Predicting pulmonary complications and cost burden in Saudi orthopedic patients: A prospective modified ARISCAT score validation

Background: Postoperative pulmonary complications (PPCs) are a major cause of morbidity in orthopedic surgery, yet the Assess Respiratory risk in Surgical Patients in Catalonia (ARISCAT) score remains under-validated in Saudi populations with unique metabolic and environmental risk profiles. Methods: We conducted a prospective cohort study (2024–2025) of 600 adults undergoing elective/urgent orthopedic surgery at King Abdulaziz Medical City. Using a prespecified +5-point adjustment for cemented arthroplasty (accounting for bone cement implantation syndrome), we calculated ARISCAT scores preoperatively and assessed PPCs within 7 days using European Society of Anesthesiology and Intensive Care criteria. Secondary outcomes included intensive care unit admissions, length of stay (LOS), and hospitalization costs. Results: The overall PPC incidence was 19. 2%, with stepwise increases by risk category: 4. 1% (low risk, ≤25 points), 17. 3% (intermediate), and 44. 8% (high-risk, ≥45; P < 0. 001). The model demonstrated excellent discrimination (area under the curve AUC = 0. 83, 95% confidence interval CI 0. 78–0. 88) and calibration (P = 0. 27). High-risk patients had 5. 2× greater PPC odds (adjusted odds ratio OR 5. 2, 95% CI: 3. 1–8. 7), 3. 1-day longer LOS, and 2350 higher costs versus low-risk patients (all P < 0. 001). Cemented arthroplasty independently predicted PPCs (OR 1. 8, 95% CI: 1. 1–3. 0). Conclusion: This prospective Saudi validation demonstrates ARISCAT’s strong predictive performance in orthopedic surgery, with notable enhancement when applying the cemented procedure modification. The substantial clinical burden observed in high-risk patients (44. 8% PPC rate) and the associated economic impact highlight an urgent need for targeted preoperative optimization and resource-stratified care pathways. These findings reinforce ARISCAT’s utility in guiding surgical planning and underscore the value of tailoring risk assessment tools to the unique metabolic and environmental risk profile of Saudi orthopedic populations.