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.