Clinical Study On Feasibility Of Three Supraglotic Ventilation Modes In Comfort FOB

Objective（s）:In recent years,flexible bronchoscopy（FOB）has become an important means of diagnosis and treatment for some respiratory diseases such as airway,lung and mediastinum.However,this invasive operation is highly stimulating and patients are prone to nervousness and fear.Patients may have serious respiratory reactions and violent body movements during the operation,which seriously affects FOB operation.There are even cardiovascular and cerebrovascular accidents.With the continuous development of the concept of comfort medicine,more and more anesthesiologists apply painless technology in the diagnosis and treatment of FOB.However,in the painless technique,the inhibitory effect of sedative/analgesic drugs on respiration and the sharing of airway with endoscopic physicians make it difficult to manage comfort FOB,which requires both appropriate sedation depth and airway safety.Among them,the choice of ventilation tools is an important factor affecting respiratory management.In this study,patients who received comfort FOB in the daytime operating room of our hospital from March 2022 to December 2022 were selected to compare the feasibility of three different supraglotic ventilation modes of KHC mask,endoscopic mask and modified non-inflatable laryngeal mask in comfort FOB diagnosis and treatment.Methods:360 patients who performed comfort FOB in the daytime operating room of our hospital were randomly divided into three groups:KHC mask（group K）,endoscopic mask（group M）,and non-inflatable laryngeal mask（group L）,with 120 patients in each group（n=120）.The three groups received total intravenous anesthesia with propofol combined with sufentanil and retained spontaneous respiration combined with hand-controlled ventilation.Group K and M received slow intravenous injection of sufentanil 0.1-0.15μg/kg,L group 0.2μg/kg;propofol was induced from 1mg/kg,and the dosage of propofol was adjusted according to BIS.Group K and group M were given oxygen inhalation with their own face masks,when BIS 60-80,FOB is performed.In group L,modified i-gel laryngeal mask was inserted at BIS 60-80 then FOB was performed.When the Sp O₂of the three groups of patients was less than 90%,group K and group M raised the mandible and manually controlled assisted breathing,and group L manually controlled assisted respiration.The percutaneous arterial oxygen saturation（Sp O₂）,heart rate（HR）,mean arterial pressure（MAP）,and bispectral index（BIS）of the patients in the three groups were recorded before induction（T1）,before induction of fiberoptic bronchoscope into the nasal cavity or oral cavity（T2）,during tracheal internal surface anesthesia（T3）,during fiberoptic bronchoscope examination（T4）,and at the end of examination（T5）;End expiratory carbon dioxide at T2 and T5(P_ETCO₂);The excellent rate of airtightness of the system at T2-T4.Record the beginning FOB time,FOB time,patient’s recovery time,sedative dosage,choking,body movement and tongue drop during the examination and other adverse events;Evaluate the satisfaction of patients and endoscopic physicians.The statistical software SPSS24.0 was used to analyze the data,in which the patient count data were described by frequency or percentage,and the differences between groups were analyzed by chi-square test;the measurement data were described by Mean±SD（（?）±s）,and the differences between groups were analyzed by multivariate analysis of variance and multiple comparisons afterwards.P<0.05 was considered to be statistically significant.Results:There was no significant difference in age,height,BMI,sex ratio,ASA classification,complications and adult PONV simplified risk score among the three groups.Main results:There was no significant difference in HR at each time point among the three groups（P>0.05）;The Sp O₂values of the three groups from T3to T5 were（99.57±1.00）,（99.50±1.02）,and（99.56±1.13）%in Group L,（98.30±2.57）,（98.12±2.51）,and（98.57±2.03）%in Group K,and（98.33±2.50）,（97.51±2.79）,and（98.45±1.87）%in Group M,respectively;The Sp O₂of group K at T4 was higher than that of group M（P<0.05）.The MAP values from T2 to T5 in the three groups were（80.92±15.01）,（97.28±14.94）,（89.02±15.17）,（88.68±15.20）mm Hg in group K,（82.09±18.87）,（98.75±18.60）,（91.53±15.04）,（89.10±14.77）mm Hg in group M,and（75.90±14.58）,（83.15±6.32）,（78.39±14.99）,（81.35±15.26）mm Hg in group L,respectively（P<0.05）.There was no significant difference in MAP between group K and group M（P>0.05）.The BIS values of patients in group K,M and L at T4 were（68.05±4.63）,（69.32±4.90）and（66.27±4.23）respectively,and the BIS values in group L were significantly lower than those in the other two groups（P<0.05）.There was no significant difference in P_ETCO₂among the three groups at T2（P>0.05）.Compared with the same group,The P_ETCO₂at T5 was significantly higher than that at T2 in the same group（P<0.05）.At T5,P_ETCO₂in K group（38.88±9.54mm Hg）and M group（39.64±8.67mm Hg）was significantly higher than that in L group（36.66±8.20mm Hg）（P<0.05）.There was no significant difference in P_ETCO₂between K group and M group,but they were still at the normal level.All patients in group M could not achieve airway tightness during examination.The excellent and good rate of airway tightness in T3 and T4 was significantly lower than that in group K（95.8%,95.8%）and group L（94.2%,89.7%）（P<0.05）.There was no significant difference in FOB time among the three groups（P>0.05）.The onset time of FOB（2.36±0.25min）and recovery time（2.46±3.74min）in group L were significantly longer than those in group K（1.17±0.14min,0.63±1.70min）and group M（1.18±0.15min,0.82±1.32min）（P<0.05）.The dosage of propofol in group L（1.96±0.51 mg/kg）was also significantly higher than that in group K（1.71±0.35 mg/kg）and group M（1.72±0.40 mg/kg）（P<0.05）;There was no significant difference in FOB start time,recovery time and propofol dosage between group K and group M（P>0.05）.The number of cases with cough in T3 and the score of cough in L group were 90（75.0%）,（1.93±1.43）,which were significantly lower than those in K group 116（96.7%）,（2.67±1.01）and M group 117（97.5%）,（2.87±1.03）（P<0.05）.There was no significant difference in cough and the amount of lidocaine used for topical anesthesia among T4 groups（P>0.05）.No tongue drop occurred in group L,but 28 cases（23.3%）in group K,24 cases（20.0%）in group M were significantly higher than that in group L（P<0.05）.During the whole examination,Sp O₂≤90%occurred in 22 cases（18.3%）in group K,35 cases（29.1%）in group M,which was significantly higher than that in3 cases（2.5%）in group L（P<0.05）,while that in group K was significantly lower than that in group M（P<0.05）.In group L,36 cases（30.0%）had hypotension（MAP was more than 20%lower than the base value）,which was significantly higher than that in group K 17 cases（14.1%）and M（16 cases（13.3%）,respectively）（P<0.05）.Secondary results:After the examination,there were 42 cases（35%）of pharyngeal discomfort,14 cases（11.7%）of odynophagia and 7 cases（5.8%）of vomiting in group L,which were higher than those in group K 18 cases（15.0%）,1case（0.8%）,0 case（0.0%）and group M 26 cases（21.7%）,0 case（0.0%）,0 case（0.0%）（P<0.05）.There was no significant difference between group K and group M（P>0.05）;The incidence of nasal discomfort in 11 cases（9.2%）of group M was higher than that in 2 cases（1.7%）of group L（P<0.05）,and there was no significant difference compared with group K（P>0.05）;The incidence of postoperative cough in10 cases（8.3%）of group K was less than that in 28 cases（23.3%）of group M and 32cases（26.7%）of group L（P<0.05）.After examination,the NRS score of odynophagia in group K（0.07±0.39 points）and group M（0.18±0.84 points）was lower than that in group L（0.51±1.42 points）（P<0.05）,and there was no significant difference between group K and group M（P>0.05）.The patient satisfaction of group K（4.54±0.61 points）was higher than that of group L（4.34±0.70 points）（P<0.05）,and there was no significant difference compared with group M（P>0.05）;There was no significant difference between group K（4.91±0.29 points）and group L（4.92±0.28 points）in endoscopic surgeon’s satisfaction with operation（P>0.05）,but it was significantly higher than group M（4.63±0.56 points）（P<0.05）.Conclusion（s）:KHC mask and first-generation endoscopic mask ventilation can satisfy the oxygen supply of comfort FOB for a short time.Modified non-inflatable laryngeal mask can provide the best oxygenation for comfort FOB and endoscopic physicians have high satisfaction with operation.Comfort FOB requires anesthesiologists and endoscopists to choose the most appropriate supraglottic ventilation according to the individual conditions of patients.If the airway operation is complex,it takes a long time,and there are many high risk factors for patients,KHC mask and non-inflatable laryngeal mask can be selected for ventilation;patients with good general condition,short examination time and skilled endoscopic physicians can also choose KHC mask and first-generation endoscopic mask for ventilation.