Cognitive effects of hospital calls in anaesthesiologists

The work hours of Norwegian physicians are under scrutiny because of an increased public focus on patient safety. Ample international research indicate harmful effects of doctor fatigue based on studies on physicians working long weeks and on-call shifts of more than 30 consecutive hours. There is a lack of research on effects relevant for short or intermediate length of work weeks and call shifts. This study intended to study cognitive effects of short or intermediate duration in-hospital calls.

Eighteen anaesthesiology residents working on-call at an operation ward or an intensive care unit at Haukeland University Hospital were invited to participate. Schedules were adapted to allow for two additional experimental shifts. Participants were subjected to Cambridge Neuropsychological Test Automated Battery cognitive testing in a rested state and on three occasions after call. Amount of sleep and self-assessed sleepiness were recorded.

Ten residents completed all four tests during 10 months. Reaction time was longer post-call. It was significantly increased only after the 18 h night call, by 21.1 and 20.5 ms for simple and five-choice reaction time, respectively. Executive function was not significantly altered post-call. Visual memory was improved post-call. Karolinska Sleepiness Score was increased by 3.3 (long day), 2.1 (short night) and 2.5 (long night) points post-call.

Reaction times were increased after 18 h night calls and non-significant increases in reaction times were apparent after the other on-call shifts. Self reported sleepiness was increased post-call. We were not able to conclude whether executive function or memory was negatively affected post-call.