Transdermal Nitroglycerin Enhances Lidocaine And Neostigmine for Intravenous Anesthesia in Patients Undergoing Hand Surgery. A Prospective Randomized Double Blind Placebo Control Study.

Abstract

In a prospective randomized blind study, we investigated the effects of adding transdermal nitroglycerine for lidocaine and neostigmine for intravenous regional anesthesia in adult patients undergoing hand surgery. Patients and Methods Sixty patients (ASA grade I, aged 20-60 years) of both sexes were enrolled. The patients were randomly allocated to receive either 40ml of 0.5% lidocaine plus a transdermal placebo patch (control group n=15), 40ml of 0.5% lidocaine with 0.5mg of neostigmine plus a transdermal placebo patch (Neostigmine group, n=15), 40ml of 0.8% lidocaine plus a transdermal nitroglycerine patch (Nitroglycerine group, n=15) or 40ml of 0.5% lidocaine with 0.5mg of neostigmine plus a transdermal nitroglycerine patch (Neostigmine - Nitroglycerine group, n=15). All routine hemodynamic parameters and O2 saturation were monitored, surgical time, sensory and motor block onset times, sensory and motor block recovery times and time to first analgesic requirement were measured. Operative conditions and quality of anesthesia were also recorded. Results Sensory and motor block onset times were shorter in the neostigmine – nitroglycerine group compared with all other groups (p<0.05). Sensory block recovery time was significantly prolonged and the quality of anesthesia was better in the neostigmine – nitroglycerine group compared with all other groups (p<0.05). Conclusion We found that the addition of 0.5mg neostigmine to 40ml of 0.5% lidocaine for intravenous regional anesthesia with a 5mg transdermal nitroglycerine patch improved the operating conditions and quality of anesthesia and prolonged postoperative relief with no adverse effects.