Dermal patch anesthesia: pain-free puncture of blood access in hemodialysis patients

Clinical application of dermal patch anesthesia to relieve pain at venous cannulation of blood-access was studied in hemodialysis patients. Aqueous gel of 10% lidocaine base with 3% glycyrrhetinic acid monohemiphthalate disodium (GA MHPh 2Na) was applied for 60 minutes to the skin of the patients. Degree of pain was expressed as a pain score. Analgesic effect of the lidocaine gel was evaluated in 16 patients in a placebo-controlled, double-blind, cross-over design by comparing the gel with lidocaine with a placebo gel without lidocaine. The mean pin-prick pain score (1.0 +/- 0.5) in the lidocaine gel patch (n = 16) was significantly lower than that (2.3 +/- 0.3) in the placebo gel patch (P < 0.01). In 8.8% of the patients, blood pressure was elevated after venous cannulation, but this tendency was modified by dermal patch anesthesia with the lidocaine gel. Plasma concentration of lidocaine was under the detection limit of assay (< 0.05 micrograms/mL) after dermal patch anesthesia in six subsequent dialysis treatments.