Effects of acetaminophen for intravenous regional anesthesia Vol. 58, No. 4, April 2010 Introduction Intravenous regional anesthesia (IVRA) was first used by August Bier in 1908 [1]. This technique is easy, reliable and cost- effective when used in short operative procedures of hand or forearm [2]. Tourniquet pain and lack of postoperative analgesia after tourniquet release are the major limitations to this technique. To improve the efficacy of IVRA, various agents such as tramadol [3], clonidine [4], neostigmine [5] are added to the local anesthetics. Also various nonsteroidal anti-inflammatory drugs (NSAIDs) have been demonstrated to enhance analgesia such as ketorolac, in IVRA [6,7]. Acetaminophen is an analgesic which relieves pain and reduces fever. PerfalganTM (Bristol-Myers Squibb, France) is a solution of acetaminophen administrated intravenously in order to relieve pain or reduce fever following surgery. We planned this study to evaluate the effect of intravenous acetaminophen and ketorolac on sensory block onset times, tourniquet pain and postoperative analgesia when added to lidocaine for IVRA. Materials and Methods Sixty patients with American Society of Anesthegiologists (ASA) physical status I or II, aged between 17 and 60 years, who were scheduled for surgery of the hand or the forearm were included in this study after informed consent. Patients with sickle cell anemia, Raynaud’s disease, history of drug allergy, liver disease, kidney disease were excluded from the study. This prospective, double-blinded, randomized, interventions study, conducted in the patients undergoing hand or forearm surgery were randomly assigned in three groups: Group C- patients received 0.5% lidocaine diluted with 0.9% normal saline Table 1. Demographic Data, Total Operation Time and Total Tourni- quet Application Time Group C (n = 20) Group P (n = 20) Group K (n = 20) Age (yr) 40.0 ± 12.5 42.7 ± 13.9 40.3 ± 16.2 Gender (M/F) 11/9 10/10 11/9 Weight (kg) 65.2 ± 5.9 64.6 ± 13.6 64.7 ± 10.8 Height (cm) 165.5 ± 8.0 165.3 ± 10.7 166.6 ± 10.0 Duration of operation (min) 36.8 ± 16.9 34.0 ± 22.1 29.0 ± 15.1 Tourniquet application time (min) 50.2 ± 14.5 47.3 ± 13.3 47.6 ± 13.3 Values are number of patients or mean ± SD. Group Creceived 0.5% lidocaine diluted with 0.9% normal saline to a total volume of 40 ml for IVRA. Group P received 0.5% lidocaine diluted with intravenous acetaminophen 300 mg to a total volume of 40 ml. Group K re- ceived0.5% lidocaine diluted with 0.9% normal saline plus ketololac 10 mg to a total volume of 40 ml. There are no significant difference among the groups. 358 to a total volume of 40 ml (n = 20), Group P- patients received 0.5% lidocaine diluted with intravenous acetaminophen 300 mg (Perfalgan 30 ml) to a total volume of 40 ml (n = 20) and Group K- patients received 0.5% lidocaine diluted with 0.9% normal saline plus ketorolac 10 mg to a total volume of 40 ml (n = 20). There was no significant difference among groups for age, height, weight, duration of operation time, tourniquet time and sex ratio (Table 1). The types of operations performed are presented in Table 2. There were no exclusions from the study due to technical failure. After the patients had been taken to the operating room, mean arterial blood pressure (MAP), peripheral oxygen saturation (SpO2), and heart rate (HR) were monitored. Before establishing the anesthetic block, two cannulae were placed; one in dorsal vein of the operative hand for anesthetic drug administration and the other in opposite hand for crystalloid infusion. The operative arm was exsanguinated with an Esmarch bandage, and a pneumatic tourniquet was placed around the upper arm. The proximal cuff was inflated to 250 mmHg and maintained in the same position. Circulatory isolation of arm was verified by inspection, absence of radial pulse, and loss of pulse oximetry tracing of the ipsilateral index finger. After the bandage was removed, 40 ml of the respective solutions were injected for the period of 60 seconds. The sensory block was assessed by a pinprick test using a 22- gauge short-beveled needle taken out continuously every 30 seconds. Patient response was evaluated in the dermatomal sensory distribution of the medial and lateral antebrachial cutaneous, ulnar, median, and radial nerves. After sensory block was achieved, the distal cuff was inflated to 250 mmHg followed by release of the proximal tourniquet and operation was then started. Assessment of tourniquet pain using the visual analog scale Table 2. Typesof Operations Performed The types of operation Ganglion excision Finger fracture close reduction Carpal tunnel syndrome Radius fracture close reduction Hardware removal of forearm Hand laceration Mallet finger Trigger thumb 3 3 5 3 2 3 1 0 Values are number of patients. Group Creceived 0.5% lidocaine diluted with 0.9% normal saline to a total volume of 40 ml for IVRA. Group P received 0.5% lidocaine diluted with intravenous aceta- minophen 300 mg to a total volume of 40 ml. Group K received 0.5% lidocaine diluted with 0.9% normal saline plus ketololac 10 mg to a total volume of 40 ml. Group C (n = 20) Group P (n = 20) Group K (n = 20) 4 2 3 1 5 1 1 3 4 0 5 1 3 3 3 1 www.ekja.org