Clinical Observation Of The Effect Of Low Tidal Volume Combined With Lung Recruitment On Patients With Prone Position During General Anesthesia.

Objective:By the analysis of different mechanical ventilation modes of patients with prone position,to observe the effect of low tidal volume combined with lung recruitment on respiratory and circulatory system and prognosis,in order to find a most safe and effective way to reduce postoperative complications.Method:90 patients undergoing spinal surgery in prone position,male 57 cases,female 33 cases,who aged 30-65 yrs,BIM 20-28kg/m2,ASA class I-II,were randomly divided into three groups.After cinventional induce and intubation,set the parameters of ventilation mechanical ventilation:the concentration of inhaled oxygen(FiO2)was 1.0,the oxygen flow rate was 2L/min,the ratio of suction to aspiration is 1:2,Group A:Vt=6ml/kg,frequency(f)=14-18 breaths/min,every 2 hours for once lung recruitment;group B:Vt=6ml/kg,frequency(f)=14-18 breaths/min;group C:Vt=9ml/kg,frequency(f)=10-12 breaths/min.arterial partial pressure of carbon dioxide(PaCO2),arterial oxygen pressure(PaO2),the oxygenation index(PaO2/FiO2),mean arterial pressure(MAP),heart rate(HR)were recorded at the time before intubation(T1),prone position after 30 minutes(T2),prone position after 2 hours(T3);30 min after extubation(T4);The Peak index(Ppeak),end tidal carbon dioxide partial pressure(PETCO2)were recorded at T2,T3;postoperative pulmonary complications index within 48 hours after operation(T5).Results:At the time point of T1-T4,PaO2、PaO2/FiO2 in three groups had no difference(P>0.05);At the time point of T2-T3,Ppeak in group C was much higher than that in group A(P<0.05);MAP and HR had no difference in three groups(P>0.05);At the time point of T2-T3,three groups had no difference between PaCO2(P>0.05);The incidence rate of atelectasis in A group was 0,group B was 13.3%,group C was 10%;the incidence rate of pneumonia in group A was 0,group B and C was 3.3%;The PPCs:A group 0,group B was 16.6%,group C was 13.3%(P<0.05).Conclusions:1.Ventilation in the prone position under general anesthesia:low tidal volume with RM and conventional tidal volume and low tidal volume alone can maintain oxygenation,has no obvious effect on lung function during the operation;2.low tidal volume combined with RM can significantly reduce the postoperative pulmonary complications;3.low tidal volume combined with RM does not significantly affect the hemodynamics during operation.