Suzuki Satoshi
Department of Intensive Care, Okayama University Hospital, 2-5-1, Shikata-cho, Kita-ku, Okayama, 700-8558 Japan.
J Intensive Care. 2020 Oct 14;8:79. doi: 10.1186/s40560-020-00498-5. eCollection 2020.
Most postoperative surgical patients routinely receive supplemental oxygen therapy to prevent the potential development of hypoxemia due to incomplete lung re-expansion, reduced chest wall, and diaphragmatic activity caused by surgical site pain, consequences of hemodynamic impairment, and residual effects of anesthetic drugs (most notably residual neuromuscular blockade), which may result in atelectasis, ventilation-perfusion mismatch, alveolar hypoventilation, and impaired upper airway patency. Additionally, the World Health Organization guidelines for reducing surgical site infection have recommended the perioperative administration of high-dose oxygen, including during the immediate postoperative period. However, supplemental oxygen and hyperoxemia also have harmful effects on the respiratory and cardiovascular systems, with several clinical studies having reported an association between high perioperative oxygen administration and worse clinical outcomes. Recently, the increased availability of new and short-acting anesthetic drugs, comprehensive pharmacological knowledge, postoperative multimodal analgesia, and new minimally invasive surgery options could result in lower incidences of postoperative hypoxemia. Moreover, recommendations promoting high oxygen administration to prevent surgical site infections have been challenged, considering the lack of scientific investigations, and have not been widely accepted. Given the potential harmful effects of hyperoxemia, routine postoperative oxygen administration might not be recommended. Recent clinical studies have indicated that a conservative approach to oxygen therapy, where oxygen administration is titrated to achieve slightly lower oxygen levels than usual, could be safely implemented and decrease acutely ill patients' susceptibility to hyperoxemia. Based on current evidence, appropriate monitoring, including peripheral oxygen saturation, and oxygen titration should be required during postoperative oxygen administration to avoid both hypoxemia and hyperoxemia. Future trials should therefore focus on determining the optimal oxygen target during postoperative care.
大多数术后外科手术患者通常接受补充氧气治疗，以预防因肺复张不完全、手术部位疼痛导致的胸壁和膈肌活动减少、血流动力学损害后果以及麻醉药物的残留效应（最显著的是残留神经肌肉阻滞）而可能发生的低氧血症，这些情况可能导致肺不张、通气-灌注不匹配、肺泡通气不足以及上呼吸道通畅性受损。此外，世界卫生组织降低手术部位感染的指南建议围手术期给予高剂量氧气，包括术后即刻。然而，补充氧气和高氧血症对呼吸和心血管系统也有有害影响，多项临床研究报告围手术期高剂量吸氧与更差的临床结局之间存在关联。最近，新型短效麻醉药物的可及性增加、全面的药理学知识、术后多模式镇痛以及新的微创手术选择可能导致术后低氧血症的发生率降低。此外，考虑到缺乏科学研究，促进高氧给药以预防手术部位感染的建议受到了挑战，并且尚未被广泛接受。鉴于高氧血症的潜在有害影响，可能不建议常规术后吸氧。最近的临床研究表明，可以安全地实施保守的氧疗方法，即调整吸氧剂量以达到略低于通常水平的氧含量，并降低重症患者发生高氧血症的易感性。基于目前的证据，术后吸氧期间应进行适当监测，包括外周血氧饱和度监测，并进行氧滴定，以避免低氧血症和高氧血症。因此，未来的试验应专注于确定术后护理期间的最佳氧目标。
