THE EFFECT OF MODERATE HYPOCAPNIA ON THE CEREBRAL ARTERIO‐VENOUS DIFFERENCE OF ACETOACETATE, d‐β‐HYDROXYBUTYRATE AND OXYGEN IN CHILDREN

Summary Cerebral arterio‐venous differences of aceto‐acetate, D‐β‐hydroxybutyrate, glucose, glycerol, FFA, lactate, pyruvate and oxygen were determined during normo‐ and hypocapnia in children anaesthetized in connection with surgical operations or X‐ray procedures. Cerebral flow equivalent values were used to calculate the relative changes in uptake or production of substrates during hypocapnia. The uptake of ketone bodies was proportional to the cerebral blood flow and to the arterial concentration. In comparison with reported values in adults the estimated uptake of ketone bodies at a given arterial concentration was about four times higher in children. During hypocapnia, but not during normocapnia children had a significant lactate production. The vasodilating effect of carbon dioxide on the cerebral blood vessels seems to be the same in children and adults.