Division of Anaesthesia and Intensive Care, Department of Clinical Science, Intervention and Technology (CLINTEC), Karolinska Institutet, Stockholm, Sweden.
Perioperative Medicine and Intensive Care, Karolinska University Hospital Huddinge, Stockholm, Sweden.
Acta Anaesthesiol Scand. 2019 Feb;63(2):144-153. doi: 10.1111/aas.13265. Epub 2018 Sep 20.
Increased oxygen extraction, the ratio of consumption to delivery, has been associated with poor outcome after surgery. Oxygen consumption (VO2) can change in several ways in the perioperative period, but is seldom monitored directly in routine care. This study investigates the effects of general anaesthesia on VO2.
We searched PubMed, EMBASE, and Cochrane Library 1946-2018 for studies including VO2 measurements before and after anaesthesia induction. Quality was assessed by Cochrane risk of bias tool and NIH Quality Assessment tool for before-and-after studies. Changes in VO2 after anaesthesia induction were pooled in a random effects model meta-analysis with standardized mean differences transformed to absolute changes of VO2. Changes in VO2 after surgical incision and after recovery from anaesthesia were analysed as secondary outcomes in the included studies.
Twenty-four studies including 453 patients were analysed for VO2 changes induced by anaesthesia. Studies were published during 1969-2000 and mean age of patients ranged 28-70 years. VO2 decreased after anaesthesia induction by -65 (-75; -55, 95% CI) mL min and indexed VO2 (VO2I) by -33 (-38; -28, 95% CI) mL min m . After surgical incision and in the post-operative period VO2 increased again. Heterogeneity was considerable among the studies and the overall quality of evidence was very low.
General anaesthesia probably reduces oxygen consumption but the effect estimate is uncertain. Given the limited generalizability and low quality of the available evidence, new studies in modern perioperative settings and in today's older high-risk surgical patient populations are needed.
耗氧量（oxygen consumption，VO2）增加，即消耗与输送的比例增加，与手术后的不良预后相关。围手术期 VO2 可能会以多种方式发生变化，但在常规护理中很少直接监测。本研究旨在调查全身麻醉对 VO2 的影响。
我们检索了 PubMed、EMBASE 和 Cochrane Library 1946-2018 年收录的包括麻醉诱导前后 VO2 测量的研究。使用 Cochrane 偏倚风险工具和 NIH 前后研究质量评估工具评估质量。采用随机效应模型荟萃分析，将标准化均数差值转换为 VO2 的绝对值变化，以汇总麻醉诱导后 VO2 的变化。在纳入的研究中，将手术切口后和麻醉恢复后的 VO2 变化作为次要结局进行分析。
分析了 24 项研究共 453 例患者的麻醉诱导后 VO2 变化。这些研究发表于 1969-2000 年，患者的平均年龄为 28-70 岁。麻醉诱导后 VO2 降低了 -65（-75；-55，95%置信区间）mL/min，VO2I 降低了 -33（-38；-28，95%置信区间）mL/min·m。在手术切口和术后期间，VO2 再次增加。研究间存在较大的异质性，证据的总体质量非常低。
全身麻醉可能会降低氧耗，但效应估计不确定。鉴于现有证据的有限普遍性和低质量，需要在现代围手术期环境中，以及在当今高龄高危手术患者人群中开展新的研究。
