[Clinical study of SMT-Ⅱ video laryngoscope with difficult airway intubation in emergency department].

To observe the clinical feasibility and security of SMT-Ⅱ video laryngoscope in difficult airway intubation in emergency department. This study took 90 adults with difficult airway who were admitted to the rescue room of Jingxi court of Beijing Chao-Yang Hospital, Capital Medical University from January 2015 to December 2016.The patients were randomly divided into 2 groups(SMT-Ⅱ video laryngoscope group: =45, Macintosh direct laryngoscope group: =45), which were treated with endotracheal intubation and ventilator assisted ventilation.The evaluation of difficult mask ventilation(DMV) independent risk factor score, Wlison score, Cormack-Lehane grade, mouth opening, thyromental distance, visualization of the glottis, time for laryngoscopy, time for tracheal intubation, first-pass success rate of intubation, complications, mean arterial pressure(MAP) and heart rate(HR) before induction, after laryngoscopy, after induction, after intubation 5 minutes, 10 minutes were recorded.ANOVA, -test, Chi-square test was used to analyze differences data, respectively. There was no significant difference between the two groups in terms of gender, age, height, weight and other general data, mouth opening, DMV independent risk factor score, Wlison score, and thyromental distance(χ(2)=0.045, =-0.367, =0.684, =0.511, =0.330, =-0.724, =1.219, =1.034, all >0.05). A Cormack-Lehane grade Ⅰ or Ⅱ view were 44 cases in SMT-Ⅱ video laryngoscope group and 14 cases in Macintosh direct laryngoscope group. It significantly improved with the use of SMT- Ⅱ video laryngoscope, compared with Macintosh direct laryngoscope(χ(2)=52.096, <0.01). The time to best view was shorter in SMT-Ⅱ video laryngoscope group compared to that in Macintosh direct laryngoscope group with (15.0±1.0) seconds . (24.2±3.4) seconds(=-26.319, <0.05). The tube passage time was shorter with SMT-Ⅱ video laryngoscope (31.6±4.3) seconds . (12.7±0.9) seconds(=-21.698, <0.05)). The first -pass success rates in SMT-Ⅱ video laryngoscope group and Macintosh direct laryngoscope group were 100% and 84.4%, respectively(χ(2)=5.577, <0.05). For complications, pharyngorrhagia at intubation occurred in 1 case in SMT-Ⅱ video laryngoscope group and 9 cases in Macintosh direct laryngoscope group(χ(2)=5.513, <0.05), dislocation of tooth at intubation occurred in 0 case in SMT- Ⅱ video laryngoscope group and 6 cases in Macintosh direct laryngoscope group (χ(2)=4.464, <0.05). The mean arterial pressure values before induction, after laryngoscopy, after induction and after intubation 5 minutes, 10 minutes were (84.8±3.3), (89.2±3.6), (90.8±3.6), (86.6±3.4), (85.4±3.6) mmHg(1 mmHg=0.133 kPa) in SMT-Ⅱ video laryngoscope group and (85.8±3.1), (91.9±3.4), (96.1±2.9), (90.0±2.5), (86.5±2.9) mmHg in Macintosh direct laryngoscope group. There was a significant difference between the two groups at the 5-time points of MAP (=16.619, =0.000). The heart rate values before induction, after laryngoscopy, after induction and after intubation 5 minutes, 10 minutes were(77.4±4.3), (80.8±4.3), (83.3±4.9), (78.8±4.2), (76.9±4.2) rate/minutes in SMT-Ⅱ video laryngoscope group and (75.7±4.0), (85.3±4.4), (90.7±4.4), (84.3±4.1), (78.3±4.2) rate/minutes in the Macintosh direct laryngoscope group.There was a significant difference between the two groups at the 5-time points of HR(=15.857, =0.000). SMT-Ⅱ video laryngoscope uesd in difficult ariway enable better visualization of the glottic opening, short opertive time, enhance the success rate of intubation.It indicucates that SMT-Ⅱ video laryngoscope is safer than Macintosh direct laryngoscope in patients with difficult airway.