Hemodynamic effects of sodium bicarbonate in critically ill neonates.
OBJECTIVE
To analyze the cardiovascular effects of sodium bicarbonate in neonates with metabolic acidosis.


METHODS
Prospective, open, non-randomized, before-after intervention study with hemodynamic measurements performed before and 1, 5, 10, 20, and 30 min after bicarbonate administration.


METHODS
Neonatal intensive care unit, tertiary care center.


METHODS
Sequential sample of 16 paralysed and mechanically ventilated newborn infants with a metabolic acidosis (pH < 7.25 in premature and < 7.30 in term infants, base deficit > -8).


METHODS
An 8.4% sodium bicarbonate solution diluted 1:1 with water (final osmolality of 1000 mOsm/l) was administered in two equal portions at a rate of 0.5 mmol/min. The dose in mmol was calculated using the formula "base deficit x body weight (kg) x 1/3 x 1/2".


RESULTS
Sodium bicarbonate induced a significant but transient rise in pulsed Doppler cardiac output (CO) (+27.7%), aortic blood flow velocity (+15.3%), systolic blood pressure (BP) (+9.3%), (+14.6%), transcutaneous carbon dioxide pressure (PtcCO2) (+11.8%), and transcutaneous oxygen pressure (PtcO2) (+8%). In spite of the PaCO2 elevation, pH significantly improved (from a mean of 7.24 to 7.30), and the base deficit decreased (-39.3%). Calculated systemic vascular resistance (SVR) (-10.7%) and diastolic BP (-11.7%) decreased significantly, while PaO2 and heart rate (HR) did not change. Central venous pressure (CVP) (+6.5%) increased only slightly. By 30 min after bicarbonate administration all hemodynamic parameters, with the exception of the diastolic BP, had returned to baseline.


CONCLUSIONS
Sodium bicarbonate in neonates with metabolic acidosis induces an increase in contractility and a reduction in afterload.
Fanconi
S
S
Intensive Care Unit, University Children's Hospital, Zürich, Switzerland.
Burger
R
R
Ghelfi
D
D
Uehlinger
J
J
Arbenz
U
U
D000140:Acidosis, Lactic / Q000175:diagnosis / Q000188:drug therapy* / Q000503:physiopathology; D001639:Bicarbonates / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D001724:Birth Weight; D001784:Blood Gas Analysis; D001785:Blood Gas Monitoring, Transcutaneous; D016638:Critical Illness; D015150:Echocardiography, Doppler; D005865:Gestational Age; D006439:Hemodynamics / Q000187:drug effects*; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D007262:Infusions, Intravenous; D007363:Intensive Care Units, Neonatal; D009200:Myocardial Contraction / Q000187:drug effects; D011446:Prospective Studies; D012121:Respiration, Artificial; D012964:Sodium / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D017693:Sodium Bicarbonate
D001639:Bicarbonates; D017693:Sodium Bicarbonate; D012964:Sodium