The effect of patent ductus arteriosus treatment with paracetamol on pulmonary vascular resistance.

The effect of patent ductus arteriosus treatment with paracetamol on pulmonary vascular resistance. Murphy, Claire; Bussmann, Neidin; Staunton, David; McCallion, Naomi; Franklin, Orla; EL-Khuffash, Afif The use of paracetamol to achieve closure of a patent ductus arteriosus (PDA) in premature infants lacks robust safety data [1]. Paracetamol exerts its vasoconstrictive effect on ductal tissue by inhibition of prostaglandin H2 synthase, which is responsible for the metabolism of arachidonic acid [2]. Dysregulation of this pathway is implicated in the development of pulmonary arterial hypertension [3]. In this report, we assess the impact of paracetamol administration for PDA closure on pulmonary vascular resistance (PVR) in preterm infants <29 weeks gestation using echocardiography. This is a report of fifteen infants <29 weeks of gestation who were enroled into the PDA RCT, a randomised controlled trial of PDA treatment, who received open label paracetamol for ductal closure beyond the first week with a dose of 15 mg/kg, four times a day for 5 days (ISRCTN:13281214) [4]. Ethical approval from the Rotunda Research Ethics Committee and written parental consent was obtained. Echocardiography studies were acquired prior to paracetamol and following completion of the treatment course. We obtained measurements of PDA characteristics, left (LV) and right ventricular (RV) function, and surrogate markers of PVR using the ratio of pulmonary artery acceleration time to right ventricular ejection time (PAATi) and LV eccentricity index (LV EI). Paired data were compared using the paired student t test or the non-parametric equivalent as appropriate. Categorical variables were compared using the Chi square or the Fisher’s exact test as appropriate.