(184) Metabolic Effects of Prolonged PGE-1 Infusion: A Prospective Observational Study

Introduction: Prostaglandin E1 (PGE1) infusion is used to maintain ductal patency in duct-dependent critical congenital heart disease (CCHD) while awaiting surgery. Delay in surgery necessitates prolong PGE1 infusion, especially in resource-constraint settings. Cases of pseudo-barter syndrome and cortical hyperostosis have been reported with prolong use of PGE1 infusion. However, there is paucity of substantial clinical data. Hence, planned to study the impact of prolong (>5 days) PGE1 infusion on electrolytes and bone metabolism.

Methods: Neonates with echocardiographic evidence of duct-dependent CCHD and PGE1 infusion for 5 days were enrolled. Culture-positivity at enrolment were excluded. Baseline demographic, clinical and biochemical parameters were recorded on day 1 of enrolment, and then every 5 days until surgery or death, whichever was earlier. Data were expressed as median (IQR).

Results: Thirty neonates [males, 18; age, 11(7, 17.5) days] with CCHD were enrolled. PGE1 infusion was started at 5(3, 12.25) days of life at 20(12.5, 50) ng/kg/min. Patients received PGE1 for 21(11.25, 27) days. Cumulative dose was 388.8(216, 691.2) mcg/kg, while maximum rate of infusion was 40 (30, 57) ng/kg/min. We had total of 89 observation points, with average of three observation points per patient.
At enrolment, serum levels of sodium, potassium, chloride, calcium, phosphorus and ALP were 139 (132, 141), 5.1 (4.4, 6.0), 103 (101, 106), 8.4 (8.2, 8.6), 4.8 (4.2, 5.3) and 128 (114, 154) respectively. A negative correlation was noted between cumulative dose of PGE1 with sodium (R=-0.25, p=0.017), chloride (R=-0.21, p=0.05) and potassium (R=-0.18, p=0.082). Cumulative dose of PGE1 was positively correlated with ALP [R=0.35, p=0.0007] and serum phosphorus [R=0.24, p=0.023]. Calcium did not get affected. Two patients developed clinical and radiological evidence of cortical hyperostosis, while a patient developed pseudo-barter syndrome due to urinary loss of electrolytes (Na+, 110mEq/L, K+, 2.6mEq/L).

Conclusions: Prolong PGE1 affects electrolytes and bone metabolism, causing pseudo-barter syndrome and cortical hyperostosis in some. Patients on PGE1 infusion for more than 5 days need meticulous biochemical monitoring for early identification and intervention.