A Comparison of the Effects of Different Types of Laryngoscope on Hemodynamics: McCoy Versus the Macintosh Blade / 대한마취과학회지

BACKGROUND: This study was designed to compare the hemodynamic changes in response to direct laryngoscopy of the McCoy blade and the Macintosh blade. METHODS: Sixty patients scheduled for elective gynecologic surgery were randomly allocated into two groups. The induction of anesthesia was done with thiopental sodium 5 mg/kg, fentanyl 2 mcg/kg, vecuronium 0.1 mg/kg. When the train of four arrived came at 0/4, the vocal cords were visualized with either the McCoy or the Macintosh laryngoscope blade for 10 seconds. Heart rate and blood pressure were recorded at 1 minute intervals for 5 minutes. RESULTS: Laryngoscopy caused significant increases in arterial blood pressure in both groups, while it had no effect on heart rate in either group. There were no significant differences in blood pressure and heart rate responses to laryngoscopy in the blades. CONCLUSIONS: The McCoy and the Macintosh blade show similar changes in heart rate and blood pressure after laryngoscopy.

The Radiological Measurement of Cervical Spine Extension during Bullard or Direct Laryngoscopy / 대한마취과학회지

Background: Conventional laryngoscopy with Macintosh blade requires a movement of the head, neck and cervical spine. The Bullard laryngoscope is an anatomically shaped, potentially eliminating the need for cervical spine extension. Bullard and Macintosh laryngoscopes were compared by measuring the degree of cervical spine extension by radiological measurement. Methods: Eighteen patients requiring endotracheal intubation were studied. Anesthesia was induced in neutral head position followed by laryngoscopy. Each patients was intubated two times by Macintosh and Bullard laryngoscope in random order. Radiographic evaluation was performed to determine the degree of cervical spine extension on four occasions; before induction, during facial mask ventilation, and during Bullard and Macintosh laryngoscopy. Results: The extension of cervical spine was significantly less following Bullard laryngoscopy than Macintosh laryngoscopy for best view (p<0.05). Conclusions: The Bullard laryngoscope can be used with less cervical spine extension than Macintosh laryngoscope. It may be useful in patients in whom cervical spine movement is limited or undesirable.