Richard Johnston

I’ve been reading Miller et al’s Laboratory evaluation of Pulmonary Function which was published in 1987. That was an interesting time since PFT equipment manufacturers had mostly trans…

A friend is taking her father to a PFT lab (2500 miles away from where I am the moment so I couldn’t go along with them) because he has been short of breath for a couple of years, but oddly e…

Turbine spirometers have been around in one form or another for well over a hundred years. The accuracy of the early versions of this type of spirometer was poor, partly because of the turbine desi…

I’ve been thinking a bit about the shape of flow-volume loops lately. In part this has been about ways to accurately describe them in reports; in part speculation about the information that m…

A report came across my desk today and at first glance it looked fairly straightforward. There was a mildly reduced TLC and FVC, and although the SVC was slightly lower than the FVC it looked like …

I was reading an article recently that made an off-hand reference to the 100% oxygen shunt fraction test. Results from the test were included in the data analysis but the equations the researchers …

I often find topics for this blog in a sideways fashion. Recently while searching for something else I ran across an article about the minimum clinically important difference (MCID) of the Residual…

For the first dozen or so year that I worked in a pulmonary function lab it was with counter-weighted, volume-displacement water-seal spirometers more or less like this: Patients would do a series …

The patients whose reports I review have always been very accommodating. An issue of one kind or another catches my attention and before I know it I find several more reports that are similarly inv…

My hospital has an active liver transplantation program and all transplant candidates get a full panel of PFTs in my lab. The number of liver transplant candidates we get varies from week to week b…