Risk factors for postoperative delirium in high-altitude residents undergoing lower extremity arthroplasty at low altitudes: a prospective study

This prospective study investigated the incidence, outcomes, and independent risk factors of postoperative delirium (POD) among high-altitude residents undergoing lower extremity arthroplasty at low altitudes. This prospective study enrolled patients living in a high-altitude area who received lower extremity arthroplasty under general anesthesia between February 2022 and December 2023 at Hospital of Chengdu Office of People’s Government of Xizang Autonomous Region (Chengdu, China). Patients were categorized into the POD group and the non-POD group. The outcomes included moderate to severe pain, incidence of re-intubation, unplanned ICU, bed rest time, postoperative hospital stays and 30-day all-cause mortality. A total of 1230 patients were included in this study, and 259 (21.1%) of them developed POD within 7 days after surgery. Compared with non-POD group, the POD group had significantly higher rates of moderate to severe pain (20.8% vs. 7.6%), postoperative unplanned ICU admission (4.2% vs. 1.6%) and 30-day all-cause mortality (1.5% vs. 0.1%), as well as prolonged bed rest time (h) (8.4 vs. 8.2) and postoperative hospital stays (d) (5.0 vs. 4.0), (P < 0.05). Factors associated with POD were age ≥ 65 years (OR 1.67, 95% CI 1.14–2.46, P = 0.009), ASA status III (OR 1.65, 95% CI 1.10–2.47, P = 0.016), obesity (OR 2.12, 95% CI 1.31–3.44, P = 0.002), comorbid conditions including diabetes mellitus (OR 3.86, 95% CI 2.51–5.94, P < 0.001) and stroke history (OR 4.84, 95% CI 2.78–8.44, P < 0.001). In addition, several high-altitude-related factors such as high-altitude polycythemia (HAPC) (OR 5.71, 95% CI 3.96–8.22, P < 0.001), residence at extremely high altitude (≥ 4500 m) (OR 2.05, 95% CI 1.39–3.04, P < 0.001) and high-altitude de-adaptation time ≤ 7 days (OR 1.60, 95% CI 1.12–2.30, P = 0.010) remained significantly associated with POD in patients living at high altitudes. The incidence of POD in patients living at high altitudes and undergoing lower extremity joint arthroplasty at low altitudes in this study was 21.1%. The delirium risk in this population is associated with a distinct risk profile driven by both traditional perioperative factors and altitude-specific physiological stressors. Not applicable.