Applied Lung Physiology

Abstract

This chapter has been written by two clinicians with immense experience in the measurement and interpretation of lung function testing; one a physician and one a physiologist, but both extremely passionate about educating others in understanding lung function. As an introduction to lung function testing for the trainee respiratory physician, this chapter covers some of the essential questions including “Why test lung function?”, “What’s normal and abnormal lung function?”, and “What are the basic principles of the main lung function tests?”

The chapter has a simple overview of spirometry and its interpretation and then moves on to the various lung volume measurements commonly used. The only real test of gas exchange function—the gas transfer test—is covered in reasonable detail. Whilst these measurements probably cover 80% of the normal requests for lung function testing, the methods for respiratory muscle assessment are essential for trainees to understand and use when they diagnose and treat these patients.

Finally, cardiopulmonary exercise testing is given an overview to give you the essential features on what is a very complex physiological measurement which is often poorly understood. The reader will have a teaser of the usefulness of lung function testing. You will be challenged to interpret tests without “percentage of predicted” and the errors it introduces and you will have an excellent overview albeit an “aide-memoire” of the basics of clinical respiratory physiology.