CNS Disorder During Mechanical Ventilation in Chronic Pulmonary Disease

Abstract

Five patients with obstructive pulmonary disease developed generalized fits, coma, and multifocal central nervous system excitation following vigorous correction of chronic hypercapnia. Clinical improvement occurred prior to the onset of neurological symptoms. Alkalosis with persistent elevation of plasma bicarbonate concentration was the outstanding biochemical abnormality. Two patients recovered when their arterial CO₂ tensions were allowed to rise. Alkalosis should be avoided when treating pulmonary decompensation. Since hypoxia can be corrected rapidly by oxygen therapy, the hypercapnia can be corrected more gradually by successive increments in ventilation.