Night float at the hospital.

Night float at the hospital.

Night float at the hospital.

Health and medicine explained.
July 30 2008 1:29 PM

The Nightmare of Night Float

Is an ignorant doctor really better than a tired one?

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At first glance, reducing the number of hours that residents work would seem a no-brainer. In a survey of American medical residents, 41 percent reported fatigue as a cause of their most serious mistakes. Studies have shown that residents after a call night score lower on tests of simple reasoning, response time, concentration, and recall. Indeed, a single night of continuous sleep deprivation has been shown to be roughly equivalent to a blood alcohol level of 0.10 percent—that is, being drunk.

Once, as a sleep-deprived intern, I had to take an elderly woman with severe angina for a CT scan in the middle of the night. When we arrived in the radiology department, I made what seemed like a reasonable decision: I stopped my patient's IV drips to get her onto the radiology table. Midway through the scan, she started moaning because of severe chest pains. I suddenly realized that I had stopped her nitroglycerin drip, used to treat angina, and that she was in the early stages of a heart attack. I tried to get the drip restarted, but the IV machine just kept beeping, mixing with her groans. Panicking, I raced the stretcher alone back to the cardiac-care unit, getting lost on the way. I finally got her back to the CCU, and experienced nurses took over. My patient ended up fine.


As harrowing as that experience was, it was nothing compared with night float, in which one was operating from a position of ignorance, in the environment of a teaching hospital, which reveres knowledge and competence. That first night at Memorial, I went to see a patient with esophageal cancer and intractable hiccups. Walking into his room, I felt almost relieved. After what I had dealt with so far that night, hiccups seemed almost laughably unserious. But these were no ordinary hiccups. They had been going on for more than 24 hours, leaving the patient sleepless and utterly demoralized.

I didn't know what caused hiccups, let alone how to treat them. When I asked a nurse, she mentioned that a drug called chlorpromazine was sometimes used, so I wrote an order for it. Walking through the nurses' station, I casually checked the patient's chart. There, amid his papers, was a brief note. He had once suffered a severe reaction to this particular drug. It wasn't documented as an allergy on the sign-out sheet I'd gotten but was scribbled in a progress note. I immediately canceled the order, relieved that I had caught the mistake in time but alarmed at how easily it might have slipped through.

Night float felt worse to me than working when I was exhausted, but is it really worse for patient care? The data are mixed. A study published in 2004 in the New England Journal of Medicine showed that interns working in an intensive-care unit made 36 percent more serious medical errors during a traditional schedule as compared with a schedule that eliminated extended work shifts and reduced the number of hours worked per week from 80 to 63. On the other hand, a study in the Journal of the American Medical Association appeared to indict the cross-coverage hospitals have been relying on to conform with the work limits. It showed that increasing cross-coverage in a large urban hospital caused delays in tests and an increased number of complications that could have been prevented, like drug reactions and infections. Work limits have other troubling consequences as well, including interruption of resident learning, fracturing of traditional hospital teams, and the creation of a kind of shift-work clock-watching mentality among young doctors.

If tired residents hurt patients, but the ignorance of night float and cross-coverage also pose a danger, what should hospitals do? No doctor can work 24 hours a day, seven days a week, so cross-coverage is essential. The optimal system would provide rested night floats with all the information they need. The best way to accomplish this is for teaching hospitals to have standardized, electronic handoff systems. In medicine, as in aviation, most errors occur at transitions: by pilots, during takeoff and landing, and by doctors, after handoffs. Because of work limits, an intern today might be involved in more than 300 handoffs during an average monthlong rotation. Too many hospitals continue to rely on one intern signing out verbally to another, an invitation for error. Less than 5 percent of hospitals have electronic handoff systems in place.

Without better handoff systems, work limits may well weaken medicine more than exhausted residents ever did. As a doctor in training, you have to see a patient's illness through its course—observe the arc—to get a grip on the dynamics of disease. It is possible to overcorrect for even the most serious of problems. And in trying to get young doctors a bit more rest, we may have come up with a cure that is worse than the disease.