Comparative Study of Light Wand and Direct Laryngoscope: Correlation of Time to Intubation and Thyromental Distance, and Change of Blood Pressure and Heart Rate after Intubation.

Hwang,  Jung Won; Noh,  Gyu Jeong; Oh,  Yong Seok

doi:1999.36.6.949

Clinical Research Article

Korean Journal of Anesthesiology 1999;36(6):949-954.
DOI: https://doi.org/10.4097/kjae.1999.36.6.949

Comparative Study of Light Wand and Direct Laryngoscope: Correlation of Time to Intubation and Thyromental Distance, and Change of Blood Pressure and Heart Rate after Intubation.

Jung Won Hwang, Gyu Jeong Noh, Yong Seok Oh

¹Department of Anesthesiology, Hanil General Hospital, and College of Medicine.
²Seoul National University, Seoul, Korea.

Abstract

BACKGROUND
Direct laryngoscope may be less useful under conditions of limited visualization. Light wand is a lighted stylet to transilluminate neck tissues allowing intubation without visualization. Thus, difficult intubation due to anatomy can be overcome. For comparison of light wand and direct laryngoscope, we checked time to intubation (TTI), success rate, relation of TTI and thyromental distance (TMD), and change of blood pressure and heart rate after intubation.
METHODS
We selected and randomly allocated sixty adults to direct layngoscope group (D) and light wand group (L). Without premedication, propofol and vecuronium were injected for intubation. Time to intubation was measured from the time of grasping direct laryngoscope or light wand until the time of inserting endotracheal tube into trachea. We checked the change of blood pressure and heart rate after intubation, and studied the correlation of TTI and TMD.
RESULTS
TTI was 16.5 sec (6.53~115.3 sec) for group D and 11.8 sec (4.31~36.0 sec) for group L. There was no significant difference between the groups. The rise of blood pressure and heart rate was less with light wand. There was a correlation of [TTI]=1248- 388[TMD]-30[TMD]2 in group L patients whose TMD is less than 7 cm.
CONCLUSION
Compared with direct laryngoscope, light wand is as easy to use and can be more effective especially for patients whose anatomy may make intubation difficult or whose cardiovascular system is unstable.

Key Words: Anatomy, thyromental distance; Intubation, tracheal, direct laryngoscope, light wand, time to intubation; Monitoring, blood pressure, heart rate