Effect of therapeutic hypercapnia on inflammatory response in rat lung transplantation / 中华麻醉学杂志

ABSTRACT

Objective To investigate the effect of therapeutic hypercapnia on the inflammatory response in the rat lung transplantation. Methods Male pathogen free Wistar rats weighing 300-400 g were used in this study. The animals were anesthetized with 3% pentobarbital sodium 30 mg/kg, tracheostomized and mechanically ventilated (V_T 10 ml/kg, RR 50 bpm, FiO_2 50%). Carotid artery and femoral vein were cannulated for BP monitoring, blood sampling and fluid and drug administration. Left lung transplantation was performed using modified cuff technique. Forty-eight animals in which lung transplantation was successfully performed were randomized into 2 groups ( n = 24 each) model group (M) and hypercapnia group (H) . In group H, PaCO_2 was maintained at 80-100 mm Hg by inhalation of CO_2.Arterial blood samples were obtained before lung transplantation (To , baseline) and at 1, 2, 4 h (T_(1-3)) of reperfusion for determination of blood TNF-α, IL-1 and IL-8 concentrations. The animals were then killed and the transplanted lungs were removed for microscopic examination and calculation of wet/dry lung weight ratio. Results The MAP and PaO_2 were significantly higher in group H than in group M. The blood IL-8 and TNF-α concentrations were significantly lower at T_(1-3) in group H than in group M, but there was no significant difference in blood IL-1 concentration between the 2 groups. The elastase content in the lung tissue was significantly lower at T_2 and T_3 in group H than in group M. Microscopic examination showed that the alveolar hemorrhage, the infiltration of the lung by macrophages and neutrophils and lung edema were significantly less in group H than in group M. Conclusion Therapeutic hypercapnia can obviously inhibit the inflammatory response in the rat lung transplantation.