Mitigating Intraoperative Fatigue in Surgeons at High Altitude: A Stepped-Wedge Cluster Randomized Trial

Chen, Biao, Shuai Li, Kun He, Dunzhu Basang, Yuzhen Suolang, Fang Li, Jiangcun Silang, Hongyuan Yi, Langjie Jinmei, La Dan, Deqing Ciren, Haifeng Xu, and Dong Wu. Mitigating Intraoperative Fatigue in Surgeons at High Altitude: A Stepped-Wedge Cluster Randomized Trial. High Alt Med Biol. 00:00–00, 2026. Background: Both genetically adapted Tibetan surgeons and less-acclimatized Han surgeons deployed through the Aid-Tibet medical aid program face significant challenges from hypobaric hypoxia in the Qinghai-Xizang Plateau. Hypoxia is known to impair cognitive functions and induce fatigue, threatening surgical performance and patient safety. Traditionally, surgeons in Tibet consume Coca-Cola to combat fatigue, a potentially harmful practice lacking in scientific basis. Supplemental oxygen, recommended for better cerebral oxygen delivery, is underutilized. This study compares supplemental oxygen versus Coca-Cola in mitigating intraoperative fatigue among surgeons in Tibet, considering the influence of long-term high-altitude adaptations. Methods: We conducted a stepped-wedge cluster randomized controlled trial at the People’s Hospital of Xizang Autonomous Region in Lhasa (3,650 m altitude). Twenty-two surgeons (11 Han, 11 Tibetan) performed 24 surgeries each, receiving either 100 ml of Coca-Cola every 30 minutes or continuous 2 l/min supplemental oxygen via nasal cannula. Cognitive fatigue was assessed using the d2 Test of Attention, and physical fatigue was measured using a dynamometer, before and after surgeries. The primary outcome was change in concentration performance (ΔCP). The secondary outcome was the change in maximum voluntary contraction force (ΔMVC). Data were analyzed using a linear generalized estimating equations model. Results: All 22 surgeons completed 528 surgeries. Generally, supplemental oxygen significantly reduced cognitive fatigue compared to Coca-Cola (ΔCP: 6.08, 95% confidence interval [CI]: 1.37–10.80, p = 0.012). In subgroup analysis, oxygen significantly lowered cognitive fatigue in Han surgeons (ΔCP: 7.06, 95% CI: 0.72–13.40, p = 0.029), while the effect in Tibetan surgeons did not reach statistical significance (ΔCP: 4.82, 95% CI: −0.51–10.16, p = 0.076). No significant difference was observed in physical fatigue (ΔMVC: −0.18, 95% CI: −1.77–1.40, p = 0.822). Conclusions: Supplemental oxygen outperforms Coca-Cola in reducing cognitive fatigue during high-altitude surgery, especially for less-acclimatized Han surgeons, supporting its adoption to enhance surgeons’ performance and well-being.