Evaluation of Vapocoolant Spray Before Local Anesthetic Infiltration During Percutaneous Needle Aponeurotomy: A Randomized Controlled Trial.

Abstract

Percutaneous needle aponeurotomy (PNA) offers an effective, minimally invasive option for Dupuytren disease, but local anesthetic infiltration into the richly innervated palm can cause substantial procedural pain. Vapocoolant sprays induce rapid cutaneous cooling, potentially suppressing nociceptor activity and modulating pain transmission. Evidence for their role in hand surgery is sparse. This randomized controlled trial evaluated whether vapocoolant application before infiltration reduces injection pain during PNA. In a single-center, single-blind, randomized controlled design, adults undergoing PNA were assigned 1:1 to receive either vapocoolant spray (5 seconds, 10 cm distance) immediately before infiltration with 1% plain lignocaine or lignocaine alone. Only the first injection was assessed. The primary end point was injection pain, rated on a 10-point visual analog scale (VAS). Secondary end points included immediate adverse events. Exploratory analyses examined correlations between VAS and demographic or disease variables. Ninety-four patients (47 per arm) were analyzed. The vapocoolant group was younger (65.8 ± 9.2 years) than controls (70.8 ± 8.5 years); sex distribution and comorbidities were comparable. Fifth ray involvement predominated (43%). Vapocoolant spray produced a significant reduction in mean injection pain (-2.70 VAS units), exceeding the reported minimal clinically important difference for acute procedural pain. No adverse events or complications occurred. Age demonstrated a moderate positive correlation with pain. Preinfiltration vapocoolant spray significantly diminished injection pain during PNA without compromising safety. Given its immediacy, negligible cost, and ease of integration into clinical workflow, vapocoolant use represents a pragmatic analgesic adjunct in hand surgery. Broader adoption may enhance patient comfort, procedural tolerability, and overall satisfaction. Individual RCT/Ib.