Relationship Between Potential Opioid‐Related Adverse Effects and Hospital Length of Stay in Patients Receiving Opioids After Orthopedic Surgery

Study Objective To determine whether there is an association between opioid‐related adverse effects and postoperative hospital length of stay (p‐LOS). Design Retrospective medical record review. Setting Large academic medical center. Patients Random sample of 402 patients (mean age 60.2 yrs, 50.3% female) who underwent orthopedic spine, hip, knee, or shoulder surgery during 2007 and received opioids during or after the procedure. Measurements and Main Results Potential opioid‐related adverse effects were identified by using established criteria. Bivariate and multivariate analyses (generalized linear regression model, log transformed) were used to identify predictors of p‐ LOS . The model also estimated the effect of specific types of adverse effects and adverse‐effect combinations on p‐ LOS . Mean ± SD p‐ LOS was 3.0 ± 2.1 days; median oral morphine equivalent postoperative dose was 60 mg/day. More than half of the patients (54.2%) experienced one or more adverse effects , 25.6% experienced two or more adverse effects, and 7.2% experienced three or more adverse effects. The composite of nausea and vomiting was experienced by 36.1% of study patients, and 12.6% had at least one emesis episode. Constipation and confusion were documented in 6.5% and 3.7% of patients, respectively. Constipation (p<0.0001), emesis (p<0.001), and confusion (p<0.01) were associated with increased p‐ LOS after adjusting for other significant variables. Patients with constipation had an adjusted 49% (95% confidence interval [ CI ] 25–77%) longer p‐ LOS (additional 1.4 days) compared with patients without constipation. Emesis and confusion significantly increased p‐ LOS by 25% (95% CI 10–42%) and 38% (95% CI 11–72%), respectively. Incremental increases in p‐ LOS for patients with two adverse effects (p=0.02), three adverse effects (p<0.001), and four adverse effects (p<0.001) versus patients with no adverse effects were 15%, 40%, and 82%, respectively. Conclusion Constipation, emesis, and confusion were associated with increased p‐ LOS in patients receiving opioids after orthopedic surgery. In addition, there was a significant linear relationship between the number of adverse effects/patient and increased p‐LOS, and the strength of the association increased as the number of adverse effects increased. Although the opioid dosages and adverse‐effect rates were typical, these findings reinforce the need to balance pain management with risk of events.