All night long: an assessment of the cognitive effects of night shift work in anaesthesiology trainees

Abstract

Background: Excessive working hours and fatigue in medical training are a source of concern. Practitioner fatigue manifests itself in both risks to the patient and the medical trainee. This study aimed to quantify the effect of shift work on multiple cognitive function domains in anaesthesiology trainees at Tygerberg Academic Hospital. Secondary outcomes were to identify strategies to ameliorate shift work-related fatigue.
Methods: An analytical observational study was conducted using mixed methods. The participants, anaesthesiology registrars and medical officers, completed an electronic cognitive test battery consisting of four tests, and a paper-based questionnaire prior to and following a 14-hour night shift.
Results: Twenty-nine participants engaged in the study; including 14 males and 15 females with an age range 29–58 years. The study demonstrated a statistically significant impairment in reaction time in two of the four cognitive domains tested, ranging from 13.4–17.8%. No statistically significant change in accuracy was seen in any of the cognitive tests. A subjective increase in fatigue was also demonstrated using the Karolinska Sleepiness Scale. Further, no statistically significant correlation was found between the decline in reaction time and the individual and work-related factors which were assessed in the paper-based questionnaires.
Conclusion: Fatigue in anaesthesiology trainees after a 14-hour night shift results in a decline in reaction time in the cognitive domains of psychomotor function and attention. Accuracy, however, remained unchanged. The study was unable to identify strategies which ameliorated these effects with statistical significance. Nevertheless, the recommendations and guidelines of various anaesthesiology bodies, including the South African Society of Anaesthesiologists, are supported. Further studies using a larger and more diverse study population are suggested.