Ultrasound may help us better interpret optimal LMA positioning in pediatric patients. (Image source: Thinkstock)
Those who care for adults and children notice that when a laryngeal mask airway (LMA) is inserted, the fit or seal is not as good in a child as it is in an adult. LMAs used for children have to be repositioned more frequently. This might be due to how the LMA was developed. LMAs for children are simply smaller versions of LMAs for adults, yet the child’s airway anatomy is different than an adult’s. Dr. Hae Keum Kil, Department of Anesthesiology and Pain Medicine, Severance Hospital, Anesthesia and Pain Research Institute, Yonsei University College of Medicine, Seoul, Republic of Korea, and colleagues used ultrasound and fiberoptic bronchoscopy in 100 children to determine how frequently the LMA was displaced within the hypopharynx of children. Ultrasound can’t identify the cuff of an air-filled LMA, though it can identify positional changes of arytenoid cartilage. The results of their analysis are summarized in the article “An Ultrasound Evaluation of Laryngeal Mask Airway Position in Pediatric Patients: An Observational Study
,” published in this month’s issue of Anesthesia & Analgesia
For 84% of the children, the LMA was successfully inserted on the first attempt. For the remaining 16%, the LMA was successfully inserted on the second attempt. LMA repositioning was needed for 55 patients. The LMA had to be replaced in 8 patients.
Ultrasound could not define the position corresponding to the fiberoptic assessment of LMA fit. However, ultrasound could detect LMA rotation. When an LMA is rotated, it is also malpositioned, which can be associated with difficult ventilation.
The study suggests that ultrasound may help guide LMA positioning in pediatric patients.