aaPersistent pulmonary hypertension (PPH) is a clinical syndrome, characterized by a sustained elevation of the pulmonary vascular resistance with a right-to-left shunt across the ductus arteriosus and/or the foramen ovale, causing severe hypoxaemia. Although generally associated with diseases of term newborns PPH has been increasingly described in preterm infants as well [1]. Inhaled nitric oxide (iNO) has been described as an effective selective pulmonary vasodilator improving oxygenation in newborns including preterm infants. However, concern over iNO relates to its potential toxicity and to difficulties in developing safe and effective delivery systems. Intravenous prostacyclin (epoprostenol) is a potent vasodilator in PPH [2]. Nevertheless, its effect on systemic vasculature and on pulmonary vessels of nonventilated areas limits its clinical application. Recently, aerosolized prostacyclin has been reported both in clinical and experimental settings to be a selective pulmonary vasodilator without side-effects on the systemic vasculature [3][4][5]. No human data on topical epoprostenol-related toxicity are available. In an animal study no signs of acute pulmonary toxicity were shown from prostacyclin inhalation [6]. We here describe the effect of endotracheal instillation of prostacyclin on oxygenation and haemodynamics in four preterm infants with severe pulmonary hypertension.
Patients and methodsThe patients' underlying diseases were hyaline membrane disease (patients 1-3) and septicaemia caused by Escherichia coli (patient 4). Demographic data are listed in table 1. All patients had an arterial oxygen tension (Pa,O 2 )/ fraction of inspired oxygen (FI,O 2 ) ratio <70 despite optimum ventilator settings during at least 6 h. Oxygenation was monitored using pre-and postductal transcutaneous pulse oximetry and a pre-and/or postductal indwelling arterial catheter. The variables measured and calculated were the Pa,O 2 /FI,O 2 , the oxygenation index (OI; ((FI,O 2 × mean airway pressure)/ Pa,O 2 ) × 100) and mean systemic arterial blood pressure (MAP). Patients were only enrolled after informed consent was obtained from the parents. In all infants the presumptive diagnosis of persistent pulmonary hypertension was confirmed with air-contrast echocardiography showing a right-to-left shunt across the ductus arteriosus and/or the foramen ovale. The epoprostenol, dissolved in glycine buffer (Flolan®, GlaxoWellcome B.V., Zeist, the Netherlands), was diluted with saline (NaCl 0.9%) to a concentration of 50 ng·mL -1 . The pH of this solution was 10.3. This epoprostenol solution of 50 ng·mL -1 was instilled as a bolus of 1 mL·kg -1 endotracheally through a catheter reaching the distal end of the endotracheal tube.
Endotracheal instillation of prostacyclin in preterm infants with persistent pulmonary hypertension. A.P.M.C. De Jaegere, J.N. van den Anker. ©ERS Journals Ltd 1998. ABSTRACT: Does endotracheal instilled prostacyclin (epoprostenol) improve oxygenation in preterm infants with persistent pulmonary hypertension?Fo...