Prediction of carbon monoxide diffusing capacity of the lung in splenectomized sheep.

The steady state diffusing capacity of the lung for carbon monoxide (DLCO) was studied in 18 splenectomized adult ewes. Seven animals were anemic when studied. Weight (Wt) and, to a lesser extent, hemoglobin (Hb) level were the key predictive variables of DLCO. Sheep DLCO can be expected to range between 15 and 28 ml/min/mmHg in adult ewes which are not anemic. When DLCO measurements were repeated up to three times on the same day no significant decreases occurred. Thus, the data demonstrated no CO back-pressure caused by preceding DLCO determinations. This paper's importance is in defining a normal predictive range for this sensitive parameter of pulmonary function.