Doctor's Guide to Medical & Other News


To print: Select File and then Print from your browser's menu
---------------------------------------------------------------------------------------
Title: Improving MRI Scan Quality in Paediatric Patients Undergoing Anaesthesia: Presented at ASA
URL: http://www.pslgroup.com/dg/2161DE.htm
Doctor's Guide
October 22, 2007


By Arushi Sinha, PhD

SAN FRANCISO, CA -- October 22, 2007 -- When a patient, particularly a paediatric patient, is experiencing total intravenous anaesthesia (TIVA) with propofol or other inhalational agents, it can prohibit the quality of MRI scans. These agents may cause scan interruptions as a result of patient movement or a respiratory event. A study to help better understand this phenomenon was presented at the Annual Meeting of the American Society of Anesthesiologists (ASA).

"This was part of a series of studies that looked at the reasons for MRI scanning interruptions in children," explained Yvon Bryan, MD, Associate Professor, Department of Anesthesia, Anesthesia, Cincinnati Children's Hospital, Cincinnati, Ohio, United States.

Dr. Bryan and his team compared the rates of MRI scan interruptions with different inhalational agents, specifically sevoflurane and propofol. They also sought to further characterise the nature of these interruptions.

For the study, the researchers enrolled 200 children scheduled for brain MRI. The mean age for the patient cohort was 4.3 years. Patients were initially induced with sevoflurane, and then randomised into one of two groups. The first group of 101 patients received an additional 2% sevoflurane through the laryngeal mask airway. The second group of 99 patients received a 2-mg/kg bolus of propofol through a 200-mcg/kg/min infusion.

Through the process, if movement was detected among the patients, concentrations were increased by 0.5%-to-1.0% increments in the sevoflurane group and by 20-mcg/kg/min increments of propofol after a 0.5-to-1.0 mg/kg bolus in the propofol group.

For the purposes of this study, pausing frequency, or P score, was described as the number of MRI scan interruptions resulting in an artifact on the MRI image due to patient movement, loss or lack of monitoring, or a respiratory event, such as desaturation, apnoea, or laryngospasm.

The results demonstrated that the total pauses in the propofol group were greater than in the sevoflurane group. However, the researchers attributed this to the fact that there were two patients in the propofol group that caused two pauses, along with an additional patient who caused three pauses.

Overall, the majority of patients in each group (92% in the sevoflurane group and 80% in the propofol group) exhibited no pauses in the MRI scanning process.

Based on these observations, the researchers concluded that there were generally more pauses among patients receiving propofol than among those receiving additional sevoflurane. A total of 14% of MRI scans were paused, due most often to loss of monitoring or patient movement.

"Anaesthesia with [sevoflurane] will stop the MRI scan less frequently," concluded Dr. Bryan.


[Presentation title: MRI Scan Ianterruptions in Children: Pausing With Propofol and Smooth Sailing With Sevoflurane. Abstract A1409]

---------------------------------------------------------------------------------------------
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.