Cognitive load, medical error, sterilization, and “the checklist”

I was chatting with a veteran of the medical insurance business the other day and mentioned “cognitive load“, which is a common enough concept in psychology, systems usability, and human factors engineering, but otherwise sounds like arcane jargon. The demands on attention are labeled cognitive load, and job performance can suffer with too high a load. My companion gave me a look as if I had once again strayed far off into academic theory-land, but I made the point that high cognitive load is directly related to medical error and risk management. Indeed, liability management may be the next growth area for the new field of medical cognition.

Not so long ago I did research on limiting physician liability for Texas Medical Liability Trust because of the overhead associated with patients suing due to the adverse effects of “off label” medications. Doctors have a lot to worry about, their workflow involves high cognitive load, the proliferation of forms and paperwork subverts their job satisfaction, and of course my recommendation was to add yet another standard operating procedure!

This article in the New Yorker about “the checklist” for reducing the high cognitive load of medical professionals via a standard operating procedure opened up my eyes to the benefits of implementing best practices:

“On any given day in the United States, some ninety thousand people are in intensive care. Over a year, an estimated five million Americans will be, and over a normal lifetime nearly all of us will come to know the glassed bay of an I.C.U. from the inside. Wide swaths of medicine now depend on the lifesupport systems that I.C.U.s provide: care for premature infants; victims of trauma, strokes, and heart attacks; patients who have had surgery on their brain, heart, lungs, or major blood vessels. Critical care has become an increasingly large portion of what hospitals do. Fifty years ago, I.C.U.s barely existed. Today, in my hospital, a hundred and fifty-five of our almost seven hundred patients are, as I write this, in intensive care. The average stay of an I.C.U. patient is four days, and the survival rate is eighty-six per cent. Going into an I.C.U., being put on a mechanical ventilator, having tubes and wires run into and out of you, is not a sentence of death. But the days will be the most precarious of your life.

(snip)

Expertise is the mantra of modern medicine. In the early twentieth century, you needed only a high-school diploma and a one-year medical degree to practice medicine. By the century’s end, all doctors had to have a college degree, a four-year medical degree, and an additional three to seven years of residency training in an individual field of practice—pediatrics, surgery, neurology, or the like. Already, though, this level of preparation has seemed inadequate to the new complexity of medicine. After their residencies, most young doctors today are going on to do fellowships, adding one to three further years of training in, say, laparoscopic surgery, or pediatric metabolic disorders, or breast radiology—or critical care. A young doctor is not so young nowadays; you typically don’t start in independent practice until your mid-thirties.

We now live in the era of the super-specialist—of clinicians who have taken the time to practice at one narrow thing until they can do it better than anyone who hasn’t. Super-specialists have two advantages over ordinary specialists: greater knowledge of the details that matter and an ability to handle the complexities of the job. There are degrees of complexity, though, and intensive-care medicine has grown so far beyond ordinary complexity that avoiding daily mistakes is proving impossible even for our super-specialists. The I.C.U., with its spectacular successes and frequent failures, therefore poses a distinctive challenge: what do you do when expertise is not enough?

(snip)

Yet it’s far from obvious that something as simple as a checklist could be of much help in medical care. Sick people are phenomenally more various than airplanes. A study of forty-one thousand trauma patients—just trauma patients—found that they had 1,224 different injury-related diagnoses in 32,261 unique combinations for teams to attend to. That’s like having 32,261 kinds of airplane to land. Mapping out the proper steps for each is not possible, and physicians have been skeptical that a piece of paper with a bunch of little boxes would improve matters much.

In 2001, though, a critical-care specialist at Johns Hopkins Hospital named Peter Pronovost decided to give it a try. He didn’t attempt to make the checklist cover everything; he designed it to tackle just one problem, the one that nearly killed Anthony DeFilippo: line infections. On a sheet of plain paper, he plotted out the steps to take in order to avoid infections when putting a line in. Doctors are supposed to (1) wash their hands with soap, (2) clean the patient’s skin with chlorhexidine antiseptic, (3) put sterile drapes over the entire patient, (4) wear a sterile mask, hat, gown, and gloves, and (5) put a sterile dressing over the catheter site once the line is in. Check, check, check, check, check. These steps are no-brainers; they have been known and taught for years. So it seemed silly to make a checklist just for them. Still, Pronovost asked the nurses in his I.C.U. to observe the doctors for a month as they put lines into patients, and record how often they completed each step. In more than a third of patients, they skipped at least one.

The next month, he and his team persuaded the hospital administration to authorize nurses to stop doctors if they saw them skipping a step on the checklist; nurses were also to ask them each day whether any lines ought to be removed, so as not to leave them in longer than necessary. This was revolutionary. Nurses have always had their ways of nudging a doctor into doing the right thing, ranging from the gentle reminder (“Um, did you forget to put on your mask, doctor?”) to more forceful methods (I’ve had a nurse bodycheck me when she thought I hadn’t put enough drapes on a patient). But many nurses aren’t sure whether this is their place, or whether a given step is worth a confrontation. (Does it really matter whether a patient’s legs are draped for a line going into the chest?) The new rule made it clear: if doctors didn’t follow every step on the checklist, the nurses would have backup from the administration to intervene.

Pronovost and his colleagues monitored what happened for a year afterward. The results were so dramatic that they weren’t sure whether to believe them: the ten-day line-infection rate went from eleven per cent to zero. So they followed patients for fifteen more months. Only two line infections occurred during the entire period. They calculated that, in this one hospital, the checklist had prevented forty-three infections and eight deaths, and saved two million dollars in costs.”

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