title: Night shift decreases cognitive performance of ICU physicians.
abstract: BACKGROUND
  The relationship between tiredness and the risk of medical errors is now commonly accepted. The main objective of this study was to assess the impact of an intensive care unit (ICU) night shift on the cognitive performance of a group of intensivists. The influence of professional experience and the amount of sleep on cognitive performance was also investigated.
  
  
  METHODS
  A total of 51 intensivists from three ICUs (24 seniors and 27 residents) were included. The study participants were evaluated after a night of rest and after a night shift according to a randomized order. Four cognitive skills were tested according to the Wechsler Adult Intelligence Scale and the Wisconsin Card Sorting Test.
  
  
  RESULTS
  All cognitive abilities worsened after a night shift: working memory capacity (11.3 ± 0.3 vs. 9.4 ± 0.3; p < 0.001), speed of processing information (13.5 ± 0.4 vs. 10.9 ± 0.3; p < 0.001), perceptual reasoning (10.6 ± 0.3 vs. 9.3 ± 0.3; p < 0.002), and cognitive flexibility (41.2 ± 1.2 vs. 44.2 ± 1.3; p = 0.063). There was no significant difference in terms of level of cognitive impairment between the residents and ICU physicians. Only cognitive flexibility appeared to be restored after 2 h of sleep. The other three cognitive skills were altered, regardless of the amount of sleep during the night shift.
  
  
  CONCLUSIONS
  The cognitive abilities of intensivists were significantly altered following a night shift in the ICU, regardless of either the amount of professional experience or the duration of sleep during the shift. The consequences for patients' safety and physicians' health should be further evaluated.
authors.affiliation: Assistance Publique, Hôpitaux de Marseille, Hôpital Nord, Réanimation des Détresses Respiratoires et des Infections Sévères, Chemin des Bourrely, 13015, Marseille, France.
authors.forename: François
authors.initials: F
authors.lastname: Maltese
authors.affiliation: Assistance Publique, Hôpitaux de Marseille, Hôpital Nord, Réanimation des Détresses Respiratoires et des Infections Sévères, Chemin des Bourrely, 13015, Marseille, France.
authors.forename: Mélanie
authors.initials: M
authors.lastname: Adda
authors.affiliation: Assistance Publique, Hôpitaux de Marseille, Hôpital Nord, Réanimation des Détresses Respiratoires et des Infections Sévères, Chemin des Bourrely, 13015, Marseille, France.
authors.forename: Amandine
authors.initials: A
authors.lastname: Bablon
authors.affiliation: Assistance Publique, Hôpitaux de Marseille, Hôpital Nord, Réanimation des Détresses Respiratoires et des Infections Sévères, Chemin des Bourrely, 13015, Marseille, France.|Faculté de médecine, Aix-Marseille Université, URMITE UMR CNRS 7278, 13005, Marseille, France.
authors.forename: Sami
authors.initials: S
authors.lastname: Hraeich
authors.affiliation: Assistance Publique, Hôpitaux de Marseille, Hôpital Nord, Réanimation des Détresses Respiratoires et des Infections Sévères, Chemin des Bourrely, 13015, Marseille, France.
authors.forename: Christophe
authors.initials: C
authors.lastname: Guervilly
authors.affiliation: Assistance Publique, Hôpitaux de Marseille, Hôpital Nord, Réanimation des Détresses Respiratoires et des Infections Sévères, Chemin des Bourrely, 13015, Marseille, France.|Faculté de médecine, Aix-Marseille Université, URMITE UMR CNRS 7278, 13005, Marseille, France.
authors.forename: Samuel
authors.initials: S
authors.lastname: Lehingue
authors.affiliation: Assistance Publique, Hôpitaux de Marseille, Hôpital de la Conception, Service d'Anesthésie-Réanimation, 13005, Marseille, France.
authors.forename: Sandrine
authors.initials: S
authors.lastname: Wiramus
authors.affiliation: Faculté de médecine, Aix-Marseille Université, URMITE UMR CNRS 7278, 13005, Marseille, France.|Assistance Publique, Hôpitaux de Marseille, Hôpital Nord, Service d'Anesthésie-Réanimation, 13015, Marseille, France.
authors.forename: Marc
authors.initials: M
authors.lastname: Leone
authors.affiliation: Faculté de médecine, Aix-Marseille Université, URMITE UMR CNRS 7278, 13005, Marseille, France.|Assistance Publique, Hôpitaux de Marseille, Hôpital Nord, Service d'Anesthésie-Réanimation, 13015, Marseille, France.
authors.forename: Claude
authors.initials: C
authors.lastname: Martin
authors.affiliation: Assistance Publique, Hôpitaux de Marseille, Hôpital Nord, Service d'Anesthésie-Réanimation, 13015, Marseille, France.
authors.forename: Renaud
authors.initials: R
authors.lastname: Vialet
authors.affiliation: Assistance Publique, Hôpitaux de Marseille, Hôpital Sainte-Marguerite, Service de Santé Publique et de l'Information Médicale, 13009, Marseille, France.
authors.forename: Xavier
authors.initials: X
authors.lastname: Thirion
authors.affiliation: Faculté de médecine, Aix-Marseille Université, URMITE UMR CNRS 7278, 13005, Marseille, France.|Assistance Publique, Hôpitaux de Marseille, Hôpital Nord, Service d'accueil des Urgences, 13015, Marseille, France.
authors.forename: Antoine
authors.initials: A
authors.lastname: Roch
authors.affiliation: Assistance Publique, Hôpitaux de Marseille, Hôpital Nord, Réanimation des Détresses Respiratoires et des Infections Sévères, Chemin des Bourrely, 13015, Marseille, France.
authors.forename: Jean-Marie
authors.initials: JM
authors.lastname: Forel
authors.affiliation: Assistance Publique, Hôpitaux de Marseille, Hôpital Nord, Réanimation des Détresses Respiratoires et des Infections Sévères, Chemin des Bourrely, 13015, Marseille, France. laurent.papazian@ap-hm.fr.|Faculté de médecine, Aix-Marseille Université, URMITE UMR CNRS 7278, 13005, Marseille, France. laurent.papazian@ap-hm.fr.
authors.forename: Laurent
authors.initials: L
authors.lastname: Papazian
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D008297:Male; D003071:Cognition; D018592:Cross-Over Studies; D007362:Intensive Care Units; D019300:Medical Errors / Q000523:psychology; D061214:Patient Safety; D010561:Personnel Staffing and Scheduling; D010820:Physicians / Q000523:psychology; D011446:Prospective Studies; D012890:Sleep; D000066477:Work Performance; D014940:Work Schedule Tolerance / Q000523:psychology
keywords: Cognitive; Deprivation; ICU; Night shift; Physicians; Residents; Sleep