Effect Of Different Mechanical Ventilation Modes On Patients With Laparoscopic Surgery For Laryngeal Mask

Objectiv:The effects of VP group with neap volumetrically controlled ventilation combined with positive end-expiratory pressure and PP group with pressure controlled ventilation(PCV)under pneumoperitoneum on respiratory parameters and hemodynamics during general anesthesia in elderly patients were compared to find a more suitable intraoperative ventilation mode for laparoscopic cholecystectomy in elderly patients.Methods:According to the inclusion criteria and exclusion criteria,100 patients from the affiliated hospital of Inner Mongolia university for nationalities were selected.Patients aged 65-80 years with ASA grade Ⅰ-Ⅱ elective general anesthesia.After entering the room,the patient was put into the supine position,the upper limb vein access was established,the multifunctional monitor(ecg,body temperature,non-invasive blood pressure monitor,pulse oxygen saturation),the surgical plethysmography index(SPI),the entropy index,etc.,and the laryngeal mask was inserted after anesthesia induction.The fresh gas flow rate of the two groups and the anesthesia machine was 2 L/min and the inhalation oxygen concentration(FiO2)was 60%.Before artificial pneumoperitoneum,the ventilation mode of VCV was adopted,tidal volume(Vt)was 8 ml/kg,RR was 12 times/min,and I:E was 1:2.After the establishment of CO2 pneumoperitoneum,VP group(VCV+PEEP):Vt=6ml/kg,PEEP=5cm H2O;PP(PCV+PEEP)group:the ventilation mode of the PCV group was set and 5cm H2O PEEP was added.The two groups maintained PETCO2 at 35～45 mmHg by adjusting respiratory parameters.In the house after 5 min(T0),in 5 min VCV after laryngeal mask airway(T1),after establishing artificial pneumoperitoneum(immediate)(T2),30 min after establishing artificial pneumoperitoneum(T3),10 min after pneumoperitoneum(T4),monitoring in patients with systolic pressure,diastolic blood pressure,heart rate,SP02,records of two groups of different time T1-T4 Vt,RR,PETCO2,Pplat,Ppeak and Cdyn,on T1,T3,T4 blood collection and radial artery blood gas analysis,Oxygen partial pressure(PaO2)and carbon dioxide partial pressure(PaCO2)were monitored,and oxygenation index(01),respiratory index(RI),alveolar oxygen partial pressure difference(pa-ado2)and lung blood fraction(Qs/Qt)were calculated according to blood gas analysis results.Results:1.(1).There was no statistical difference between the two groups in age,gender,weight,height,MBI index.ASA grade,complications,etc.(p>0.05).(2).There were no statistically significant differences in anesthesia time,operation time,pneumoperitoneal time,blood loss and urine volume between the two groups(p>0.05).There was no statistical difference between the two groups.2.Inter-group comparison:there was no statistical significance in the comparison of blood pressure and heart rate between the two groups(p>0.05).Intra-group comparison:compared with T0,SBP decreased in PP mode group and VP mode group at T2 and T3.DBP increased at T2(P<0.05).HR goes down at T1.3.(1).Comparison between groups:compared with the VP group,Ppeak and Pplat in the PP group decreased at t2-4(P<0.05)and Cdyn increased at t2-4(P<0.05).Comparison within the group:compared with T1,Ppeak and Pplat at T2,T3 and T4 increased in both groups(P<0.05)and Cdyn decreased in both groups(P<0.05)(2).compared with T0,VP mode group and PP mode group reduced Vt at T1,T2,T3,T4.RR increased at T1,T2,T3 and T4.PETCO2 increases at T2 and T3;Compared with VP,Vt increases in T2 and T3.RR increased at T1,T2 and T3.(P<0.05)4.Inter-group comparison:compared with the VP group,the OI value in the PP mode group increased at T1,and the difference was statistically significant(P<0.05).There was no significant difference in PaO2,pa-ado2 and QS/QT(P>0.05)Intra-group comparison:compared with T1,PaCO2 increased in both groups at T3 and T4(P<0.05),and the difference was statistically significant.Compared with T1 and T4,QS/QT increased at T3(P<0.05).5.In this study,92 patients were followed up to the 5th day after the operation,among the 46 patients in VP group,2 patients developed pulmonary infection and 1 patient developed hypoxemia after the operation.One of the 46 patients in the PP group developed hypoxemia.Although the incidence of pulmonary complications in the VP group within 5 days after surgery was higher than that in the PP group,the difference between the groups was not statistically significant(P>0.05).Conclusion:The mechanical ventilation mode of PCV combined with PEEP with small tidal volume VCV combined with PEEP has more advantages in laparoscopic cholecystectomy in elderly patients,which can better improve the intraoperative oxygenation,and obtain better respiratory and hemodynamic parameters.