[Gas acidosis and alkalosis]

Arterial concentration of CO2 (PaCO2) is dependent of pulmonary excretion. When this excretion is lower than cellular production respiratory acid-basis occurs: rise in PaCO2 which lowers pH and produces secondary increases in bicarbonate (HCO3-) plasma concentration. Respiratory alkalosis, generated by a CO2 pulmonary excretion greater than metabolic production is characterized by a fall in PaCO2 which raises pH and induces secondary reduction of plasmatic HCO3- concentration. Attention to the possibility of serious hypoxemia, cause or consequence, should always be regarded and treated in respiratory acid-base disorders.