From the Departments of Anesthesiology and Pain Medicine.
Thoracic and Cardiovascular Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea.
Anesth Analg. 2022 Jul 1;135(1):91-99. doi: 10.1213/ANE.0000000000005967. Epub 2022 Mar 4.
A high fraction of inspired oxygen (Fio2) is administered during one-lung ventilation (OLV). However, a high Fio2 is not physiologic and may lead to various complications. We hypothesized that continuous titration of Fio2 using the oxygen reserve index (ORI) reduces oxygen exposure compared to conventional management during OLV.
In this randomized, double-blinded trial, patients undergoing thoracic surgery were assigned to an ORI (n = 64) or a control group (n = 60). In the ORI group, ORI was continuously displayed using multiwavelength pulse co-oximetry (Masimo) between 0 and 1 (0, no reserve; 1, maximum reserve), and Fio2 was titrated for a target ORI of 0.21 at 5-minute intervals during OLV. In the control group, Fio2 was adjusted using arterial blood gas analysis measured at 15 minutes after OLV initiation. The primary end point was the time-weighted average Fio2 during OLV.
Overall, time-weighted average Fio2 did not differ between the groups (control versus ORI: median [interquartile range], 0.87 [0.73-1.00] vs 0.82 [0.68-0.93]; P = .09). However, in a subgroup analysis, the ORI group reduced time-weighted average Fio2 after pulmonary vascular ligation compared to the control group (control versus ORI: median [interquartile range], 0.75 [0.70-1.00] vs 0.72 [0.59-0.89]; P = .0261). The incidence of intraoperative hypoxia (arterial oxygen saturation [Spo2] <94%; control versus ORI: 32% [19/60; 95% confidence interval (CI), 20-45] vs 19% [12/64; 95% CI, 10-31]; P = .09), and postoperative complications within the first 7 days did not differ between the groups.
ORI-guided continuous Fio2 titration does not reduce overall oxygen exposure during OLV.
单肺通气（OLV）期间通常给予较高的吸入氧分数（Fio2）。然而，高 Fio2 并不符合生理需求，可能导致各种并发症。我们假设使用氧储备指数（ORI）连续滴定 Fio2 可减少 OLV 期间的氧暴露，与常规管理相比。
在这项随机、双盲试验中，接受胸部手术的患者被分配到 ORI 组（n = 64）或对照组（n = 60）。在 ORI 组中，使用多波长脉冲血氧饱和度仪（Masimo）连续显示 0 至 1（0，无储备；1，最大储备）之间的 ORI，在 OLV 期间每 5 分钟滴定目标 ORI 为 0.21 的 Fio2。在对照组中，在 OLV 开始后 15 分钟使用动脉血气分析调整 Fio2。主要终点是 OLV 期间的时间加权平均 Fio2。
总体而言，两组间时间加权平均 Fio2 无差异（对照组与 ORI：中位数[四分位距]，0.87 [0.73-1.00] 与 0.82 [0.68-0.93]；P =.09）。然而，在亚组分析中，与对照组相比，ORI 组在肺血管结扎后降低了时间加权平均 Fio2（对照组与 ORI：中位数[四分位距]，0.75 [0.70-1.00] 与 0.72 [0.59-0.89]；P =.0261）。术中低氧血症（动脉血氧饱和度[Spo2] <94%；对照组与 ORI：32% [19/60；95%置信区间（CI），20-45] 与 19% [12/64；95% CI，10-31]；P =.09）和术后 7 天内的并发症发生率在两组之间无差异。
ORI 指导的连续 Fio2 滴定并未减少 OLV 期间的总体氧暴露。
