The protective role of hypothermic protective solution during surgey for the tetralogy of Fallot

Abstract

Objective The incidence of acute pulmonary injury occurred after cardiopulmonary bypass for fallot tetrad has been high. The severity of pulmonary ischemia-reperfusion has been found to be reduced with ulinastatin (UTI) in the animal models and clinical practice. We evaluated the effect of pulmonary artery perfusion with a hypothermic protective solution containing ulinastatin on the inflammatory response in the lung during cardiopulmonary bypass. Methods 30 children with tetralogy of Fallot (TOF) were randomly assigned into control group and protective group, 15 cases in each group. Patients would be excluded if they had signs of infections, such as the white blood cell count was over 12000 per microliter, the temperature was above 38 centi-degree and the c-reaction protein was more than 8 mg/L. Operation with routine approaches was performed in the control group and the pulmonary artery was infused with 4℃ protective solution in the protective group while the heart stoped beating. Plasma tumor necrosis factor α (TNF-α) 、CD11b and Myeloperoxidase (MPO) were measured intraoperatively and postoperatively. Blood gas、pulmonary function and clinic index of the patients were also monitored. Results The level of TNF-α was lower in the protective group as compared with that in the control group immediately and 3 hours after closing the sternum [(11.15±2.47) pg/ml vs. (14.21 ±5.55) pg/ml, P<0.05; (12.01 ±2.69) pg/ml vs. (15.94 ±4.86)pg/ml,P <0.01]. The MFI of CD11b was lower in the protective group as compared with that in the control group at 3 and 6 hoursafter closing the sternum (126.23±36.05 vs. 156.98±48.34, P<0.05; 137.27±38.85 vs. 173.27±67.43, P<0.05). The level of MPO was lower in protective group as compared with that in the control group at 3 hours, 6 hours and 24hours after closing the sternum [(156.52±17.57)U/L vs.(178.45±35.68)U/L, P<0.05; (178.28±23.63) U/L vs.(224.66±49.66)U/L, P<0.01;(130.52±57.50)U/L vs. (96.50±14.49)U/L, P<0.05]. The duration of mechanical ventilation was significantly shorter in the protective group than that in the control group (17.60±6.39 vs. 23.70±8.51,P<0.05). Alveolar-arterial oxygen pressure difference (A-aDO2, calculated as [FiO2×713-5/4×PaCO2]-PaO2) in the protective group was less than that in the control group at 3 and 6 hours after closing the sternum [(120.92±33.08)mm Hg vs. (145.52±39.38)mmHg, P<0.05;(74.76±40.16)mm Hg vs. (112.50±44.16)mmHg, P<0.01]. Dynamic compliance (Cdyn) in protective group was lower than that in control group at 3 and 6 hours after closing the sternum [(0.59±0.11)ml·cmH2O-1·kg-1 vs. (0.46±0.17)ml·cmH2O-1·kg-1, P<0.05;(0.67±0.09)ml·cmH2O-1·kg-1vs. (0.53±0.18)ml·cmH2O-1·kg-1,P<0.05). Conclusion Perfusion with hypothermic protective solution containing UTI to the pulmonary artery during cardiopulmonary bypass may reduce the inflammatory responses substantially in the lung after bypass and had a role in the lung protection. Key words: Tetralogy of Fallot; Cardiopulmonary bypass; Lung; Reperfusion injury; Perfusion, regional; Ulinastatin