Effects Of Different Inspiratory Flow Rates In Pressure-controlled Ventilation On Respiratory Function And SICAM-1 In Patients With One Lung Ventilation

Objective:To study the effects of different inspiratory flow rates on respiratory function and sICAM-1 in patients undergoing one-lung ventilation?OLV?under pressure-controlled.Method:75 patients undergoing unilateral pulmonary wedge resection were randomly divided into three groups,25 in each group.They were group A?Insp Flow 30L/Min,n=25?,group B?Insp Flow 50L/Min,n=25?and group C?Insp Flow 70L/Min,n=25?.Pressure-controlled ventilation was used during the operation.The tidal volume was adjusted to 8 ml/kg during bilateral lung ventilation and 6 ml/kg during single lung ventilation.The hemodynamic indexes?HR,BP,CVP?and respiratory dynamics indexes?Ppeak,Pplat,PEEP?were recorded 5 minutes before one lung ventilation?T₀?,30 minutes after one lung ventilation?T₁?,60 minutes after one lung ventilation?T₂?,120 minutes after one lung ventilation?T₃?.Arterial blood and central venous blood were collected at each time point for blood gas analysis,ventilation function index?Cdyn,V_D/V_T?and ventilation function index?PaO₂/FiO₂,Qs/Qt?were calculated according to the formula.Meanwhile,central venous blood was collected at various time points to detect the serum concentration of sICAM-1 by ELISA.Results:There were no significant differences in PaO₂/FiO₂,Cdyn,Qs/Qt and sICAM-1 among the three groups?P>0.05?.PaCO₂,Ppeak,Pplat,PEEP,V_D/V_T and Cdyn were different among the three groups?P<0.05?,PaCO₂,Ppeak and Pplat in group C were lower than in group A and B at T₁,T₂ and T₃?P<0.05?,PaCO₂,Ppeak and Pplat in group B lower than in group A?P<0.05?.At T₁,T₂ and T₃,PEEP in group B and C was higher than that in group A?P<0.05?,and at T₃,PEEP in group C was higher than that in group B?P<0.05?.At the time of T₁,T₂ and T_3,V_D/V_T in group C was lower than that in group A?P<0.05?,V_D/V_T in group C at T₁ and T₂ was lower than that in group B?P<0.05?,and V_D/V_T in group B at T₁ and T₃ was lower than that in group A?P<0.05?.At T₁,T₂ and T₃,Cdyn in group C was higher than that in group A?P<0.05?.At the time of T₂ and T₃,Cdyn in group C was higher than that in group B?P<0.05?.Intra-group comparison:PaCO₂,Ppeak,Pplat,PEEP,V_D/V_T,Qs/Qt and sICAM-1 were significantly different among the three groups?P<0.05?,and increased after one-lung ventilation compared with two-lung ventilation;PaO₂/FiO₂,Cdyn were significantly different among the three groups?P<0.05?,and decreased after one-lung ventilation compared with two-lung ventilation.Conclusions:In pressure-controlled one-lung ventilation,properly increasing inspiratory velocity can reduce airway pressure and promote more effective gas diffusion,reduce dead space rate,improve lung dynamic compliance,and do not increase inflammatory lung injury.