Use of magnesium sulphate in severe persistent pulmonary hypertension of the newborn

Abstract

Persistent pulmonary hypertension in the newborn (PPHN) is a neonatal emergency due to the failure to achieve normal cardiopulmonary adaptation following delivery. A clinical trial to assess the efficacy of magnesium sulphate (MgSO4) in the treatment of PPHN was conducted in the tertiary level neonatal intensive care unit of RIPAS Hospital, Brunei Darussalam over a period of 2 years. Twelve newborn babies admitted consecutively to the neonatal intensive care unit with severe hypoxemia due to persistent pulmonary hypertension were included in this trial. A loading dose of 200 mg/kg MgSO4 was given over a period of 20 min, followed by a continuous infusion at the rate of 20-150 mg/kg/h to obtain a serum magnesium level between 3.5 and 5.5 mmol/l. No other vasodilators were used and babies were not hyperventilated. Dopamine was commenced at 5-10 microg/kg/min before the loading dose of MgSO4 was given. Mean blood pressure was maintained with short periods of dopamine alone or in combination with dobutamine. Oxygen index (OI) and alveolar-arterial oxygen gradient (A-aDO2) showed significant improvement within 24 h of treatment. In this study, MgSO4 was found to be a safe and effective pulmonary vasodilator. MgSO4 could be used as a first-line vasodilator in developing countries because of its low cost and high efficacy. Parenteral MgSO4 is easy to administer and monitor during treatment. When MgSO4 is used, systemic hypotension can be adequately controlled with ionotropes.