Tag Archives: critical thinking

the n of 1

We’d like to think that medicine is entirely evidence-based, but it’s not. Some of what we do has a great amount of evidence behind it, but sometimes the evidence is a little more shaky. Sometimes there’s practically no evidence. As a paramedic put it to me in an ACLS class one day, aside from this short list of drugs, as far as the evidence goes, we could put mayonnaise in that IV and there’d be a similar amount of research to support it.

I mean, we try our best to operate under what we think to be the best. We read consensus statements from working groups, we go by clinical practice guidelines published by a committee of experts, and when we aren’t sure, we go by conjecture that we base on previous clinical experience and whatever tangentially associated evidence we happen to have packed away in our brains. We usually get pretty close, but the truth is that we could get a lot better. A lot of the time, we basically run on nothing.

In truth, we don’t really run on “nothing” — clinical experience isn’t irrelevant, and recommendations from those with more experience than us, while not exactly evidence, isn’t exactly nothing. But there’s lots of situations, especially with the sort-of new-frontier type medicine, where the answer to the question of what the best thing to do is honestly that we don’t know.

So imagine my joy when I find a document on a subject that I know has gotten little research. Somebody (in this case the Canadian Thoracic Society) has compiled all of the best available information into one document and made recommendations based on it. I skipped off to the printer (sorry, trees) and pulled out my highlighter and began swiping away at passages I found most relevant. I got two swipes and three paragraphs into the actual recommendations before I found this gem:

“Unfortunately, each of these techniques suffers from the lack of well-designed prospective trials. As such, recommendations were informed by observational studies and professional consensus.”

Professional consensus and observational studies. So clinical experience (times a lot of clinicians) plus tangentially related evidence (with a small sample size and no controlled conditions) are literally the best evidence we have. Like I said, it’s not exactly nothing, but when you consider the way things tend to fall apart under close scrutiny in this field, it’s about as close to nothing as you can get while still having a half-assed idea what you’re doing.

In school they teach us to operate on this version of ‘nothing’. They teach us models and give us context and try and assist us in developing the skills necessary to work outside the textbook. Very few patients are cookie-cutter. We operate like that a little bit when we’re brand new, but as we gain experience we learn things that are unteachable. We learn how much wiggle room we really have — that it’s not necessarily the end of the world if we try something and it doesn’t work. We learn that the limits we were given are margins of safety, and that there’s a lot of space between the margins.

Enter the patient. I’m lucky, I say — so many of my patients are heavily sedated and won’t remember what I did to them — I have a sort of list of things I can try in order to achieve the result that I want. It’s a common refrain in health care that patients don’t read textbooks, and it’s true. It’s exactly because no two patients are exactly alike that no two treatments are exactly alike. It’s the nature of what I do that I intervene and look for a particular patient response; when I don’t get the response I want, I change my intervention. In this way each patient is its own isolated experimental model: a kind of so-called n-of-1 trial.

I think if most people knew how much of my job (especially with regards to ventilating people) is “well, let’s try it and see what happens,” they’d be a little concerned. The truth is that that’s the essence of a lot of medicine. The beauty of ventilating someone with a piece of equipment that retails for more than a small condominium is that I get the benefit of immediate information about how my experiment is working. I don’t have to wait for days for antibiotics to work or steroids to kick in. I don’t even have to wait the minutes it can take for sedation to kick in. I will usually know in under 5 minutes if what I want to do is going to work or not, and because things respond so fast, unless I do something exceedingly stupid it’s actually very difficult for me to harm somebody with an experiment of this kind.

Sometimes I get another kind of immediate data: sometimes my patients are awake and talking. The home ventilator stuff I linked up there is so interesting precisely because of that. 99% of the time when I ventilate a patient, they’re out cold and I’m left to do the guesswork based on some animations and a few fluctuating numbers on an LCD screen. When the patient’s awake, they can tell me what they want and how they feel, and if they’re articulate about it and it’s a problem I can solve, in a way this gives me far more fine-grained control over what I end up doing.

He asks me questions, and the answer I have is an honest one: we don’t know, there’s not a lot of research to support this, we don’t have a lot of good models for what we’re doing, it depends on how you respond. It sounds terrifying to somebody who wants the patriarchal model of medicine to hand down a pronouncement from on high about what their therapy will entail. Sometimes we do that, but we try not to. Care plans shouldn’t be about what I think is best for you. I don’t live in your body for 24 hours a day and once you walk out those doors the life you live is your own. If I’m going to come up with something that you’re going to be able to live with day in and day out, it’s far better if we can come up with something together.

It’s easy 99% of the time with my heavily sedated patients. The tube comes out, they come to, (sometimes not in that order,) and what I’ve done is something that was profoundly uncomfortable and yet saved their life. They don’t have to live with the therapy on a day-in-day-out basis — it was a short term thing and once over, it can be forgotten.

With someone who’s vented at home, it’s an entirely different story. Their life is my therapy and without it their life would be shortened considerably. They can’t ignore what I’m doing if it’s uncomfortable and they can’t forget about it because it’s ever present. I need his feedback to do my job properly: the equipment I use in the home is 1/10th the sophistication of the equipment I use in the ICU. I lose my raw data and get subjective information and I have to glean a course of action from that.

The benefit to this is his subjective response is just as quick oftentimes. He knows his body and I can trust that. He gives me far better data than I can get off of an LCD screen and it allows me to individualize his vent settings in a way that I would never dream of doing with an acutely ill patient. Admittedly it helps that most chronic ventilator patients have healthy lungs, and I’m using settings that are far gentler than anything I’d use on someone really sick, but an experiment is an experiment and it can still go awry.

It depends heavily on the patient too. Some people become very uncomfortable if they think you don’t know. Some people are anxious and when you say “we’ll have to try it and see how it goes” they hear you say that you’re not confident in what you’re doing. (Those are times you have to be part salesman.) But most people actually respond really well to an authentic voice, when you tell them we just don’t know and in a lot of ways we have no way of knowing. I tried hard to be honest without being wishy-washy, and I think they appreciated my lack of fatalism and my willingness to be flexible.

Even inasmuch as the n of 1 is a terrible way to conduct scientific research, it’s a great way to conduct patient care. We are all individuals and what works for one of us will likely not work for the next, and applying cookie-cutter approaches doesn’t always work. At some point a really good clinician will be willing to go beyond the textbook, to look at the data they have, to try new things and to see how they work out. The ability to think critically in this way is what separates out those who really know what they’re doing from those who use the paint-by-numbers or recipe-book method of healthcare, and not just for their critical thinking skills. Some of the most valuable things to come out of such an experiment is the experience of having done it in the first place, of learning those things that are unteachable. We shouldn’t fear experimentation. It’s how we become truly great at what we do.

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the man and the machine

Gear comes up so often as an RT that a day where I don’t do at least some troubleshooting is a boring day indeed. Where most of the other equipment other team members deal with are either ways of gathering patient data (lab analyzers, patient monitors) or ways of giving drugs to the patient (IV pumps), there are relatively few situations where the patient is directly interfacing with the machine in question. It is, after all, somewhat frowned upon for patients to adjust their monitor alarms or change their IV rate.

For many RTs, though, it’s a daily thing. I can think of two examples in particular, and they’re polar opposites: the spirometer, and the ventilator.

Spirometry is a difficult test to do sometimes, as it’s almost 100% effort dependent on the part of the patient. This is in contrast with blood analysis by the lab, where the major difficulty regarding the patient is whether or not you can get blood out of the person. (Sometimes it takes the lab tech who can get blood from a stone. Sometimes it takes four strong staff and five point restraints.) The most accurate results will only happen when a patient can understand my instructions, will cooperate and follow my directions, and when they try as hard as they possibly can.

They emphasize to us in school how important it is for us to coach the patient enthusiastically, since a major portion of getting the best effort out of someone is coaching them to try their hardest. It’s not uncommon for me to look at a patient’s results on the screen or watch a patient blow and go, “you can do better than that.”

Then there’s the interface itself: I’m trying to make a person do a very specific thing to a machine, and if I can’t make that person do what I need them to do, the test is nearly useless. This is a classic example of troubleshooting the patient. I made sure at the beginning of the testing day that my machine is working correctly, so unless something catastrophically fails, the problem is almost universally one with the patient. It’s my job to look at the output the machine displays, and try and explain to the patient I’m testing what I need them to do differently in order to get the output I want. This includes noticing things like air escaping the system at the mouthpiece (and therefore not being measured,) a lack of effort on the part of the patient (meaning the results appear as if the patient has terrible lung funtion to the untrained eye,) or some things the patient has no control over, like whether their dentures are loose, whether that stroke they had five years ago means they can’t make a mouth seal at the mouthpiece, whether they can’t understand what I’m saying but are smiling and nodding anyway, or whether they’re just not going to put the effort in and I’m wasting my time trying to teach a pig to sing.

I can’t stare only at the machine and ignore the patient: the forced exhalation maneuver can cause a transient decrease in blood pressure and a transient slowing of the heart rate, especially towards the end of exhalation, where the patient is forcing against airways that are empty of air and for the most part, closed. In this way it resembles a valsalva maneuver and I need to pay attention to my patient, because if they faint and fall off the chair and bounce their skull off the concrete floor, well, I have a bigger problem than poor test results. If I don’t notice that air is leaking out the side of the patient’s mouth, I’m gonna have a really hard time figuring out why I can’t get decent results. At the same time, I can’t only stare at the patient and ignore the machine. The whole trick to the success of the test is ensuring that the patient is interfacing properly with the machine. Ignoring the machine is to ignore half of the system.

The other major example I have, the ventilator, is somewhat the opposite sort of system. In this case, the patient is often, but not always, passive (rather than with the spirometer, where the machine is passive.) With the ventilator, I’m trying to make the machine do this very specific thing, and if I can’t get the machine to do what I need it to do, then I’ve got some serious problems. The confounding extra factor, for bonus fun, is that sometimes the patient isn’t passive. Sometimes, I’ve got this machine that’s supposed to be breathing for a patient that’s trying to breathe, and a major limitation to this is that they don’t share a brain (though they’re working on that.) Sometimes the patient’s trying to breathe and the machine is trying to breathe and they end up fighting each other, or what some people call “the patient fighting the ventilator.” The term we prefer to use is ‘patient-ventilator dyssynchrony’ or, more colloquially, “hypo-sedation-emia.”

In an ideal world, the patient would initiate a breath and the ventilator would detect this and deliver a breath in synchrony with the patient’s efforts. This is called ‘triggering’ the breath. Then, when the patient is done inhaling, the ventilator can also detect this and, depending on the mode of ventilation, can stop delivering the breath near the same time the patient stops inhaling. This is called ‘cycling’ the breath.

Being as, from a gas flow physics standpoint, the sensors that make these detections are a considerable distance from the patient, sometimes the ventilator isn’t able to detect what the patient wants the ventilator to do. Accordingly, the ventilator is more likely to have a harder time the sicker you are and the worse your lungs are. The ventilator is, after all, a machine, and one of the major downfalls of machines is they don’t think, they only do what we program them to do. Sometimes we can program them with complex algorithms designed to eliminate some of the thinking, but that does not obviate the need to think.

This is where I come in. I observe both the machine and the patient and try to tweak what variables I can tweak in order to get the machine and the patient to agree with each other. I try and see what the patient is trying to do and try and manipulate the variables I have to try and make the vent do what the patient is trying to get it to do. It’s a magical sort of alchemy, and sometimes I can’t make it work. Most of the time, though, I can manage to find the sweet spot between the totally passive patient who “rides” the ventilator and the dyspneic, agitated, desaturating, magical self-extubating patient.

The opposite is also true: sometimes the patient is so sick and so short of breath that they consume so much oxygen trying to breathe (and doing so only ineffectively) that they’re better off anaesthetized so I can take over and make the patient’s lungs do what want them to do so they get some actual gas exchange going and they can get better.

The trend with new ventilator modes is to try and make it so the machine can adjust itself continually according to what the patient appears to ‘want’ according to a software algorithm. This seems like a good idea in theory, and it can work pretty good for some patients, but us RTs tend to hate these newfangled modes for one reason and one reason only: we can’t tweak them. “I can’t make the stupid thing do what want it to do” is what we think, trying to find that sweet spot. I can see what the patient is trying to get the vent to do and the software algorithm can’t.

It’s alchemy, it’s guesswork, it’s “let’s try this and see how that works”, it’s tweaking and a process of elimination. Half the time the process is a series of judgement calls and failed experiments until something works.

I’m the respiratory therapist, and when I troubleshoot a system, it’s got both a machine and a person in it, and I have to troubleshoot them both at the same time. It leads to a unique set of skills and challenges, and I don’t even think these systems are unique to my profession. I think these systems are visible in many disciplines where people interact with machines. I think most of us are just not used to seeing the person as a part of the system.

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on being called “a hero”

There’s a hazard to having a friend that’s a sociologist: she forces me to think about why things are the way they are. In this particular case, she’s turned me on to some interesting reading material that seems never to fail me for something to think about.

I am not unaccustomed to risky jobs, and the people who work in them. I work with paramedics, firefighters, prison guards,  the most commonly thought-of “life is on the line, he’s such a hero” sort of stuff. The book they’re talking about is right on the money: for the most part, they don’t think of themselves as anything other than ordinary people in control of an extraordinary situation. Any mishaps that laypeople consider to be risks inherent in the job (a cop getting shot, a firefighter dying in a fire) are not seen as particularly risky to the people engaging in them. I’ve spoken to cops about going into buildings armed against people who have gone totally butternuts and are armed to the teeth — the risks they talk about aren’t that they might get shot at — it’s the fact that butternuts in the shed over there isn’t predictable. They’re trained to predict what the rest of us think are unpredictable.

This, of course, thanks to the grooming of my friend the sociologist, makes me think of the times when I’ve been told I did something “heroic.”

Usually what happened is there was a very sick person in a very bad way, and I was part of a team of people who predicted the unpredictable and then responded. The response is to perform a number of different interventions in order to change the course of their illness or injury. I don’t think what I’m doing is heroic. I don’t think about how people are going to die if I screw up. I don’t feel the pressure, really. What I am is in control.

I can see the signs. I can measure and quantify how bad the situation is using specific parameters which allows me to manipulate those parameters with drugs or pressure or gas. I can control the oxygen or the respiratory rate. Sure, there’s a bit of a scramble trying to get to the point where you’re in control, when you’re on the move from prediction to execution, but you know what to do, so instead of being stressed about how it’s do or die time, you just stop thinking and do.

I find us RTs especially tend to think in “the worst thing that could happen is” sort of parameters. When others are afraid to extubate the patient we’re shrugging our shoulders going, “the worst thing that could happen is she/he gets reintubated.” To us, it’s no big deal. We’re trained to predict what the worst possible scenario could plausibly be, and then be prepared for it. We controlled the airway by putting in a tube, we did it once, we can do it again. If I can’t do it personally, there’s someone close by who can.

I remember a couple of these do-or-die situations happening to me and there was a lot of muscle memory in that st0p-thinking-just-do. A sick neonate thrashes a bit on the overhead warmer and self-extubates, and there’s no pediatrician within a shout’s reach? I’ve been trained for this. They taught me how to intubate precisely so that I could respond to this situation. Paralyzing myself with fear and waiting for the pediatrician to haul his ass into the room is an option, but the worst thing that could happen is I try and I miss. I’m also trained in what to do in that case: the patient would be no worse off for me missing. Besides the fact that I’m qualified and trained and skilled in intubation — the patient needs it right bloody now. If I waited for the pediatrician I’d feel like I had chosen the wrong line of work and would probably quit soon and go become an accountant. What I did was grab the (conveniently located) necessary equipment and make with the intubating. I know what has to be done, and I’m qualified to do it, so I do.

There are those times when despite your best efforts you lose control of the situation. Just like the firefighters do, I find we look for something to blame. Somebody screwed up, somebody didn’t notice the alarm, the monitor was malfunctioning, I gave up too soon and should have kept trying, we didn’t get there in time, they waited too long, and so on, and so on. I failed to predict the outcome. I failed to respond accordingly to the situation in the way in which I was trained. I look for how I could have gained control, therefore, I don’t really fear the loss of life that happens due to variables that are beyond my control.I learned very long ago as an RT that there’s some parts of the clinical situation that you just can’t change.

I’m scared of screwing up or missing something, I’m scared of missing the prediction or failing to respond. I’m also confident that the longer I spend in control and the more I refine my muscle memory, the more I lift the mental weights that allow me to consider more of the situation, the more that muscle memory allows me to automate simple tasks so I can spend more mental energy being observant to other signs, the less likely it will be that my simple screwup results in somebody’s death.

It’s happened in the past: I’ve failed to notice a sign that the patient was in cardiac arrest and then the patient died. That said, so did everyone else in the room fail to notice, and given how sick the patient was prior to going into cardiac arrest, the chances of us being successful even if we’d caught it were pretty slim anyway. No one person killed that patient. The culmination of many factors did, and some of them were beyond our control. Did I learn a hard lesson? Yes, I did. That one’s a notch on my proverbial shield that I’m not ever going to forget — and the next patient will benefit from it.

Therefore, by the same token, no one person involved in saving another’s life is “the hero.” The collective sum of our teamwork and brains and muscle memory and situational awareness and skills are the heroes. We just predicted the unpredictable. We executed our plan for how we were going to gain control. We gained control of the situation quickly and effectively, and then we held on to it. It holds no mystery to us.

We are comfortable.

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when he said thank you

I hugged him, with one arm, afterwards. I hugged him because he was afraid.

He’s a pediatrician. It’s that season, you see. The season of kids with hideous gastroenteritis, the season of dehydrated little tiny people who are justthisclose to having one of those near-death situations we talk about in PALS so much.

This little one, her heart rate was over 200. She met the standard definitions of shock. She needed a lot of fluid, and fast, before her little heart wore itself out from beating so fast. I only got called to do a cap gas really. If the results aren’t that bad, I don’t ordinarily return to the room. This was one of those situations when I returned in person to the treatment room. This child was doing that eyes-rolling-back-in-her-head-breathing-is-optional thing, being stimulated by nurses rubbing her sternum with knuckles to try and get her to wake up and take a breath. This child was close to having a cardiac arrest. These poor nurses were doing everything they could prior to the pediatrician arriving kind of thing. These poor nurses had poked this poor baby 20 times or more.

By the time the pediatrician had arrived, the favored major sites had been poked to try and get an IV. I could hear the echo of my PALS instructor (another pediatrician) in my head: “how many times do we poke and poke and poke with these sick kids, when we could just do an IO then and there, and leave those veins for after they’ve been rehydrated?”

I had nothing respiratory to do, other than prepare. I changed my mask on my bagger. I had my intubation equipment ready. I was planning for the worst, and, at the same time, I was prodding my pediatrician: “just put in an IO, just do an IO, the gun is six feet from where you’re standing, why struggle with trying to put in a fragile IV in the scalp you can’t pound some real fluid in anyway, just put in an IO.” I was naive about his previous experiences with trying to put in these fabled beasts into small children. I was unable to put myself in that picture, of the child who had suffered through multiple attempts. I was that ignorance-is-bliss voice-of-reason, where I had no clue that he had tried this before and it’d gone horribly.

He did it anyway.

After multiple attempts at an IV cannulation in this very small, very dehydrated child, he finally pulled out the IO gun to drill a needle into this tiny person’s leg bone. It’s a very squick-inducing thing. Had it not been the best method of getting some life saving fluid into this baby, I would never have suggested it. How necessary it was became obvious when they drilled into her leg and she didn’t even flinch. In goes the IO. A very large amount of fluid gets pounded into a very tiny person and very quickly does such a baby begin trying to put the ECG lead cables in her mouth rather than her eyes rolling back into her head. Relief.

“Good, her heart rate is slowing down,” I say aloud, (from the 200 earlier, I’m thinking.)

“Great, mine too,” the pediatrician says, and my heart goes out to him.

He, in truly heroic fashion, later thanked me for making him do the scary IO thing he didn’t want to do, later. I replied with a smile and a one-armed hug.

I am so pleased to have these relationships with the doctors I work with. I chafe to think at how I would work with someone who would not be receptive to input. I am extremely pleased that in this case, this child lived, and am perhaps in this case, not so immodestly proud as to think of how I perhaps may have helped to save this baby’s life by being a right royal pain in the ass.

I love my job.

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equipment monkey

It’s all at once an amusement, a pain in the ass, and a blessed distraction to be one of the only direct-patient-care health professionals that keeps a toolbox in her office.

I feel a certain sense of pride and accomplishment when I’m walking down the hall past the ICU, packing a two pound crescent wrench, or a pair of pliers, or an assortment of screwdrivers and hex keys. I work in this normally sterile environment and here I am getting my hands dirty, hauling tanks, spinning nuts and bolts, tightening connections, taking apart malfunctioning equipment to fix it, replacing bulbs and batteries and sensors and analyzing cells. Some equipment is less dirty than others; tanks are by far the dirtiest job. Some equipment is bigger and heavier than others; the blood gas machine is by far the tiniest and most finicky.

On the other hand, being the only person in the building besides the biomed (and the one who keeps the more extensive hours) I end up being the one getting phone calls about “why is this leaking” or “this isn’t working and I need you to come take a look at it” for pretty much any piece of equipment I lay my hands on in my scope of practice. It becomes somewhat frustrating when I have people to deal with (people can’t lay broken on the counter for a month and then be fixed at my convenience) but at the same time I rely so much on the equipment in order to do my job that it becomes just part of the job to ensure that what I rely on is optimally tuned and ready to go.

At the same time, while it can be grating to get multiple phone calls to come fix a piece of equipment that can wait, it’s absolutely lovely during times of “office” drama to be able to disappear with my toolbox and let them all hash it out.

I think the tendency for us to be the fixers comes from several sources. There’s first, the fact that my entire job revolves around equipment. Oxygen equipment, pulse oximeters, the ventilator, suction equipment, intubation equipment, that damned blood gas analyzer, and on and on and on. Then there’s the fact that since so much of my job is equipment, a significant chunk of my training is troubleshooting equipment. When you’re keeping a patient alive with equipment, you’d better know how to troubleshoot when things start to go awry. (Significant in this training: “is it a problem with the equipment or a problem with the patient?”) Lastly, and this is just a loose theory, there seems to be this predilection towards mechanical inclination that’s common among RTs, and combined with all of the above, when there’s one of me and between two and twenty nurses watching me do my job, it becomes common knowledge among the healthcare team that I’m the one who just knows how to fix things. I imagine that’s how I get roped into performing a 3am-on-a-Saturday resuscitation on the printer, anyway.

With so much more equipment being software-controlled, there’s going to need to be an inclination towards computers moreso too, I think. Maybe not so much as the biomed needs, but it’s looking like it’s going to be more and more necessary to troubleshoot software problems as well as problems with the mechanics of it all.

All in all, though, I’m happy to be the one with the toolbox. And not only because when I’m resuscitating equipment, if my patient dies, with enough tools and time and parts and knowledge, I can pretty much always bring it back to life.

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