Eur J Anaesthesiol. 2019 May;36(5):320-326. doi: 10.1097/EJA.0000000000000980.
The WHO recommends routine intra-operative and early postoperative use of high inspired oxygen concentrations (hyperoxia). However, a high intra-operative inspired oxygen fraction (FiO2) might result in an increased risk of postoperative respiratory complications.
To test the hypothesis that intra-operative FiO2 of 80% compared with 30% inspired oxygen decreases the postoperative ratio of arterial saturation to fraction of inspired oxygen (SpO2/FiO2). Secondarily, to evaluate whether an intra-operative inspired FiO2 of 80% increases the incidence of pulmonary complications.
Posthoc subanalysis of a large alternating cohort trial.
Cleveland Clinic, Cleveland, United States, from 2013 to 2016.
Adults having colorectal surgery. Cases lasting less than 2 h, re-operations on the same hospitalisation, and cases with missing intra-operative or postoperative data were excluded.
Maintaining intra-operative FiO2 at 30 or 80% and alternating this management every 2 weeks for a study period of 39 months.
Minimal SpO2/FiO2 ratio value in the postanaesthesia care unit. Secondary outcome was a composite of postoperative pulmonary complications throughout hospitalisation.
A total of 5056 patients were included. Groups were well balanced on all demographic, baseline and procedural variables. Median time-weighted averages of intra-operative FiO2 in the 30 and 80% groups were 43% (IQR 38 to 54%, N=2486) and 81% (IQR 78 to 82%, N=2570), respectively. No difference was found in the lowest SpO2/FiO2 ratio (estimated median difference 0 [95% confidence interval: 0, 0], P = 0.91). The incidence of postoperative pulmonary complications was 16.3 and 17.6% in the 30 and 80% FiO2 groups, respectively (relative risk 1.07 [95% confidence interval: 0.95, 1.21], P = 0.25).
Intra-operative hyperoxia did not change the postoperative SpO2/FiO2 ratio or the risk for pulmonary complications. Clinicians should not refrain from using hyperoxia for fear of provoking respiratory complications.
ClinicalTrials.gov identifier: NCT01777568.
世界卫生组织（WHO）建议在术中及术后早期常规使用高吸入氧浓度（高氧）。然而，术中高吸入氧分数（FiO2）可能会增加术后呼吸并发症的风险。
检验假设，即与吸入氧分数 30%相比，术中吸入氧分数 80%是否会降低术后动脉血氧饱和度与吸入氧分数的比值（SpO2/FiO2）。其次，评估术中吸入氧分数 80%是否会增加肺部并发症的发生率。
大型交替队列试验的事后亚分析。
美国克利夫兰克利夫兰诊所，2013 年至 2016 年。
行结直肠手术的成年人。排除持续时间少于 2 小时、同一住院期间再次手术以及术中或术后数据缺失的病例。
在 39 个月的研究期间，将术中 FiO2维持在 30%或 80%，并每两周交替进行此管理。
麻醉后护理单元中最小的 SpO2/FiO2 比值。次要结局是整个住院期间的术后肺部并发症的综合结果。
共纳入 5056 例患者。两组在所有人口统计学、基线和手术变量方面均平衡良好。术中 FiO2 的时间加权平均值在 30%和 80%组分别为 43%（IQR 38 至 54%，N=2486）和 81%（IQR 78 至 82%，N=2570）。最低 SpO2/FiO2 比值无差异（估计中位数差值 0[95%置信区间：0，0]，P=0.91）。30%FiO2 组和 80%FiO2 组术后肺部并发症发生率分别为 16.3%和 17.6%（相对风险 1.07[95%置信区间：0.95，1.21]，P=0.25）。
术中高氧并未改变术后 SpO2/FiO2 比值或肺部并发症的风险。临床医生不应因担心引发呼吸并发症而避免使用高氧。
ClinicalTrials.gov 标识符：NCT01777568。
