The Protective Effect Of Combined Protective Mechanical Ventilation With Sildenafil Strategy In Infants With Acute Lung Injury After Cardiopulmonary Bypass

Objective: To explore the effects of combined protective mechanical ventilation and sildenafil on lung protection in infants and young children with acute lung injury after cardiopulmonary bypass(CPB).Methods: Thirty patients with congenital heart defect suffered from acute lung injury after CPB were randomly allocated into 3 groups. Conventional mechanical ventilation strategy (positive end expiratory pressure 2~4cmH2O,tidal volume 10~15ml/kg,respiratory frequency20~30/min) was used in 10 patients (the conventional group ). Protective mechanical ventilation (positive end expiratory pressure 8-12cmH2O ,tidal volume 6~8ml/kg,respiratory frequency25~40/min) was used in other 10 patients (the protective group ). Combined protective mechanical ventilation (positive end expiratory pressure 8-12cmH2O,tidal volume 6~8ml/kg,respiratory frequency25~40/min) with sildenafil(0.5-1 mg/kg.t,bid )strategy was used in another 10 patients ( the study group). Clinical parameters included ventilator-assisted ventilation time, intensive care time and post-operative hospitalization time etcetera were recorded . At the same time, blood samples within 48 hours were collected to measure the plasma levels of IL-6,TNF-α, and oxygenation index(OI) .Results: The ventilator-assisted ventilation time, intensive care time and post-operative hospitalization time between the protective group and the study group were no significant difference (P> 0.05), but were lower than the conventional group and there were statistical significance (P <0.05). The levels of OI ,IL-6 and TNF-αdeclined gradually within 48 hours,the decline of the protective group and the study group were more sooner and more pronounced than the conventional group(P <0.05). The levels of IL-6 and TNF-αwere no significant difference between the protective group with the study group,but the decline of OI was more sooner and more significant in the study group(P <0.05).Conclusions: Combined protective mechanical ventilation with sildenafil is more conducive to the lung protection in infants with acute lung injury after cardiopulmonary bypass.