Effect of I.V. acetaminophen on postoperative hypoxemia after abdominal surgery

Researchers speculated that postoperative I.V. acetaminophen might reduce the duration of hypoxemia after abdominal surgery by curtailing the need for opioids, which can trigger ventilatory depression and hypoxemia. In a randomized trial, the Cleveland Clinic colleagues analyzed outcomes in 570 patients assigned to either I.V. acetaminophen or to normal saline placebo at the start of surgery. Administration continued every 6 hours until reaching 48 postoperative hours or until hospital discharge, whichever occurred first. The primary endpoint was total duration of hypoxemia, defined as hemoglobin oxygen saturation of less than 90% per hour. The duration was 0.7 minutes per hour in the intervention group vs. 1.1 minutes per hour in the controls; however, the difference was not considered statistically significant. None of the eight secondary outcomes—including sedation, nausea and vomiting, and respiratory function—were markedly different between groups. Therefore, the study authors conclude, the trial results do not support the use of I.V. acetaminophen in this setting.