Association Between Intravenous to Oral Opioid Transition Time and Length of Hospital Stay After Posterior Spinal Fusion for Adolescent Idiopathic Scoliosis

Introduction: The aim of this study was to investigate the impact that longer IV to oral opioid transitions have on length of stay (LOS) after posterior spinal fusion (PSF) for adolescent idiopathic scoliosis (AIS).

Methods: The medical records of 129 adolescents (10 to 18 years old) with a diagnosis of AIS undergoing multilevel, posterior spinal fusion at a major academic institution between 2013 and 2020 were reviewed. Patients were categorized based IV to oral opioid transition time, normal (≤ 2 days) versus prolonged (≥ 3 days). Weighted patient demographics, comorbidities, deformity characteristics, intraoperative variables, physical therapy scores, postoperative complications, LOS, discharge disposition, and unplanned readmission rate were assessed. A multivariate stepwise logistic regression was used to determine the odds ratio for risk-adjusted extended LOS.

Results: A total of 129 patients were included in this study, of which 70.5% were categorized as Normal IV to oral transition time (n = 91) and 29.5% (n = 38) were found to be Prolonged. Patient demographics and comorbidities were similar between the cohorts. The major curve degree (p=0.762), and median number of levels fused were similar (p=0.447), however operative time was significantly longer in the Prolonged cohort (p=0.009). Post-operative complications rates were similar between the cohorts. Patients with Prolonged transitions from IV to oral narcotics had significantly longer LOS than Normal transitions (Normal: 4.6 ± 1.3 days vs Prolonged: 5.1 ± 0.8 days, p< 0.001). On univariate analysis, IV to oral opioid transition time was significantly associated with extended LOS [OR: 2.0, p=0.014], but only trended towards significance on multivariate analysis [aOR: 2.1, p=0.062].

Conclusion : Our study suggests that longer postoperative IV to oral opioid transitions after PSF for AIS may have implications on hospital length of stay. Further studies are necessary to better identify approaches that may reduce IV to oral opioid transition times.