Clinical Significance of Elevated DLCO

Interpretation of DLCO Values

The American Thoracic Society recommends that DLCO be used to evaluate gas transfer in the lungs and is widely used in the preoperative evaluation of patients with lung cancer 1, 2
Low DLCO values (<60%) are associated with higher mortality and pulmonary morbidity postoperatively, while high values do not typically indicate severe pathology 2, 3

The European Respiratory Society suggests that both FEV1 and DLCO should be measured systematically in the preoperative evaluation of patients with lung cancer, regardless of the preoperative level of FEV1 2, 3
A reduced DLCO (<60%) is associated with a 25% mortality rate and 40% pulmonary morbidity in patients undergoing lung resection 2, 3

Hemorrhage into the lung can be a less common cause of elevated DLCO 4
The European Respiratory Society recommends that DLCO be interpreted in conjunction with spirometry and lung volume assessment to aid in the diagnosis of underlying disease 4, 5
Adjustments for changes in hemoglobin and carboxyhemoglobin are important, especially in situations where patients are being monitored for possible pharmacological toxicity 4
The lower limit of normal for DLCO should be the 5th percentile of the reference population 5, 6