Sodium bicarbonate causes dose-dependent increases in cerebral blood flow in infants and children with single-ventricle physiology

BACKGROUND: Sodium bicarbonate (NaHCO3) is a common treatment for metabolic acidemia; however, little definitive information exists regarding its treatment efficacy and cerebral hemodynamic effects. This pilot observational study quantifies relative changes in cerebral blood flow (Delta rCBF) and oxy- and deoxyhemoglobin concentrations (Delta HbO(2) and Delta Hb) due to bolus administration of NaHCO3 in patients with mild base deficits. METHODS: Infants and children with hypoplastic left heart syndrome (HLHS) were enrolled before cardiac surgery. NaHCO3 was given as needed for treatment of base deficit. Diffuse optical spectroscopies were used for 15 min postinjection to noninvasively monitor Delta Hb, Delta HbO(2), and Delta rCBF relative to baseline before NaHCO3 administration. RESULTS: Twenty-two anesthetized and mechanically ventilated patients with HLHS (aged 1 d to 4 y) received a median (interquartile range) dose of 1.1 (0.8, 1.8) mEq/kg NaHCO3 administered intravenously over 10-20 s to treat a median (interquartile range) base deficit of -4 (-6, 3) mEq/l. NaHCO3 caused significant dose-dependent increases in Delta rCBF; however, population-averaged Delta Hb and Delta HbO(2) as compared with those of controls were not significant. CONCLUSIONS: Dose-dependent increases in cerebral blood flow (CBF) caused by bolus administration of NaHCO3 are an important consideration in vulnerable populations wherein risk of rapid CBF fluctuations does not outweigh the benefit of treating a base deficit.