Preface

“The condition of exercise is not a mere variant of the condition of rest, it is the essence of the machine.” Sir Joseph Barcroft (1934) People are usually breathless when they are doing something, so it makes sense to assess their symptoms and make physiological measurements during exercise rather than to rely on investigations performed at rest. Cardiopulmonary exercise testing is therefore an excellent way to work out why someone is breathless and to quantify their limitation. Maximum oxygen uptake (VO2max) during exercise is also one of the best predictors of operative mortality and of prognosis in chronic cardiac or respiratory disease (as well as being an excellent measure of overall fitness in athletes). The cardiopulmonary exercise test (CPET), during which VO2max is routinely measured, is an increasingly common component of preoperative assessment and the management of patients with chronic lung or heart problems. This book is a guide for clinicians and works logically through the main parameters that are measured during a CPET. The physiology behind the calculation of these parameters is explained, so that interpretation of the results is based on a full understanding of the scientific principles from which they are derived. Clinical scenarios, key points, and practical tips all make this book easy to follow.