During the DLCO single breath technique, how long should the patient hold their breath?

In the DLCO (Diffusing Capacity of the Lung for Carbon Monoxide) single breath technique, the recommended breath-holding time is typically around 10 seconds. This duration is crucial for allowing sufficient time for carbon monoxide (CO) to diffuse across the alveolar-capillary membrane into the bloodstream.

Holding the breath for 10 seconds maximizes the contact time between the alveoli and the inhaled gas, ensuring that the measurement reflects an accurate assessment of the lung's diffusing capacity. If the breath-holding time is shorter, the measurement may underestimate the diffusing capacity, while a longer duration might lead to inaccuracies due to the re-distribution of the gas or changes in lung mechanics.

This timing is standardized in pulmonary function testing to maintain consistency across different tests and subjects, aligning with the established guidelines for DLCO testing.