Continuous Versus Intermittent Intravenous Sildenafil in Critically Ill
Infants with Pulmonary Hypertension
Abstract
Abstract Continuous intravenous (IV) sildenafil may avoid the acute
systemic vasodilatory effects of bolus dosing in infants with pulmonary
hypertension (PH). We aimed to examine the tolerability of different
methods of IV sildenafil administration. Methods: We retrospectively
evaluated subjects less than 12 months old with PH, who had been started
on IV sildenafil. Vital signs, oxygen requirement, and
vasoactive-inotropic score (VIS) before and after sildenafil initiation
were noted, as was the need for discontinuation due to side effects.
Results: Forty-three subjects were identified (23 continuous, 20
intermittent dosing). There were no statistically significant
differences between groups in gender or gestational age, but higher
baseline inspired oxygen (FiO2) and VIS in the continuous group
suggested a higher baseline severity of illness (p=0.012). After
sildenafil initiation, there were no significant differences in the
change in blood pressure, oxygen saturation, FiO2, or VIS between
groups, and no difference in the number of subjects requiring
discontinuation due to side effects (4 in the continuous group, 1
intermittent, p=0.35). Eight subjects (34.8%) in the continuous group
and 3 (15%) in the intermittent group died (p=0.024). Conclusions: In
this small cohort of infants with PH treated with continuous or
intermittent IV sildenafil, there were no statistically significant
differences between groups in the change in vital signs, VIS, and oxygen
requirement, or the need for discontinuation of therapy due to side
effects. A higher mortality rate in the continuous infusion group may be
explained by higher baseline illness severity.