To print: Select File and then Print from your browser's menu --------------------------------------------------------------------------------------- Title: New Approaches for Reducing Patient Movement During Neurosurgery: Presented at ASA URL: http://www.pslgroup.com/dg/21620A.htm Doctor's Guide October 23, 2007
By Arushi Sinha, PhD SAN FRANCISO, CA -- October 23, 2007 -- Remifentanil reduces the risk of movement in the absence of muscle relaxants among patients undergoing elective craniotomy, researchers reported here at the Annual Meeting of the American Society of Anesthesiologists (ASA). In the case of neuroanaesthesia surgeries, muscle relaxants may not be indicated, particularly if intraoperative monitoring of motor evoked potentials or electromyography are involved. Alternative agents, such as remifentanil and propofol, may be used in such settings according to recent research. Marco Maurtua, MD, Assistant Professor, Department of Anesthesiology, Cleveland Clinic Foundation, Cleveland, Ohio, United States, and his colleagues designed a study to characterise the role of remifentanil in reducing movement associated with neurosurgical stimuli and to examine the incidence of bradycardia and hypotension in elective craniotomy patients. The study enrolled 131 patients with a mean age of 45 years (75% female) undergoing elective craniotomy who were randomised to one of 12 different remifentanil dosage regimens ranging from 0.10 to 0.21 mcg/kg/min. Patients received no premedication, such as nitrous oxide, prior to the beginning of anaesthesia, and remifentanil was initiated 2 to 4 minutes before induction. Propofol (2-4 mg/kg) and succinylcholine (1-2 mg/kg) were administered for intubation purposes, and isoflurane (0.6% end-tidal concentration) was used to maintain anaesthesia. Any movement by the patient was continuously recorded up to 5 minutes after head incision, as were heart rate and blood pressure. Results showed that at 0.13 mcg/kg/min of remifentanil dosing, patient movement was predicted to be at the 50% probability level. At 0.19-mcg/kg/min remifentanil dosing, patient movement was reduced to a 25% probability level. Accordingly, at the 0.13-mcg/kg/min remifentanil dosing level, the probability of hypotension was found to be 50%, and increased to 75% at 0.20 mcg/kg/min of remifentanil. Similarly, for bradycardia, the probability was 25% at 0.12 mcg/kg/min, and increased to 50% at 0.17 mcg/kg/min. "Our study was extremely sensitive for patient movement. Coughing or small movements were considered a positive movement and recorded," explained Dr. Maurtua during his presentation. Based on these results, the researchers concluded that remifentanil reduced the risk of movement in the absence of muscle relaxants for neurosurgical patients. For those patients receiving greater than a 0.13-mcg/kg/min dose of remifentanil, they exhibited at least 50% immobility, but hypotension and bradycardia were more frequent in the high-dose patients. "According to our findings, the range for remifentanil is 0.13 to 0.19 mcg/kg/min," concluded Dr. Maurtua. He added, "It will help clinicians to know this information." [Presentation title: Remifentanil Prevents Movement During Neurosurgery in the Absence of Neuromuscular Blockade. Abstract A1481] --------------------------------------------------------------------------------------------- Copyright © 1999 P\S\L Consulting Group Inc. All rights reserved. Republication or redistribution of P\S\L content is expressly prohibited without the prior written consent of P\S\L. P\S\L shall not be liable for any errors, omissions or delays in this content or any other content on its sites, newsletters or other publications, nor for any decisions or actions taken in reliance on such content. --------------------------------------------------------------------------------------------- This news story was printed from *Doctor's Guide to the Internet* located at http://www.docguide.com --------------------------------------------------------------------------------------- Return to News Story Page This site is maintained by webmaster@pslgroup.com Please contact us with any comments, problems or bugs. All contents Copyright (c) 1998 P\S\L Consulting Group Inc. All rights reserved.