Hemodynamic effects of sodium bicarbonate administration

Objective: To describe the hemodynamic changes that occur with sodium bicarbonate (NaHCO 3 ) administration in premature neonates. Study Design: This retrospective study included premature neonates 23 to 31+6 weeks of gestational age who underwent continuous cardiac and cerebral monitoring as participants in prospective trials at our institution, and who received NaHCO 3 infused over 30 min in the first 24 h of life. Blood pressure (BP), heart rate, cardiac output (CO), SpO 2 and cerebral oximetry (StO 2 ) were captured every 2 s. A baseline was established for all continuous data and averaged over the 10 min before NaHCO 3 administration. Baseline was compared with measurements over 10 min epochs until 80 min after administration. Arterial blood gases before and within 1 h of administration were also compared. Significance was set at P <0.05. Results: A total of 36 subjects received NaHCO 3 (1.3±0.3 mEq kg −1 ) in the first 24 h (14±8.5 h) of life. NaHCO 3 administration increased pH (7.23 vs 7.28, P <0.01) and decreased base deficit (−8.9 vs −6.8, P <0.01) and PaCO 2 (45 vs 43 mm Hg, P <0.05). There was a transient but significant ( P <0.05) decrease in systemic BP coinciding with an increase in cerebral oxygenation without an increase in oxygen extraction. CO did not change. Conclusion: Early postnatal NaHCO 3 administration does not acutely improve CO but does cause transient fluctuations in cerebral and cardiovascular hemodynamics in extremely premature infants.