Archives for August 2012

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.



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.



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 to expand

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

  1. 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.
  2. 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.
  3. Expect obese, bearded, elderly, toothless, or traumatic patients to be difficult to bag.
  4. 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