Infusion of alkali for the treatment of neonatal acidosis has been a standard practice in delivery rooms and neonatal intensive care units for the past 15 years. The ready availability of vials of hyperosmolal (1 M) sodium bicarbonate has led to the use of this base in the treatment of neonatal asphyxia and the respiratory distress syndrome (RDS). Recent reports of controlled studies, however, prompt reevaluation of this therapeutic approach. In fact, both laboratory and clinical investigations indicate that the routine use of bicarbonate in these clinical situations is rarely efficacious, is frequently dangerous, and may well be contraindicated.
Sodium bicarbonate can function as a buffer because its acid form, H2CO3, dissociates into water and a volatile gas, CO2. Most buffers have a maximum effect on pH when the ratio of dissociated anion to acid is 1:1. The bicarbonate system, however, works well despite a HCO