Effects of sodium bicarbonate correction of metabolic acidosis on regional tissue oxygenation in very low birth weight neonates.
OBJECTIVE
To determine the effects of sodium bicarbonate (NaHCO3) correction of metabolic acidosis on cardiopulmonary, laboratory, and cerebral, renal and splanchnic regional oxygen saturation (rSO2) and fractional tissue oxygen extraction (FTOE) in extremely premature neonates during the first postnatal week.


METHODS
Observational cohort data were collected from 500 to 1250 g neonates who received NaHCO3 'half' corrections (0.3 * Weight (kg) * Base Deficit (mmol l(-1))) for presumed renal losses.


RESULTS
Twelve subjects with normal blood pressure and heart rate received 17 NaHCO3 corrections. Mean (±s.d.) gestational age was 27±2 week and birth weight was 912±157 g. NaHCO3 corrections provided a mean (±s.d.) 4.5±1.0 ml kg(-1) fluid bolus, shifted mean (±s.d.) base deficit from 7.6±1.8 to 3.4±2.1 mmol l(-1) (P<0.05), and increased median (±s.d.) pH from 7.23±0.06 to 7.31±0.05 (P<0.05). No significant changes in blood pressure, pulse oximetry, PCO2, lactate, sodium, blood urea nitrogen, creatinine or hematocrit were observed. Cerebral, renal and splanchnic rSO2 (74%, 66% and 44%, respectively, at baseline) and FTOE (0.21, 0.29 and 0.52, respectively, at baseline) were unchanged following NaHCO3 correction.


CONCLUSIONS
NaHCO3 infusions decreased base deficits and increased pH though produced no discernible effects or benefits on cardiopulmonary parameters including rSO2 and FTOE. These findings warrant further prospective evaluation in larger populations with more significant metabolic acidosis to determine the utility of tissue oxygenation monitoring in differentiating metabolic acidosis due to oxygen delivery/consumption imbalance versus renal bicarbonate losses.
Department of Pediatrics, Division of Neonatal-Perinatal Medicine, Stony Brook Children's Hospital, Stony Brook, NY, USA.
J P
JP
Mintzer
Department of Pediatrics, Division of Newborn Medicine, The Regional Neonatal Intensive Care Unit, Maria Fareri Children's Hospital at Westchester Medical Center, Valhalla, NY, USA.
B
B
Parvez
Department of Pediatrics, Division of Newborn Medicine, The Regional Neonatal Intensive Care Unit, Maria Fareri Children's Hospital at Westchester Medical Center, Valhalla, NY, USA.
G
G
Alpan
Department of Pediatrics, Division of Newborn Medicine, The Regional Neonatal Intensive Care Unit, Maria Fareri Children's Hospital at Westchester Medical Center, Valhalla, NY, USA.
E F
EF
LaGamma
D000138:Acidosis / Q000188:drug therapy*; D001724:Birth Weight; D005865:Gestational Age; D006400:Hematocrit; D006801:Humans; D062071:Infant, Extremely Premature; D007231:Infant, Newborn; D019102:Infant, Very Low Birth Weight; D015931:Intensive Care, Neonatal; D008991:Monitoring, Physiologic / Q000379:methods*; D010092:Oximetry / Q000379:methods; D010101:Oxygen Consumption / Q000187:drug effects*; D011446:Prospective Studies; D017693:Sodium Bicarbonate / Q000627:therapeutic use*
D017693:Sodium Bicarbonate