Richard Johnston

Once again my lab was questioned by a research study’s primary investigator and study coordinator about why our lung volume results came out significantly lower than another lab’s. In o…

Last week I was discussing the use of DL/VA to differentiate between the different causes of gas exchange defects with a physician. DL/VA is DLCO divided by the alveolar volume (VA). It is an often…

Oddly enough, I recently got a couple emails on the same day about the FEF25-75 and ended up corresponding for a while with the authors. FEF25-75 is a subject that somehow manages to keep resurrect…

In patients with lung disease the use of supplemental oxygen during exercise increases oxygen consumption, endurance time and maximum workload, and decreases the sensation of dyspnea without increa…

Although we routinely use mouthpieces, noseclips and occasionally masks for our testing, all of these alter respiration in one way or another. Opto-electronic plethysmography (OEP) is a completely …

Since I started performing exercise tests I’ve used both treadmills and bicycle ergometers. There are a several reasons that make ergometers somewhat better for exercise testing than treadmil…

Reports are how patient test results are distributed. Paper versions have become less common because reports are now stored electronically in hospital information systems. Even if the way in which …

I was reviewing PFT reports today and noticed that a patient appeared to have had the wrong gender entered in their demographic information. Specifically, the patient had an unambiguously masculine…

Recently a patient was referred to my lab for a CPET by his oncologist. The patient had been complaining of excessive shortness of breath particularly when climbing only a few stairs. The patient r…