Grote R, Wetz A J, Bräuer A, Menzel M
Klinik für Anästhesie, Notfallmedizin, Operative Intensivmedizin und Schmerztherapie, Klinikum Wolfsburg, Sauerbruchstraße 7, 38440, Wolfsburg, Deutschland.
Klinik für Anästhesiologie, Universitätsmedizin Göttingen, Göttingen, Deutschland.
Anaesthesist. 2018 Jan;67(1):27-33. doi: 10.1007/s00101-017-0384-3. Epub 2017 Nov 20.
Inadvertent perioperative hypothermia, which is defined as a core body temperature of less than 36.0 °C, can have serious consequences in surgery patients. These include cardiac complications, increased blood loss, wound infections and postoperative shivering; therefore, the scientific evidence that inadvertent perioperative hypothermia should be avoided is undisputed and several national guidelines have been published summarizing the scientific evidence and recommending specific procedures. The German AWMF guidelines were the first to emphasize the importance of prewarming for surgery patients to avoid inadvertant perioperative hypothermia; however, in contrast to intraoperative warming, prewarming is so far not sufficiently implemented in clinical practice in many hospitals. Furthermore, a recent study has questioned the effectiveness of prewarming.
The aim of this retrospective investigation was to evaluate the hypothermia rates that can be achieved when prewarming in the anesthesia induction room is introduced into the clinical practice and performed in addition to intraoperative warming.
The ethics committee of the Medical Faculty of the Martin Luther University Halle Wittenberg gave approval for data storage and retrospective data analysis from the anesthesia database. According to the existing local standard operating procedure, prewarming with forced air was performed in addition to intraoperative warming in the anesthesia induction room in 3899 patients receiving general anesthesia with a duration of 30 min or longer from January 2015 to December 2016. The results were compared with a control group of 3887 patients from July 2012 to August 2014 who received intraoperative warming but were not subjected to prewarming. Tracheal intubation was carried out in all patients and temperature measurements after the induction of anesthesia were performed using esophageal, urinary catheter or intra-arterial temperature probes.
The mean duration of prewarming was 25 min in the treatment group. Patients subjected to prewarming showed an intraoperative hypothermia rate of 15.8% and a postoperative hypothermia rate of 5.1%. Patients without prewarming showed an intraoperative hypothermia rate of 30.4% and a postoperative hypothermia rate of 12.4%. This means a 52% reduction of the intraoperative hypothermia rate and a 41% reduction of the postoperative hypothermia rate for patients who received prewarmimg (p < 0.0001). Multivariate logistic regression revealed that the lack of prewarming was independently associated with intraoperative hypothermia with an odds ratio of 2.5 (95% confidence interval CI 2.250-2.841; p < 0.0001) and postoperative hypothermia with an odds ratio of 2.8 (95% CI 2.316-3.277; p < 0.0001).
Prewarming, as recommended in the AWMF guidelines, resulted in a significant and clinically relevant reduction in the incidence of inadvertent perioperative hypothermia; therefore, prewarming can still be regarded as an effective method to avoid perioperative hypothermia. Hypothermia rates of 15.8% intraoperatively and 5.1% postoperatively can be achieved in clinical practice, when prewarming is performed in addition to intraoperative warming in the anesthesia induction room directly before the start of surgical procedures.
围手术期意外低温被定义为核心体温低于36.0°C，这可能给手术患者带来严重后果。这些后果包括心脏并发症、失血增加、伤口感染和术后寒战；因此，应避免围手术期意外低温这一科学证据是无可争议的，并且已经发布了多项国家指南，总结了科学证据并推荐了具体程序。德国AWMF指南率先强调了对手术患者进行预加温以避免围手术期意外低温的重要性；然而，与术中加温相比，目前许多医院在临床实践中对预加温的实施还不够充分。此外，最近的一项研究对预加温的有效性提出了质疑。
这项回顾性研究的目的是评估将麻醉诱导室预加温引入临床实践并与术中加温同时进行时所能达到的低温发生率。
马丁路德大学哈雷-维滕贝格医学院伦理委员会批准了从麻醉数据库中存储数据和进行回顾性数据分析。根据现有的当地标准操作规程，在2015年1月至2016年12月期间，对3899例接受持续时间30分钟或更长时间全身麻醉的患者，在麻醉诱导室除了术中加温外还进行了强制空气预加温。将结果与2012年7月至2014年8月期间3887例仅接受术中加温但未进行预加温的患者组成的对照组进行比较。所有患者均进行气管插管，并在麻醉诱导后使用食管、导尿管或动脉内温度探头进行体温测量。
治疗组的平均预加温时间为25分钟。接受预加温的患者术中低温发生率为15.8%，术后低温发生率为5.1%。未进行预加温的患者术中低温发生率为30.4%，术后低温发生率为12.4%。这意味着接受预加温的患者术中低温发生率降低了52%，术后低温发生率降低了41%（p < 0.0001）。多因素逻辑回归显示，未进行预加温与术中低温独立相关，比值比为2.5（95%置信区间CI 2.250 - 2.841；p < 0.0001），与术后低温独立相关,比值比为2.8（95%CI 2.316 - 3.277；p < 0.0001）。
如AWMF指南所推荐的预加温，可显著且临床上切实地降低围手术期意外低温的发生率；因此，预加温仍可被视为避免围手术期低温的有效方法。在手术程序开始前直接在麻醉诱导室除术中加温外进行预加温时，临床实践中术中低温发生率可达到15.8%，术后低温发生率可达到5.1%。
