EtCO₂ Was Used To Study The Effect Of Fiberoptic Bronchoscopy In Guiding Difficult Endotracheal Intubation

PURPOSE To evaluate the effect of preset assisted fiberoptic bronchoscope guided transnasal difficult endotracheal intubation with end-expiratory carbon dioxide monitor,and to explore its value in the teaching of airway management in the standardized training of resident physicians.METHODS 1.Sixty patients with expected difficult airway under general anesthesia in oral and maxillofacial surgery with nasotracheal intubation from November 2018 to January 2019 were selected.ASA graded I-II patients were randomly divided into two groups(n=30).In group II,patients were kept in the preset position with end-expiratory carbon dioxide monitor under spontaneous breathing,and then were intubated via nasal endotracheal tube with fiberoptic bronchoscopy.The operation was performed by the same senior anesthesiologist,who recorded the success rate of the first endotracheal intubation,the time of endotracheal intubation,and the number of attempts.The incidence of endotracheal intubation complications was observed and recorded.2.Twenty anesthesiology residents,aged 24-26 years old,were selected from the ninth people’s hospital affiliated to the school of medicine of Shanghai jiaotong university for standardized training of anesthesiology residents.After the use of simulated human training fiberoptic bronchoscopy,all trainees were randomly divided into two groups,A and B(n=10).A total of 100 patients with expected difficult airway were selected for oral and maxillofacial surgery through nasal endotracheal intubation from December 2018 to February 2019.Each student in the two groups underwent endotracheal intubation in 5 different patients.The intubation method in group A was the same as that in group I and the intubation method in group B was the same as that in group II.The success rate of the first intubation,the time of endotracheal intubation and the number of attempts were recorded,and the learning curve was drawn.Changes in central rate,blood pressure and oxygen saturation,and the incidence of endotracheal intubation complications were recorded.RESULTS 1.The success rate of first endotracheal intubation was 90.0% in group I and 93.3% in group II,P=0.2196.The average number of endotracheal intubation was 1.2±0.2 times in group I and 1.1±0.1 times in group II,P=0.6451.The average time of endotracheal intubation was 29.5±2.3s in group I and 15.8±1.2s in group II,P=0.0192.The incidence of tachycardia(HR>100 times/min)was 6.6% in group I and 3.3% in group II,P=0.1246.The incidence of increased blood pressure(20% higher than the basic blood pressure)during intubation was 10.0% in group I and 6.7% in group II,P=0.2541.The incidence of oxygen saturation decrease(SPO2<90%)during intubation was 13.3% in group I and 6.7% in group II,P=0.0412.The incidence of epistaxis was 16.7% in group I and 6.7% in group II,P=0.0224.The incidence of postoperative pharyngeal pain was 6.7% in group I and 3.3% in group II,P=0.2203.The incidence of postoperative hoarseness was 0 in both groups.The incidence of postoperative adverse memory was 6.7% in group I.Group II was 3.3%,P=0.1652.2.Fiberoptic bronchoscope intubation time and times: total average intubation time: students in group A were 85.7±3.4s,students in group B were 61.8±2.2s,P=0.0114;The total average intubation times of students in the two groups were 2.7±0.2 times in group A and 2.1±0.5 times in group B,P=0.0414.The success rate of first endotracheal intubation was 34.0% in group A and 58.0% in group B,P=0.0219.Tachycardia incidence: 14.0% in group A,10.0% in group B,P=0.2138;The incidence of increased blood pressure was 14.0% in group A and 12.0% in group B,P=0.5487.The incidence of oxygen saturation decrease during endotracheal intubation was 8.0% in group A and 2.0% in group B,P=0.0492.The incidence of epistaxis was 16.0% in group A and 8.0% in group B,P=0.0389.The incidence of postoperative pharyngeal pain was 6.0% in group A and 4.0% in group B,P=0.6632.The incidence of postoperative hoarseness was 0 in both groups.The incidence of postoperative adverse memory was 2.0% in group A and 2.0% in group B.Compared with the students in group A,the learning curve of resident physicians in group B decreased rapidly and reached A flat stage in A relatively short time.CONCLUSIONS Transnasal endotracheal intubation with a preset endexpiratory carbon dioxide monitor can shorten the intubation time,improve the success rate of endotracheal intubation,reduce the incidence of epistaxis and oxygen saturation decrease(SPO2<90%),and improve the efficiency of endotracheal intubation while ensuring the safety of patients.Compared with the traditional fiberoptic bronchoscopy teaching,the scheduled position of the end-expiratory carbon dioxide monitor is conducive to the learning and application of resident doctors.It has high application and promotion value in the standardized training of anesthesiology residents.