Alterations in acid-base status and blood gas dynamics during progressive hyperkalaemia in neonatal calves.

Alterations in acid-base status and blood-gas dynamics were studied during induced progressive hyperkalaemia in neonatal calves. The hyperkalaemia was associated initially with respiratory alkalosis in arterial blood when plasma K+ was increased to 6.08 +/- 1.02 mmol litre-1. The rise of plasma K+ above 6.08 +/- 1.02 mmol litre-1 led to the development of metabolic acidosis in arterial and venous blood. There was partial respiratory compensation. Plasma K+ concentrations at or above 11.03 +/- 0.34 mmol litre-1 were associated with a decrease in arterial oxygen tension and arterial oxygen saturation. The oxygen extraction ratio was increased during hyperkalaemia.