Milrinone for pulmonary hypertension: Additional benefits, concerns, and caution

Perioperative sildenafil therapy in pulmonary hypertension associated with congenital cardiac disease: An updated meta-analysis

To provide an updated meta-analysis to evaluate the efficacy and safety of sildenafil on pediatric patients with pulmonary hypertension (PH) associated with congenital heart disease (CHD). To assess the efficacy and safety of sildenafil, five outcomes, time duration of post-operative need for mechanical ventilation, time duration of post-operative ICU stay, length of hospitalization (LOH), the incidence of mortalities and pulmonary arterial pressure to aortic pressure ratio (PAP/AoP) were regarded as primary efficacy outcomes. Standardized mean difference (SMD) was calculated for continuous data. In comparison to the control group (CG), there was a significant decrease in the time duration of ICU stay in the sildenafil group (SG) (SMD = -0.61 [95% CI -1.17, 0.04]; P < 0.01, I2 = 85%). Length of hospitalization was assessed in the sildenafil and control groups (SMD = -0.18 [95% CI -0.67, 0.31] P = 0.05, I2 = 62%). However, there was no significant difference seen in mortality rates between the SG and CG (SMD = 0.53 [ 95% CI 0.13, 2.17] p = 0.61, I2 = 0%), in the time duration of postoperative mechanical ventilation between the SG and CG (SMD = -0.23 [95% CI -0.49, 0.03] p = 0.29, I2 = 19%), or PAP/AoP ratio between the SG and CG (SMD = -0.42 [95% CI -1.35, 0.51] P < 0.01, I2 = 90%). Based on our analysis, sildenafil has little to no effect in reducing postoperative morbidity and mortality due to PH in infants and children with CHD.

Postoperative use of oral sildenafil in pediatric patients with congenital heart disease

We sought to determine the efficacy of postoperative oral sildenafil therapy (OST) in pediatric patients with congenital heart disease (CHD). A retrospective review of 45 postoperative patients with CHD who received OST was performed. Patients were categorized into three groups according to clinical indications: (1) to stabilize pulmonary vascular reactivity after biventricular repair (group 1 [n = 15]), (2) to lower pulmonary vascular resistance after bidirectional cavopulmonary shunt (group 2 [n = 12]), and (3) to improve post-Fontan hemodynamics (group 3 [n = 18]). Thirty-four patients (34 of 45 [75.6%]) had received inhaled nitric oxide (iNO) while on OST. Mean pulmonary arterial pressure (mPAP), mean systemic blood pressure (mSBP), and peripheral oxygen saturation (SpO(2)) were recorded during the first 24 hours after the initiation of OST. In group 1, the baseline mPAP/mSBP ratio (0.60 +/- 0.17) decreased significantly after the second (0.46 +/- 0.14, p = 0.004) and fourth (0.50 +/- 0.18, p = 0.025) doses of OST. In group 2, baseline SpO(2) (71.0 +/- 12.3%) increased after the fourth dose (75.1 +/- 12.3%, p = 0.04) of OST, without significant changes in mPAP. In group 3, baseline mPAP (14.8 +/- 3.3 mmHg) decreased significantly after the first (13.9 +/- 2.8 mmHg, p = 0.025) and second (13.3 +/- 1.9 mmHg, p = 0.016) doses of OST, without changes in SpO(2). In thirty-one (31 of 34 [92%]) subjects, iNO was discontinued within a median of 2 days after the initiation of OST, without rebound phenomena. There were no OST-related complications. Sildenafil citrate can be used safely in postoperative pediatric patients with CHD. Benefits from OST may be manifested differently in various clinical settings.

Effects of Escalating Doses of Sildenafil on Hemodynamics and Gas Exchange in Children With Pulmonary Hypertension and Congenital Cardiac Defects

OBJECTIVE

Sildenafil (Viagra, Pfizer) is being increasingly used to treat pulmonary hypertension in children. However, there are limited data available to suggest dosage regimens. The purpose of this study was to determine the effects of escalating doses of sildenafil on hemodynamics and gas exchange in children with pulmonary hypertension because of congenital cardiac defects.

DESIGN

Prospective, observational study.

SETTING

Pediatric intensive care unit in a tertiary care children's hospital.

PARTICIPANTS

Ten children with pulmonary hypertension because of congenital cardiac defects who were in the intensive care unit and on nitric oxide after cardiac surgery.

INTERVENTION

Patients received sildenafil every 4 hours via a gastric tube in incremental doses of 0.5 mg/kg, 1 mg/kg, 1.5 mg/kg, and 2.0 mg/kg along with nitric oxide during their stay in the intensive care unit until they were extubated. Hemodynamic and arterial blood gas measurements were taken before (baseline) and 60 minutes after the administration of sildenafil.

MEASUREMENTS AND MAIN RESULTS

All doses of sildenafil caused significant reduction in pulmonary artery pressure with no significant effect on systemic arterial and central venous pressures. Arterial partial pressure of oxygen was decreased after a 2.0 mg/kg dose of sildenafil but not significantly. No significant differences were found among the 4 doses.

CONCLUSION

For the treatment of pulmonary hypertension in children with congenital cardiac defects, a 0.5 mg/kg dose of sildenafil every 4 hours is therapeutically as effective as a 2.0 mg/kg dose every 4 hours. However, a large dose-ranging and pharmacokinetic study of sildenafil in children with pulmonary hypertension because of congenital cardiac defects is needed to validate the safety and efficacy of the dose-range and dosing interval suggested by this study.