Use Of Tolazoline In Infants With Severe Hypoxemia Associated With Pulmonary-Disease

Following our initial report regarding the use of tolazoline in infants with persistent pulmonary hypertension, we have reviewed our subsequent experience with this drug in patients with hyaline membrane disease (HMD) and meconium aspiration syndrome (MAS) who had severe hypoxemia unresponsive to usual therapy. From 10/74-10/77 we infused tolazoline to infants on assisted ventilation when their PaO2 fell below 50 torr while in an FiO2 of 1.0 and requiring peak inspiratory pressures of > 40 cm H2O. A bolus of 1-2 mg/kg was given via scalp vein, followed by 1-2 mg/kg/hr to a maximum of 10 mg/kg/hr. Five of 15 patients with HMD who met this criteria survived, with only one survivor weighing < 1500 gm. Overall survival in infants with HMD was 71%. Seven of 15 infants with MAS survived compared to an overall survival of 82% with MAS. Following tolazoline the initial increase in PaO2 was greater in surviving infants of both groups, but hypotension developed more commonly in infants with HMD. Poor prognostic signs following colazoline include: poor response of PaO2, development of hypotension and requirements for concentrations of tolazoline greater than 2 mg/kg/hr.