Hemodynamic effects of sodium bicarbonate administration

OBJECTIVE: To describe the hemodynamic changes that occur with sodium bicarbonate (NaHCO3) 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 NaHCO3 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 NaHCO3 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 NaHCO3 (1.3 +/- 0.3 mEq kg(-1)) in the first 24 h (14 +/- 8.5 h) of life. NaHCO3 administration increased pH (7.23 vs 7.28, P < 0.01) and decreased base deficit (-8.9 vs -6.8, P < 0.01) and PaCO2 (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 NaHCO3 administration does not acutely improve CO but does cause transient fluctuations in cerebral and cardiovascular hemodynamics in extremely premature infants.