Incidence of adverse events for procedural sedation and analgesia for cardioversion using thiopental in elderly patients: a multicenter prospective observational study

Aim: The incidence and characteristics of thiopental-related adverse events (AEs) in elderly patients during procedural sedation and analgesia (PSA) have not been well studied. We aimed to characterize thiopental-related AE in elderly patients during PSA and compare the incidence of AE in elderly patients with non-elderly adults. Methods: This is a secondary analysis of the Japanese Procedural Sedation and Analgesia Registry (JPSTAR). We included all adult patients who received thiopental for PSA in the emergency departments and excluded patients who received concomitant sedative(s) in addition to thiopental or patients with missing body weight data. We compared the incidence of AE between the non-elderly (18-64 years) and elderly groups (≥65 years). Results: The JPSTAR had data on 379 patients who received thiopental for PSA and included 311 patients for analysis. Most (222/311, 71.3%) were elderly. Cardioversion was the most common reason for PSA (96.1%). The AE incidence between groups overall was similar, however, hypoxia was significantly more frequent in the elderly compared with the non-elderly group (10.3% versus 2.2%; adjusted odds 5.63, 95% confidence interval 1.27-25.0). The initial and total doses of thiopental were significantly lower in the elderly group than in the non-elderly group (1.95 mg/kg versus 2.21 mg/kg and 2.33 mg/kg versus 2.93 mg/kg, respectively). Conclusions: Although elderly patients received lower doses of thiopental, hypoxic events were significantly more frequent in this group compared with the non-elderly patients. However, the AE incidence was similar.