Hemodynamic and Oximetric Response to Sodium Bicarbonate Boluses in Children with Single Ventricle Parallel Circulation: A Retrospective, Single-Center Study

Abstract

Abstract The aim of the study was to evaluate the hemodynamic and oximetric changes in patients with parallel circulation (Norwood, hybrid, and BT-shunted) after sodium bicarbonate bolus administration. This study was a retrospective analysis of physiologic data. To eliminate confounders, sodium bicarbonate boluses concurrently administered with normal saline, 5% albumin, epinephrine boluses, blood transfusions, change in vasoactive inotropic score or mechanical circulatory support were excluded. Blood pressure, arterial oxygen saturation, heart rate (HR), and cerebral and renal near infrared spectroscopy were continuously recorded from 1-hour pre to 1-hour post each intervention. Out of 429 boluses, 293 boluses met the inclusion criteria. Measurements show an increase in blood pressure ( p  = 0.01) and HR ( p  < 0.01), and a decrease in pulmonary-to-systemic flow ratio ( p  = 0.02) and renal oxygen extraction ratio (rOER) ( p  = 0.04) at some point during the first hour postbolus. The arterial oxygen saturation increased, and the rOER decreased for those patients with pre-bolus pH < 7.20 and/or pre-bolus serum bicarbonate level < 18 mEq/L, according to linear regression models ( p  < 0.05). Sodium bicarbonate was associated with improvement of hemodynamic and oximetric parameters in this cohort, particularly for those patients with pH < 7.20 and/or serum bicarbonate level < 18 mEq/L. This finding is consistent with an increase in cardiac output due to the removal of the acidotic negative inotropic effect by the sodium bicarbonate.