving only the nasal passage for an airway.

One useful tip: positioning the bag directly opposite your EC hand and pulling it downward can help seal off the most common point for leaks.

Does the EC technique work? It can work. And it’s fast and versatile to apply, so it’s a reasonable place to start. However, if you find that it’s not working, don’t be too surprised. You would be wise to practice the hell out of it on mannequins (or ideally in an OR or similar setting), but not everyone has that opportunity. What’s the alternative?

Use two hands. The inelegant nature of the EC clamp has been widely recognized for years, despite the fact that many of us in emergency medicine pretend otherwise. In fact, if you flip open your EMT textbook or the handouts from your last CPR class, you will notice that one-person BVM use is strongly discouraged. (In my Limmer textbook, it’s last in preference after the two-person BVM and even the pocket mask.) In the field, this is ignored, because we adopt the attitude that any EMT should be able to sit at the patient’s head and “handle the airway” without help. But that doesn’t change the fact that it’s a crummy technique, and many of the patients who are “bagged” this way only survive because they didn’t need much help to begin with.

What does work reliably is placing both hands on the mask, thumbs toward the feet and fingers behind the jaw. This way you have a hand on both sides and can easily obtain a seal (and if there is a leak it’s readily located), while also providing a strong bilateral grip to protract the jaw. You can sustain this position for a long time, and as a bonus, it tends to open rather than close the mouth.

A slightly different version with thumbs wrapped around, resembling a "double EC"

The downside is that it doesn’t leave a hand to squeeze with. Ideally, another rescuer should squeeze the bag. This lets you focus on maintaining the airway while they focus on bagging slowly, gently, and at an appropriate rate. (But remind them to stop squeezing when they see chest rise; with two hands it’s tempting to try and empty the whole bag, which is far in excess of what’s necessary if you have a good seal.) It can even help to separate the mask from the bag entirely, position it perfectly on the face, clamp down your grip, and then allow the bag to be attached and ventilation begun; this ensures everything is where it ought to be. On scene you often have enough personnel for this; in the back of the ambulance you may or may not. Can you still execute this method alone?

You can, and I highly recommend that you work out the logistics now, with your own unique body type and equipment. For patients in a bed or a high stretcher, you can often stand behind the head, hold the seal with your hands, and squeeze the bag with your elbow against your side. In the patient compartment, you can sit in the tech seat and squeeze the bag against one leg with your elbow, or between your knees if you’re an experienced Thighmaster. A supine patient on the ground can be the trickiest position; you may be able to squeeze the bag against a leg or something similar, but often your best bet will simply be to recruit help. (Again, please experiment with this now, so you’re not improvising while a patient turns blue.) Just remember that using two people to bag isn’t a failure, and has no impact on your sexual adequacy; it’s a legitimate method which is supported by literature and explicitly recommended by the experts we’re supposed to be listening to.

The Sniffing Position

We understand now that successful BLS airway management means maximizing the passable upper airway and minimizing obstructions. Bringing the jaw forward will always be helpful, by pulling the tongue and other anterior structures away from the posterior pharyngeal wall. Now let’s look a little closer at the position of the head itself.

We’re taught to rotate the head back in the head-tilt chin-lift maneuver. Why do we do this? In essence, because it helps align the oral and nasal passages with the pharynx.

In other words, in a neutral position there’s an angle that approaches 90 degrees between the oral cavity (through which air initially passes — or the nasal cavity, which is nearly parallel) and the pharynx (the initial portion of the passage down into the lungs). Such a sharp angle increases the resistance to air and increases the likelihood of occlusion. By rotating the head backwards along the atlanto-occipital joint — i.e. where the skull meets the spine — we can straighten out this corner. We can’t make it completely straight, because the head doesn’t rotate that far (if it did you’d be able to directly face the sky without leaning), but we can improve the angle substantially.

The trouble is that when we do this, we change another angle too. The angle between the pharynx and the trachea tends to sharpen in the vicinity of the larynx as we tilt the head backward. Since the pharynx follows the alignment of the upper neck and lower head, and the trachea follows the alignment of the lower neck and thorax — with the larynx and glottis smack in the middle — there’s an additional angle here that should be straightened as much as possible.

Image courtesy of http://tinyurl.com/c6logld

The good news is that with a supine patient lying on a flat surface, such as a bed or stretcher, simply rotating the head back will partially accomplish this. That’s because our occiput — the back of the skull — is somewhat bulbous and protruding, and when you tilt the head back, it rolls over this rounded prominence, elevating the head. Thus, a standard head tilt produces a small amount of neck-to-thorax flexion, which helps improve the angle at the larynx.

Many patients benefit from greater head movement, however. What we’re trying to do is shift the head forward — anteriorly — while maintaining (not increasing or decreasing) atlanto-occipital extension. In combination, this creates what’s known as the sniffing position, as it resembles someone ostentatiously “sniffing the air.” (“Leading with the chin” may be a more intuitive description.) It’s widely taught as the optimal position for intubation, but it can also reduce resistance to BVM ventilation; you may even encounter patients with perilaryngeal swelling (particularly epiglottitis) who assume this position intuitively to maintain their narrowing airway.

To establish the sniffing position, you need to pad behind the head. It’s sensible to treat each patient somewhat individually, but a good starting point is to elevate the head until the ear (that is, the canal or meatus) is horizontally aligned with, or slightly in front of, the notch of the clavicles. This is often only a few inches (average is ~7cm) beyond the elevation you’ll get from the occiput against the bed alone, but you’ll certainly need to put something back there. Pillows are usually too soft unless you fold them gratuitously, but a folded towel or blanket can work well, or really anything flat.

A few special cases are worth mentioning. First, children. Kids are notorious for having enormous heads compared to their bodies, and the frequent result is that after rotating the cranium, you’ll have created all the anterior movement you need. In fact, it’s possible you’ll need to pad the back and upper shoulders in order to avoid hyperflexion of the neck.

Image courtesy of http://www.narenthorn.or.th/node/77?page=0%2C2

Now consider obese patients. Their general airway challenges make them great candidates for this technique, but because they have extra adipose tissue on their back — which elevates their torso relative to their head — they have the opposite problem as kids: you may need to provide substantially more padding behind the head in order to achieve ear-sternal alignment.

Interestingly, though, in very big patients you may encounter a different situation. Because relatively more adipose tissue collects in the lower back and hips than in the upper back and shoulders, while supine, the morbidly obese patient may actually be “upside down”; their torso is angled uphill, resulting in their head and chest being crunched together even while lying “flat.” To achieve anything like reasonable airway positions, you’ll need to first correct this by elevating (really just leveling) their upper back. This is called ramping, and may require a substantial amount of linen, although you might be able to get part of the way there by raising the back of the stretcher a little (thus preferentially elevating their upper back, since most people slip down a fair amount). Once you’ve achieved body normality, you can create your sniffing position, aligning ear to clavicles in the usual fashion.

Image courtesy of http://bariatrictimes.com/2012/02/16/airway-management-in-bariatric-surgery-a-challenge-for-anesthesiologists/

Truth be told, there are advantages to sitting up almost any respiratory patient. It reduces the chance of airway occlusion from soft tissues, helps blood and secretions drain, reduces impedance on the chest wall, and prevents the abdominal viscera from compressing the diaphragm. The only reason we don’t manage everyone this way is because it’s hard to do much with a patient sitting high or semi-Fowler’s, such as bagging them or airway insertion. But for the patient who’s still breathing spontaneously, the simplest airway intervention is simply to keep them upright or perhaps in the lateral recovery position.

Key Points

The two-hand BVM technique is preferable to the EC technique whenever possible, and it’s far easier to perform with a second person to assist.
Optimal airway diameter and angles can be achieved by protracting the jaw and simultaneously elevating and extending the head into a “sniffing position.”
Pediatric patients may not need additional head elevation to achieve this, or may even need padding of the back.
Obese patients may need substantial head elevation.
Very obese patients may need to be “ramped” to level their torso before attempting other airway maneuvers.
When more aggressive management is not needed, an upright or lateral supine position provides the simplest protection of the airway.

Tune in next time for a few extra tricks to increase our airway options, and a comprehensive approach for bringing it all together.

Continued at Mastering BLS Ventilation: Supplemental Methods and finally Mastering BLS Ventilation: Algorithms

Mastering BLS Ventilation: Hardware

Continued from Mastering BLS Ventilation: Introduction

The basic tool of BLS oxygenation is the bag-valve-mask, aka the bag-mask (as the AHA calls it), aka the Ambu-Bag (as most in-hospital staff call it, after one of the popular manufacturers), aka the self-inflating resuscitator. We’ll talk about techniques for optimizing for BVM success later. For the moment, let’s discuss some of the other auxiliary aids available. As we do, remember our main challenges: if we don’t minimize the resistance to airflow into the trachea, we’ll be prone to inflating the stomach instead of the lungs. And if we don’t minimize obstructions higher in the pharynx, we won’t be able to introduce any air at all.

Nasopharyngeal and Oropharyngeal airways

The NPA (or nasal trumpet) and OPA are the mainstays of BLS airway adjuncts. Essentially, they’re just curved pieces of plastic or rubber, designed to be inserted into the upper airway to prevent soft tissue from collapsing and obstructing the lumen.

When I first learned about these, it was just after hearing about the head-tilt chin-lift and jaw thrust, which were purportedly enough to open any self-obstructing airway. Why did we need these tools? “This way,” my instructor advised, “you don’t have to sit there holding their airway open.”

Well, yes and no.

The standard theory behind these devices is this: in a supine, unconscious patient, the tongue (and other soft tissue) wants to collapse into the pharynx. If we can jam something in the way, it will essentially “splint” open the passage — stick a foot in the door — much as if we were holding tissue back with a tongue depressor. Positioning the head and neck in such a way that it widens the relevant gaps would accomplish the same thing.

Under this thinking, we have several redundant tools to accomplish the same purpose. Whether we open the airway by tilting their head and lifting their jaw, or by sticking an OPA in the mouth, or by sticking an NPA in the nose, the result is the same.

But this doesn’t quite reflect reality. Sometimes it will, but in many patients with difficult airways, it’s not so simple to maintain a patent passage for airflow. In an obese patient with challenging upper airway anatomy, the amount of soft tissue standing in your way may be profound, and it can obstruct the lumen in multiple places. Additionally, tone may be so lacking that it easily “molds” around anything you stick in there.

In other words, if you place a BLS airway, the only breathable passage you’re really guaranteed is the lumen enclosed by the device itself: the central hole or grooves. And that’s not very much room. Our goal isn’t to create a tiny breathing tube, it’s to maximize the amount of usable airway — we’d like to be able to ventilate through as large a diameter as possible. That means using everything we can.

So proper positioning is helpful. So is an OPA. And perhaps an NPA. Or two.

In fact, if at all possible, it’s always worth trying to insert multiple airways. This is typically not taught to EMTs (since textbooks subscribe to the the “splinting” rather than the “protected lumen” theory), but it’s widely practiced in the ED and by experienced paramedics. If you’re having any difficulty at all bagging, shoot for an OPA with bilateral NPAs; filling all the available holes with patent airways is always a good idea.

Remember what you’re actually doing with each airway. With an NPA, you’re separating the soft palate from the superior and posterior nasopharynx, and if it’s properly sized, it should be long enough to create a passage through the laryngopharynx, nearly to the epiglottis. (If it’s too long, it can stimulate the gag reflex, or jam into the vallecula or epiglottis, actually obstructing the larynx; if it’s too short, it may not protect the laryngopharnyx, or even may not fully span the nasopharynx, allowing the soft palate to shut.) With an OPA, you’re separating the lips, depressing the tongue to prevent it from obstructing the oral cavity, and more importantly protecting the laryngopharynx in the same way the NPA does — keeping the tongue or other anterior structures clear.

So if you only insert an NPA, the nose is your only guaranteed airway. If the mouth itself is shut — and we typically squeeze it shut when we bag using the “EC clamp” technique — nothing will flow through the oropharynx. Conversely, if we only insert an OPA, there is no guarantee that the nasopharynx will remain patent, particularly where the soft palate wants to meet the posterior pharynx.

So use both, because we want it all.

OPAs are more widely used, but it’s a shame to neglect the NPA. The advantage, of course, is that patients with an intact gag reflex can still tolerate an NPA, whereas the OPA may stimulate vomiting. It’s unwise to use the “try and see” approach with the OPA, because there’s nothing quite like copious emesis to make a difficult airway more difficult. Kyle David Bates teaches the helpful tip of inspecting for saliva and secretions collecting in the mouth; if there are none, the patient likely has an intact gag reflex. If they are present, an OPA is probably safe. But suction is always worth keeping on-hand and prepared.

It’s taught that NPAs are contraindicated in patients with significant facial or cranial trauma, on the theory that you may pass the device through a basal skull fracture right into the brain. This is probably a negligible risk; the entire concept seems to be based on two (yes, that’s the number before three) case reports in the literature. If your suspicion is quite high (blood from the nose with a positive halo test, for instance), you may want to steer clear, but with a truly difficult airway, remember that oxygenation is more important than an extremely remote risk of poking the patient’s noodle.

NPA placement can be facilitated by ensuring you lubricate the device first (water-based jelly should be available, although traditionally the patient’s saliva can be used as a last resort), aiming “in” (posteriorly) rather than “up” (superiorly), and lifting the nose to facilitate this angle. Also, remember that each nasal fossa has erectile tissue which takes turns engorging and partially obstructing airflow (allowing cyclical “resting” of the mucosa), so at any given time, one nare will likely allow easier NPA passage than the other; if you’re having difficulty, just switch sides. (Stripping part of this tissue away from the concha will occasionally cause post-insertion bleeding, but it’s rarely significant.)

As for the OPA, we usually teach insertion with the tip pointing up, followed by a 180-degree rotation once it’s fully inserted. Just remember that it’s also acceptable and sometimes easier to insert it tip-down while holding back the tongue with a tongue depressor or finger.

Another somewhat prosaic benefit to the OPA is that it may help provide structure to edentulous [toothless] patients when you’re trying to bag them, although simply leaving dentures in place can also work.

Apneic Oxygenation

You may not think that the lowly nasal cannula and non-rebreather mask really qualify as useful airway tools in an apneic patient. But oh, you would be wrong.

Pop quiz: is it possible to oxygenate the blood without actively moving any air? In other words, can you breathe without breathing?

You might say no. But why not? Gas exchange in the alveoli is not an active process; you’re not forcing the O2 molecules across the membrane by any chemical or muscular exertion. They simply diffuse passively, like gin dispersing into your tonic. All you’re doing when you breathe (either spontaneously or via positive-pressure ventilation) is providing a fresh supply of air to ensure that the concentration of oxygen in the alveoli remains higher than the concentration in the blood (thus allowing diffusion to occur). If we can keep the alveolar oxygen levels high without breathing, that’s just fine.

Suppose, for instance, that we place the apneic patient on a nasal cannula at relatively high flow. This should fill the pharynx with near-100% O2. Even without breathing, gas exchange is occurring in the alveoli; oxygen is diffusing across the membrane into the blood where it binds hemoglobin, and carbon dioxide is diffusing the opposite direction. Far less CO2 is moving out than oxygen is moving in, however (due to differences in solubility and hemoglobin affinity), so there’s actually a net “loss” of gas. This creates some “suction” or a partial vacuum in the alveoli, which will draw in whatever gas is waiting in the upper airway to fill it. Since we’ve flushed that space with pure O2, oxygen will move down that gradient, enter the alveoli, and continue diffusing into the blood, creating a continuous flow. Using this method, patients have been demonstrated to maintain reasonable sats for ridiculously long periods (up to 100 minutes in ideal circumstances).

This is a technique called apneic oxygenation. Although referred to by different names, it’s not new (among other things, it’s a traditional component of most brain-death evaluations), but it’s recently been getting more publicity. In particular, Scott Weingart of EMcrit and Richard Levitan recently published a paper comprehensively describing its use in difficult intubations. They advise placing a cannula at 15 L/min in order to suffuse the pharynx with near-100% O2, and this recommendation has some support in the literature. (Interestingly, whether the patient has their mouth open or closed may not matter.) We’re usually taught that nasal cannulae shouldn’t be used at flows this high, since it’ll dry and irritate the mucosa of the nose, and this is true; however, for short periods in critical patients, a dry nose is not the foremost concern.

How could this be useful for our purposes? Our main challenge with the BVM is ensuring that positive pressure goes where we want it to. This is obviously essential. But if bagging is initially challenging, could we potentially buy time? As long as the airway down to the glottis is open to flow, at least partially, it takes no skill at all to place a cannula (probably already present) and run up the flow to 15 L/min. Even if we’re totally unable to ventilate effectively, this will help keep the patient oxygenated and saturated while we work on a more definitive solution.

A couple of caveats: first, there must actually be a somewhat patent (if not totally secure) airway for this to work. If upper airway structures (or even a foreign body) have totally occluded the nasopharynx or laryngopharynx, no oxygen will reach the trachea. Second, this is a short-term temporizing measure only, because although it may help oxygenate, it will not help to “ventilate,” meaning to remove waste carbon dioxide; as discussed, CO2 is much less capable of passively diffusing without actual tidal movement to clear the alveolar space. Sustained apnea will therefore lead to continually increasing hypercapnia. Finally, this is really intended for patients with largely normal V/Q ratios; it will probably be of limited use for patients with significant shunt (e.g. bronchoconstriction, pulmonary edema, etc.) or dead space (e.g. pulmonary embolism). In other words, it’s of little help to your respiratory patients, whose problem is that their lungs aren’t working properly; if they’re moving air at all, they’re most likely suffusing their alveoli with high-concentration O2, it’s just that they’re just unable to exchange it. They need something like CPAP to help recruit more usable alveoli. Apneic oxygenation is for patients with working lungs who merely aren’t breathing spontaneously or adequately protecting their airway.

Can’t you just use a mask for this? Eh. Studies suggest that O2 from a non-rebreather tends to remain outside the face (in the bag and mask itself) unless the patient actually breathes, since it’s easier for the gas to simply overflow from the exhalation ports than to penetrate their airway; this is distinguished from the cannula, which actually shoots pressurized oxygen directly into the nasopharynx.

However, when it comes to patients who do still have some spontaneous respirations, a non-rebreather can certainly be useful, and here’s a way to supercharge it. Contrary to popular belief, you’re not actually delivering 100% oxygen with a typical mask at 15 L/min — more like 60–70% in most cases. This is due both to the poor seal it generally forms with the face and to the fact that at least one external port is usually left open to room air, so that if the oxygen supply is interrupted or becomes inadequate the patient won’t be suffocated. However, you can get closer to 100% FiO2 by simply cranking up the flow. Once you hit around 30–60 L/min, enough surplus oxygen is overflowing through the mask that the patient should be breathing nearly pure O2. Your portable oxygen tank probably won’t allow a flow this high (and it’d quickly run empty if it did), but most wall- or ambulance-mounted regulators should, although it may be near their maximum flood. Just crank the regulator up to 15 and keep turning until it won’t turn anymore; the indicator won’t change, but the flow will keep increasing. (Although I won’t be the one to recommend it due to the [likely overstated] safety concerns, you could probably also get good results by taping over any valveless ports in the mask, and holding it tightly sealed to their face — or better yet, letting them hold it.)

It may seem convenient, incidentally, to simply press a BVM against their face. Although this may — may — produce an effective seal, it provides poor O2 flow for spontaneous respirations; often times patient-initiated breaths simply bypass the reservoir and draw room air.

Key Points

When it comes to BLS airway adjuncts, the more the better. Two NPAs and an OPA is ideal.
NPAs are generally safe; the risk of penetrating the cranial vault is probably negligible.
Don’t go poking around with the OPA in already-difficult airways; make an effort to determine whether a gag reflex is present before stimulating it.
If an open airway to the lungs exists, but ventilations are difficult, a nasal cannula at 15 L/min is an excellent way to provide apneic oxygenation as a temporizing measure to maintain saturation.
The only “high-flow” oxygen device on your ambulance for a spontaneously-breathing patient is a non-rebreather with flow of 30+ L/min.

A general reminder: although we are cavalier with failing to include in-line or footnoted citations, these are all evidence-based recommendations, and readers are encouraged to inquire for the literature behind anything that seems surprising or dubious.

Continued at Mastering BLS Ventilation: Core Techniques, then Mastering BLS Ventilation: Supplemental Methods, and finally Mastering BLS Ventilation: Algorithms

Mastering BLS Ventilation: Introduction

Sometimes, patients can’t breathe. When that happens, we need to breathe for them.

Simple enough. This is life support at its most fundamental, and many of the interventions classified as “BLS” are found here — techniques and devices for artificially supporting the body’s airway and breathing.

And it doesn’t seem so hard. When they taught it in class, it only took a day or two, and a few pages in the textbook encompassed the subject. How to size an OPA, how to hold the BVM, something about jaw thrusts, and you’re through. Spend a few minutes playing with a mannequin and now you’re an expert.

In the real world, though, this is not child’s play. Managing the airway of a sick, apneic patient is, at best, a high priority; at worst, it’s an unqualified catastrophe. Case reports and horror stories of airways gone wrong can be found under every roof: the failed intubation, the disastrous cricothyrotomy, the foreign body obstruction that couldn’t be cleared. These are emergencies because as we all know, without an airway, you cannot survive. It’s simple stuff.

And then there’s the BVM — aka the bag-valve-mask or “Ambubag.” Ask a room full of novice EMTs and they’ll all agree it’s about as straightforward as tying your shoes: slap it on, squeeze, any idiot could do it. But ask the senior medic in the corner, and he may paint a grimmer picture. Jeff Guy has described it as a more difficult skill than endotracheal intubation, yet one of the hot topics today in prehospital medicine is whether paramedics should remove intubation from their scope of practice because it’s too hard. But nobody’s going to take away the BVM. It’s irreplaceable; it’s the first and last line, the means of ventilation that any patient starts with, and the fallback if your next move fails. The only problem is that doing it well, and for really tough patients, doing it at all, is a purely skill-based exercise. It’s the Jedi’s lightsaber: simple, versatile, but designed for an expert.

The point is that establishing a patent airway in a sick person who can’t do it themselves, and ventilating them using that airway, is such an important task that it generally mandates a large toolbox. Airways are often managed via complex flowcharts or algorithms, where one method can yield to another if it fails, and then to another and another. Countless different devices and methods are available, so that even when obstacles are present, any moron can stumble onto something that works before the patient crashes altogether.

And then there’s us. The Basic EMT stands at the bottom of the spectrum in terms of training, yet is expected to oxygenate any patient using nothing but the meager BLS jump-kit. He has the BVM, a couple of basic airways, masks, cannulas, suction, positioning — and beyond that, just his wits and skills. And as for those, he probably spent little to no time actually practicing them in class, and may perform them only rarely in the field.

This won’t do. When it comes to psychomotor skills, these are the most essential, because we don’t have a Plan B. If BLS techniques fail, our only recourse is to sprint for the hospital or ALS, and hope nobody dies along the way.

So let’s talk about all the principles and tricks of creating a BLS airway and ventilating with the BVM. First, we’ll need to understand why it’s hard.

Basic Physiology

Ordinarily, we suck at breathing.

I mean we literally suck. We drop the diaphragm and widen the ribs, expanding the area inside our chest. This expands the lungs, forcing them to suck air into the only opening available — through the mouth and nose, down the pharynx, through the trachea, and into the bronchial tree.

That’s assuming that the airway is open, of course.

Now, what if I whack you over the head, and your body loses the ability to spontaneously breathe? We’ll want to breathe for you. Can we pull down your diaphragm and expand your chest? Not very easily, unless we stick a plunger on your sternum, or put you in an iron lung. Instead, we reverse this process: rather than creating negative pressure inside the chest, we force positive pressure in from the outside. Rather than sucking, we blow.

Blowing is a little tricky, though. One of the main problems is that there’s more than one place for air to go. Consider the pharynx, the working area of your upper airway. We can get there via two paths: the oropharynx (via the mouth and over the tongue), or the nasopharynx (via the nostrils), but they arrive at the same place, the laryngopharynx (or hypopharynx). What happens next?

If we peered into your hypopharyngeal space, we would see that two openings emerge below. One leads to a tube which lies posterior (toward your back): your esophagus, which conveys cheeseburgers and beer into your stomach. One leads to a tube which lies anterior (toward your front): your trachea, which brings air into the lungs for gas exchange. Remember these relative positions — the trachea is in front, and you can palpate it at the neck (the “Adam’s apple” is part of it). The esophagus lies behind this, and is not usually externally palpable.

Given that food and air both enter via the pharynx, how do we ensure that cheeseburgers ends up in the esophagus and air ends up in the trachea? Well, the gatehouse to the trachea is the larynx (the “voicebox,” where vocalization occurs), and the opening to this chamber is called the glottis. The glottis is normally open, but when you swallow, a couple of drape-like vestibular folds and a little flap, the epiglottis, are pulled in to cover the larynx. The result is that food is forced into the esophagus.

What about the other direction? The esophagus is formed from rings of muscles called esophageal sphincters, which help “milk” food downward when you swallow. The bottommost ring is the lower esophageal sphincter, which opens during swallowing, but otherwise is mostly constricted, sealing off the esophagus from the stomach itself. This prevents air from passing down and gastric contents from coming up (something we know as heartburn).

To summarize, as you sit here reading this, your esophagus is clamped off by your lower esophageal sphincter, and your trachea is open, allowing you to breathe. But if you take a bite of your coffee-cake, your epiglottis and vestibular folds will block off your airway, your esophageal sphincter will open, and the food bolus will be directed into your stomach.

Down the wrong pipe

The trouble with blowing instead of sucking is that we have no way of aiming where we blow.

I know what you’re thinking. If we force air down the pharynx, the esophageal sphincter should block off the stomach, ensuring that it flows into the larynx and down the trachea. Right?

Here’s the problem. Even ordinarily, your esophageal sphincter only clamps down with a small amount of force — say around 30 cmH2O (centimeters of water, a unit of pressure). This is plenty to prevent air from flowing in during regular respiration. But if air were to be pushed in with greater than 30 cmH2O of force, it will squeeze past the sphincter and enter the stomach. And if we clamp a BVM over your face and squish the bag, we can easily exceed that much pressure.

It gets worse. In order for the esophageal sphincter to work even that well, it requires muscular tone (constant stimulation), just like your postural muscles need tone to keep you from falling over. What happens when you’re unconscious? Sphincter tone decreases. So in the people we’ll actually be bagging, opening pressure may be 20–25 cmH2O or even less. Thus it’s even easier for positive pressure ventilations to force their way into the stomach.

The result? When squeezing the BVM, air often enters the stomach along with (or instead of) entering the lungs. Not only is this pointless, it makes it even harder to inflate the lungs (a bigger abdomen creates pressure on the diaphragm), decreases cardiac preload, and increases the risk of vomiting — which will further obstruct the airway.

The easiest solution is to put a tube into the trachea and seal it off — i.e. endotracheal intubation (or variations on that theme, such as a blind airway). Then we can blow air directly into the lungs without any chance that it’ll enter the wrong pipe. Unfortunately, those are tools we often lack as BLS providers.

Angles and Tissues

All of those structures we’ve been describing? They’re soft.

Soft and squishy. And it’s not just the esophageal sphincter that loses tone when you become unconscious.

In ordinary circumstances, the airway is a supple but structured arrangement of tissues that maintains its form. This is important, because there’s not very much space in there. So in the unresponsive patient, it’s no surprise that some of those tissues might collapse together, blocking off the lumen between them. (Check out this fluoroscopic video.)

The tongue is the worst. Tongues are basically big blobby muscles, attached at only one end, and if you remove all firming tone, they just flop wherever gravity takes them. So put an unconscious person supine, and gravity pulls the tongue back into the pharynx, blocking all airflow.

Or the larynx and supralaryngeal tissues run into the posterior pharyngeal wall. Or the soft palate does. Either way, anterior structures end up touching posterior structures, leaving no room in between. Our airway involves a tight 90 degree turn, and this is not a design that remains open without active maintenance. So if we want to breathe for these people, we need to find a way to unblock everything. (Like the jaw thrust — check out this airway cam.)

Mask Madness

Trying to push air into someone’s lungs by holding a mask over their face is like trying to blow up a tire by… well, holding a mask over the valve.

I teach CPR, and I can count on one hand the number of times I’ve handed the BVM to somebody and watched them achieve chest rise on the mannequin the first time. Heck, I demo the things and I don’t always pull it off.

Effectively sealing an air-filled plastic mask to someone’s face and then squeezing the bag is a task meant for more hands than any human possesses. Doing it on somebody who’s dying is exponentially more difficult. Add in the fact that they’re probably obese, toothless, vomiting, crumpled in a corner or bouncing around an ambulance, and enshrouded in a thick ZZ Top beard. Now try to get it all done without losing your cool or breaking your proper ventilatory rate. Having fun yet?

Key points

BLS ventilation using basic airways, positioning, and the BVM is a difficult, complex, and undertrained skillset for the EMT-B. Yet since we often lack rescue devices or alternate ventilation methods, it is critical that we learn to master it.
Preventing gastric inflation would be difficult even in healthy people, and is extremely difficult in the apneic and unresponsive patient.
Loss of tone in unconscious patients lying supine reliably produces soft tissue airway obstruction which must be cleared.
Obtaining a proper mask seal is a necessary prerequisite for BVM use, but is often difficult or impossible for a single rescuer.

Tune in next time to see some solutions to these challenges.

Continued at Mastering BLS Ventilation: Hardware, then Mastering BLS Ventilation: Core Techniques, then Mastering BLS Ventilation: Supplemental Methods, then finally Mastering BLS Ventilation: Algorithms

The Curious Incident of the Dog in the Diagnosis

“Is there any point to which you would wish to draw my attention?”

“To the curious incident of the dog in the night-time.”

“The dog did nothing in the night-time.”

“That was the curious incident,” remarked Sherlock Holmes.

Sir Arthur Conan Doyle, Silver Blaze

We can learn a lot from Sherlock Holmes.

If there’s anybody who better personifies the ultimate diagnostician, I don’t know who. Sir Arthur Conan Doyle, creator of the Holmes canon, was himself a physician and purportedly based his famous detective on Dr. Joseph Bell — who, it was said, could glean a dozen esoteric facts of a patient’s background, history, and complaints from a single glance. (Holmes himself, of course, was not a medical man; that role was played by Watson, the earnest physician who carried his stethoscope wrapped inside his hat.)

Holmes didn’t diagnose illness. Instead, he diagnosed crimes. But the methods were the same, so much so that among the countless fictional characters based upon the Holmesian archetype, some have been crime-solvers (cf. Monk), yet others have been medical doctors (House is the best). Perhaps we shouldn’t model ourselves after the man, who was a single-minded addict and misanthrope, but when it comes to diagnosis — something we can’t escape in medicine — he knows whereof he speaks.

The diagnostic method

Holmes tells us in The Sign of Four that detection involves nothing more than three skills: observation, deduction, and knowledge. Let us consider what he means when faced with, for example, a complaint of chest pain.

Observation: we perceive a middle-aged male, alert and seated upright, rubbing at his sternum with a pained expression. His skin is slightly pale, his respiratory rate is slightly elevated, and he is hypertensive. He complains of “tight” 4/10 chest pain whenever he breathes. Upon auscultation we detect diffuse, bilateral, biphasic wheezing. We note a history of coronary artery disease, diabetes, and COPD.

Knowledge: Chest pain in adults indicates a high risk for acute coronary syndromes. Pallor, tachypnea, and hypertension are consistent with this diagnosis. Sharp, mild, pleuritic pain is not, nor is wheezing, all of which are more consistent with a primarily respiratory etiology. But we also know that MI often presents atypically, particularly in diabetics.

Deduction: Both cardiac (ACS) and respiratory (COPD exacerbation) diagnoses top our differential. An ECG and biomarkers are needed to further evolve the odds.

So what just happened? We observed using our medical assessment — the history, physical, and diagnostic tests — thus yielding a collection of facts and data. We took the set of background knowledge we already possessed, regarding pathophysiology, epidemiology, and hazard ratios, and used it to “fill in the blanks” and provide context to our assessment findings. Finally, we connected the dots together and used deduction to decide what we’re dealing with.

Holmes knew this method well. He might observe your tattered boots, and using knowledge he possessed of typical wear patterns in the various trades, deduce that you make your living as a longshoreman. Simplicity itself.

Why is this a useful model for diagnosis? Because it highlights the fact that these three skills are entirely distinct, though all quite essential. Observation requires skill with the physical exam, the ability to take a nuanced history, the acumen to interpret diagnostics — it’s simply the trait of being aware. (Holmes, succinctly: “Data, data, data! I can’t make bricks without clay.”) Knowledge is knowledge: it’s memorized facts, what you learn in school or from books, and it gives us the basis to understand the raw material we discover in our assessment. Finally, deduction is the mental capacity to analyze, discover patterns, weigh odds, use your imagination, and extract from the vast pool of observation and knowledge the particular pieces that are actually relevant. (Holmes: “… to recognize out of a number of facts which are incidental and which are vital.”)

The hidden danger

Here’s the rub: we’re almost too good at deduction. Humans are excellent at finding patterns in anything. If I leave you my tea-cup for long enough, you’ll undoubtedly find an image revealed in the leaves.

That’s good — but it’s an error. Because there’s not really any image in the tea leaves. But if you’re good at observing details, and have a strong imagination, you’ll still “deduce” many wonderful things from it. Call it apophenia: people want to connect the dots, even when there aren’t any. So we create connections that may be true, but are not always true. We develop stereotypes. Simplifications. False associations.

In medicine, we’re especially prone to this. Because we do know that the human body is interconnected, and that patterns are the rule rather than the exception. Indeed, a large part of developing experience and clinical judgment is increasing your catalog of mental connections. Crackles mean CHF. Irregular pulses mean A-fib. People with Foley catheters have UTIs. Homeless people are drunk. Toe pain is a nonsense complaint. We can’t avoid making the connections, because just like when Holmes examines your boots, those connections are essential to doing our job. But at the same time, we need to learn when to reign them in, or we enter an inescapable diagnostic tunnel after the first moments of patient contact.

It is a capital mistake to theorize before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts.

A Scandal in Bohemia

What’s the secret? Knowledge.

Sure, we gather the pieces from our assessment, and we automatically start to connect them together. We can’t help that; patterns jump out at us, we’re natural pattern-finding machines. But using our knowledge, we can look past those simplistic, eye-catching patterns, because knowledge tells us something more subtle: what’s missing.

She’s all false positives. See, that’s the trouble with naturals. They don’t see what’s missing.

Lie to Me, “Moral Waiver”

Okay, Friday night, a “man down” call for a homeless guy on the sidewalk. You’re already thinking: drunk. And the initial observations confirm it: he rouses sluggishly, slurs his speech, and pushes you away as he rolls back over. But then you open the mental box that you filled with this sort of thing in your training, and you reflect: where’s the bottle? And this is a strange spot — it’s cold, wet, public and unsheltered. And come to think of it, is that a medical alert bracelet? We should probably check this guy out a little more. Maybe take his blood sugar, look for any trauma, shake him awake and ask some questions.

The initial pattern recognition is there, but you don’t have to be a slave to it, because you know what else to look for. Even if five clues say one thing, if we don’t see five others that ought to be there, that tells us something different. Pertinent negatives, they call ’em in the business.

Maybe there’s nothing else; maybe the drunk is just drunk. But we’re too smart to make that kind of assumption. Because we know that getting it right doesn’t just mean registering the hits — it means checking off the misses, too.

Holmes would expect no less.