[Risk factors for pulmonary hypertensive crisis (PHC) following VSD repair in infants].

We examined 100 patients who had undergone VSD repair from 1988 to 1991 to determine the risk factors to induce PHC postoperatively. We analyzed age, weight, preoperative Pp/Ps, Rp/Rs, Qp/Qs, and postoperative Pp/Ps using discriminant analysis. We had 34 cases of pulmonary hypertension (PH: Pp/Ps > 0.7) preoperatively. Among 100 cases, PHC developed in 6 patients and 2 of them died postoperatively. Incidence of PHC in all patients was 6%, and that in patients with PH was 18%. PHC fatality rate was 33%. The analysis revealed that the occurrence of PHC was significantly higher among those whose ages were below 2.1 years, and with weight of under 9.85 kg, preoperative Pp/Ps > 0.73, Rp/Rs < 0.34, and postoperative Pp/Ps > 0.43. In those with preoperative PH, the risk for PHC increased significantly when their postoperative Pp/Ps exceeded 0.44.