The Evaluation Of The Relationship Between Intragastric Intake And Positive Pressure Ventilation During Anesthesia Induction By Real-time Ultrasound

Objective:During anesthesia induction of systemic positive pressure ventilation,The area of the gastric antrum and the bottom of stomach was measured by ultrasonography,To evaluate the relationship between intake of stomach and positive pressure ventilation;To find a positive pressure ventilation value that can guarantee enough blood oxygen saturation and minimize the intake of the stomach?Methods:We selected 120 patients undergoing elective gynaecological anesthesia in our hospital with an average age of 43.67±9.4 years and a body mass index of 18-30 kg/m2.Patients were randomly divided into positive pressure ventilation groups of 10 cm water column?P10?in 37 patients and 15cm water column group.?P15?35 cases,48 cases of 20 cm water column?P20?.All patients received an intravenous injection of midazolam 0.06 mg/kg and long toning 1 mg before induction of anesthesia.20 mg of muscle relaxant were given during anesthesia induction.The antrum data were measured before and after induction of anesthesia in 120patients by a sonician.Fifty-two patients underwent gastric fundus measurements at the same time and recorded relevant data,which were analyzed in combination with positive pressure ventilation values.Result:1.The gastric antrum and gastric fundus data of all patients before and after ventilation were tested for homogeneity and homogeneity of variance?P>0.05?,which was in accordance with normal distribution and variance.All patients were statistically analyzed for age,height,and weight?P>0.05?,and the difference was not statistically significant.2.The total display rate of gastric antrum was 85.0%?102/120?,among which P10 was 83.8%?31/37?,P15 was 91.4%?32/35?,and P20 was 81.3%?39/48?.The total gastric display rate was 76.9%?40/52?,with 81.8%?9/11?in the P10 group,85.7%?12/14?in the P15 group,and 70.3%?19/27?in the P20group.There was no significant difference in gastric antrum and fundus display rate under different positive pressure ventilation?P>0.05?.Under the same positive pressure ventilation value,there was no significant difference in the rate of gastric antrum and fundus display.3.There was no significant difference in gastric antral area changes between different positive pressure ventilation values.It was suggested that there was no significant difference in gastric antrum area before and after ventilation with changes in pressure values.4.Multiple comparisons of changes in gastric fundus area between different positive pressure ventilation values showed that significant air intake was observed in the stomach when airway pressure was 20 cm water column,and there was no significant difference between P10 and P15 groups;SP02was shown in groups P10 and P15.The difference was statistically significant?P=0.008<0.05?.There was no statistically significant difference between P15and P20.It was concluded that when the positive pressure ventilation value was controlled at 15 cm H₂O,the patient's oxygen saturation and intragastric elevation The air volume is the best.Conclusion:SP0₂ can ensure better oxygen saturation of patients in 15cm water column.There is a significant difference in air volume between the stomach and the air before and after different positive pressure ventilation?P<0.05?.The air intake is significant at 20cm water column.Positive pressure ventilation was controlled at 15cm water column.Under this condition,sufficient blood oxygen saturation was ensured,and the amount of gas in the stomach was minimized.