Milrinone and nitric oxide: combined effect on pulmonary artery pressures after cardiopulmonary bypass in children.

OBJECTIVE

To investigate the effect of milrinone combined with nitric oxide (NO) on the pulmonary artery pressures (PAP) after cardiopulmonary bypass (CPB), for repair of congenital heart defects (CHD) in children.

DESIGN

Prospective, randomized, double-blind study.

SETTING

University affiliated community hospital.

PARTICIPANTS

Ninety children with pulmonary hypertension and repair of CHD.

INTERVENTIONS

After weaning from CPB, patients (30 in each group) received 3 drug regimens: group 1, nitric oxide (NO); group 2, a continuous infusion of milrinone; and group 3, a combination of the 2. Drugs were started after CPB and given for 20 minutes.

MEASUREMENTS AND MAIN RESULTS

Pulmonary and systemic pressures, PaCO(2), SaO(2), and pH values were recorded before bypass, after weaning from CPB, 10 and 20 minutes after starting each regimen, and 10 minutes after the cessation of treatment. Mean systemic blood pressure was lower (p < 0.05) in the combined treatment group after discontinuation of the drugs. Although mean PAP values were lower in the combined group (p < 0.05), no difference was recorded with regard to pH, PaCO(2), and PaO(2). The ratio between pre- and post-treatment mean PAP was highest in group 3(1.26 +/- 0.5) and lowest in group 2 (0.99 +/- 0.3, p < 0.001). The mean PAP recorded after discontinuation of the drug was lower than the baseline value in groups 1 and 3 (p < 0.05).

CONCLUSIONS

The combination of milrinone and NO produced a more pronounced decrease in PAP than milrinone alone.