Postoperative Sedation in General Care Wards: A Retrospective Cohort Study

Abstract

BACKGROUND: We hypothesized that deeper sedation in the postanesthesia care unit (PACU) increases the risk of subsequent sedation in general care wards (ward sedation) and that patients with ward sedation have more postoperative adverse events than those without ward sedation. METHODS: We reviewed the health records of adult patients who underwent procedures with general anesthesia at Mayo Clinic from May 5, 2018, through December 31, 2020, and were discharged from the PACU to the general care ward. Patient groups were dichotomized as with ward sedation (Richmond Agitation-Sedation Scale [RASS], ≤–2) and without ward sedation (RASS, ≥–1) within the first 24 hours after PACU discharge. Multivariable logistic regression was used to assess the association between clinical variables and ward sedation. RESULTS: A total of 23,766 patients were included in our analysis, of whom 1131 had ward sedation (incidence, 4.8 [Poisson 95% confidence interval, CI, 4.5–5.0]) per 100 patients after general anesthesia. Half of the ward sedation episodes occurred within 32 minutes after PACU discharge. The risk of ward sedation increased with the depth of PACU sedation. The odds ratios (95% CI) of ward sedation for patients with a PACU RASS score of –1 was 0.98 (0.75–1.27); –2, 1.87 (1.44–2.43); –3, 2.98 (2.26–3.93); and ≤–4, 3.97 (2.91–5.42). Adverse events requiring an emergency intervention occurred more often for patients with ward sedation (n = 92, 8.1%) than for those without ward sedation (n = 326, 1.4%; P < .001). CONCLUSIONS: Among patients who met our criteria for PACU discharge, deeper sedation during anesthesia recovery was associated with an increased risk of ward sedation. Patients who had ward sedation had worse outcomes than those without ward sedation.