BICARBONATE THERAPY AND INTRACELLULAR ACIDOSIS

1, The correction of metabolic acidosis with sodium bicarbonate remain s controversial, Experiments in vitro have suggested possible deleteri ous effects after alkalinization of the extracellular fluid, Disequili brium of carbon dioxide and bicarbonate across cell membranes after al kali administration, leading to the phenomenon of 'paradoxical' intrac ellular acidosis, has been held responsible for some of these adverse effects, 2, Changes in intracellular pH in suspensions of leucocytes f rom healthy volunteers were monitored using a fluorescent intracellula r dye, The effect in vitro of increasing extracellular pH with sodium bicarbonate was studied at different sodium bicarbonate concentrations , Lactic acid and propionic acid were added to the extracellular buffe r to mimic conditions of metabolic acidosis, 3, The addition of a larg e bolus of sodium bicarbonate caused intracellular acidification as ha s been observed previously, The extent of the intracellular acidosis w as dependent on several factors, being most evident at higher starting intracellular pH, When sodium bicarbonate was added as a series of sm all boluses the reduction in intracellular pH was small, Under conditi ons of initial acidosis this was rapidly followed by intracellular alk alinization, 4, Although intracellular acidification occurs after addi tion of sodium bicarbonate to a suspension of human leucocytes in vitr o, the effect is minimal when the conditions approximate those seen in clinical practice, We suggest that the observed small and transient l owering of intracellular pH is insufficient grounds in itself to aband on the use of sodium bicarbonate in human acidosis.