Incidence, risk factors, and outcomes of postanaesthetic complications: a prospective cohort study in the Mulago National Referral Hospital adult postanaesthesia care unit

Abstract

Postanaesthetic complications in the postanaesthesia care unit (PACU) carry significant implications for patient recovery, contributing to increased morbidity, prolonged PACU stays, and unplanned ICU admissions where bed availability is limited. Standardised postanaesthetic care pathways enhance early identification of patients at risk of deterioration and improve outcomes. This study aimed to determine the incidence, risk factors, and outcomes of postanaesthetic complications at Mulago National Referral Hospital (MNRH). A prospective cohort study was conducted at the MNRH PACU, enrolling 370 adult participants (≥ 18 years) between June and August 2023. Data were collected using REDCap and analysed with Stata 17. A modified Poisson generalised linear model (GLM) with robust standard errors generated crude risk ratios (CRRs) and adjusted risk ratios (ARRs). Associations between complications and outcomes were evaluated using Fisher’s exact test (95% CI); p < 0.05 was considered statistically significant. The cumulative incidence of postanaesthetic complications was 74% (95% CI: 68.8–77.8%), reflecting an inclusive operational definition capturing physiological deviations meeting predetermined thresholds under continuous real-time surveillance, including transient events. Notably, 98.2% of participants had favourable outcomes, indicating that most recorded events were mild and clinically manageable. Hypothermia was the most frequent complication (50.5%), followed by tachycardia (24.1%) and pain (16.8%); 40.8% experienced multiple complications. Intraoperative hypotension (ARR 1.23; 95% CI 1.08–1.41, p = 0.003), significant blood loss (ARR 1.29; 95% CI 1.09–1.52, p = 0.002), and hypoxia (ARR 1.38; 95% CI 1.21–1.56, p < 0.001) were independently associated with postanaesthetic complications, as were intraoperative opioid use (ARR 1.68; 95% CI 1.15–2.46, p = 0.008) and anaesthesia duration of 2–3 h (ARR 1.35; 95% CI 1.12–1.63, p = 0.002). A cumulative postanaesthetic complication incidence of 74% was observed, with 98.2% of participants achieving favourable outcomes. The identified risk factors and high incidence of hypothermia support standardising PACU care in line with WHO-WFSA and ASA recommendations, prioritising enhanced intraoperative monitoring, active warming protocols, and judicious opioid stewardship.