Background: A lighted stylet is an effective alternative to a direct laryngoscope and has been reported to be particularly useful in patients with difficult airways. A high Mallampati class indicates poor visibility of the oropharyngeal structures. Because a lighted stylet does not require direct oropharyngeal visualization, we hypothesized that the lighted stylet would be easier to use than a direct laryngoscope in patients with a high Mallampati score. To examine our hypothesis, we performed a prospective, randomized study comparing a lighted stylet (Surch-Lite) with direct laryngoscopy in patients with high Mallampati scores. Success rate, time required for intubation, and hemodynamic changes were compared.
Methods: Mallampati Class III patients were enrolled and were randomly assigned to the Surch-Lite group (Group SL) or the direct laryngoscopy group (Group DL). Patients' tracheas were intubated with the randomly selected intubation device after induction of general anesthesia. Heart rate (HR) and mean arterial blood pressure were measured immediately before and every 30 s after intubation for 5 min. The time to intubation and success rate were recorded. Postoperative pharyngolaryngeal complaints were also assessed.
Results: Thirty patients were enrolled in each group. The success rate on the first attempt was significantly higher in Group SL (29 of 30) than in Group DL (24 of 30). The difference between maximal HR and baseline HR was significantly higher in Group DL (25 +/- 13 bpm) than in Group SL (16 +/- 10 bpm). The change in mean arterial blood pressure was also higher in Group DL (38 +/- 14 mm Hg) than in Group SL (20 +/- 13 mm Hg). The time to intubation was significantly shorter in Group SL (12 +/- 6 s) than in Group DL (17 +/- 12 s). Postoperative pharyngolaryngeal complaints were not significantly different between the two groups.
Conclusions: The Surch-Lite showed a higher success rate on the first intubation attempt and produced an attenuated hemodynamic response to endotracheal intubation of patients with high Mallampati score. Thus, the Surch-Lite is an effective alternative to direct laryngoscopy in these patients.