Respiratory Acidosis

Abstract

RESPIRATORY ACIDOSIS is the abnormal physiologic state which occurs when the blood level of dissolved CO₂, and consequently of carbonic acid, is elevated. The term respiratory acidosis will be used to apply even to those conditions in which the blood is not abnormally acid in reaction, following a clinical usage of the term. Nevertheless it should be clear that the major problem in hypercapnic states lies in the elevation of CO₂ tension in blood and tissues, rather than in the varying degree of acidosis of the blood. Respiratory acidosis is unique in that the acid (as dissolved CO)₂ penetrates cells and cerebrospinal fluid rapidly, rather than with the slower movement characteristic of ions. Consequently intracellular acidosis occurs more rapidly. Alveolar ventilation and CO₂ production determine the alveolar and therefore arterial and tissue levels of P_co2. The following equation expresses this relationship in simplified form. where Vco₂ is the CO₂ output