Analgesic Effects of Additional Nitroglycerine in Intravenous Regional Lidocaine-Based Anesthesia Through Forearm Surgery

Abstract

Background: Intravenous regional anesthesia (IVRA) (or Bier's block) is the administration of a local anesthetic drug to an organ intravenously, when compressed by tourniquet. Simple use in outpatient and emergency settings, being regional instead of general anesthesia and having reasonable costs make IVRA most acceptable. Objectives: Nitroglycerine, as a safe and available medication, was evaluated by the current study in the search for better analgesia withlower complications that plays the role of a suitable adjuvant in regional anesthesia by lidocaine. Patients and Methods: Through a randomized controlled clinical trial, two types of anesthesia were used regionally for 70 cases of forearm surgery between 2010 and 2011. Elective cases of forearm surgery with American Society of Anesthesiologist (ASA) class I or II were enrolled in the study and were randomly divided to two groups of cases and controls. For the control group, lidocaine was used alone for IVRA while for the intervention group lidocaine as well as 200 µg of nitroglycerin was used through the procedure. Results: On average, sensory block started in 3.48 and 6.5 minutes, for the case and control groups, respectively. The mean motor block time was 4.18 and 6.98 minutes for the cases and controls, respectively. The groups differed in terms of times required for sensory and motor blocks. Recovery time was longer among cases (118.32 ± 7.8 minutes) when compared to the controls. Conclusions: Nitroglycerin at a dose range between 200 and 400 µg, as an adjunct for lidocaine, can evidently improve regional anesthesia, increase block recovery time and postpone the need for postoperative analgesics, especially opioids.