Inhaled nitric oxide and intravenous magnesium sulphate for the treatment of persistent pulmonary hypertension of the newborn.

INTRODUCTION: The aim of this study was to compare the response and survival rates of term infants with persistent pulmonary hypertension of the newborn (PPHN) on high frequency oscillatory ventilation (HFOV) treated with either inhaled nitric oxide (iNO) or intravenous magnesium sulphate (MgSO4). METHODS: This was a randomised controlled study. The inclusion criteria were infants with respiratory distress, oxygen index equal to or greater than 25 despite HFOV support, and echocardiographic evidence of PPHN. Infants in the MgSO4 group (n is 13) were loaded with MgSO4 200 mg/kg infused over half an hour, followed by continuous infusion at 50-150 mg/kg/hour to attain a serum magnesium level of 5.0-7.0 mmol/L. Infants in the iNO group (n is 12) were administered nitric oxide at an initial concentration of 20 ppm. Analysis was done on an intention-to-treat basis. RESULTS: There was no significant difference in the median age when the vasodilators were commenced (MgSO4 group: 14.0 hours, interquartile range [IQR]: 7.5, 27.0; iNO group: 14.8 hours, IQR: 12.5, 35.3, p is 0.8). There was no significant difference in the proportion of infants who responded primarily to either vasodilator (MgSO4: 23.3%, iNO: 33.3%, p is 1.0) . After switching over to iNO following a failed MgSO4 therapy, a significantly higher proportion (9 out of 10) of the non-respondents in the MgSO4 group recovered from PPHN and survived compared to the non-respondents in the iNO group (1 out of 8) who switched over to intravenous MgSO4 (p is less than 0.03). CONCLUSION: Infants who were administered iNO following a failed MgSO4 therapy were associated with a better outcome than those who were administered MgSO4 following a failed iNO therapy.

Predictors of failed closure of patent ductus arteriosus with indomethacin.

INTRODUCTION: The aim of this study was to determine predictors of failed closure of patent ductus arteriosus (PDA) following a single course of indomethacin in symptomatic preterm infants. METHODS: This prospective observational study was carried out on 60 preterm infants weighing less than 1,750 g with symptomatic PDA confirmed by echocardiography. At a median age of 7.0 days (interquartile range 4.0), they were given indomethacin of 0.1 mg/kg/day intravenously daily for six days. Closure of PDA was reassessed by echocardiography upon completion of therapy. RESULTS: The PDA of 40 percent (n=24) of these infants remained patent. Forward logistic regression analysis showed that the only significant predictors of failed PDA closure in these infants were: PDA size (adjusted odds-ratio [OR] is 7.0; 95 percent confidence interval [CI] of OR is 2.0, 24.8; p-value is 0.002), birth weight (adjusted OR is 0.996; 95 percent CI of OR is 0.993, 1.000; p-value is 0.03) and platelet count (adjusted OR is 0.987; 95 percent CI is 0.975, 1.000; p-value is 0.045). Gestational age, maternal age and left atrium/aorta ratios were not significant predictors. CONCLUSION: Larger PDA, lower birth weight and lower platelet count were significant predictors of high failure in indomethacin therapy given late at one week of life.