Tolazoline therapy for persistent pulmonary hypertension after congenital diaphragmatic hernia repair

To determine whether vasodilators are useful in persistent pulmonary hypertension associated with congenital diaphragmatic hernia, we reviewed the clinical course, laboratory data, and outcome of 37 patients with respiratory distress and diaphragmatic hernia requiring an operation before 24 hours of life. These patients were divided into two groups, Group I (n = 17) included patients treated prior to the use of tolazoline; Group II (n = 20) included those treated after tolazoline became available. Postoperative severe respiratory distress was observed in ten patients in Group I, and all died. In Group II, 16 patients had severe postoperative respiratory distress and four survived; 12 of these 16 patients received tolazoline, including all four survivors. Treated survivors had significantly higher increase in Pao2 after a test dose of tolazoline than did nonsurvivors. A transient "honeymoon period" of adequate oxygenation correlated with good response to tolazoline, and the presence of both was predictive of survival. No patient survived with the combination of no "honeymoon period" and no response to tolazoline, whereas response to tolazoline without a honeymoon period was sometimes followed by survival. All nonsurvivors had severe lung hypoplasia at autopsy.