Lidocaine spray 10% prior to intravenous catheterisation in dogs

A common and to some degree painful procedure in veterinary practice is to insert an intra-venous catheter. In both human and veterinary medicine, a topical mixture of lidocaine and prilocaine (EMLA cream) has shown to reduce the pain, however a period of 60 min between application and initiation of the procedure is recommended. This time lapse is not always suitable for clinical practise and a shorter time before anaesthetic effect is therefore desirable. Lidocaine has a shorter time lapse (1-3 min) when used on mucus membrane; however, the effect of lidocaine for desensitization of skin has shown variable results in humans. The aim of the study was to evaluate the effect of topical lidocaine spray 10% on the response to placement of venous catheters in dogs. Topical lidocaine spray 10% or NaCl 0.9% was administered prior to placing an intravenous catheter in the cephalic vein. A cross-over of treatment with 2 h wash out period was used before placing a catheter in the opposite cephalic vein. The procedure was video recorded and the dogs' responses were later scored by three persons blinded to treatment using a visual analogue scale. The VAS scores were normalised and the mean difference between treatments were compared using Wilcox signed-rank test. This study could not find a statistical difference between the treatments (P = 0.1763) and could conclude that no significant difference in response to intravenous catheterisation was found between application of NaCl 0.9% or lidocaine 10% prior to the procedure.