LETTERS TO THE EDITOR
Year : 2021 | Volume
: 15 | Issue : 1 | Page : 73--74
Comparing anaesthesia for MRI using inhalational anaesthesia and sedation using propofol - The answer is not in black and white
Gauri R Gangakhedkar
Department of Anaesthesiology, Critical Care and Pain, Tata Memorial Hospital, Homi Bhabha National Institute, Tata Memorial Centre, Mumbai, Maharashtar, India
Dr. Gauri R Gangakhedkar
Address - 13/14, Chandangad Apartments, Next to Rahul Nagar, Near Karve Putala, Kothrud, Pune - 411 038, Maharashtra
|How to cite this article:|
Gangakhedkar GR. Comparing anaesthesia for MRI using inhalational anaesthesia and sedation using propofol - The answer is not in black and white.Saudi J Anaesth 2021;15:73-74
|How to cite this URL:|
Gangakhedkar GR. Comparing anaesthesia for MRI using inhalational anaesthesia and sedation using propofol - The answer is not in black and white. Saudi J Anaesth [serial online] 2021 [cited 2022 Aug 19 ];15:73-74
Available from: https://www.saudija.org/text.asp?2021/15/1/73/306162
The article by Thampi et al. gives an interesting perspective to the conduct of paediatric cases in Magnetic Resonance Imaging (MRI) suite. Since MRI is usually a day-care procedure, early recovery from anaesthesia is the most crucial aspect. While for other day-care procedures, regional anaesthesia can be used, it is not an option in in children undergoing MRI. Achieving faster induction, and avoiding airway instrumentation, as promised by the use of propofol, in such patients thus seems like a lucrative option to facilitate faster turn over in busy hospitals.
Thampi et al. found no significant difference in the time to recovery whether general anaesthesia with a supra-glottic airway device or intravenous anaesthetic was used for maintenance. The authors mention the contrast in findings by Bryan et al. in a similar study, but this contrast can largely be attributed to the use of sevoflurane and not isoflurane by Bryan et al. When Delvi et al. compared the use of isoflurane and sevoflurane in children undergoing MRI, they found that with the use of isoflurane, the mean time to recovery was three times that of the other group. The time taken for discharge, in the isoflurane group was also significantly longer in comparison to the sevoflurane group. This raises a question as to whether the use of Sevoflurane as an inhalational agent even for maintenance, would have led to a different conclusion for this study.
Additionally, agitation and emergence were not seen in the propofol group but were present in the isoflurane group (10%). A metabolomic profiling in children undergoing MRI by Jacob et al. has in fact demonstrated that the use of inhalational agents, such as sevoflurane, led to higher concentrations of glucose and lactate in the parietal cortex, and that these 1.2-fold higher values of lactate, in comparison to propofol, thus explaining the significantly higher agitation emergence scores in children, on using inhalational agents.
A grave concern raised by Thampi et al. in the Isoflurane group, was the significantly higher incidence of airway incidents in the form of desaturation and laryngospasm, which would definitely pose a deterrent to its choice for maintenance. While they do mention the constraints of a resource poor setting, it must be noted, that the authors have not mentioned the use of Mean Alveolar Concentration (MAC) to monitor depth of anaesthesia. It remains possible that the lack of MAC monitoring in conjunction with the slow alveolar uptake of isoflurane led to inadvertant light planes of anaesthesia, thus leading to these airway mishaps. This theory finds validation in the fact that in studies where MAC monitoring was employed, airway incidents were reported in a significantly smaller proportion of patients.,
Given that both inhalational and intravenous agents come with their own benefits and drawbacks, but remain safe and effective, it becomes imperative to individualise management for patients depending on the individual institutional infrastructure and the patient requirements.
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Conflicts of interest
There are no conflicts of interest.
|1||Thampi SM, Jose R, Kothandan P, Jiwanmall M, Rai E. Timeliness of care and adverse event profile in children undergoing general anesthesia or sedation for MRI: An observational prospective cohort study. Saudi J Anaesth 2020;14:311-7.|
|2||Bryan YF, Hoke LK, Taghon TA, Nick TG, Wang Y, Kennedy SM, et al. A randomized trial comparing sevoflurane and propofol in children undergoing MRI scans. Paediatr Anaesth 2009;19:672-81.|
|3||Delvi MB, Samarkandi A, Zahrani T, Faden A. Recovery profile for magnetic resonance imaging in pediatric daycase--sevoflurane vs. isoflurane. Middle East J Anaesthesiol 2007;19:205-11.|
|4||Jacob Z, Li H, Makaryus R, Zhang S, Reinsel R, Lee H, et al. Metabolomic profiling of children's brains undergoing general anesthesia with sevoflurane and propofol. Anesthesiology 2012;117:1062-71.|