Cardiovascular effects of low-dose dexamethasone in very low birth weight neonates with refractory hypotension

Background: Administration of hydrocortisone and relatively high doses of dexamethasone increase blood pressure in volume- and pressor-resistant hypotensive preterm infants. However, little is known about the temporal relationship of dexamethasone administration and the improvement in blood pressure and the weaning of pressors/ inotropes. Furthermore, there are no sufficient data available on whether a smaller dose of dexamethasone would also be effective in treating refractory hypotension. Objective: To study the cardiovascular responses to low-dose dexamethasone in very low birth weight neonates with volume- and pressor-resistant hypotension. Methods: Retrospective database review. Twenty-four preterm neonates ( gestational age 26 ( 23 - 34) weeks; birth weight 801 ( 457 - 1,180) g; postnatal age 2 ( 1 - 24) days, medians ( ranges)) who remained hypotensive despite volume administration and combined dopamine and dobutamine treatment at >= 30 mu g/kg/ min received dexamethasone 0.1 mg/kg followed by 0.05 mg/kg intravenously every 12 h for 5 additional doses if still on pressors >= 8 mu g/kg/ min. Results: Two hours after the first dose of dexamethasone the mean blood pressure increased from 30 +/- 5 to 34 +/- 6 mm Hg ( p < 0.001) and remained elevated at 4, 6, 12, and 24 h after treatment was started ( p ! 0.001). Six hours after the initial dose of dexamethasone the pressor/inotrope requirement decreased from 34 +/- 9 to 24 +/- 13 mu g/ kg/ min ( p = 0.001) and continued to decrease at 12 and 24 h ( p < 0.001). Urine output also increased significantly during the first 6 h after dexamethasone ( p < 0.001). Conclusions: Low-dose dexamethasone rapidly increases blood pressure and decreases pressor requirements in very low birth weight neonates with volume- and pressor-resistant hypotension. Copyright (C) 2006 S. Karger AG, Basel.