KETAMINE PLUS NITROGLYCERIN VERSUS KETAMINE AS ADJUNCTS TO LIDOCAINE FOR INTRAVENOUS REGIONAL ANESTHESIA IN ADULT PATIENTS UNDERGOING HAND SURGERY

Abstract

Background: Different agents have been used as adjutants to lidocaine for intravenous regional anesthesia (IVRA) to improve the quality of analgesia.
Objective: The aim of this double blinded randomized controlled trial is to evaluate if adding nitroglycerin to ketamine is more effective than using ketamine alone as an adjuvant to lidocaine for IVRA.
Methods: Fifty adult ASA I-II patients undergoing hand surgery using IVRA were divided into two equal groups: ketamine/nitroglycerin (K/N) group received lidocaine 3mg/kg (maximum 200 mg) with ketamine 0.1 mg/kg (maximum 10 mg) plus nitroglycerin 2 mcg/kg (maximum 200 mcg) and ketamine (K) group received lidocaine 3 mg/kg (maximum 200 mg) with ketamine 0.1 mg/kg (maximum 10 mg). Statistical analysis was done using Student's t test or Chi square analysis whenever appropriate.
Results: The two groups were similar in demographic data and patients characteristics. The onset times of sensory and motor blockades were significantly shorter in K/N group. Although the preoperative visual analogue scale for pain intensity (VAS) was comparable, the intra-operative and postoperative VAS, were significantly less in K/N group. The intra-operative fentanyl consumption as an intra-operative analgesia was significantly less in K/N group. Also, the time to call for the first postoperative analgesia was significantly longer in K/N group than K group. However the postoperative analgesics consumption showed no significant difference between the two groups.
Conclusion: In comparison to ketamine, adding a combination of ketamine and nitroglycerin to lidocaine for IVRA improved the quality of anesthesia without inducing significant clinical side effects.
Key words: Nitroglycerin, ketamine, intravenous, regional, anesthesia.