The effects of acidemia on electrolyte levels are complex. In general, acute respiratory acidemia causes no change or only a slight increase in extracellular potassium and phosphate levels. Respiratory effects Normally, CO 2 is a respiratory stimulant. Maximal effect is obtained when the pCO 2 ranges from 100-150 mmHg. At higher levels, stimulation is reduced and eventually CO 2 acts as a respiratory depressant.
Acute hypercapnia causes depression of diaphragmatic contractility and decreases endurance time.
However, excess CO 2 itself can contribute to hypoxemia. This is predicted by the Alveolar Gas Equation, or simply put, the summation of pO 2 and pCO 2 . 2 PAO 2 . Therefore, PACO 2 is ultimately dependent on the level of inspired oxygen. Practically speaking, pCO 2 values greater than 90 mmHg are unlikely to occur because the concomitant degree of hypoxia would be incompatible with survival.