Visual rigid laryngoscopes versus Macintosh laryngoscopes for completing endotracheal intubation in modified Mallampati grade Ⅲ- Ⅳpatients

Objective To compare the effect of visual rigid laryngoscopes versus Macintosh laryngoscopes in completing endotracheal intubation in patients with modified Mallampati test (MMT) score Ⅲ -Ⅳ. Methods Sixty patients with MMT scoreⅢ -Ⅳ scheduled for surgery under general anesthesia with endotracheal intubation in Chinese PLA General Hospital from June to December in 2017 were enrolled and they were randomly divided into two groups with 30 cases in each group. Endotracheal intubation was performed with visual rigid laryngoscope in group V and Macintosh laryngoscope in group M. The glottic exposure view, time required for intubation, intubation times as well as the incidence of sore throat at 6 hours after surgery were recorded. Results There was no significantly statistical difference in sex, age, height, weight, mouth opening, thyromental distance and MMT score between the two groups (all P> 0.05). There were 28 cases of good glottic exposure in group V, greater than 16 cases in group M (P=0.031). The success rate of intubation for the fi rst attempt in group V and group M was 93% and 73% respectively, with significant difference (P=0.039). The time required for intubation in group V was significantly shorter than that of group M(21±9) s vs (49±21) s, P=0.043. The incidence of sore throat at 6 hours after surgery in group V and group M was 10% and 23%respectively, with significant difference (P=0.037). Conclusion Compared with Macintosh laryngoscope, visual rigid laryngoscope can provide better glottic exposurea, higher success rate of intubation for the fi rst attempt, shorter intubation time and lower incidence of sore throat at 6 hours after surgery in patients with MMT gradeⅢ-Ⅳ.