A comparison of the King-LT to endotracheal intubation and Combitube in a simulated difficult airway

Prehospital endotracheal intubation (ETI) is a complex skill to maintain proficiency. Several airway adjuncts are available for prehospital providers. A recent alternative is the King Laryngeal Tube (LT) approved for use by the FDA in 2003. The aim of this study was to determine if the King-LT offers improved placement success and times over the Combitube (ETC) and endotracheal tube (ETT) in a simulated difficult airway.

Sixty-nine prehospital providers (EMT-Bs and EMT-Ps) were timed in a series of trauma scenarios involving the placement of an ETT, ETC, and LT in a difficult airway simulator. Primary outcome measures were placement time (seconds) and success for each device. Successful placement in the manikin was defined by adequate placement depth, inflation of device cuffs, the presence of breath sounds, and the absence of epigastric sounds.

EMT-P mean placement times were 91.3 seconds (76.6-106.0) for ETT, 53.7 seconds (48.3-59.1) for ETC, and 27.0 seconds (24.3-29.7) for LT. EMT-B mean placement times were 46.4 seconds (37.5-55.3) for ETC and 22.5 seconds (19.0-26.0) for LT. Subgroup analysis was completed and compared in groups that either checked or did not check device balloons prior to insertion. EMT-Ps successfully placed an ETT in 68.9% (31/45) of attempts. EMT-P success for ETC and LT scenarios were 82.2% (37/45) and 100% (45/45). EMT-B success in the ETC was 87.5% (21/24) and 100% (24/24) with the LT. Differences in successful placement between all devices were significant for paramedics only. A survey was provided following the scenarios to assess comfort and ease of each device; 17/45 EMT-P participants noted the ETT to be "difficult" to place versus 38/45 reporting the King-LT to be "easy" or "very easy."

The King-LT is a relatively new airway device with time and successful placement advantages over ETT and ETC.