Acute Pain Predictors of Remote Postoperative Pain Resolution After Hand Surgery

INTRODUCTION: Chronic postsurgical pain (CPSP) is a global issue with high prevalence. This study compared acute pain descriptors among patients undergoing carpal tunnel release (CTR) or trigger finger release (TFR). We hypothesized worst pain intensity on postoperative day (POD) 10 would be best to predict the time to pain resolution. METHODS: In this secondary analysis of a negative, randomized, double-blind placebo-controlled trial, adult veterans undergoing CTR or TFR were enrolled January 2012–January 2014, with data analysis February 2020–October 2020. Participants were randomized to receive minocycline 200 mg or placebo 2 h prior to the operation, then minocycline 100 mg or placebo twice daily for 5 days. The Brief Pain Inventory, assessed daily, captured three pain scores: average and worst pain over the past 24 h, and current pain intensity. Fifteen acute pain descriptors based on the pain scores (clusters, mean, median, pain scores on POD 10, and linear slopes) were compared as predictors of time to pain resolution. RESULTS: Of 131 randomized participants, 114 (83 CTR, 31 TFR) were included. Average pain over the last 24 h reported on POD 10 best predicted time to pain cessation. Every one-point increase in the average pain score was associated with a 36.0% reduced rate of pain cessation (HR, 0.64, 95% CI 0.55–0.74, p < 0.001). Average pain on POD 10 was significantly associated with the development of CPSP at 90 days (OR 1.74, 95% CI 1.30–2.33, p value < 0.001). The optimal cutoff score for the high-risk group was determined as average pain on POD 10 ≥ 3. CONCLUSIONS: This study validates prior work and demonstrates the importance of assessing pain severity on POD 10 to identify patients at high risk for CPSP who are most likely to benefit from early pain intervention. Future research in diverse surgical cohorts is needed to further validate pain assessment on POD 10 as a significant predictor of CPSP.