Association of perineural hydromorphone added to ropivacaine with early analgesic outcomes in proximal humerus fracture surgery: a retrospective cohort study.

BACKGROUND

The analgesic benefit of adding perineural hydromorphone (HYD) to ropivacaine (ROP) for proximal humerus fracture surgery remains unclear.

OBJECTIVE

The aim of this study is to examine whether adding perineural hydromorphone to ropivacaine was associated with early analgesic outcomes and short-term adverse events.

METHODS

This single-center retrospective cohort included 130 consecutive eligible adults (ROP, n = 68; ROP + HYD, n = 62). The primary outcome was 12-h analgesia success, defined as resting visual analog scale (VAS) ≤3. We used multivariable logistic regression and propensity score analyses to account for measured treatment-preceding differences. Sensitivity analyses considered the combined block techniques, intraoperative medications, and postoperative analgesic co-interventions. A 1-point difference on the 0-10 VAS was used to interpret clinical importance.

RESULTS

Analgesia success at 12 h occurred in 39/62 patients (62.9%) in the ROP + HYD group and 26/68 (38.2%) in the ROP group [absolute difference 24.7 percentage points, 95% confidence interval (CI) 7.5-39.9; unadjusted odds ratio (OR) 2.74, 95% CI 1.35-5.57; number needed to treat 4.1]. The adjusted OR was 3.72 (95% CI 1.66-8.77), and propensity score analyses gave similar estimates. A sensitivity model that also accounted for superficial cervical plexus and T2 paravertebral field supplementation gave an OR of 3.83 (95% CI 1.67-9.31). Mean VAS differences favored ROP + HYD at 6 h (-0.33, 95% CI -0.65 to -0.02) and 12 h (-0.58, 95% CI -0.86 to -0.29), but both were smaller than 1 point; no difference was detected at 24 h. Median total 24-h rescue opioid consumption was 4.8 morphine milligram equivalents (MME) with ROP + HYD and 6.4 MME with ROP (p = 0.044). An unadjusted exploratory comparison found lower 6-h cortisol with ROP + HYD, but interpretation is limited by heterogeneous routine assay methods and multiple secondary comparisons. No between-group differences in the recorded short-term adverse events were detected.

CONCLUSIONS

Adding perineural hydromorphone was associated with a higher proportion of patients achieving resting VAS ≤3 at 12 h. The average VAS differences were modest and no difference was detected at 24 h. Because treatment was not randomized, these findings should be confirmed in a prospective trial.