후두마스크를 통한 맹목적 기관내 삽관의 성공률은 기관튜브 및 유도침의 종류에 따라 다른가?

Background : Tracheal tubes are different on the flexibility, material and bevel angle according to the manufacturers. These may affect the success rate of blind tracheal intubation through laryngeal mask airway (LMA). In addition, using straight-tip exchanger or curved-tip introducer, we tried to compare the success rate of tracheal tube insertion through LMA. Methods : After receiving informed consents, 30 patients were enrolled. Blind tracheal intubation was tried with reinforced tracheal tube (M group), or one of two kinds of conventional tracheal tube (P group and B group). Tracheal tube was selected in random order and advanced into the trachea through LMA one by one. If all the three attempts was unsuccessful, we considered the blind tracheal intubation through LMA a failure. We also compared the success rate of blind tracheal insertion through LMA using straight-tip exchanger or curved-tip introducer. The first trial was performed on the neutral head position. The exchanger or introducer was rotated during the second trial. If the second attempt was unsuccessful, the exchanger- or intubator-guided intubation was performed on the sniffing position and, as a last and fourth trial, while mandible was being elevated with hands. Results : Success rate of blind tracheal intubation through LMA was 50% (15/50) in group P and 36.7% (11/30) in group M, 33.3% (10/30) in group B (P=0.05). By using curved-tip introducer, intubation through LMA was successful in 80% (16/20), while it was successful only in 35% (7/20) via straight-tip exchanger. Conclusion : Blind tracheal intubation through LMA was dependent on the types of tracheal tube. Also, curved tip introducer may be a more valuable aid in performing blind tracheal intubation through LMA. Its use seems to be better technique than directly inserting tracheal tube through LMA. (Korean J Anesthesiol 1999; 36: 220∼224)