Base administration or fluid bolus for preventing morbidity and mortality in preterm infants with metabolic acidosis.
BACKGROUND
Metabolic acidosis in the early newborn period is associated with adverse outcomes in preterm infants. The most commonly used strategies to correct metabolic acidosis are intravascular infusion of base, for example sodium bicarbonate, and intravascular infusion of a fluid bolus, usually a crystalloid or colloid solution.


OBJECTIVE
To evaluate the available evidence from randomised controlled trials that either infusion of base, or of a fluid bolus, reduces mortality and adverse neurodevelopmental outcomes in preterm infants with metabolic acidosis.


METHODS
We used the standard search strategy of the Cochrane Neonatal Review Group. This included searches of the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 1, 2005), MEDLINE (1966 - January 2005), EMBASE (1980 - January 2005), CINAHL (1982 - January 2005).


METHODS
Randomised or quasi-randomised controlled trials that evaluated the following treatments for preterm infants with metabolic acidosis:1. Infusion of base versus no treatment.2. Infusion of fluid bolus versus no treatment.3. Infusion of base versus fluid bolus.


METHODS
We extracted the data using the standard methods of the Cochrane Neonatal Review Group, with separate evaluation of trial quality and data extraction by two authors, and synthesis of data using relative risk and risk difference.


RESULTS
We found two small randomised controlled trails that fulfilled the eligibility criteria (Corbet 1977; Dixon 1999). Corbet 1977 compared treating infants with sodium bicarbonate infusion (N = 30) versus no treatment (N = 32) and did not find evidence of an effect on mortality [Relative risk 1.39 (95% confidence interval 0.72 to 2.67), risk difference 0.12 (95% confidence interval -0.12 to 0.36)], or in the incidence of intra/peri-ventricular haemorrhage [Relative risk 1.24 (95% confidence interval 0.47 to 3.28), risk difference 0.05 (95% confidence interval -0.16 to 0.25)]. Dixon 1999 compared treatment with sodium bicarbonate (N = 16) versus fluid bolus (N = 20). The primary outcome assessed was arterial blood pH/base excess two hours after the intervention. Other clinical outcomes were not reported. Neither trial assessed longer term neurodevelopmental outcomes.


CONCLUSIONS
There is insufficient evidence from randomised controlled trials to determine whether infusion of base or fluid bolus reduces morbidity and mortality in preterm infants with metabolic acidosis. Further large randomised trials are needed.
Lawn
C J
CJ
Neonatal Medicine, Royal Sussex County Hospital Brighton, Eastern Road, Brighton, East Sussex, UK, BN2 5BE. cassielawn@doctors.org.uk
Weir
F J
FJ
McGuire
W
W
D000138:Acidosis / Q000150:complications / Q000188:drug therapy* / Q000401:mortality; D002021:Buffers; D005440:Fluid Therapy / Q000379:methods; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D007235:Infant, Premature, Diseases / Q000188:drug therapy* / Q000401:mortality; D016032:Randomized Controlled Trials as Topic; D017693:Sodium Bicarbonate / Q000008:administration & dosage*; D014325:Tromethamine / Q000008:administration & dosage
D002021:Buffers; D014325:Tromethamine; D017693:Sodium Bicarbonate