Airway scope versus macintosh laryngoscope in patients with simulated limitation of neck movements.
BACKGROUND
Tracheal intubation in patients with suspected neck injuries should achieve two contradicting goals-sufficient laryngeal exposure and the least cervical spine movement. Because the former involves displacements of the cervical vertebrae, intubation under immobilization is widely performed today to prevent exacerbation of spinal code injuries. The unique curving blade of the Airway Scope (AWS) is designed to fit the oropharyngeal anatomy. A camera at the tip of the blade displays the view of the larynx, but unlike the direct laryngoscope, it needs no line-of-sight of the oral, pharyngeal, and tracheal axis. Our purpose is to determine whether AWS could be a suitable airway device for the intubation of patients with potential neck injury.


METHODS
Thirty-six patients scheduled for surgery were randomly assigned to undergo intubation using either AWS or Macintosh laryngoscope (MLS). After general anesthetic induction, the patient's head was set in a neutral position, and an appropriately sized semi-rigid neck collar was placed. Measurements include intubation time, number of attempts, success rate, Cormack-Lehane classification, airway optimization maneuver, Intubation Difficulty Scale scores, and complications.


RESULTS
Intubation time proved no statistical significance (mean ± SD, AWS, 62.9 seconds ± 26.0 seconds, MLS, 55.6 seconds ± 26.0 seconds; p = 0.42). AWS scored less in Cormack-Lehane classification (median [range], AWS I [I-I], MLS IIIa [I-IIIb]; p < 0.0001), required fewer additional airway optimization maneuvers (p = 0.0003), and scored less in Intubation Difficulty Scale scores (AWS 0 [0-1], MLS 2 [0-5]; p < 0.0001).


CONCLUSIONS
In neck-immobilized patients using semi-rigid cervical collars, AWS improves laryngeal exposure and facilitates tracheal intubation. AWS may be a suitable intubation device for trauma patients.
Aoi
Yoshihiro
Y
Department of Anesthesiology and Critical Care Medicine, Yokohama City University, School of Medicine, Yokohama, Kanagawa, Japan. yoshibird@hotmail.com
Inagawa
Gaku
G
Nakamura
Kyota
K
Sato
Hitoshi
H
Kariya
Takayuki
T
Goto
Takahisa
T
D000328:Adult; D000368:Aged; D000768:Anesthesia, General / Q000295:instrumentation; D004867:Equipment Design; D005260:Female; D019416:Head Movements / Q000502:physiology*; D006801:Humans; D007442:Intubation, Intratracheal / Q000295:instrumentation*; D020704:Laryngoscopes; D008297:Male; D008875:Middle Aged; D019838:Neck Injuries / Q000503:physiopathology*; D012149:Restraint, Physical; D013124:Spinal Injuries / Q000503:physiopathology*; D013996:Time and Motion Studies