Blind tracheal intubation by paramedics through the LMA-Unique.
OBJECTIVE
The manufacturer of the laryngeal mask airway (LMA) reports success rates of 30-93% by practitioners attempting tracheal intubation through the LMA-Classic. No prior studies describe success rates through the (disposable) LMA-Unique by paramedics. The objective of this study was to measure the success rate of paramedics attempting to intubate the trachea blindly through the LMA-Unique.


METHODS
During a paramedic refresher class and an emergency medical services teaching day conference, paramedics previously trained in the use of the LMA-Unique as a "rescue" airway device were instructed in the technique of tracheal intubation through the LMA-Unique. A Laerdal LMA-mannequin was immobilized with an extrication collar and held by an investigator in the head-neutral position. Paramedics were first asked to insert the LMA-Unique as previously trained, and to confirm adequate ventilation by seeing inflation of the mannequin's lungs. Then, subjects were asked to pass a well-lubricated 6-0 Mallinckrodt endotracheal tube through the LMA-Unique within a 60-second period. Tracheal placement of the endotracheal tube was then confirmed by visualization of the expanding mannequin lungs. Rates of success of LMA-Unique placement and endotracheal tube placement were measured.


RESULTS
Fifty of the 52 (96%; CI 91% to 100%) paramedics successfully inserted the LMA-Unique on the first attempt. Only 11 of the 52 (21%; CI 10% to 32%) paramedics were successful in blind placement of the endotracheal tube into the trachea through the LMA-Unique within a 60-second period. The failures (41 of the 52) were visually confirmed to be located in the esophagus.


CONCLUSIONS
In this study, when attempting blind tracheal intubation through the LMA-Unique, paramedics were rarely successful in tracheal placement. Basic LMA-Unique insertion, however, had a very high success rate.
Department of Emergency Medicine, SUNY Upstate Medical University, 750 East Adams Street, Syracuse, NY 13210, USA. dave@barnes.org
David R
DR
Barnes
David B
DB
Reed
Gail
G
Weinstein
Lawrence H
LH
Brown
D002983:Clinical Competence; D015331:Cohort Studies; D016001:Confidence Intervals; D004632:Emergency Medical Services / Q000592:standards*; D004634:Emergency Medical Technicians / Q000193:education* / Q000592:standards; D004638:Emergency Treatment / Q000379:methods / Q000592:standards; D005260:Female; D006801:Humans; D007442:Intubation, Intratracheal / Q000379:methods / Q000592:standards*; D017214:Laryngeal Masks / Q000592:standards*; D008297:Male; D011336:Probability; D011446:Prospective Studies; D018570:Risk Assessment; D013997:Time Factors