Warm Lidocaine/Tetracaine Patch Versus Placebo Before Pediatric Intravenous Cannulation: A Randomized Controlled Trial

Study objective

We compare the pain of intravenous (IV) cannulation in pediatric emergency department (ED) patients after applying a topical lidocaine/tetracaine patch versus placebo. We hypothesized that application of the active patch would reduce the pain of IV cannulation by at least 15 mm.

Methods

We conducted a randomized, double-blind, placebo-controlled trial in a suburban academic ED. Patients aged 3 to 17 years who required nonemergency IV cannulation were eligible for enrollment. At triage, a nurse placed a commercially available topical lidocaine/tetracaine patch or an identical-looking placebo patch over the antecubital or hand vein in patients for whom an IV catheter was anticipated. After IV cannulation by the treating nurse, the pain of cannulation was measured on a validated 100-mm visual analogue scale or Wong Baker scale. Outcomes were compared between groups with Mann-Whitney U, Student t, and χ² tests. A sample of 40 patients had 80% power to detect a 13-mm difference in pain scores.

Results

Forty-five patients were randomized to lidocaine/tetracaine patch (22) or placebo (23), and IV cannulation was attempted in 40 of these patients. Mean age was 10 years (SD=4.3), 35% were female patients. The median pain of IV cannulation in the active treatment group (18 mm [interquartile range (IQR) 1 to 40 mm]) was significantly lower than in the placebo group (35 mm [IQR 20 to 59 mm]; P=.04). Adequate pain relief was more common in the active treatment group (75% [95% confidence interval (CI) 53% to 89%] versus 35% [95% CI 18% to 57%]; difference 40% [95% CI 6% to 64%]). The number of successful IV cannulations after the first attempt was similar in both the lidocaine/tetracaine and the placebo groups (90% [95% CI 70% to 97%] versus 85% [95% CI 64% to 95%]; difference 5% (95% CI –21% to 30%).

Conclusion

Application of a topical lidocaine/tetracaine patch resulted in a modest reduction in the pain of IV cannulation in pediatric ED patients and did not alter the rate of successful cannulations.