A Comparison of Two Types of Tracheal Tube for Use in Intubating Laryngeal Mask Airway Assisted Blind Orotracheal Intubation

Kim, Hyung Joo; Lee, Sang Kyi

Abstract

BACKGROUND: The conventional laryngeal mask airway (LMA) has been used to facilitate blind tracheal intubation in numerous situations where laryngoscopy and conventional intubation has been difficult, but it has the disadvantage that its airway tube is too long and narrow for intubation. The intubating laryngeal mask airway (ILM) has been specifically designed to increase the success rate of blind intubation. A specially constructed ILM tracheal tube is available for use with the ILM, But this tube is in short supply and expensive. Thus, this study was performed to compare the success rate and time of blind intubation through ILM with reinforced tracheal tube or specially-designed tracheal tube, and to assess the use of reinforced tracheal tube as a substitute for specially-designed tracheal tube.
METHODS
After acquiring informed consent, 60 ASA grade 1 or 2 patients undergoing anesthesia for elective surgical procedures who normally required tracheal intubation were randomized into two groups. In group 1 (n = 30), the patients were intubated with a specially-designed tracheal tube through ILM. In group 2 (n = 30), reinforced tracheal tubes were used. The patients were induced and relaxed with an iv injection of thiopental sodium, fentanyl-ketamine-midazolam mixture and vecuronium. When an adequate level of anesthesia was achieved, the ILM was inserted. After adequate ventilation was confirmed, blind tracheal intubation with either of the two types of tracheal tubes through the ILM was attempted. Then we recorded success rate, intubation time and adjusting maneuvers.
RESULTS
The ILM was successfully inserted at first attempt in 59/60 (98%) patients, but in 1 patient, adequate ventilation was not acheived. The success rate of tracheal intubation was 27 (93%) in group 1 and 28 (93%) in group 2. In group 1, 21 (72%) patients were successfully intubated on the first attempt, 1 (4%) patient on the second attempt, and 5 (17%) patients on the third attempt. In group 2, 20 (67%) patients were successfully intubated on the first attempt, 2 (6%) patients on the second attempt, and 6 (20%) patients on the third attempt. The mean time taken for intubation was 116.9 sec in group 1 and 122.3 sec in group 2.
CONCLUSIONS
The authors conclude that the reinforced tracheal tube can be substitute for a specially- designed tracheal tube.