Laryngeal mask airway Unique™ position in paediatric patients undergoing magnetic resonance imaging (MRI): prospective observational study

Abstract

BackgroundLaryngeal mask UNIQUE® (LMAU) is supraglottic airway device with good clinical performance and low failure rate. Little is known about the ideal position of the LMAU on the magnetic resonance imaging (MRI) and whether radiological malposition can be associated with clinical performance (audible leak) in children. The primary aim of the study was to evaluate incidence of the radiologic malposition of the LMAU according to size. The secondary outcome was the clinical performance and associated complications (1st attempt success rate, audible leak) in LMAUs in correct position vs. radiologically misplaced LMAUs.MethodsIn prospective observational study, all paediatric patients undergoing MRI of the brain under general anaesthesia with the LMAU were included (1.9.2016–16.5.2017). The radiologically correct position: LMAU in hypopharynx, proximal cuff opposite to the C1 or C2 and distance A (proximal cuff end and aditus laryngis) ≤ distance B (distal cuff end and aditus laryngis). Malposition A: LMAU outside the hypopharynx. Malposition B: proximal cuff outside C1-C2. Malposition C: distance A ≥ distance B. We measured distances on the MRI image. Malposition incidence between LMAU sizes and first attempt success rate in trainees and consultant groups was compared using Fisher exact test, difference in incidence of malpositions using McNemar test and difference in leakage according to radiological position using two-sample binomial test.ResultsOverall 202 paediatric patients were included. The incidence of radiologically defined malposition was 26.2% (n = 53). Laryngeal mask was successfully inserted on the 1st attempt in 91.1% (n = 184) cases. Audible leak was detected in 3.5% (n = 7) patients. The radiologically defined malposition was present in 42.9% (n = 3) cases with audible leak. The rate of associated complications was 1.5% (n = 3): laryngospasm, desaturation, cough. In 4.0% (n = 8) the LMAU was soiled from blood.Higher incidence of radiological malposition was in LMAU 1.0, 1.5 and LMAU 3, 4 compared to LMAU 2 or LMAU 2.5 (p < 0.001).ConclusionMalposition was not associated with impaired clinical performance (audible leak, complications) of the LMAU or the need for alternative airway management.Trial registrationClinicaltrials.gov (NCT02940652) Registered 18 October 18 2016.

Effect of Laryngeal Mask Airway on Image Quality in Pediatric Patients Undergoing Brain Magnetic Resonance Imaging: A Randomized Controlled Trial

“…The LMA has also gained more popularity in MRI in pediatrics in the past years through airway complication rate reduction, lower intrusive nature, excellent clinical performance, and low failure rate ( 11 ). Our results presented that the MRI scan performed by LMA was superior to Guedel oral airway in image quality with comparable needed anesthesia (the mean sevoflurane percent and patients who required propofol boluses were comparable between both groups).…”

“…The LMA was positioned through the conventional technique, partially inflated, and the tip of the mask was lubricated by clear liquid lubricating jelly after the induction of anesthesia with the patient’s head in the neutral position. The LMA proper position was described as placement in the hypopharynx, the proximal cuff of LMA opposing C1 or C2 vertebrae, with a distance between proximal cuff end and aditus laryngis (distance A) as well as between distal cuff end and aditus laryngis (distance B) ( 11 ). If LMA or airway displacement during anesthesia occurred, their position was corrected, and MRI was restarted.…”

Utility of ultrasound evaluation of I‐Gel® placement in children: An observational study

“…13,15,16 The structural optimal positioning of the SGA has been evaluated using fiberoptic bronchoscopy, 5 US, 6,17 CT, and MRI. 18,19 In previous studies, SGA location was scored according to the degree of visible structure of the SGA inner outlet using fiberoptic bronchoscopy. 5,20 The position of the SGA was considered to be unstable when larynx obstruction was observed, the SGA was rotated on fiberoptic view.…”

“…The structural optimal positioning of the SGA has been evaluated using fiberoptic bronchoscopy, 5 US, 6,17 CT, and MRI 18,19 . In previous studies, SGA location was scored according to the degree of visible structure of the SGA inner outlet using fiberoptic bronchoscopy 5,20 .…”

Airway Management in Pediatric Patients: Cuff-Solved Problem?

“…[ 48 , 49 , 50 , 51 ] with comparable efficacy and lower incidence of associated complications in comparison to tracheal tubes [ 52 , 53 ], the supraglottic airways should always be considered as the device of choice in all situations possible (fasted patient, low risk of aspiration/regurgitation, and possible access to head and airway of the patient). Currently, multiple types of laryngeal masks are available on the market, but the majority are equipped with an inflatable cuff to obtain an adequate perilaryngeal seal (cuff located in the hypopharynx) after inflation [ 54 ]. The proper cuff management is vital also in case of laryngeal mask cases due to the risk of oropharyngeal and hypopharyngeal mucosal cuff-related pressure damage.…”