Respiratory-Circulatory Interactions in Health and Disease PDF

Preface

The cardiovascular and respiratory systems are both concerned with the transport of oxygen and metabolic byproducts to and from peripheral tissues. Indeed, it has been known for many years that the two systems are intimately linked to each other. They are connected mechanically both serially and in parallel, and neurophysiologically by virtue of the proximity of control centers in the brainstem. This makes great teleological sense since the whole organism's response to emergent challenges involves both systems. Indeed, research into the field has been carried out for decades along roughly parallel lines, one being the mechanical and one the neurophysiological interactions. With the advent of critical care, in which dysfunction of both systems occurs, or in which manipulation of one system leads to changes in the function of the other, understanding of heart–lung interactions took on new interest.

In the first edition of this book, published over a decade ago, the emphasis was clearly on mechanical interactions of clinical significance, including effects of lung volume, intrathoracic pressure, ventricular interdependence, and respiratory muscle function. Over the last decade, many of the questions dealt with in the first edition have come into greater focus. Further, investigators into other important diseases—such as left ventricular failure, obstructive sleep apnea, and sudden infant death syndrome—have emphasized the importance of both mechanical and neuro physiological heart–lung interactions in the pathogenesis of these clinical conditions. Finally, there have been advances in our understanding of the humoral/molecular biological basis of disease leading to cardiorespiratory failure, especially the sepsis syndrome. The importance of signaling molecules, especially nitric oxide, in this syndrome is being increasingly understood.

This book, a continuation of Heart–Lung Interactions in Health and Disease, attempts to touch on all these aspects. The traditional mechanical interactions are all dealt with, and emphasis has been placed on developments over the last decade. Additionally, the reader will recognize where new topics relevant to these topics have been introduced. As such, expanded coverage of sleep-disordered breathing, left ventricular failure, and cardiopulmonary failure in sepsis has been included. As in the previous edition, each chapter gives its authors' point of view on the state of the art of the field and, often, where they believe future research should be directed.

The book is divided into three parts. Part One (Basic Physiology) includes discussion of those areas necessary for understanding the basic principles of cardiocirculatory interactions. This section includes description of pulmonary mechanics, respiratory muscle function, exercise physiology, control of venous return and cardiac output, as well as various aspects of cardiocirculatory function, and cardiopulmonary interactions. New topics include the control of tissue metabolism, the development of the sympathetic nervous system, mathematical modeling of mechanical heart–lung interactions, and image analysis as a tool for investigating cardiocirculatory function. Part Two (Pathophysiology) includes topics related to the generation of disease states. New topics include molecular/cellular mechanisms underlying acute hypoxic pulmonary vasoconstriction, neurophysiological interactions during sleep, effects of muscle reflexes on respiration and circulation, and the effects of systemic inflammatory response on cardiovascular function. Part Three (Clinical Problems) includes chapters describing a number of important clinical conditions in terms of basic physiology and pathophysiology. We have included chapters on the effects of heart failure including abnormal control of circulation and ventilation, the use of respiratory maneuvers to support the failing circulation, and the effects of chronic obstructive lung disease on cardiocirculatory function. The last subsection of Part Three deals with the application of the principles of heart–lung interactions in the critical care unit. This includes sections of the use of the balloon-tipped catheter, including the controversies surrounding this mode of diagnosis and treatment, important causes of cardiocirculatory failure in sepsis (especially as related to the production of NO), and chapters on the principles of heart–lung interactions in some specific clinical situations. Finally, the use of a respiratory treatment, inhaled NO, to treat circulatory failure has been covered.

As in the first edition of this book, it is our hope that the material contained herein will provide the reader with a rational basis for understanding the ways in which the cardiovascular and respiratory systems interact in normal and abnormal situations. Hopefully, the material will be provocative and controversial, and stimulate some investigation into these important problems. In this way, we hope to continue to expand the corpus of knowledge in this area.