In patients with atrial septal defect in whom pulmonary hypertension could develop as a consequence of left-to-right shunt, the extent of neutrophil-mediated lung injury induced by cardiopulmonary bypass (CPB) is related to the degree of increase in the preoperative pulmonary artery pressure. In the present study, we investigated the relationship between levels of granulocyte elastase (GEL) after CPB and preoperative pulmonary hemodynamics or changes in pulmonary function after the operation in patients with mitral valve disease, in whom pulmonary hypertension could develop as a result of pulmonary venous congestion. The plasma levels of GEL were measured before and after CPB in patients who underwent mitral valve replacement. Respiratory index (RI) was evaluated preoperatively and postoperatively. Preoperative pulmonary hemodynamics were determined within one month of the operation. Granulocyte elastase level rose significantly after CPB from baseline (134.3 +/- 44.6 mg/L versus 2042.1 +/- 1215.0 mg/L; p <0.001). Peak level of GEL was significantly correlated with preoperative systolic pulmonary artery pressure (r = 0.71; p = 0.020), mean pulmonary artery pressure (r = 0.64; p = 0.046), pulmonary capillary wedge pressure (r = 0.68; p = 0.032), and pulmonary-to-systemic arterial pressure ratio (r = 0.64; p = 0.045), but not with the hemodynamic variables for pulmonary blood flow or pulmonary resistance. Moreover, the value of (Postoperative RI - Preoperative RI)/Preoperative RI was positively correlated with the peak level of GEL (r = 0.76; p = 0.011). In conclusion, in patients with mitral valvular disease, as in those with atrial septal defect, the increase in GEL level after CPB is proportional to the increase in preoperative pulmonary artery pressure, which may cause the accordant pulmonary vascular damage.
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