title: The impact of heat stress on operative performance and cognitive function during simulated laparoscopic operative tasks.
abstract: BACKGROUND
  Increasing ambient temperature to prevent intraoperative patient hypothermia remains widely advocated despite unconvincing evidence of efficacy. Heat stress is associated with decreased cognitive and psychomotor performance across multiple tasks but remains unexamined in an operative context. We assessed the impact of increased ambient temperature on laparoscopic operative performance and surgeon cognitive stress.
  
  
  METHODS
  Forty-two performance measures were obtained from 21 surgery trainees participating in the counter-balanced, within-subjects study protocol. Operative performance was evaluated with adaptations of the validated, peg-transfer, and intracorporeal knot-tying tasks from the Fundamentals of Laparoscopic Surgery program. Participants trained to proficiency before enrollment. Task performance was measured at two ambient temperatures, 19 and 26°C (66 and 79°F). Participants were randomly counterbalanced to initial hot or cold exposure before crossing over to the alternate environment. Cognitive stress was measured using the validated Surgical Task Load Index (SURG-TLX).
  
  
  RESULTS
  No differences in performance of the peg-transfer and intracorporeal knot-tying tasks were seen across ambient conditions. Assessed via use of the six bipolar scales of the SURG-TLX, we found differences in task workload between the hot and cold conditions in the areas of physical demands (hot 10 [3-12], cold 5 [2.5-9], P = .013) and distractions (hot 8 [3.5-15.5], cold 3 [1.5-5.5], P = .001). Participant perception of distraction remained greater in the hot condition on full scoring of the SURG-TLX.
  
  
  CONCLUSIONS
  Increasing ambient temperature to levels advocated for prevention of intraoperative hypothermia does not greatly decrease technical performance in short operative tasks. Surgeons, however, do report increased perceptions of distraction and physical demand. The impact of these findings on performance and outcomes during longer operative procedures remains unclear.
authors.affiliation: Division of Trauma Surgery and Surgical Critical Care, Los Angeles County Medical Center-University of Southern California, Los Angeles, CA.
authors.forename: Regan J
authors.initials: RJ
authors.lastname: Berg
authors.affiliation: Division of Trauma Surgery and Surgical Critical Care, Los Angeles County Medical Center-University of Southern California, Los Angeles, CA. Electronic address: kinaba@surgery.usc.edu.
authors.forename: Kenji
authors.initials: K
authors.lastname: Inaba
authors.affiliation: Department of Surgery, USC Keck School of Medicine, Los Angeles, CA; USC Surgical Skills Simulation and Education Center, Department of Surgery, Keck School of Medicine, Los Angeles, CA.
authors.forename: Maura
authors.initials: M
authors.lastname: Sullivan
authors.affiliation: Division of Trauma Surgery and Surgical Critical Care, Los Angeles County Medical Center-University of Southern California, Los Angeles, CA.
authors.forename: Obi
authors.initials: O
authors.lastname: Okoye
authors.affiliation: Division of Trauma Surgery and Surgical Critical Care, Los Angeles County Medical Center-University of Southern California, Los Angeles, CA.
authors.forename: Stefano
authors.initials: S
authors.lastname: Siboni
authors.affiliation: USC Surgical Skills Simulation and Education Center, Department of Surgery, Keck School of Medicine, Los Angeles, CA.
authors.forename: Michael
authors.initials: M
authors.lastname: Minneti
authors.affiliation: Division of Trauma Surgery and Surgical Critical Care, Los Angeles County Medical Center-University of Southern California, Los Angeles, CA.
authors.forename: Pedro G
authors.initials: PG
authors.lastname: Teixeira
authors.affiliation: Division of Trauma Surgery and Surgical Critical Care, Los Angeles County Medical Center-University of Southern California, Los Angeles, CA.
authors.forename: Demetrios
authors.initials: D
authors.lastname: Demetriades
mesh_terms: D000328:Adult; D003071:Cognition; D003080:Cold Temperature; D018592:Cross-Over Studies; D013502:General Surgery / Q000193:education; D006358:Hot Temperature; D006801:Humans; D007035:Hypothermia / Q000517:prevention & control; D010535:Laparoscopy / Q000193:education / Q000523:psychology*; D008297:Male; D013312:Stress, Physiological; D055815:Young Adult