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Byrne JE, Rodriguez-Patarroyo FA, Mascha EJ, Han Y, Bravo M, Bloomfield MR, Rao SM, Sessler DI: Cooling vest improves surgeons’ thermal comfort without affecting cognitive performance: a randomised cross-over trial. Occup Environ Med 2023; 80: 339-345

May 4, 2023

Objectives
Surgeons become uncomfortable while performing surgery because heat transfer and evaporative cooling are restricted by insulating surgical gowns. Consequently, perceptions of thermal discomfort during surgery may impair cognitive performance. We, therefore, aimed to evaluate surgeons’ thermal comfort, cognitive performance, core and mean skin temperatures, perceptions of sweat-soaked clothing, fatigue and exertion with and without a CoolSource cooling vest
(Cardinal Health, Dublin, Ohio, USA).
Methods
Thirty orthopaedic surgeons participated in a randomised cross-over trial, each performing four total- joint arthroplasties with randomisation to one of four treatment sequences. The effects of cooling versus no cooling were measured using a repeated-measures linear model accounting for within-subject correlations
Results
The cooling vest improved thermal comfort by a mean (95% CI) of −2.1 (–2.7 to –1.6) points on a 0–10 scale, p<0.001, with no evidence of treatment- by-period interaction (p=0.94). In contrast, cooling had no perceptible effect on cognition, with an estimated mean difference (95% CI) in Cleveland Clinic Cognitive Battery (C3B) Processing Speed Test score of 0.03 (95% CI –2.44 to 2.51), p=0.98, or in C3B Visual Memory Test score with difference of 0.88 (95% CI –2.25 to 4.01), p=0.57. Core temperature was not lower with the cooling vest, with mean difference (95% CI) of −0.13 (–0.33°C to 0.07°C), p=0.19, while mean skin temperature was lower, with mean difference of −0.23 (95% CI –0.40°C to –0.06°C) lower, p=0.011. The cooling vest significantly reduced surgeons’ perceptions of sweat-soaked clothing, fatigue and exertion. Conclusions
A cooling vest worn during surgery lowered core and skin temperatures, improved thermal comfort, and decreased perceptions of sweating and fatigue, but did not improve cognition. Thermal discomfort during major orthopaedic surgery is thus largely preventable, but cooling does not affect cognition.
Trial registration number NCT04511208.