The Influence of Sodium Bicarbonate on Cerebral Oxygenation and Hemodynamics in Preterm Infants Investigated Using Near Infrared Spectrophotometry (NIRS)

Abstract 117

Aims: To compare the influence of rapid vs. slow injection of sodium bicarbonate (NaBic) on cerebral oxygenation and hemodynamics in preterm infants with metabolic acidosis.

Material: Twenty-one preterm infants with metabolic acidosis (base deficit < -6 mmol/L) were randomized in 2 groups. Group 1 (n=13, GA 31.7±1.3 wk, BW 1457±376 g) was treated with a rapid injection of NaBic 4.2% (1.1±0.3 mmol/kg). Group 2 (n=8, GA 31.3±1.6 wk, BW 1480 ± 279 g) was treated with a slow injection (in 30 min) of NaBic 4.2% (1.1±0.2 mmol/kg).

Measurements: Concentration changes of oxyhemoglobin (ÄcO₂Hb), deoxyhemoglobin (ÄcHHb) and total hemoglobin (ÄctHb) in brain (in ìmol/100 g), were continuously measured with NIRS for 1 h. ÄcO₂Hb and ÄcHHb reflect changes in cerebral O₂ supply, ÄctHb reflects changes in cerebral blood volume. Changes in cerebral blood flow velocity (ÄCBFV) (pulsed Doppler US) in the internal carotid artery (in % of pre-injection value) were determined at 5, 15 and 45 min after the injection.

Results: (Table) No statistically significant differences were found within and between the groups.

Table 1 No caption available.

Conclusion: Both rapid and slow injection of NaBic had no effect on cerebral oxygenation and hemodynamics. Rapid injection of NaBic as therapy for metabolic acidosis in preterm infants is justified.