Efficacy of a Vapocoolant Spray in Reducing Pain During Capillary Glucose Testing: A Randomized Crossover Trial

BACKGROUND: Capillary blood glucose measurement is frequently performed in emergency departments but may cause pain and discomfort. Vapocoolant spray is a rapid, non-invasive, and low-cost analgesic option, although its effectiveness during glucose testing remains insufficiently studied. OBJECTIVE: This study aimed to investigate the pain-relieving effect of vapocoolant spray during blood glucose measurement. METHODS: This study was a single-center, randomized, placebo-controlled crossover study conducted in the emergency department of a tertiary care hospital. Adult patients requiring at least 2 capillary glucose measurements were included. Patients received a vapocoolant spray and a placebo spray containing sterile water prior to the glucose measurement in a randomized sequence. The primary outcome was pain perception assessed immediately after each measurement using a 100-mm Visual Analog Scale (VAS). RESULTS: Of the 109 patients evaluated, 80 were randomized, and 77 completed both measurements for the paired primary analysis. The median age of the patients was 65 years (interquartile range [IQR], 58-72), and 55.0% were male. The median VAS score was 29 mm (IQR, 18-43) with the vapocoolant spray, compared to 40 mm (IQR, 31-56) with the placebo. The vapocoolant spray significantly reduced pain, within-subject percent reduction in pain was 33.3% (IQR, 14.8%-47.3%, p < 0.001). No serious adverse events were observed during the study, and all observed adverse effects were mild and transient. CONCLUSION: Vapocoolant spray significantly reduced pain during capillary blood glucose testing and was well tolerated. Its rapid and practical application may improve patient comfort during this common emergency department procedure. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT06789055.