Comparison of Two Insertion Techniques of Proseal Laryngeal Mask Airway by Unskilled Personnel in Children

Overview

The ProSeal laryngeal mask airway (PLMA) is one of the alternative methods for effective airway management. It is an advanced form of laryngeal mask airway(LMA) with a softer and larger cuff to improve sealing and a drain tube to permit venting of the stomach. However, the larger cuff is more difficult to save space for insertion in the mouth and is more likely to fold over. Particularly, a relatively large tongue, a floppy epiglottis, a cephalad and more anterior larynx and frequent presence of tonsillar hypertrophy may disturb PLMA insertion in pediatric patients. The manufacturer recommends inserting PLMA using digital manipulation or with an introducer, but these techniques have lower success rates compared to those of LMA insertion. McIvor blade is a tongue retractor with a thin and curved blade and a flat handle. It is used to secure the operating field by pressing tongue during tonsillectomy. The investigators hypothesized that McIvor blade would provide more space in the mouth for PLMA insertion, and therefore it could improve the PLMA insertion as well as reducing injuries to the pharyngeal wall. The investigators compared the success rate and the incidence of complications of the digital technique with those of McIvor blade-guided insertion by unskilled anesthesia residents.

Rapid and successful airway management is important for the patient's outcome in emergency care. Tracheal intubation with an endotracheal tube is the gold standard for airway management, but tracheal intubation by paramedical staff in pre-hospital setting can be time-consuming and difficult. The ProSealTM laryngeal mask airway (PLMA) is one of the alternative methods for effective airway management. It is an advanced form of laryngeal mask airway(LMA) with a softer and larger cuff to improve sealing and a drain tube to permit venting of the stomach. However, the larger cuff is more difficult to save space for insertion in the mouth and is more likely to fold over. Particularly, a relatively large tongue, a floppy epiglottis, a cephalad and more anterior larynx and frequent presence of tonsillar hypertrophy may disturb PLMA insertion in pediatric patients. The manufacturer recommends inserting PLMA using digital manipulation or with an introducer, but these techniques have lower success rates compared to those of LMA insertion. The first attempt success rate of PLMA insertion by inexperienced personnel was reported to be 83%. Several techniques have been introduced to improve the insertion success rate; the use of fiberoscopy, gum-elastic bougie, and a suction catheter. However, all of them can not save enough oral space for PLMA insertion and it would not be easy for the unskilled personnel to use them in emergency situations. A larger space between tongue and retropharynx, not being accompanied with an index finger for insertion would make make it easier for the unskilled personnel to insert the PLMA. McIvor blade is a tongue retractor with a thin and curved blade and a flat handle. It is used to secure the operating field by pressing tongue during tonsillectomy. We hypothesized that McIvor blade would provide more space in the mouth for PLMA insertion, and therefore it could improve the PLMA insertion as well as reducing injuries to the pharyngeal wall. We compared the success rate and the incidence of complications of the digital technique with those of McIvor blade-guided insertion by unskilled anesthesia residents.