Table 3

 Relation between Petco2 values and severity of lung disease

Severe (n = 12)Mild-moderate (n = 8)
Mean (SD)95% CIp ValueMean (SD)95% CIp Value
All CO2 values in kPa. Severe lung disease, PAo2/Pao2 ratio <0.3; mild-moderate lung disease, PAo2/Pao2 ratio ⩾0.3.
P(a-Et)co21.21 (0.76)0.87 to 1.88<0.0010.99 (1.16)−0.61 to 1.370.013