Respiratory acidosis.

In the initial specimen, the pH is acidotic and the pCO2 is greater than 40 mm Hg, indicating that the lung has retained acid in the body and is at least a partial cause for the acidosis. The serum bicarbonate is 24, indicating that the kidney has not had time to compensate for the respiratory problem.

Hematocrit          52 %
Serum bicarbonate   24 meq/l

        Day 1, 63% O2 by hood      Day 3, 25% O2
------------------------------------------------
pO2         107      63                  57
pCO2         48      45                  36
pH         7.35    7.37                7.43