Bedside rebreathing technique for measuring carbon-monoxide uptake by the lung.

The uptake of carbon monoxide can be measured at the bedside by a rebreathing technique using an anaesthetic bag. A good correlation was found between this method and the standard single-breath measurement in normal subjects and in patients with interstitial lung disease. The rebreathing technique was as sensitive as the single-breath method in detecting lung haemorrhage in a patient with Goodpasture's syndrome, and was able to monitor its resolution as quickly.