Category pftblog

The March 1, 2014 issue of the American Journal of Respiratory and Critical Care Medicine had an article on the use of the Lung Clearance Index (LCI) with bronchiectasis. The study showed that the …

Closing Volume (CV) is a measurement made from a single-breath nitrogen washout (SBNW) test. It was commonly performed decades ago and elevated values were considered to be an indication of small a…

In 1844 John Hutchinson published his first paper describing his spirometer and his research on the Vital Capacity. He was the first person to use the word “spirometer” to describe his instrument a…

I was reviewing a pre- and post-bronchodilator spirometry report that showed a relatively large increase in FVC but the change in FEV1 was not significant. It’s not impossible for a patient t…

The current ATS/ERS guidelines require that an individual have a post-bronchodilator increase in FEV1 or FVC of at least 12% and 200 ml in order for it to be considered a significant response. Nume…

Patients with COPD often have a ventilatory limitation as their primary limitation to exercise. A ventilatory limitation to exercise has traditionally been assessed by the breathing index or the br…

I was about to put a PFT report I’d been reviewing in my outbox when I noticed something odd about the flow-volume loop. What I saw was that the final inspiration of the FVC maneuver had ende…

Recently I was discussing a flow-volume loop with one of our pulmonary physicians. His concern was whether the loop, which was from a patient with a cracked hyoid, was showing inspiratory obstructi…

Recently I was reviewing a cardio-pulmonary exercise test (CPET) that at first glance seemed to show the patient had a pulmonary mechanical limitation. Specifically, the patient’s minute vent…