Acid-base Balance and Metabolic Acidosis in Neonates

ABSTRACT

Metabolic acidosis is commonly encountered issues in the management of critically ill neonates and especially of preterm infants during early neonatal days. In extremely premature infants, low glomerular filtration rate and immaturity of renal tubules to produce new bicarbonate causes renal bicarbonate loss. Higher intake of amino acids, relatively greater contribution of protein to the energy metabolism and mineralization process in growing bones are also responsible for higher acid load in premature infant than in adult. Despite widespread use of sodium bicarbonate in the management of severe metabolic acidosis, use of sodium bicarbonate in premature infants should be restricted to a reasonable but unproven exception such as ongoing renal loss. Despite concern about the low pH value (<7.2) which can compromise cellular metabolic function, no treatment guideline has been established regarding the management of metabolic acidosis in premature infants. Appropriately powered randomized controlled trials of base therapy to treat metabolic acidosis in critically ill newborn infants are demanding.