Yes, DLCO testing can be performed on patients with severe COPD, provided they can hold their breath for the required 10 seconds. In cases where your FEV1 is below 35% of the predicted value, we may adjust the manoeuvre to ensure you don’t feel overly distressed. This test is crucial for distinguishing between chronic bronchitis and emphysema. We’re here to provide the specialised support and expertise needed to make this process accessible for everyone.