What are the Diffusing Capacity of the Lung for Carbon Monoxide (DLCO) criteria for lung resection?

From the Guidelines

Patients with a DLCO value greater than 60% of predicted are generally considered safe for proceeding with lung resection, while those with DLCO less than 30% of predicted are at significantly increased risk for postoperative complications and mortality. For patients with DLCO between 30-60% of predicted, additional cardiopulmonary exercise testing should be performed to assess oxygen consumption capacity. When DLCO is borderline, combining it with FEV1 (forced expiratory volume in one second) in the form of predicted postoperative (ppo) values provides better risk assessment. A ppoDLCO and ppoFEV1 both greater than 40% indicate acceptable surgical risk, as suggested by 1. DLCO is particularly important because it reflects the functional surface area available for gas exchange in the lungs and correlates with oxygen transport capacity, as noted in 1. Low DLCO values suggest impaired gas exchange that may worsen after lung tissue removal, potentially leading to respiratory failure, prolonged mechanical ventilation, or death. For high-risk patients with marginal DLCO values, preoperative pulmonary rehabilitation for 4-6 weeks may improve functional capacity and surgical outcomes. Some key points to consider in the evaluation of DLCO for lung resection include:

• The use of predicted postoperative DLCO (ppoDLCO) and predicted postoperative FEV1 (ppoFEV1) to assess surgical risk, as recommended by 1
• The importance of considering both DLCO and FEV1 in the evaluation of patients for lung resection, as highlighted in 1
• The potential benefits of preoperative pulmonary rehabilitation for high-risk patients with marginal DLCO values, as suggested by 1. Overall, the evaluation of DLCO is a critical component of the preoperative assessment for lung resection, and should be considered in conjunction with other factors, such as FEV1 and cardiopulmonary exercise testing, to determine the optimal course of treatment for each patient.

From the Research

DLCO Criteria for Lung Resection

The Diffusing Capacity of the Lung for Carbon Monoxide (DLCO) is a crucial parameter in evaluating the suitability of patients for lung resection. The criteria for DLCO in lung resection are as follows:

• If the predicted postoperative DLCO (%ppo-DLCO) is ≥ 60%, the patient is considered to be at low risk for anatomic lung resection 2, 3.
• If the %ppo-DLCO is < 60%, further evaluation with a cardiopulmonary exercise test is recommended 2, 3.
• If the %ppo-DLCO is < 40%, exercise testing is necessary to assess the patient's suitability for lung resection 4, 5.
• A %ppo-DLCO > 35% of normal values and a peak exercise VO2 > 15 mL/kg/min indicate an acceptable surgical risk 5.

Preoperative Evaluation

The preoperative evaluation of patients for lung resection involves a step-wise approach:

• Initial assessment of cardiac risk and spirometric indexes, including FEV1 and DLCO 2, 3, 4.
• Estimation of predicted postoperative values of FEV1 and DLCO 2, 3, 4.
• Cardiopulmonary exercise test for patients with %ppo-DLCO or %ppo-FEV1 < 60% 2, 3.
• Quantitative lung scanning to estimate postoperative spirometry and diffusing capacity for patients with FEV1 or DLCO < 60% predicted 4, 5.