Wednesday, January 21, 2015

Recognition

The following is based on an actual case that occurred a long time ago in a galaxy far, far away.

A 65-year-old man arrived in the emergency department by ambulance after being found unresponsive. His respiratory rate was 40/minute, heart rate was 170/minute, and temperature was 102.2°. He did not respond to Narcan or an ampule of 50% dextrose. Blood sugar was 600 mg/dL. The diagnosis of diabetic ketoacidosis was made. IV fluids and an insulin drip were given. After some hydration he became more alert and complained of abdominal pain. On examination, his abdomen was tender to palpation. Four hours after arrival, a surgical consultant was called and diagnosed an incarcerated inguinal hernia. Before the patient could be taken to surgery, he suffered a cardiac arrest and could not be resuscitated. Review of the case revealed that although blood cultures were drawn and were eventually positive, antibiotics had not been ordered.

What happened? The possibility that this patient was septic never occurred to the doctors managing the case. I am sure that if a scenario like this appeared on a test, those doctors would have immediately chosen the right antibiotics. Some doctors are "book smart" but can't deal with a real live patient.

Although the doctors didn't do a very thorough abdominal exam at first, the real problem here was recognition.

I was reminded of this case by a recent article about a 2013 paper that appeared in a journal called Human Factors. The paper, "The Effectiveness Of Airline Pilot Training for Abnormal Events," pointed out that pilots doing their periodic training know that certain crises—stalls, low-level wind shear, engine failures on takeoff—are part of every simulator session and will occur in predictable ways.

The authors presented those situations in unexpected ways, measured pilots' reactions, and found that experienced pilots responded less skillfully.

From the paper: Our control conditions demonstrate that pilots’ abilities to respond to the “schoolhouse” versions of each abnormal event were in fine fettle. The problems that arose when the abnormal events were presented outside of the familiar contexts used in training demonstrate a failure of these skills to generalize to other situations.

They suggested four ways to improve training and testing.

1) Change it up. In other words, don't practice things the same way every time.

2) Train for surprise.

3) Turn off the automation. Don't let the pilots depend on automated systems to help them recognize what is going on because if those systems fail, pilots will have trouble dealing with the situation.

4) Reevaluate the idea of teaching to the test which can "present the illusion that real learning has taken place when in fact it has not."

Item #3 is particularly relevant because of some recent interest in the negative effects that automation is having on pilots and possibly society in general. The 2009 crash of an Air France plane into the South Atlantic Ocean has been analyzed in several recent publications. (Here and here)

The cockpit voice recorder transcript is chilling. In a storm, the autopilot failed, and the plane stalled. Three pilots failed to recognize what happened and did all the wrong things.

I have been saying for years that we need to teach med students and residents how to think. Recognition of rare events would be a good area to focus on.

10 comments:

JEN said...

Was he hypotensive? what was his WBC? These things may have have been helpful to know.

artiger said...

JEN, if his BP was 110/70 and his WBC was not elevated, would anything have changed? The failure was not in recognizing the effect, but rather, not recognizing the cause.

frankbill said...

There is a Dr Jerome Groopman that wrote a book called How Doctors Think. While I have not read the book I have seen parts of it on the web . Such as this site http://www.npr.org/templates/story/story.php?storyId=8892053

Since I am a non medical person this is my point of view. It this case had they started antibiotics what is the likelihood of him recovering? Wasn't it all ready to late?

In the case of this man We don't know the past history. Why did he wait so long to get medical help? Had he tried to get help but they were the missing the DX?

To easy for providers to say it is all in your head and not take the time to look for the real DX. Would agree with the need to improve training and testing.

Anonymous said...

Thanks Skep, teach them to think and you take all the fun out of it when we figure out the problems before they do. I admit I have a different relationship with the docs who can think. I "present" more like a medical student, including research. I even present differential diagnoses and why I rule them out too.

My sisters' best friend, her sister died from sepsis. They never recognized it, 24 hours after an ER visit. Signs were all there.

I've had a number of docs that were book smart but not people smart. They had their ego get in the way too.

One of the biggest issues I've seen? Computer says labs are normal. Some don't treat until you are more than below normal. They don't realize that what is "normal" for a computer may not be "normal" for the human. They'll give psychotropic drugs out like candy rather than go ... hmmm ... lets see if X works.

I still am an advocate of putting "zebra" patients in to medical students. I would volunteer and take my own time off work to help students learn how to deal with complex and "zebra" patients.

If you hear Captain Smith, the Titanic Captain, he had never been in a shipwreck. He didn't know how to react. One of the things about teaching the military is how to react in situations so the teaching takes over and they don't hesitate ... that can cause death. Same thing for students. I think it would be very useful also to put them in more office vs. hospital situations. How many truly are going to be ED, surgeon, hospitalists? If not, put them in the communities so they learn how to do deal with patients and offices, rather than somewhat handicapping them to a hospital situation.

Skeptical Scalpel said...

I don't recall his BP or WBC. I agree that those numbers if normal would not rule out sepsis.

Why did he wait until he had passed out on the floor? You're a patient. You tell me.

Anon, I agree with everything you wrote.

frankbill said...

There is always the money that gets in the way of getting treatment.

With me it becomes a useless thing as no one takes the time to think of why I am having shortness of breath. Even though the EKG is showing abnormal ST and sometimes Q waves. Or blood phosphate levels one hole numbers below normal. They just say it is all in my head.

To be fair I have had stress tests and echo done. Ct scan showed 2 cm adenoma on left adrenal gland a 2.2 cm exophytic low density lesion off the mid pole of the left kidney which measures 34 HU,
indeterminate and greater than expected for a simple cyst.

Have had B/P readings of 199/100. Have had EMTs thinking I was having heart attack.

After a while it becomes useless to call 911 but I think one of these I will be the one passed out on the floor and most likely not get the help I need.

Moose said...

Typically high blood sugars in a diabetic come on slowly and are easily spotted and treated quickly. However, illness-related hyperglycemia (and HHNS, which, if they didn't actually check for ketones, this could have been) can hit and exacerbate rapidly. Once your sugars start to rise AND you get dehydrated you run the risk of being in a state where you're too confused to help yourself. Whether it was the sepsis itself or something that caused it, it probably happened relatively quickly and the poor guy never saw it coming.

(not a doctor, but I play a diabetic on tv. and in my body.)

Skeptical Scalpel said...

Moose, thanks for the personal insight into diabetic coma.

Marjorie Stiegler said...

This is such a hugely important topic, especially as medicine becomes increasingly specialized, training hours are ever-shrinking, and touches with the actual patient (instead of the EMR) are diminishing. You might enjoy this video - http://goo.gl/53cd3t - a quick 15 minutes or so about how "memorableness" and pattern matching replace the differential diagnosis as we become more experienced. Therefore, while students generate tons of ideas, experts typically have made up their minds before they even realize it on the conscious level. When we are wrong at the very first input of medical decision making, which I would describe as the "pattern recognized?" point, we will make the kinds of errors described in your post. It is easy to engage in analytical thinking when we know we don't recognize the diagnosis. However, when we do think we know it, and we are wrong ("premature closure"), we almost never self-correct.

Skeptical Scalpel said...

Marjorie, I finally had some time to watch your video. Very well done and highly relevant to my post. Every med student and resident should watch it too. Thanks for your contribution.

Post a Comment