The influence of small tidal volume combined with low level of positive end expiratory pressure for respiratory function of aged patients who underwent laparoscopic radical gastrectomy under general anesthesia

Objective:To investigate the influence of small tidal volume combined with low level of positive end expiratory pressure(PEEP)for respiratory function of aged patients who underwent laparoscopic radical gastrectomy under general anesthesia.Methods:Thirty-four aged patients in ASA I or II who were performed laparoscopic radical gastrectomy were divided into two groups.The mechanical ventilation of group A was intermittent positive pressure ventilation(IPPV)plus 5cm H2O PEEP,tidal volume(VT)=6ml/kg,frequency(f)=16bpm.The mechanical ventilation of group B was IPPV,tidal volume(VT)=9ml/kg,f=12bpm.The PaO2,PaCO2,PETCO2,A-aDO2,mean arterial pressure(MAP)and central venous pressure(CVP)were observed at the time points of before operation(T1),30min after tracheal intubation(T2)and 15min after tracheal extubation(T3).Peak airway pressure(Ppeak)was recorded during operations.Results:In T3,PaO2 of group A was significantly higher than that of group B(P0.05),A-aDO2 of group A was significantly lower than that of group B(P0.05).In other time points,the difference of PaO2,PaCO2,PETCO2,A-aDO2,MAP,CVP and Ppeak between two groups was not significant(P0.05).Conclusions:Small tidal volume combined with low level of PEEP in laparoscopic radical gastrectomy can improve the postoperative hyoxemia of old patients and decrease complications of lung.It is beneficial to recovery of respiratory function,and doesn't affect hemodynamics obviously.It is a safe and effective method of ventilation for aged patients who will accept laparoscopic upper abdominal surgery under general anesthesia.