Xu He, Wang Zijing, Guan Xin, Lu Yijuan, Malone Daniel Charles, Salmon Jack Warren, Ma Aixia, Tang Wenxi
School of International Pharmaceutical Business, China Pharmaceutical University, No.639 Longmian Street, Jiangning District, Nanjing, 211198, China.
Center for Pharmacoeconomics and Outcomes Research, China Pharmaceutical University, No.639 Longmian Street, Jiangning District, Nanjing, 211198, China.
BMC Anesthesiol. 2020 Aug 15;20(1):202. doi: 10.1186/s12871-020-01065-z.
Previous studies have shown that intraoperative hypothermia was associated with higher risks of clinical adverse events, but we found otherwise from recent evidences. This study aims to synthesize the existing evidence evaluating safety of intraoperative hypothermia.
Articles, reviews, ongoing trials and grey literatures were retrieved from PubMed, The Cochrane Library, Clinical Trails and CNKI (a Chinese national database) till February 2nd, 2019. Both randomized controlled trials and observational studies compared incidences of all sorts of intra- and post-operative consequences between hypothermia and normothermia were included. Researches comparing different warming systems were excluded. We also examined risks of hypothermia using lowered standards (35.5 °C and 35 °C) from a Chinese trial (ChiCTR-IPR-17011099).
A total of 9 RCT studies and 11 observational studies were included. RCT-synthesized results showed that intraoperative hypothermia was associated with higher risks of bleeding (MD = 131.90, 95%CI: 117.42, 146.38), surgical site infection (RD = 0.14, 95%CI: 0.06, 0.21) and shivering (RD = 0.32, 95%CI: 0.06, 0.58) but with no significant differences in duration of surgery, hospital stay or mortality. Observational study-synthesized evidences showed that intraoperative hypothermia did not result in higher risks in any of these adverse events. Results didn't change even if the standard of hypothermia was lowered by 0.5-1.0 °C.
The study indicates that the synthesized risks resulted by intra-operative hypothermia might be overestimated and the eligibility of 36 °C to define hypothermia is not sensitive enough. Given body-temperature protection has not been popularized in China, it is still critical to normalize the hypothermia prevention at this stage.
既往研究表明，术中低体温与临床不良事件的较高风险相关，但我们从近期证据中得出了相反的结论。本研究旨在综合现有证据，评估术中低体温的安全性。
从PubMed、Cochrane图书馆、临床研究数据库和中国知网（一个中国国家数据库）检索截至2019年2月2日的文章、综述、正在进行的试验和灰色文献。纳入比较低体温与正常体温之间各种术中和术后后果发生率的随机对照试验和观察性研究。排除比较不同升温系统的研究。我们还使用中国一项试验（ChiCTR-IPR-17011099）中降低的标准（35.5°C和35°C）检查低体温风险。
共纳入9项随机对照试验研究和11项观察性研究。随机对照试验综合结果显示，术中低体温与出血风险较高（MD = 131.90，95%CI：117.42，146.38）、手术部位感染（RD = 0.14，95%CI：0.06，0.21）和寒战（RD = 0.32，95%CI：0.06，0.58）相关，但手术时间、住院时间或死亡率无显著差异。观察性研究综合证据显示，术中低体温在这些不良事件中均未导致更高风险。即使将低体温标准降低0.5 - 1.0°C结果也未改变。
该研究表明，术中低体温导致的综合风险可能被高估，以36°C定义低体温的标准不够敏感。鉴于体温保护在中国尚未普及，现阶段规范低体温预防仍至关重要。
