INDOMETHACIN REGIMES FOR PATENT DUCTUS ARTERIOSUS IN PREMATURE NEWBORNS

Siu K-L, Wan K-M, Law C-W, LEE W-H

Queen Elizabeth Hospital, Hong Kong SAR, China

Objective: To evaluate the incidence of patent ductus arteriosus (PDA) in premature newborns (500- 1500 gm) in Queen Elizabeth Hospital (QEH) admitted in year 1994; their responses to two intravenous indomethacin regimes A: (0.2 mg/kg/dose Q 12 hours X 3 then 3 further doses Q 24 hours) and B: (0.1 mg/kg/day X 6 days); and the side effects of treatment.

Methods: Ninety-four premature newborns of birth weight between 500 gm to 1500 gm were divided into two groups. There were 36 PDA-newborn with 20 in Group A(n=45) and 16 in Group B(n=49). PDA was confirmed by presence of murmur and by 2-D Echocardiogram. PDA-newborn with ventilator dependency were treated with intravenous indomethacin. Group A PDA-newborn received indomethacin regime A while Group B PDA-newborn received indomethacin regime B. Ductus closure was defined as persistent disappearance of heart murmur. Side effects related to indomethacin treatment were recorded. Student t-test and chi-square tests were used .

Results: Both groups had comparable mean gestation, birth weight and sex distribution. Incidence of PDA was 38.3 % (20 in Group A and 16 in Group B). Nineteen out of 20 PDA-newborn in Group A and 9 out of 16 PDA-newborn in Group B were given indomethacin. Mean age of starting indomethacin was Day 8.3 in Group A PDA-newborn and Day 5.6 in Group B PDA-newborn. All 28 indomethacin treated PDA-newborns in both groups had received full course of indomethacin. After the first course of indomethacin, PDA was closed in 84.2 % of Group A PDA-newborn and 77.7% of Group B PDA-newborn. The overall ductal closure rate ((PDA closure without indomethacin + PDA closure after the first course indomethacin) /total PDA-newborn in either group) were 80% and 81.3% in Group A-PDA newborn and Group B PDA-newborn respectively. The common side effects were thrombocytopenia and raised serum Creatinine. Suspected necrotizing enterocoiltis (NEC) was seen in 21% of Group A-PDA newborn and 11% of Group B-PDA newborn (11%). Bleeding tendency or progression of intraventricular haemorrhage was not encountered.

Conclusion: PDA was found in 38.3 % of studied premature newborns who weighed between 500 gm to 1500 gm. This incidence was close to most published series. The need for pharmacological closure was ventilator dependency. Both regimes were effective in ductus closure ( Group A: 84.2%, Group B : 77.7 % ) and the results were comparable to the National Collaborative Study (79%: Gersony-1983). Side effects included NEC, thrombocytopenia, and raised serum creatinine.