Study of a combined percutaneous local anaesthetic and nitric oxide-generating system for venepuncture

Nitric oxide (NO) may be generated and delivered into the skin via a novel system of sodium nitrite and ascorbic acid. This placebo-controlled, double-blind trial compared the analgesic properties of this system alone and when supplemented with lidocaine. The pain of dorsal hand vein cannulation was assessed in 100 volunteers. The NO-generating system was prepared by mixing two gels, the first KY jelly and sodium nitrite (10% w/v), the second KY jelly and ascorbic acid (10% w/v). NO-generating gel was the placebo treatment, and when combined with lidocaine (final concentration 5%), formed the active treatment. The gels were applied to the dorsum of the hands bilaterally and simultaneously for 10 min. Following cannulation, pain perception was measured with a verbal rating score (VRS) and a visual analogue score (VAS). The active formulation significantly decreased the VRS (p < 0.0001) and also reduced the mean VAS by > 40% compared with placebo (p < 0.001). This investigation suggests a 10-min topical application of anaesthetic combined with the NO-generation system may provide effective analgesia for venous cannulation in adults.