The Effects Of Low Tidal Vlume Ventilation With Different PEEP On The Patients Udergoing Elective Gastrointestinal Surgery

ObjectiveA large number of studies have investigated the different effects on patients or animals between the low tidal volume ventilation and the conventional tidal volume ventilation,while the studies about the effects of the low tidal volume ventilation with different PEEP on patients without Preexisting Lung Injury are sparse.Therefore,we investigated the functional and structural effects of low tidal volume ventilation with different PEEP on patients without Preexisting Lung Injury.MethodThirty patients udergoing elective gastrointestinal surgery were randomly divided into 3 groups:Group L1 (Low tidal volume ventilation without PEEP VT=8ml/kg, with the respiratory frequency(f) 12times/min), Group L2 (low tidal volume ventilation with 5cmH2o PEEP, VT=8ml/kg,f=12 times/min),and Group L3 (low tidal volume ventilation with 10cmH2o PEEP, VT=8ml/kg,f=12 times/min). After intubation all patients were mechanically ventilated with IPPV model, and the PETC02 was kept on 35±5mmHg by adjusting respiratory frequency during ventilation.The ventilation time should be controlled in 3-5h.Respiratory parameters, airway parameters and the blood gas analysis should be measured continuously until the first hour after extubation. Blood samples were colleted from peripheral artery at different time points including before induced,3 hours after ventilation,1 hour after extubation and 24 hours after operation. The serums were stored in refrigerator at-70℃and the IL-8 and SP-D in the serums were quantified by ELISA.Result1.There were no significant differences in general conditions and postoperation conditions among the groups. While the A-aDo2 of Group L3 was less than other GroupS after 2 hours ventilation(P<0.05).2.We did not find any significant differences in serum IL-8 level among GroupS,but the serum IL-8 level at afer 3h ventilation is higher than before induced in Group L1 and Group L3 (P<0.05).The SP-D of Group L1 and L2 were higher than Group L3 at 24 hours after operation(P<0.05).Besides, The SP-D of Group L1 and L2 at 24 hours after operation were higher than before induced,3 hours after ventilation and 1 hour after extubation(P<0.05).Conclusion1.Compared with Group L1 and L2, L3 may attenuate the SP-D releasing.2.The A-aDo2 of Group L3 was less than other Groups after 2 hours ventilation.