Background: The use of supplemental oxygen (SO) for procedural sedation and analgesia (PSA) is still controversial. Although SO might prevent hypoxia during PSA, it also could delay detection of hypoxia. The number of visits to EDs by elderly patients is increasing globally, including in the US. It is not uncommon to perform PSA on elderly patients in the ED. Although elderly patients are at high risk for respiratory depression and hypoxia, the efficacy of SO to reduce the incidence of hypoxia for these patients during ED PSA has not been well described. We aimed to determine the incidence of hypoxia during ED PSA in elderly patients and whether SO prevents hypoxia or not. We hypothesize that SO reduces the incidence of hypoxia during ED PSA.
Methods: We conducted a 6-center prospective observational study, the Japanese Procedural SedaTion and Analgesia Registry (JPSTAR). We prospectively collected data on all patients undergoing PSA in the ED from May 2017 through December 2018. We included patients who were 65 years or older. We excluded patients who received sedation for airway management or excited delirium. The primary outcome was the incidence of hypoxia (SpO2<90%) from PSA. We used logistic regression analysis adjusted for age, American Society of Anesthesiologists physical status classification (ASA) and sedation depth
Results: Among 570 patients in the registry, 328 (57.5%) patients were 65 years or older. Of these, 205 (62.5%) patients received SO and 123 (37.5%) patients did not receive SO. Cardioversion was the most common indication in both groups (46.8% vs 60.2%, p<0.001). Age was not significantly different between two groups (77.6 vs 77.6, p=1). The SO group had more patients with an ASA 3 or higher compared to the non-SO group (26.3% vs 16.3%, p<0.001). Fifty-six (27.3%) patients in the SO group and 27 (22.0%) patients in the non- SO group received deep sedation (p<0.001). The incidence of hypoxia was lower in the SO group compared to the non- SO group(19.5% vs 4.9%; p<0.001; difference 14.6%; 95%CI 6.9-22.3%) In a logistic regression analysis, SO was independently associated with lower incidence of hypoxia (odds ratio 0.226; 95%CI 0.102-0.501).
Conclusion: In a multicenter observational study, supplemental oxygen reduced the incidence of hypoxia in the elderly patients during ED PSA.