The implication of using dominant hand to perform laryngoscopy: an analysis of the laryngoscopic view and blade-tooth distance

Background: Existing laryngoscopes are designed to be handled by the left hand, whereas most healthcare professionals are right-handed. However, controlling the laryngoscope device requires considerable strength and refinement to control the blade. We examined the usefulness of a right-handed laryngoscope to validate its clinical applicability. Methods: One hundred sixty-four patients for general anesthesia were involved. Laryngoscopy was performed twice for each patient, once using a conventional left-handed Macintosh No. 3 laryngoscope and once using a right-handed one, by 25 right-handed and 18 left-handed laryngoscopists. The perpendicular distance from the tip of the maxillary incisor to the flange of each blade was measured when the maximum visibility of the glottis was obtained. We compared the distances, chances of directly contacting the tooth, laryngoscopic views and subjective feeling of difficulty in handling device between the two laryngoscopes. Results: For the right-handed laryngoscopists, distance varied significantly between the two laryngoscopes (5.0 ± 3.5 and 5.7 ± 3.7 mm [mean ± standard deviation] for the conventional and right-handed laryngoscopes, respectively [P < 0.001]). The right-handed laryngoscope was associated with a decreased chance of directly contacting the teeth (P = 0.001). Additionally, the right-handed laryngoscope provided a better view than the conventional one (P = 0.005). Conversely, most of the left-handed laryngoscopists felt that the procedure using a conventional laryngoscope was easier than with a right-handed one. Conclusions: When a right-handed laryngoscopist uses a right-handed laryngoscope, a better laryngoscopic view and a reduced chance of blade contact with the teeth can be achieved. Keywords: Laryngoscope; Laryngoscopic view; Left-handed; Right-handed; Tooth