The LMA-Supreme versus the I-gel in simulated difficult airway in children

Abstract

Supraglottic airway devices such as the LMA-Supreme (LMA-S) and I-gel, which have an additional lumen for the insertion of a gastric tube, can be useful in the management of the difficult airway. To test the performance of these two devices in the difficult paediatric airway. Randomised double-blind study. Anaesthesia department, university hospital. Sixty American Society of Anesthesiologists (ASA) I-II children undergoing elective surgery. After obtaining ethical approval and written informed consent from the parents, we compared the size 2 LMA-S with the I-gel in a simulated airway scenario made more difficult by using a cervical collar to limit mouth opening and neck movement. The primary aim was to compare the oropharyngeal leak pressure of the LMA-S and the I-gel. The secondary aims were to compare success rate, insertion time, time to pass a gastric tube and fibreoptic view of the larynx. Oropharyngeal leak pressure (mean ± SD) for the LMA-S was significantly higher than with the I-gel (20.9 ± 3.2 versus 18.9 ± 3.2 cmH2O, P = 0.019). First attempt success rate for the LMA-S was 100 and 90% for the I-gel (P > 0.05). Insertion time of the LMA-S was shorter than I-gel (11.2 ± 1.8 versus 13.5 ± 2.4 s, P = 0.001). Gastric tube placement was possible in all patients. The mean insertion time of the gastric tube was shorter with the LMA-S than with the I-gel (10.3 ± 3.6 versus 12.7 ± 3.2 s, P = 0.009). Fibreoptic laryngeal views were similar in both groups. In the simulated difficult airway in children, both airway devices provided effective ventilation. Paediatric size 2 LMA-S sustained a higher airway pressure before leaking and was quicker to insert than the I-gel equivalent. These differences may not be clinically significant.