Year : 2012 | Volume
: 28 | Issue : 2 | Page : 153-
Airway management devices for general anesthesia for magnetic resonance imaging
Kirti N Saxena
Department of Anesthesiology, Maulana Azad Medical College, New Delhi, India
Kirti N Saxena
B-302, Geetanjali Apartments, Vikas Marg Extension, New Delhi - 110 092
|How to cite this article:|
Saxena KN. Airway management devices for general anesthesia for magnetic resonance imaging.J Anaesthesiol Clin Pharmacol 2012;28:153-153
|How to cite this URL:|
Saxena KN. Airway management devices for general anesthesia for magnetic resonance imaging. J Anaesthesiol Clin Pharmacol [serial online] 2012 [cited 2021 Mar 6 ];28:153-153
Available from: https://www.joacp.org/text.asp?2012/28/2/153/94823
Anesthesia for magnetic resonance imaging (MRI) requires special equipment that can be used in the presence of a magnetic field. Since MRI is a time-consuming process, sedation or general anesthesia is required for children undergoing MRI. Insertion of an airway device is essential during administration of general anesthesia as it is difficult to access the airway because the size of the child is small compared to the MRI machine and the whole body of the child enters the gantry. In this issue, Taxak et al.  highlight the airway management of patients administered general anesthesia for MRI, which is an important aspect in the delivery of anesthesia for such patients.
MRI does not require very deep anesthesia as it is not a painful procedure. Although endotracheal tubes can be used to secure the airway, their use requires a greater depth of anesthesia for insertion and tolerance than that required by supraglottic devices. Airway complication rates are also higher with endotracheal intubation and extubation than with supraglottic devices such as laryngeal mask airway (LMA). 
The i-gel is a reliable, easily inserted airway device that provides an adequate seal, and has a low morbidity rate.  It is designed to achieve a mirrored impression of the pharyngeal and laryngeal structures and to provide a perilaryngeal seal without cuff inflation. It has no inflatable cuff and therefore no pilot balloon. It scores over the classic LMA in that it has a drain tube that allows insertion of a gastric tube thereby preventing aspiration. It has also been used widely in children and found to be useful. 
As pointed by Taxak et al., there is little choice when using a supraglottic device for airway management for MRI due to presence of ferromagnetic material.  A simulation study of six supraglottic devices in the MRI environment showed that magnetic susceptibility artifact is more prominent with the use of LMA ProSeal.  The artifacts of the LMA Classic, LMA Unique, and LMA Supreme were similar and related to the ferromagnetic material in the pilot balloon valve. There were no artifacts with the Ambu disposable LMA and with the i-gel supraglottic airway.
The search for airway devices for patients undergoing MRI continues. Evidence of safe use of more airway devices for conduct of anesthesia for MRI is required.
|1||Taxak S, Bhardwaj M, Gopinath A. The i-gel TM - A Promising Airway device for MRI suite. J Anaesthesiol Clin Pharmacol 2012;28:263.|
|2||Sharma R, Dua CK, Saxena KN. A randomized controlled study comparing the effects of laryngeal mask airway and endotracheal tube on early postoperative pulmonary functions. Singapore Med J 2011;52:875.|
|3||Beylacq L, Bordes M, Semjen F, Cros AM. The I-gel® , a single-use supraglottic airway device with a non-inflatable cuff and an esophageal vent: An observational study in children. Acta Anaesthesiol Scand 2009;53:376-9.|
|4||Beringer RM, Kelly F, Cook TM, Nolan J, Hardy R, Simpson T, et al. A cohort evaluation of the paediatric i-gel™ airway during anaesthesia in 120 children. Anaesthesia 2011;66:1121-6.|
|5||Zaballos M, Bastida E, Del Castillo, Guzmán de Villoria T, Jiménez de la Fuente C. in vitro study of the magnetic resonance imaging artifacts of six supraglottic airway devices: 19AP1-2. Airway Management. Eur J Anaesthesiol 2010;27:244-5.|