Abstract

 

 

Objectives: Using digital techniques, the insertion success of the ProSeal Laryngeal Mask Airway (PLMA) is generally lower than that of the standard laryngeal mask airway (LMA). We therefore evaluated a new PLMA insertion technique in anesthetized and paralyzed patients.

 

Design: Patients not requiring tracheal intubation for airway management were enrolled into this prospective, but non-consecutive observational study.

 

Setting: The study was performed at a community hospital.

 

Patients: One hundred patients undergoing elective general surgical or urological operative procedures were investigated.

 

Operators: The operators (5 staff anesthetists, 2 anesthesia residents, and one qualified anesthesia nurse) were experienced users of the GlideScope Video Laryngoscope (GVL) and the LMA, but had less experience with the use of the PLMA. They first received formal hands-on training on an airway model, were instructed during the early series of performance on patients by an experienced PLMA user, and performed PLMA insertion attempts on from 10 to 16 (median: 12) patients.

 

Interventions: The new PLMA insertion technique involved priming the esophageal drain tube of the PLMA with a gastric tube (GT, with a stiffening device inside), placing the GT into the esophagus under video laryngoscopic view, and inserting the PLMA (using the GT as guide) into the hypopharynx. The study design provided only one PLMA insertion attempt. During inflation of the cuff, the air-tight PLMA seal was judged by spirometry.

 

Measurements and Main Results: The GVL provided a panoramic view of anatomical structures for atraumatic insertion of the GT; the laryngeal views obtained were visualization of the entire laryngeal aperture and visualization of at least parts of the laryngeal aperture in 84 and 16 patients, respectively, and the esophageal lumen was visible in 74 patients. PLMA insertion and ventilation was successful in all patients. Cuff volumes required and cuff pressures measured [median (range)] were 16 (10 to 30) ml and 28 (18 to 44) mbar for size 4 PLMAs (used in 44 patients) and 20 (10 to 36) ml and 26 (18 to 40) mbar for size 5 PLMAs (used in 56 patients), respectively. The laryngeal views through the airway tube of the PLMA obtained with a flexible fiberoptic laryngoscope were visualization of the laryngeal aperture and visualization of the laryngeal aperture and the posterior epiglottis in 60 and 40 patients, respectively. In 48 patients, the GT was further advanced for gastric drainage; GT advancement was successful at the first attempt in all these patients.

 

Conclusions: The new PLMA insertion technique reliably guided the PLMA into the correct position. We speculate, that less-experienced PLMA users will have a higher succes rate with this evaluated PLMA insertion technique. Judgement of the air-tight PLMA seal by spirometry may require minor cuff volumes than recommended, resulting in limited cuff pressures measured.  

 

 

Introduction