Sahu Bikash, Chauhan Sandeep, Kiran Usha, Bisoi Akshay, Lakshmy Ramakrishnan, Selvaraj Thiruvenkadam, Nehra Ashima
Department of Cardiac Anesthesiology, All India Institute of Medical Sciences, New Delhi, India.
J Cardiothorac Vasc Anesth. 2009 Feb;23(1):14-21. doi: 10.1053/j.jvca.2008.07.010. Epub 2008 Sep 24.
Hypothermia followed by rewarming during cardiopulmonary bypass can lead to cerebral hyperthermia, which has been implicated as 1 of the causes for postoperative deterioration in neurocognitive function in patients undergoing coronary revascularization. Hence, the authors studied the effects of 2 different rewarming strategies on postoperative neurocognitive function in adult patients undergoing coronary artery bypass graft surgery with the aid of cardiopulmonary bypass.
This was a randomized clinical trial.
A cardiothoracic center of a tertiary level referral, teaching hospital.
A total of 80 adult patients aged 45 to 70 years undergoing elective primary isolated coronary artery bypass graft surgery with cardiopulmonary bypass under moderate hypothermia at 30 degrees C were included in this study.
The patients were randomly allocated into 2 groups of 40 each. In group A, patients were rewarmed to a nasopharyngeal temperature of 37 degrees C; whereas, in group B, patients were rewarmed to a nasopharyngeal temperature of 33 degrees C before weaning off bypass. The anesthetic and bypass management were standardized for both groups.
All patients were assessed for neurocognitive function preoperatively and on the fifth postoperative day using the Post Graduate Institute Memory Scale. The amount of blood loss and need for blood and blood product transfusion postoperatively, the need for pacing, increased inotrope or vasodilator use, and time to extubation were also noted. Serum S100beta levels were measured after anesthetic induction and at 24 hours postoperatively. The jugular venous oxygen saturation and oxygen tension were noted at 30 degrees C and at the end of full rewarming (ie, at 37 degrees C or 33 degrees C, respectively, in the 2 groups).
There was a significant deterioration in neurocognitive function postoperatively as compared with preoperative function in patients of group A (37 degrees C). This was associated with higher S100beta levels 24 hours postoperatively in group A (37 degrees C) compared with group B (33 degrees C) patients. Also, there was a significant decrease in jugular venous oxygen saturation in group A (37 degrees C) as compared with group B (33 degrees C) at the end of rewarming. The time to extubation was longer in group B (33 degrees C). No significant differences were noted in the amount of postoperative blood loss, blood and blood product use, inotrope or vasodilator use, and the need for pacing.
Weaning from CPB at 33 degrees C may be a simple and useful strategy to lower the postoperative impairment of neurocognitive function and may be used as a tool to decrease morbidity after coronary revascularization.
体外循环期间体温过低后再复温可导致脑高温，这被认为是接受冠状动脉血运重建术患者术后神经认知功能恶化的原因之一。因此，作者借助体外循环研究了两种不同复温策略对接受冠状动脉搭桥手术的成年患者术后神经认知功能的影响。
这是一项随机临床试验。
一家三级转诊教学医院的心胸中心。
本研究纳入了80例年龄在45至70岁之间、在30℃中度低温下接受择期原发性单纯冠状动脉搭桥手术并进行体外循环的成年患者。
患者被随机分为两组，每组40例。A组患者复温至鼻咽温度37℃；而B组患者在脱离体外循环前复温至鼻咽温度33℃。两组的麻醉和体外循环管理均标准化。
所有患者在术前和术后第5天使用研究生医学教育记忆量表评估神经认知功能。还记录了术后失血量、输血及血液制品需求、起搏需求、增加血管活性药物或血管扩张剂的使用情况以及拔管时间。在麻醉诱导后和术后24小时测量血清S100β水平。在30℃时以及完全复温结束时（即两组分别为37℃或33℃时）记录颈静脉血氧饱和度和氧分压。
与术前功能相比，A组（37℃）患者术后神经认知功能显著恶化。与B组（33℃）患者相比，A组（37℃）患者术后24小时的S100β水平更高。此外，复温结束时，A组（37℃）的颈静脉血氧饱和度较B组（33℃）显著降低。B组（33℃）的拔管时间更长。术后失血量、输血及血液制品使用量、血管活性药物或血管扩张剂的使用情况以及起搏需求方面未观察到显著差异。
在33℃脱离体外循环可能是一种简单且有用的策略，可降低术后神经认知功能损害，并可作为降低冠状动脉血运重建术后发病率的一种手段。
