Airwayscope (AWS), which has been used successfully for difficult airway in general anesthesia, has been anticipated that hemodynamic response to tracheal intubation in the difficult airway may be attenuated. Also, there is a series of reports demonstrating the successful use of lightwand to open the difficult airway. Thus, we decided to conduct a survey to compare AWS to lightwand and to direct laryngoscopy of cardiovascular response to tracheal intubation.

Of 64 healthy patients without cardiovascular disease, 22, 21, 21 patients were randomly assigned to AWS group, lightwand group and direct laryngoscope group. After induction of general anesthesia, intubation was performed with manual in-line neck stabilization. During laryngoscopy, a modified Cormack-Lehane grade was assessed and time to intubation was measured. Systolic arterial pressure (SAP) and heart rate (HR) were recorded at the following timepoints: baseline, just before intubation, 1 min, 2 min, 3 min, 4 min and 5 min after intubation.

There were no significant differences between the 3 groups in SAP, HR (P > 0.05). However modified Cormack-Lehane grade of all patients in the AWS group was I, while that in direct laryngoscope group was IIB or III. In addition, the mean time to intubation of the direct laryngoscope group was significantly longer than that of the AWS and lightwand (P < 0.05).

In the difficult airway, AWS was very effective in improving laryngeal view and decreasing time to intubation compared to direct laryngoscopey. In addition, lightwand reduced the time to intubation. However we could not find any significant difference in hemodynamic response to tracheal intubation among the 3 groups.