The effect of intraoperative mild hypothermia on the development of perioperative cardiac ischemia

我们评估了围手术期心肌缺血合并亚低温作为神经外科手术的辅助处理的风险。47例神经外科择期手术患者随机分为亚低温组(H，n=24)和常温组(N，n=23)。H组在主要神经外科手术后降温至34.5℃(鼓膜温度)复温，N组维持常温状态。入室后24小时动态心电图监测诊断为心肌缺血，年龄、性别、体重、身高、心脏病发生率、麻醉方法、手术内容等人口学资料均无差异。H组最低体温(34.6±0.5vs35.9±0.6)和麻醉结束时体温(35.9±0.9vs36.5±0.5)均显著低于N组(P<0.05)。术后心电图ST段压低分别为3例(H组)和5例(N组)，术后寒战分别为3例(H组)和2例(N组)。两组发病率差异无统计学意义(卡方检验，p=0.05)。我们的结论是，术中亚低温可能不会增加神经外科手术患者围手术期心肌缺血的风险。

We evaluated the risk of perioperative cardiac ischemia associated with mild hypothermia as adjunct management for neurosurgical procedures. Forty-seven elective neurosurgical patients were randomly assigned to either hypothermic group (H, n=24) or normothermic one (N, n=23). Patients in group H were cooled to and maintained at 34.5 degrees C (tympanic membrane temperature) and rewarmed after main neurosurgical manipulation, while ones in group N were kept in normothermic state. Cardiac ischemia was diagnosed with Holter electrocardiogram monitored for 24 hours after admission to the operating room.No differences were observed in demographic data including age, gender, weight, height, rate of having cardiac disease, anesthesia methods, and contents of surgery. Temperature was significantly lower in group H than N both at the lowest point(34.6*O.5 vs 35.9*0.6, means*SD) and at the conclusion of anesthesia (35.9*0.9 vs 36.5*0.5). Electrocardiographic ST segmental depression was observed in 3 (group H) and 5 cases (group N), and postoperative shivering occurred in 3 (group H) and 2 cases (group N), respectively. Those incidences were not statistically significant (chi-square test, p was set at 0.05). We concluded that intraoperative mild hypothermia might not increase the risk of perioperative cardiac ischemia in patients underwent neurosurgical procedures.