Tracheal intubation with the PENTAX-AWS (airway scope) reduces changes of hemodynamic responses and bispectral index scores compared with the Macintosh laryngoscope.

The PENTAX-AWS, a novel video laryngoscope, allows indirect visualization of the vocal cords on a color monitor display and enables tracheal intubation without upward lifting force required to expose the glottis. This study compared hemodynamic changes, bispectral index scores, and postoperative sore throat before and after laryngoscopy between the Macintosh laryngoscope and the airway scope (AWS). Forty patients (American Society of Anesthesiologists I-II), randomly assigned to either the Macintosh group (n=20 each) or AWS group, were enrolled in this study. After induction with fentanyl (0.001 mg/kg), propofol (1.5 mg/kg), and vecuronium (0.1 mg/kg), tracheal intubation was performed. Hemodynamic parameters were compared before and after laryngoscopy. Patients were assessed for postoperative sore throat at 24 hours after extubation. No significant differences in patient characteristics were observed between groups. Significant increases in both systolic blood pressure (P<0.05 vs. baseline) and heart rate (P<0.001 vs. baseline) after laryngoscopy were seen using the Macintosh blade, whereas the AWS provided no increases in either parameter. The AWS also caused a lesser increase in bispectral index (P<0.05 vs. Macintosh group). Postoperative sore throat was observed in both groups (2 out of 20 in AWS and 6 out of 20 in Macintosh), although this difference did not reach statistically significant level (P=0.23). In conclusion, the AWS offers a reduced degree of hemodynamic stimulation compared with the Macintosh laryngoscope, suggesting that tracheal intubation with the AWS is advantageous to prevent hypertension after laryngoscopy in neurosurgical patients.