Florian Ernst1, Markus Rauchenzauner2, Heinz Zoller3, Andrea Griesmacher4, Angelika Hammerer-Lercher4, Roger Carpenter5, Gerhard Schuessler6, Michael Joannidis7. 1. Division of Intensive Care and Emergency Medicine, Department of Internal Medicine, Medical University of Innsbruck, Innsbruck, Austria; Department of Neurology, Paracelsus Medical University Salzburg, Salzburg, Austria. 2. Department of Pediatrics, Saint Vincent Hospital Zams, Zams, Austria; Department of Pediatrics IV, Medical University Innsbruck, Innsbruck, Austria. 3. Department of Gastroenterology, Medical University of Innsbruck, Innsbruck, Austria. 4. Institute of Medical and Chemical Laboratory Diagnostics (ZIMCL), University Hospital Innsbruck, Innsbruck, Austria. 5. Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, UK. 6. Department of Medical Psychology, Medical University of Innsbruck, Innsbruck, Austria. 7. Division of Intensive Care and Emergency Medicine, Department of Internal Medicine, Medical University of Innsbruck, Innsbruck, Austria. Electronic address: michael.joannidis@i-med.ac.at.
Abstract
OBJECTIVES: On-call duty (OCD) is frequently associated with health and safety risks for both physicians and patients. The lack of studies conducted in clinical care environments and the ongoing public dialogue concerning OCD led to a detailed investigation of a working schedule including sleep fragmentation and extended work hours. DESIGN: Within-person randomized cross-over trial. SETTING: Comparison of a 24h on-call shift (OCD) compared to a routine working-day (non on call, NOC) in hospital. PARTICIPANTS: 30 residents and senior physicians of the Department of Internal Medicine, Neurology and Otorhinolaryngology at the University Hospital Innsbruck. MAIN OUTCOME MEASURES: Sleep variables, cognitive performance (Concentration-Endurance d2 test), emotional status (Eigenschaftswoerterliste 60S), serum-cortisol, urinary cortisol and noradrenaline, heart-rate variability, and saccadic eye movements were determined before and after OCD and NOC respectively. RESULTS:Concentration-endurance performance was significantly reduced after OCD as compared to NOC by 16.4% (p<0.001). Changes in emotional status consisted in a reduction of subjective concentration and performance related activation after OCD by 17.4% (p<0.001) and 16.0% (p<0.001) respectively together with a 21.8% increase of general deactivation (p<0.001) and a 29.2% rise of fatigue (p<0.001). On the contrary, subjective activation and raised mood showed an 18.3% and 21.7% increase after OCD (p<0.01). Urinary noradrenaline excretion (46 μg/24 h, 19-97) was greater during OCD when compared to NOC (36 μg/24 h, 10-54, p<0.01). Sympathetic activity measured by heart rate variability was significantly higher during OCD in contrast to NOC (p<0.05). Serum-cortisol was lower in the morning after (132 ng/l, 60-273) than the morning before OCD (p<0.01). Finally, the number of short saccadic latencies was reduced after OCD (p<0.05) compared to NOC. CONCLUSIONS: 24 h OCD alters both, the sympathetic-adrenomedullary system as well as the hypothalamic pituitary-adrenocortical axis. Moreover, physicians' emotional state, cognitive and oculomotor performance seems to be influenced independently from sleep interruptions. The discrepancy between subjective feeling and objective cognitive impairments pose a risk for performing complex manual and cognitive tasks. Hence, our findings argue against an oversimplified interpretation of alterations in the physicians' psychoneuroendocrine structure in terms of impaired mood and neurocognitive deterioration combined with up-/dysregulated stress axes associated with OCD as a consequence of sleep deprivation.
RCT Entities:
OBJECTIVES: On-call duty (OCD) is frequently associated with health and safety risks for both physicians and patients. The lack of studies conducted in clinical care environments and the ongoing public dialogue concerning OCD led to a detailed investigation of a working schedule including sleep fragmentation and extended work hours. DESIGN: Within-person randomized cross-over trial. SETTING: Comparison of a 24h on-call shift (OCD) compared to a routine working-day (non on call, NOC) in hospital. PARTICIPANTS: 30 residents and senior physicians of the Department of Internal Medicine, Neurology and Otorhinolaryngology at the University Hospital Innsbruck. MAIN OUTCOME MEASURES: Sleep variables, cognitive performance (Concentration-Endurance d2 test), emotional status (Eigenschaftswoerterliste 60S), serum-cortisol, urinary cortisol and noradrenaline, heart-rate variability, and saccadic eye movements were determined before and after OCD and NOC respectively. RESULTS: Concentration-endurance performance was significantly reduced after OCD as compared to NOC by 16.4% (p<0.001). Changes in emotional status consisted in a reduction of subjective concentration and performance related activation after OCD by 17.4% (p<0.001) and 16.0% (p<0.001) respectively together with a 21.8% increase of general deactivation (p<0.001) and a 29.2% rise of fatigue (p<0.001). On the contrary, subjective activation and raised mood showed an 18.3% and 21.7% increase after OCD (p<0.01). Urinary noradrenaline excretion (46 μg/24 h, 19-97) was greater during OCD when compared to NOC (36 μg/24 h, 10-54, p<0.01). Sympathetic activity measured by heart rate variability was significantly higher during OCD in contrast to NOC (p<0.05). Serum-cortisol was lower in the morning after (132 ng/l, 60-273) than the morning before OCD (p<0.01). Finally, the number of short saccadic latencies was reduced after OCD (p<0.05) compared to NOC. CONCLUSIONS: 24 h OCD alters both, the sympathetic-adrenomedullary system as well as the hypothalamic pituitary-adrenocortical axis. Moreover, physicians' emotional state, cognitive and oculomotor performance seems to be influenced independently from sleep interruptions. The discrepancy between subjective feeling and objective cognitive impairments pose a risk for performing complex manual and cognitive tasks. Hence, our findings argue against an oversimplified interpretation of alterations in the physicians' psychoneuroendocrine structure in terms of impaired mood and neurocognitive deterioration combined with up-/dysregulated stress axes associated with OCD as a consequence of sleep deprivation.