Drug Families: Stimulants and Depressants

There are many, many, many, many, many, many drugs.

And I think it’s noble and wise for a sharp EMT-B to learn as much as he can about as many of them as he can. General mechanism, typical routes, notable adverse effects and contraindications. The most common meds are encountered so frequently that you can’t help but become familiar with them.

But what about all the rest? (You remember those — many, many, many, etc.) Memorize them all? Maybe, but that’s a task on par with memorizing the map of London. I’ll freely admit that my own mental encyclopedia of pharmacology is weaker than it should be.

Use a reference? These are certainly handy; printed quick-books are available, as are digital versions you can access with a smartphone (Epocrates and Medscape are a couple good ones — see the Droid Medic for guidance). But we really ought to have at least a surface recognition of most drugs we come across, without having to consult an Ouija board.

Fortunately, 80-90% of the drugs you’ll encounter can be broadly categorized into a few major types. If you understand these types, and their basic physiological behavior, you’ll understand most of what’s relevant to your care; and it’s easy business to memorize which type a drug belongs to. So let’s go over some of these categories.

Some of these groups seem to fall naturally into matched opposites. So today, let’s discuss…

 

Stimulants and Depressants

Basically, it’s all about speeding up, or slowing down.

Most of us have heard of the “fight or flight” response, our body’s instinctive ability to step on the gas in times of need — an acute stress response that lets us climb trees, hunt mammoths, and escape from tigers. It’s the get-up-and-go state, and its physiological trigger is known to laymen as adrenaline. This is partly correct; in actuality, your body creates this high-output condition through a variety of hormonal mediators (including adrenaline, more commonly known in the US as epinephrine, but also dopamine and norepinephrine). Overall, this functionality of your autonomic nervous system is known as the sympathetic system.

Some of us have also heard of the reverse state of fight-or-flight, often called “rest and digest” (or sometimes “breed and feed”). This is the slow down, recover, repair, rebuild, and relax state; this is the brake to the sympathetic’s gas. Although slowing down is the last thing you want when escaping from sabre-toothed tigers, it’s just the ticket when you’re enjoying supper or having a snooze. This side of things is known as the parasympathetic system.

(How to keep these two straight? Try this mnemonic: the s in sympathetic is for “stress,” because this is your fight-or-flight stress response. The p in parasympathetic is for “peace,” because this is your peaceful, resting state. Thanks to Mark O’Brien for this one.)

Together, these two systems keep your body tuned like a guitar string. It’s a mistake to think that when one is active, the other is switched off; actually, they’re both active at all times, merely to different degrees. Although their combined results are directly antagonistic, they’re independent systems, which means that you can have a mixture of a little sympathetic, a lot of parasympathetic, vice versa, a lot of both, or any combination thereof.

Think of it like the hot and cold knobs on your sink. You adjust them separately, but the result is a single water temperature. A little hot and a little cold will give you warm water, but so will a lot of hot and a lot of cold. And if you want to cool it down, you can either turn up the cold, or turn down the hot. Simple.

Well, the secret is that many of the drugs we use in medicine function primarily by adjusting this balance.

A drug that turns up the sympathetic system (thus “speeding you up”) is known as a sympathomimetic. A drug that turns down the sympathetic system is known as a sympatholytic.

A drug that turns up the parasympathetic system (thus “slowing you down”) is known as a parasympathomimetic. A drug that turns down the parasympathetic system is known as a parasympatholytic.

Okay, so those are mouthfuls. But the important thing to remember is that, while they’re not identical, the result of both a sympathomimetic and a parasympatholytic will be to support your fight-or-fight responses (run from the lion!), and the result of both a parasympathomimetic and a sympatholytic will be to support your rest-and-digest behavior (take a nap!). So whichever end you approach it from, there are still only two important end results here — up and down.

Virtually the entire body is controlled by these systems. If you can keep track of how each organ system is affected when you nudge this balance one way or the other, you’ll be able to understand a great deal of how drugs do their work.

For instance, consider epinephrine itself, which we use in auto-injectors to treat severe anaphylaxis. The life-threatening effects of an allergic reaction are primarily shock, due to vascular dilation, and respiratory distress, due to bronchial constriction. Epinephrine is a sympathomimetic (okay, “mimetic” means “mimick,” and epinephrine is actually one of the body’s own sympathetic hormones, so it’s not really mimicking anything — but bear with me here). So it produces a fight or flight response. What is the sympathetic effect on the skin and peripheral vascular system? Vasoconstriction (to pull blood away from the periphery into the core). What is the sympathetic effect on the lungs? Bronchodilation (to allow for greater air exchange during exertion). So the entire cocktail of epi’s beneficial results in anaphylaxis comes from stimulating sympathetic tone.

What if I shoot some heroin? My breathing will become slower and weaker. My level of consciousness will decrease. I will become generally slowwww, because heroin (like all opiates) is fundamentally a depressant. And my pupils, pleasantly parasympathetic, will constrict — the third hallmark sign of opiate use. Who needs light when we’re relaxing?

 

Subtypes

Now, not all drugs from the same neck of the woods are identical, of course. The effects of the same neurotransmitters can be radically different depending on where they bind. An important distinction should be made between non-selective drugs like epinephrine, which binds with all of the primary adrenergic receptor sites (alpha-1, beta-1, and beta-2), and selective agonists like albuterol, which primarily binds only at certain receptors (beta-2 in that case). In brief:

  • Alpha-1 (properly styled, α1) receptors are mainly in the blood vessels, and cause systemic vasoconstriction. Alpha-1 blockers, or antagonists, therefore cause systemic vasodilation.
  • Beta-1 (β1) receptors are mainly in the heart, and increase heart rate and contractility. Beta-1 antagonists therefore slow and reduce cardiac output. (Mnemonic: you have 1 heart.)
  • Beta-2  (β2) receptors are mainly in the lungs, and cause bronchodilation. Beta-2 antagonists therefore cause bronchoconstriction. (Mnemonic: you have 2 lungs.)

Naturally, none of these categories tell the whole story of a drug. (If they did, we wouldn’t need so many different ones.) Caffeine, atropine, and crystal meth are all very different drugs, even though they all fall roughly into the category of stimulants. But you can keep track of a good deal of their shared effects by understanding their common nature.

 

Examples

  • Drugs ending in -zepam (or sometimes -zolam — eg. diazepam, triazolam) are benzodiazepines, which have broad sedative effects.
  • Drugs ending in -alol (or -ilol, -olol — eg. atenolol, labetalol) are beta blockers, which have a sedative effect, usually localized to the heart via beta-1 antagonism.
  • Drugs ending in -erol (e.g. albuterol, clenbuterol) are beta-2 agonists, or bronchodilators; they are stimulants that primarily cause bronchodilation via beta-2 receptors.

Most pain killers, sedatives, and anesthetic agents are depressants.

Note: most common suffixes are only applicable to generic drug names. Trade names are usually unique.

More Drug Families: Steroids and Antibiotics; ACE Inhibitors and ARBs; Anticoagulants and Antiplatelets

Helping

“He always said if there was any way he could help someone, he would.”

Carolyn Delaney

Not too many people know about Joe Delaney anymore.

He was a running back. Played for the Kansas City Chiefs, just a couple seasons — 1981 and ’82. Played high school and college ball before that, and ran track too. He was very good.

Delaney looked like he’d make a real mark in the NFL, but his career was short, and nowadays he’s been mostly forgotten. Sure, he held some long-standing records, but who hasn’t?

His claim to fame was something different.

One day in the summer of ’83, at a park in Monroe, Louisiana, three young children waded out too far into an artificial pond, floundered, and began to drown. Delaney, nearby, heard their cries for help. Although unable to swim, he immediately dove into the water to attempt a rescue.

The situation was chaotic, stories differ, and any definitive account of the events has been lost over the years. Whatever happened, the aftermath found Delaney drowned alongside two of the children; the third had made it to safety. One of the victims had eventually been rescued, but died at the hospital; the other was recovered by divers, DOA, along with Delaney himself.

 

This is an EMS website, and I’m not retelling this story as a teachable moment. As public safety professionals, we instinctively turn up our lip at Delaney’s actions. “Noble, but foolish,” we quip; becoming a victim, or a martyr, is no help to anyone. Perhaps the American Red Cross tells this same story in its lifeguarding courses to illustrate the importance of safe rescue methods. I’m certainly not recommending diving into pools if you can’t swim, or running into burning buildings without protection, or jumping out of planes without a parachute. This isn’t about heroism.

I want to use Joe Delaney’s example to illustrate something else.

“People ask me, ‘How could Joe have gone in that water the way he did?’ And I answer, ‘Why, he never gave it a second thought, because helping people was a conditioned reflex to Joe Delaney.’ ” (Sports Illustrated, 1)

He was fast, and he could handle a ball, but those weren’t the kind of stories people told about this rookie running back. Instead, they talked about how he “… mowed this woman’s lawn in the dead of Louisiana summer…” “… gave this person money to get through a bad stretch…” “… turned this child away from drugs…” And how every time, he did these things without question, without hesitation. Merely out of a basic, instinctive drive to help people.

 

Our job as EMTs is to stabilize. Treat and transport. Provide field assessment and triage. Activate appropriate resources. It’s medicine, or it’s public safety. Or something.

There’s a lot of somethings, and I’m not sure if I can remember them all the next time the tones drop. For sure I don’t think we’re getting paid enough to do ten different jobs.

But then there’s Joe Delaney.

He always said if there was any way he could help someone, he would.

Just that. If there was a way — any way — that he could help another human being, he would. That was only criterion. Simplicity itself.

What if that was the attitude we adopted? What if that was the job of the EMT?

 

The nice thing about wanting to help is that it’s pretty simple. When that’s all you want, you don’t need much more.

Joe Delaney was known for his thriftiness, for living simply even after going pro.

“Don’t you want nothing for yourself?” Carolyn would ask Joe.

“Nah,” he’d say. “You just take care of you and the girls.” (Sports Illustrated, 2)

And it’s funny. But when you view your job as helping your patients, in any way you can, a lot of other stuff seems to fall by the wayside. Is transporting this sort of patient your business? Do you really need to fluff this pillow? I don’t know; does it help? If it does, does anything else matter?

Naturally, there are things to consider. Because typically, the way we can help is through clinical intervention, through skilled medical assessment and treatment. If we helped in another way, they’d call us something else, like “plumbers” or “dentists.” And if we’re better at our craft, we can help more. That’s why we open the books and palpate the rubber mannekins. Because we recognize that if Joe did know how to swim, more lives might have been saved that day.

But the technical aspect is a means to an end, and just one means of many.

If you ask around the base, and people are truly honest, many will admit they got into this job at least partly from a desire to help people. It’s an organic urge, and a good one, and it brings us to the table, but then the years and the worries and the details of how and why and but… start to muddy the waters, and at some point we find ourselves forgetting that basic passion. Striving towards other goals. Elevating the details. And sometimes that’s okay.

But the next time we roll up those garage doors, maybe we can think back, and remember what matters. Maybe we can take a page from Joe Delaney, and every day assert this simple promise: if there’s any way we can help someone, we will.

Lifting Things Up and Putting Them Down

It’s interesting to consider the things we do that come to symbolize our roles. Sometimes, they make sense: the pilot would not feel like a pilot if he did not fly planes, because flying planes is why his job exists. His day may consist of 99% paperwork and 1% flying, but flying is nevertheless sine qua non for piloting. At other times, the symbol is more metaphorical than real; for instance, the white lab coat has come to symbolize the physician’s trade (new graduates even receive them in elaborate ceremonies), despite the fact that a doctor’s job is not to wear coats.

Many paramedics consider endotracheal intubation to be an important part of their identity, for reasons that are unclear, but probably related to the drama, the skill, and especially the exclusivity of the act; relatively few players in the medical field are permitted to intubate, so the medic is proud of the privilege and responsibility. (Obviously, this has nothing to do with whether or not putting tubes down throats helps anybody, but that’s a topic for another day.) And in the public’s eyes, throwing a stethoscope around your neck will instantly identify you as a medical professional.

With all of that said, however, on a typical day we can do our job very well without an ET tube or a dangling scope; those are tools, but not essential tools. We do have essential tools, but they are often nothing more than boring, everyday practices, and as a result we don’t talk about them as much as we should. Know what the biggest one of all is?

 

Lifting

EMS is not the infantry, or even the fire service, and the level of physical fitness required to do our job is… well, let us say that most of us live up to the requirements, and no more. We rarely run anywhere and the most we’ll sweat is during a stairchair carry or the occasional chest compression. However, one physical ability is part of our job description, and that’s the ability to lift patients.

All of us do this countless times a day, whether we’re large or small, male or female, tall or short. It’s therefore tempting to say that it’s not difficult, and that even the weak can do it. The truth is, though, that a strong individual, lifting with excellent biomechanics, is simply better in this business than a weaker colleague. The difference is not always obvious, which is why both strong and weak do manage to survive in this job, but you can also “survive” in this job being barely literate or mostly blind, and nobody would doubt that those negatively impact your work. Strong people transfer patients from stretcher to bed smoothly and without bumps or drops. They can easily maneuver the unconscious patient out of the cramped, awkward corner he’s found in. And most of all, they can always, always lift and carry anyone, without requiring either extra assistance or elaborate workarounds. We all know the tiny EMT who’s otherwise a fine partner, but who needs to call for a lift assist in order to boost the stretcher when there’s anything heavier than a bird’s nest on it — and while this is often not a problem, and we may know and love that EMT, he would be a better EMT if he could lift more, and that’s simply that. More selfishly, he would also remain physically capable of doing this job as long as he cares to, no small feat in a field where back injuries are more the rule than the exception.

The good news is almost anyone can learn to lift and get stronger. In my opinion, the easiest approach to this is a simple linear strength program using barbells — and although for novices, a broad and well-rounded program is ideal, the single most important lift for the EMT is undoubtedly the deadlift.

The deadlift involves bending over, grabbing an object with your hands, and standing up. This is the exact movement that you execute when lifting a stretcher, and variations of it are used in everything from carrying the stairchair to performing a fore-and-aft lift. The primary driver of this movement is extension (straightening) of the hips using the glutes and hamstrings, and the primary static challenge is maintaining a straight and rigid spine against the load trying to round it forward, which is the job of the spinal erectors. The hips are the engine, the back is the transmission.

Extension of the knees, which is performed by the quadriceps, is generally considered a secondary driver in the deadlift, since it’s weaker than hip extension. However, performing the lift with the butt lower and torso more upright does have the advantage of keeping the spine more vertical, which makes it easier to prevent it from rounding during the lift. Although you can lift in complete safety with a very horizontal back, and the more vertical stance does limit the weight you can lift, this is generally considered a good tradeoff in EMS (where we’re not trying to lift maximal weights, so much as lift many submaximal weights in complete safety). This is why the occupational safety poster on the garage wall tells you to “lift with your knees, not with your back” (a clumsy way of saying to bend the knees more and the hips less, remaining fairly upright; you never really “lift with your back” unless you’re doing things very wrong).

The “sumo” deadlift, which uses a wider stance, more upright posture, and arms inside (rather than outside) the legs, is the closest approximation to how we typically lift a stretcher. It lets us get as close to the load as possible, which again reduces the shearing force on the spine; the conventional (non-sumo) deadlift tends to force us to lift with the load dangling out in front of us, because our knees get in the way. But no matter what, the primary challenge is to maintain a flat, rigid back, and deadlifting trains us to do this by teaching the proper posture, as well as improving our ability to hold that posture against heavy loads by taxing and strengthening the erectors.

Sumo deadlift start position

Conventional deadlift start position

For the purposes of this job, it is probably worth training both the sumo and conventional deadlift. My own background is primarily with the conventional, so I have some bias, but even if (like me) you primarily “pull” with conventional form, it’s worth practicing the sumo on occasion, in order to master the technique — again, when you lift stretchers and other real-life items, it’s generally more sumo than not. In sumo style, the movement of lifting a stretcher can be replicated exactly in the gym using a barbell, with the exception of the position of your palms, which are supinated (underhand, or palms forward) on a stretcher, but pronated (overhand, or palms in) with the barbell. Deadlifting heavy with a supinated grip carries some risk of shoulder strain or tearing a bicep, so it’s not worth practicing.

It’s difficult to put numbers on things, and your ability to use the right tricks and techniques in the field may let you get away with less muscular strength. But in my humble opinion, a good goal for every working EMT or paramedic should be to safely and manageably (that is, not as a back-breaking, hitching maximal lift, but something you could perform for repetitions) deadlift 200 pounds. For small females, this may be a substantial challenge that requires some training. Many moderate-sized to heavy males will be able to pull this weight with no training; those individuals should aim for 300+ pounds. 300lb is a deadlift that will allow you to handle 99% of what this job throws at you.

These are not serious weights. True strength athletes deadlift many times this (I pull around 435 myself, and am not even close to being strong), and I’m not suggesting you go down that road, although if you enjoy the training, it has many benefits. Rather, this is a readily achievable milestone, low-hanging fruit that any healthy individual who does this job should be able to work towards within a period of several months. And once strength is obtained, it’s a fairly durable adaptation; unlike some physical skills (such as cardiovascular endurance), it sticks with you even if you’re no longer training it. Once you’re there, it would be good to keep lifting at least once a week or so, but even if you do not, the daily exertions of the job should be enough to largely maintain your level of strength. This is a gift that will keep on giving, and it’s very worth setting as a goal.

Vital Signs: Blood Pressure

For other Vital Signs posts, see: Respirations and Pulse

In the grand scheme of medical skills, taking a manual blood pressure is far from difficult, but sick people and austere conditions can combine to make it another thing entirely. Obtaining a BP on an ill patient while rattling down the road is legitimately one of the most difficult psychomotor skills an EMT-Basic has to master.

Mastering it starts with stacking the odds in your favor. A good stethoscope is better than a lousy one — you don’t need a $500 cardiology model, but something with good insulation and tight-fitting earpieces can make a real difference. Of course, you’ll also want to try to take your blood pressures at times of peace: on scene, before the rig starts moving, or even shoehorned in while stopped at traffic lights.

The elbow-supported technique for finding the brachial pulse is also ideal for taking a BP; trying to hear anything when the arm is slightly flexed is a recipe for frustration. But ensure that however you arrange things, the arm is completely relaxed, because muscular tension can radically throw a measurement; this will require fully supporting the arm and sometimes reassuring the patient. “Just relax” is the line I always deliver while busily pumping the bulb.

Where to put the gauge? Wherever. I’ll usually clip it to one of the stretcher straps, but you can find a bit of blanket that it’ll nestle into, secure it to a shirt, clip it to your watchband or the edge of the cuff, or just ask the patient to hold it for you. The built-in strap on the cuff is only a good location if you’re at the patient’s right side, which is typically not where we sit while we’re transporting. There’s probably a huge market niche out there for “EMS style” cuffs with their handedness reversed… but I digress.

Although I don’t always follow all of these steps, here’s the basic approach I recommend for a routine blood pressure check:

  • Support the arm, ideally at a position that is horizontally level with the heart.
  • Palpate the antecubital fossa until you find the pulse point. Note this location.
  • Palpating at the radial or the AC, pump up the cuff until you lose the pulse. Note this number and deflate the cuff.
  • Place your scope on the AC and inflate the cuff past the previous number. Obtain your pressure in the ordinary fashion.

Starting with a palpated pressure may seem redundant, and it can be, but it has two advantages: first, it gives you a rough sense of what systolic to look for, and second, if you’re unable to auscultate a pressure, you’ll still have a palpated one to record. This is actually the officially recommended method, although it seems rarely done nowadays.

Palpated pressures are legitimate, although when they start becoming the norm it can be a sign of lazy care. The diastolic can be a valuable number, though, particularly in traumatic or cardiac cases, so remember that auscultating is still the default standard of care. And remember, particularly if you’re mixing methods, that palpated pressures often will differ from auscultated pressures (including those taken by machine), usually by 10-15 points on the low side.

What if you’re not getting anything from the arm? Well, you can try the other arm, of course. But really, the thing to remember is that you can take a blood pressure anywhere there’s a pulse, although it’s much easier when that pulse is strong and the artery proximal to it can be easily occluded. Remember that although you can palpate a pressure from any distal spot on the same artery, near or far (barring anastamoses), auscultation — which is essentially listening to the turbulence created immediately downstream of the occlusion — requires placing your scope just below the cuff, and will not be successful farther downstream. Putting the cuff (pedi cuffs when needed) on the forearm and measuring at the radial is effective; thigh cuffs work too, although the popliteal can be an evasive pulse to locate. You can even cuff the lower calf and palpate a pedal or tibial pulse, if you’re daring. Go nuts, and try to experiment before the call when you actually need it. Do make an effort, though, to use an appropriate sized cuff for the extremity; mis-sized cuffs can actually yield significantly erroneous readings. For the morbidly obese, I usually prefer to place a regular cuff on the forearm than to use a thigh cuff on the upper arm, but see what works for you.

As a final note, remember that cuffing the neck and palpating the temporal pulse is never an appropriate method of patient assessment, no matter how little blood you may suspect is reaching their brain.

On maintenance: during your morning checkout, pump some air into the cuff, close the valve and give the whole thing a squeeze to check for leaks. There’s nothing better than discovering these after you’ve wrapped it around a critical patient’s arm.

On sphygmomanometers: for obvious reasons, the resting point for the needle should be at zero. (Very cheap cuffs sometimes have a pin-stop here for the needle to rest against; this is a problem because the dial can be miscalibrated without showing it. Pin-stop gauges shouldn’t be used unless your service is seriously broke.) If you have one that needs zeroing, most cuffs can be adjusted by pulling the tubing off the dial, grasping the metal nipple with some pliers (or very strong fingers), and twisting it in either direction until the needle is zeroed. Alternately, fans of mental math can just add or subtract the false “zero” number each time they take a pressure.

And finally, on tourniquets: the immortal Dr. Scott Weingart of Emcrit has described his practice of using BP cuffs as tourniquets. You’ll hear about this from time to time, but there’s always someone who points out the damned things leak like sieves and that’s the last property you want in a tourniquet. Dr. Weingart’s solution is to pump up the cuff until bleeding is controlled (or 250mmHg, whichever is sooner), then clamp both tubes with locking hemostats. (He uses smooth ones to avoid damaging the rubber; he recommends padding with a 4×4 if you’re using a ridged hemostat.) My hemostats are all in the shop, and this may or may not fly with your agency — modifying equipment for “off-label” use is always somewhat shaky ground for us field peons — but I think it’s a splendid idea if you can swing it.

Vital Signs: Pulse

For other Vital Signs posts, see: Respirations and Blood Pressure

Ah, the almighty pulse. If I have a favorite vital sign, this is it; let me lay hands on a patient and take a pulse and my assessment is already well under way.

On the conscious patient our go-to point is the radial pulse, and like golf, mastering the radial is all in the grip. Techniques may vary here, but I always find the radial easier to palpate if you approach from the ulnar side of the arm, coming “underneath” rather than over the top of the radius. This also lets you take a pulse while easily holding onto their limb, rather than forcing you to find a place to rest it, or supporting the arm with one hand while you palpate with the other. Just grab and count, very natural. If you have no luck, you can always keep hold of their arm while using your other hand to do some searching.

The textbooks always seem to show this being done with two delicate fingers, which is silly; more fingers means more coverage, so I always use at least three. (Your little finger is kinda short, otherwise it’d be four.) Use a moderate pressure, but if you’re having trouble, try pressing both lighter and firmer, as well as moving to different spots. (While I usually wear my watch in the normal position, you’ll notice here that when taking a pulse this way, I flip it around my wrist so I can see the face.)

The main way to ensure you’re never baffled by the pulse, however, is by always being willing to look elsewhere. Some people simply won’t have a radial, and this fact may or may not have significance — it may mean they’re hypotensive, or that their arm is locally hypoperfused, but it also may be a chronic condition. Hemodialysis patients with arterio-venous fistulas in their arm are especially notorious for having peculiar or absent radial pulses, as the arteries near the fistula have been scavenged and rerouted. Make like a picky renter — go elsewhere!

Your next attempt after the radial should be the brachial. Now, in classes and textbooks I have always been taught to look for a radial in the upper arm, beneath the bicep, but I’ve never had luck with this. Rather, my target is the antecubital fossa, the same territory made popular by blood pressures and large-bore IV sticks.

Again, positioning is key here. To effectively feel this pulse, the elbow should be in full extension, but relaxed. Depending on the patient’s position, you may accomplish this by wrapping your arm around theirs and holding their elbow in your hand, but from your bench seat in the truck, an easier way to do it is to simply rest their elbow on your knee. (Either way, it’s important to support them at the elbow, because this allows gravity to force their arm into extension.) The brachial can be a real lifesaver when a radial isn’t forthcoming, and I go to it readily and often.

Logically, the next step would be a carotid pulse, but the truth is that on conscious, alert patients, this is always a little awkward; people don’t like having their neck touched. If they need it, they need it, but for the routine pulse check, I try to steer clear. The same goes for a femoral pulse, for the same reasons; there was a story at my old service of a brash young EMT who got canned for “feeling a femoral” on an inebriated coed from a campus we served.

Instead, if I can’t find a radial or brachial on either arm, I’ll often take an apical “pulse,” simply auscultating at the chest for heart sounds. This is not, strictly speaking, a pulse, insofar as it’s not counting actual perfusing beats so much as counting any cardiac noise (it therefore tells you nothing about blood pressure), but it’s a good fallback — and if you’re very suave it can even yield additional clinical information, regarding murmurs, rubs, etc.

Here are a some other tricks that can be useful:

  • Inflate a BP cuff and count the bounces on the sphygmomanometer needle. Although this is not an indicator of systolic or diastolic pressure, it is a legitimate way to measure a pulse.
  • If pulse oximetry is available, the device will usually calculate a pulse for you, and if there’s a displayed waveform you can also confirm it from that.
  • The aforementioned AV fistulas can be used to your advantage. Gentle palpation of visible, active fistulas should let you feel a pulsing vibration called a thrill (an indicator of healthy flow), and this is easily counted for an accurate pulse rate. (Auscultating at the fistula should reveal a buzzing sound called bruit, which can be used similarly.)
  • If you’re able to locate a difficult pulse point, such as a dorsalis pedis, X’ng the spot with a pen can make subsequent checks much easier.
  • Lowering the arm below the level of the heart can occasionally make a radial more readily palpable, especially in hypotensive situations.

Finally, when all else fails, remember your perpetual fallback: skin signs. A patient with no available pulses and no obtainable blood pressure can still give you a general sense of perfusion, both centrally and to each extremity, if you assess the color and temperature of his skin. (This is especially valuable for infants, for whom proper pulse checks can be difficult, and blood pressures even more so.) And then there’s the sidekick to this, which is capillary refill. Current teaching is that cap refill is not a meaningful sign except in the very young, because numerous chronic conditions can cause delayed refill without poor arterial pressure, and this is true; a slow cap refill in an adult shouldn’t mean much to you. However, a rapid refill is still a pretty specific sign of good perfusion, because there’s not many conditions that can fake that (with the possibly exception of distributive shocks, such as septic or anaphylactic). A quick pat-down is an ever-ready way to rapidly assess anyone’s hemodynamic status within a couple seconds.