Efficacy of left parapharyngeal pressure combined with cricoid pressure in preventing gastric insufflation during positive pressure ventilation by facemask / 中华麻醉学杂志

Objective:To compare the efficacy of left parapharyngeal pressure (PLP) combined with cricoid pressure in preventing gastric insufflation during positive pressure ventilation by facemask.Methods:Two hundred and forty patients of both sexes, aged 18-75 yr, of American Society of Anesthesiologists physical status Ⅰ or Ⅱ, undergoing surgery under general anesthesia requiring endotracheal intubation, were selected and randomly divided into 4 groups ( n=60 each) using a random number table method: cricoid pressure group (group CP), left PLP group (group LP), cricoid pressure combined with left PLP7 group (group CP+ LP), and control group (group C). The gastric antrum cross-sectional area (CSA) was measured by ultrasound in all the patients before induction of anesthesia, and facemask ventilation in pressure-controlled mode with suction pressure of 25 cmH 2O was applied, the patients in 4 groups were treated with different manipulations, and 3 min later the CSA of gastric antrum was measured again.The gastric antrum CSA before and after ventilation and the difference were recorded.The occurrence of gastric insufflation was examined by ultrasound after ventilation. Results:Compared with the baseline before ventilation, the CSA of gastric antrum was increased after ventilation in C, CP and LP groups ( P<0.01), and no significant change was found in the CSA after ventilation in CP+ LP group ( P>0.05). The difference of gastric antrum CSA was decreased in turn in C, CP, LP and CP+ LP groups ( P<0.05 or 0.01). The incidence of gastric insufflation were 53%, 30%, 12% and 0 in C, CP, LP and CP+ LP groups, respectively.Compared with group C, the incidence of gastric insufflation was significantly decreased in LP and CP+ LP groups ( P<0.05), and no significant change was found in group CP ( P>0.05). Compared with group CP, the incidence of gastric insufflation was significantly decreased in group CP+ LP ( P<0.05), and no significant change was found in group LP ( P>0.05). Conclusion:The combination of left PLP and cricoid pressure can effectively prevent gastric insufflation during positive pressure ventilation by facemask.

Effect of laryngeal mask and endotracheal tube ventilation on gastric insufflation during general anesthesia with ultrasound evaluation / 上海交通大学学报（医学版）

Objective • To observe the correlation between streamlined liner of pharynx airway (SLIPA) and gastric insufflation. Methods • Seventy patients who underwent elective general anesthesia in Jiading District Central Hospital Affiliated to Shanghai University of Medicine & Health Sciences from September 2017 to May 2018 were included. They were randomly divided into SLIPA group (S group, n=35) and endotracheal tube group (T group, n=35). The gastric antrum ultrasonography was performed at four time points before induction, immediately after intubation (insertion of laryngeal mask), before extubation (laryngeal mask), and immediately after extubation (laryngeal mask), to measure the cross sectional area (CSA) of gastric insufflation. Gastric intake was assessed by ultrasonic measurement of CSA and "comet tail sign" in ultrasound imaging. Pulse oxygen saturation (SpO2), end-tidal pressure of carbon dioxide (PETCO2), peak inspiratory pressure (PIP) and CSA were recorded and compared at the corresponding time points. Results • There was no significant difference in gastric insufflation rate between the two groups during anesthesia (P=0.894). There was no significant difference in SpO2 at each time point between the two groups (all P>0.05). At the end of surgery, PETCO2 in group S was significantly higher than that in group T (P=0.000). Conclusion • Compared with endotracheal tube, the SLIPA does not increase gastric insufflation during general anesthesia.

Ultrasound assessment of gastric insufflation in obese patients receiving transnasal humidified rapid-insufflation ventilatory exchange during general anesthesia induction / 南方医科大学学报

OBJECTIVE@#To assess the effect of transnasal humidified rapid-insufflation ventilatory exchange (THRIVE) on gastric insufflation during general anesthesia induction in obese patients.@*METHODS@#Ninety obese patients (BMI 30-39.9 kg/m@*RESULTS@#The incidence of gastric insufflation was significantly higher in Group M and Group M+T than in Group T (@*CONCLUSIONS@#Ultrasound monitoring of the comet tail sign and the changes of CSA-GA in the gastric antrum is feasible and reliable for detecting gastrointestinal airflow, and in obese patients, the application of THRIVE for induction of anesthesia can ensure the oxygenation level without further increasing gastric insufflation.

Comparison of the changes of antrum and fundus cross‐sectional area measured by bedside ultrasonography on gastric insufflation during general anesthesia in non‐obese women / 中华超声影像学杂志

Objective To compare the changes of antrum and fundus cross‐sectional area ( CSA ) measured by bedside ultrasonography on gastric insufflation during anesthesia induction in non‐obese female patients and analyze the relationships between these changes as well as postoperative nausea and vomiting ( PONV ) . Methods Fourty‐six patients scheduled for elective gynecological laparoscopic operations were enrolled in the study . T he patients w ho appeared the comet‐tail artifacts were defined as gastric insufflation positive group( GI+ group) ,w hile the ones without comet‐tail artifacts were defined as gastric insufflation negative group( GI‐ group) . Blood oxygen saturation ( SPO 2 ) ,end‐expiratory partial pressure of CO 2 ( PET CO2 ) ,tidal volume( T V ) were recorded after 180 seconds ventilation in both groups . T he longitudinal and anteroposterior diameters of gastric antrum and fundus were measured before and after facemask ventilation respectively and the corresponding CSA were calculated . T he cutoff values of prediction of gastric insufflation were determined according to the ROC curve and the corresponding sensitivity and specificity were calculated . PONV of the two groups were also recorded . Results T he analysis was based on the remaining 41 data sets actually . T here were 13 patients in GI‐group and 28 ones in GI+ group . Compared with GI‐group ,the changes of T V and fundus CSA in GI+ group had significantly differences( P ＜0 .05) ; w hile compared with before mask ventilation ,the changes of antrum and fundus CSA in both groups had significantly differences ( P ＜0 .05).T he areas of antrum and fundus CSA under the ROC curve (95% CI) were 0 .67 and 0 .80 ,with cut‐off value 3 .19 cm2 and 24 .90 cm2 ,sensitivity 0 .93 and 0 .93 and specificity 0 .39 and 0 .69 ,respectively .T he incidence of PONV in GI+ group was higher than that in GI‐group( P ＜0 .05). Conclusions Changes of fundus CSA by ultrasonography might be superior to antrum CSA in gastric insufflation caused by 20 cm H2 O peak airway pressure of facemask ventilation during anesthesia induction . Gastric insufflation caused by positive pressure ventilation is related with PONV for young female patients undergoing gynecological laparoscopic operation .