Poor postoperative pain control is associated with prolonged length of stay after elective spine surgery: an observational cohort study

Abstract Background Prolonged length of stay (LOS) after elective spine surgery is associated with an increased risk of in-hospital complications and higher healthcare costs. This ambispective cohort study investigates the association between poor postoperative pain control and prolonged LOS, while adjusting for known risk factors and perioperative adverse events. Methods Consecutive adult patients undergoing elective spine surgery were enrolled. The primary outcome was prolonged LOS (≥75th percentile; ≥6 days). The primary independent variable was poor pain control on postoperative day 1 (POD1; mean numeric rating scale >4 in the first 24-hours after surgery). Baseline demographics, surgical characteristics, and perioperative adverse events were collected. Univariable and multivariable logistic regression analyses with multiple imputation were performed to investigate the relationship between poor pain control and prolonged LOS. Results In 1078 patients, the mean LOS was 4.8 days, and 57% of patients experienced poor pain control. Multivariable analyses revealed poor pain control was independently associated with prolonged LOS (OR 1.83 [95% CI=1.16-2.89], p=0.009), after adjusting for age (p=0.27), female sex (p=0.002), perioperative blood transfusion (p=0.030), postoperative airway/breathing/circulation adverse events (p<0.001), constipation (p=0.013), urinary tract infection (p=0.002), urinary retention (p<0.001), hematoma (p<0.001), surgical site infection (p<0.001), neurologic deterioration (p<0.001), POD1 morphine equivalent dose (p<0.001), preoperative disability score (p=0.04), ASA physical status score (p=0.03), smoking status (p=0.03), surgical levels (p<0.001), estimated blood loss (p=0.012), intraoperative dural tears (p=0.04), and fusion surgery (p<0.001). Conclusion Poor POD1 pain control was independently associated with prolonged LOS. Improved postoperative pain experience may lead to reduced LOS after elective spine surgery. Classifications Complications, epidemiology, cervical degenerative non-deformity, lumbar degenerative non-deformity.