Why USB-endoscope laryngoscopy is as effective as video laryngoscopy.

To compare the efficacy of a low-cost custom-made universal serial bus (USB) endoscope laryngoscope for intubation with a direct laryngoscope and a high-cost video laryngoscope in a mannequin study. We used one intubation simulator model (mannequin) in our study. A USB endoscope was mounted to the direct laryngoscope as a custom-made USB endoscope laryngoscope (USB-L). We used a video laryngoscope (Glidescope®, Verathon, USA) and a direct laryngoscope (Macintosh) for comparison. Intubation time and the correct placement of the tube were measured. Intubations were performed by two operators and results were compared. We found a statistically significant difference between the video and direct laryngoscope groups (p < 0.001), as well as between the USB-L and direct laryngoscope groups (p = 0.001) for Operator 1. For Operator 2, there was a statistically significant difference between the video laryngoscope group and the direct laryngoscope group (p = 0.022); however, we did not find a significant difference between the USB-L group and the direct laryngoscope group (p = 0.154). Furthermore, there were no significant differences between the USB-L and video laryngoscope groups for either operator (p=0.347 for Operator 1 and p>0.999 for Operator 2). Our study showed that USB endoscope laryngoscope provided similar intubation time to video laryngoscopy at a fraction of the cost; and both had superior times in comparison with direct laryngoscopy.