Exhaled breath condensate (EBC) analysis is useful in assessing patients who are having difficulty breathing. Though the technique is non-invasive, it can be difficult for sick patients, according to researchers from St. Vincent’s Hospital in Sydney, Australia.

The researchers recruited patients who were admitted via the ER and were diagnosed with either community acquired pneumonia (CAP) or acute cardiogenic pulmonary edema.

The researchers measured the biomarkers C-reactive protein, neopterin, and 5N-terminal pro-brain natriuretic peptide and fractional exhaled nitric oxide. The results of the analyses were compared with those from 15 healthy control subjects.

Originally, the researchers recruited 20 subjects from each group, however, not all of the patients were able to complete the EBC collection. In order to complete that collection, the patients were required to breathe into a device for 10 minutes. Several asked to stop before enough EBC was collected.