Learning critical thinking: a personal example

post by Swimmer963 (Miranda Dixon-Luinenburg) (Swimmer963) · 2013-02-14T20:43:06.521Z · LW · GW · Legacy · 28 comments

Contents

  The skills
  The mistakes
  The implications
  References
None
28 comments

Related to: Is Rationality Teachable

“Critical care nursing isn’t about having critically ill patients,” my preceptor likes to say, “it’s about critical thinking.”

I doubt she's talking about the same kind of critical thinking that philosophers are, and I find that definition abstract anyway. There’s been a lot of talk about critical thinking during our four years of nursing school, but our profs seem to have a hard time defining it. So I’ll go with a definition from Google.

Critical thinking can be seen as having two components: 1) a set of information and belief generating and processing skills, and 2) the habit, based on intellectual commitment, of using those skills to guide behaviour. It is thus to be contrasted with: 1) the mere acquisition and retention of information alone, because it involves a particular way in which information is sought and treated; 2) the mere possession of a set of skills, because it involves the continual use of them; and 3) the mere use of those skills ("as an exercise") without acceptance of their results.¹

That’s basically rationality–epistemic, i.e. generating true beliefs, and instrumental, i.e. knowing how to use them to achieve what you want. Maybe part of me expected, implicitly, to have an easier time learning this skill because of my Less Wrong knowledge. And maybe I am more consciously aware of my mistakes, and the cognitive factors that caused them, than most of my classmates. When it’s forty-five minutes past the end of my shift and I’m still charting, I’m also calling myself out on succumbing to the planning fallacy. I once went through the first half hour of a shift during my pediatrics rotation thinking that one of my patients had cerebral palsy, when he actually had cystic fibrosis–all because I misread my prof’s handwriting as ‘CP’ when she’d written ‘CF’. I was totally confused by all the enzyme supplements on his list of meds, but it still took me a while to figure it out–a combination of priming and confirmation bias, taken to the next level. 

But, overall, even if I know what I'm doing wrong, it hasn’t been easier to do things right. I have a hard time with the hospital environment, possibly because I’m the kind of person who ended up reading and posting on Less Wrong. My cognitive style leans towards Type 2 reasoning, in Keith Stanovich’s taxonomy–thorough, but slow. I like to understand things, on a deep level. I like knowing why I’m doing something, and I don’t trust my intuitions, the fast-and-dirty product of Type 1 reasoning. But Type 2 reasoning requires a lot of working memory, and humans aren’t known for that, which is the source of most of my frustration and nearly all of my errors–when working memory overload forces me to be a cognitive miser.

Still, for all the frustration, I’m pretty sure I’ve ended up in the perfect environment to learn this skill called ‘critical thinking.’ I’m way out of my depth–which I expected. No fourth year student is ready to work independently in a trauma ICU, but I decided to finish my schooling here in the name of tsuyoku naritai, and for all the days when I’ve gone home crying, it’s still worth it. I’m learning.

 

The skills

 1.     A set of information and belief generating and processing skills.

Medicine, and nursing, are a bit like physics, in that you need to generate true beliefs about systems that exist outside of you, and predict how they’re going to behave. This involves knowing a lot of abstract theory, which I’m good at, and a lot of heuristics and pattern-matching for applying the right bits of theory to particular patients, which I’m less good at. That’s partly an experience thing; my brain needs patterns to match to. But in general, I have decent mental models of my patients. I’m curious and I like to understand things. If I don’t know what part of the theories applies, I ask.

2.     The habit, based on intellectual commitment, of using those skills to guide behaviour.

So you’ve got your mental model of your patient, your best understand of what’s actually going on, on a physiological and biochemical level, down under the skin where you can’t see it. You know what “normal” is for a variety of measures: vital signs, lung sounds, lab values, etc. Given that your patient is in the ICU, you know something’s abnormal, or they wouldn’t be there. Their diagnosis tells you what to expect, and you look at the results of your assessments and ask a couple of questions. One: is this what I expect, for this patient? Two: what do I need to do about it?

I’m not going to be surprised if a post-op patient has low hemoglobin. It’s information of a kind, telling the doctor whether or not the patient needs a transfusion, and how many units, but it’s not really new information, and a moderately abnormal value wouldn’t worry me or anyone else. If their hemoglobin keeps dropping; okay, they’re actively bleeding somewhere, that’s irritating, and possibly dangerous, and needs dealing with, but it’s not surprising.

But if a patient here for an abdominal surgery suddenly has decreased level of consciousness and their pupils aren’t reacting normally to light, I’m worried. There’s nothing in my mental model that says I should expect it. I notice I’m confused, and that confusion guides my behaviour; I call the doctor right away, because we need more information to update our collective mental model, information you can’t get just from observation, like a CT scan of the head. (Even this is optimistic–plenty of patients are admitted to the ICU because we have no idea what’s wrong with them, and are hoping to keep them alive long enough to find out.)

The basics of ICU nursing come down to treating numbers. Heart rate, blood pressure, oxygen saturations, urine output, etc; know the acceptable range, notice if they change, and use Treatment X to get them back where they’re supposed to be. Which doesn’t sound that hard. But implicit in ‘notice if they change’ is ‘figure out why they changed’, because that affects how you treat them, and implicit in that is a lot of background knowledge, which has to be put in context.

I’m, honestly, fairly terrible at this. It’s a compartmentalization thing. I don’t like using my knowledge as input arguments to generate new conclusions and then relying on those conclusions to treat human beings. It feels like guessing. Even though, back in high school, I never really needed to study for physics tests–if I understood what we’d learned, I could re-derive forgotten details from first principles. But hospital patients ended up in a non-overlapping magisterium in my head. In order for me to trust my knowledge, it has to have come directly from the lips of a teacher or experienced nurse.

My preceptor, who  hates this.  “She needs to continue to work on her critical thinking when it comes to caring for critically ill patients,” she wrote on my evaluation. “She knows the theory, and is now working to apply it to ICU nursing.” Shorthand for, she knows the theory, but getting her to apply it to ICU nursing is like pulling teeth. A number of our conversations have gone like this:

Me: “Our patient’s blood pressure dropped a bit.”

Her: “Yeah, it did. What do you want to do about it?”

Me: “I, uh, I don’t know... Should I increase the vasopressors?”

Her: “I don’t know, should you?”

Me: “Uh, maybe I should increase the phenylephrine to 40 mcg/min and see what happens. How long should I wait to see?”

Her: “You tell me.”

Me: “Well, let’s say it’ll take a few minutes for what’s in the tubing now to get pushed through, and it should take effect pretty quickly because it’s IV, like a minute... So if his blood pressure’s not up enough in five minutes, I’ll increase the phenyl to 60. Does that sound okay?”

Her: “It’s your decision to make." 

Needless to say, I find this teaching method extremely stressful and scary, and I’m learning about ten times more than I would if she answered the questions I asked. Because “the mere acquisition and retention of information alone” isn’t my problem. I have a brain like an encyclopaedia. My problem, in the critical care nursing context, is the “particular way in which information is sought and treated.” I need to know the right time to notice something is wrong, the right place to look in my encyclopaedia, and the right way to take the information I just looked up and figure out what to do with it.

 

The mistakes

Some of my errors, unsurprisingly, boil down to a failure to override inappropriate Type 1 responses with Type 2 responses–in other words, not thinking about what I’m doing. But most of them are more of a mindware gap–I don’t yet have the “domain-specific knowledge sets” that the nurses around me have. Not just theory knowledge; I do have most of that; but the procedural habits of how to stay organized and prioritize and dump the contents of my working memory onto paper in a way that I can read them back later. Usually, when I make a mistake, I knew better, but the part of my brain that knew better was doing something else at the time, that small note of confusion getting lost in the general chaos. 

Pretty much all nurses keep a “feuille de route”–I have yet to find a satisfactory English word for this, but it’s a personal sheet of paper, not legal charting, usually kept in a pocket, and used as an extended working memory. In med/surg, when I had four patients, I made a chart with four columns; name and personal information, medications, treatments/general plan for the day, and medical history; and as many rows as I had patients. If something was important, I circled it in red ink. This system doesn’t work in the ICU, so my current feuille de route has several aspects. I fold a piece of blank paper into four, and take notes from the previous shift report on one quarter of one side, or two quarters if it’s a long report. Across from that, I draw a vertical column of times, from 8:00 am to 6:00 pm (or 8:00 pm to 6:00 am). 7:00 pm and 7:00 am are shift change, so nothing else really gets done for that hour. I use this to scribble down what I need to get down during my twelve hours, and approximately when I want to do it, and I prioritize, i.e. from 1 to 5 most to least important. Once it’s done, I cross it off–then I can forget about it. On the other side of the paper, I make a cheat sheet for giving report to the next nurse, or presenting my patient to the doctors at rounds.  

This might be low-tech and simple, but it takes a huge load off my working memory, and reduces my most frequent error, which is to get so overwhelmed and frazzled that my brain goes on strike. In other words, the failure to override Type 1 responses due to the lack of cognitive capacity to run a Type 2 process. It’s drastically cut down on the frequency of this mental conversation:

Me: “I turned off the sedation, and my patient isn’t waking up as fast as I expected. I notice I’m confused–”

My brain: “You’re always confused! Everything around here is intensely confusing! How am I supposed to use that as information?” 

Odd as it might sound, I often don’t notice when my brain starts edging towards a meltdown. The feeling itself is quite recognizable, but the circumstances that lead to it, i.e. overloaded working memory, mean that I’m not usually paying attention to my own feelings.

“You need to stop and take a breath,” my preceptor says about fifty times a day. Easier said than done–but it’s more efficient, overall, to have a tiny part of my mind permanently on standby, keeping an eye on my emotions, noticing when the gears start to overheat. Then stop, take a breath, and let go of everything except the task at hand, trusting myself to have created enough cues in my environment to retrieve the other tasks, once I’m done. Humans don’t multitask well. Doing one thing while trying to remember a list of five others is intense multitasking, and it’s no wonder it’s exhausting.

 

The implications

“You can’t teach critical thinking,” my preceptor says, but I’m pretty sure that’s exactly what she’s doing right now. A great deal of what I already know is domain-specific to nursing, but most of what I’m learning right now is generally applicable. I’m learning the procedural skills to work through difficult problems, under what Keith Stanovich would call average rather than optimal conditions. Sitting in my own little bubble in front of a multiple choice exam–that’s optimal conditions. Trying to figure out if I should be surprised or worried about my patient’s increased heart rate, while simultaneously deciding whether or not I can ignore the ventilator alarm and whether I can finish giving my twelve o’clock antibiotic before I need to do twelve o’clock vitals–that’s not just average conditions, it’s under-duress conditions.

I’m hoping that after a few more weeks, or maybe a few more years, I’ll be able to perform comfortably in this intensely terrifying environment. And I’m hoping that some of the skills I learn will be general-purpose, for me at least. It’d be nice if they were teachable to others, too, but I think my preceptor might be right about one thing–you can’t teach this kind of critical thinking in the classroom. It's about moulding my brain into the right shape, and everyone's brain starts out in a different shape, so the mould has to be personalized. 

But the habits are general ones. Notice when you're faced with a difficult problem, or making an important decision. Notice that you're doing this while distracted. Stop and take a breath. Get out a piece of paper. Figure out how the problem is formatted in your mind, and format it that way on the paper. (This is probably the hardest part). Dump your working memory and give yourself space to think. Prioritize from 1 to n. Keep an eye on the evolving situation, sure, but find that moment of concentration in the midst of chaos, and solve the problem. 

Of course, it's far from guaranteed that this will work. I'm making an empirical prediction; that the skills I'm currently learning will be transferable to non-nursing areas, and that they'll make a difference in my life outside of work. I'll be on the lookout for examples, either of success or failure.

 

References

Scriven, Michael; Paul, Richard. Defining critical thinking. (2011). The critical thinking community. http://www.criticalthinking.org/pages/defining-critical-thinking/410

 

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