Dyspnea: Mechanisms, Measurement, and Management
http://www.100md.com
《新英格兰医药杂志》
This book on dyspnea will be useful to a wide audience of clinicians, and the book's subtitle, "Mechanisms, Measurement, and Management," reveals its important focus. The appealing chapter on the history of dyspnea by Kieran Killian tells the story from the origins of the illness as recorded in hieroglyphics in Mesopotamia (3300 B.C.) to modern views of sensory physiology and psychophysics.
In a remarkable chapter, "Language of Dyspnea," Richard M. Schwartzstein brings the reader up to date on the development of dyspnea questionnaires, clusters of dyspnea descriptions, and examples of phrases used by patients to describe their perceptions of dyspnea. The art of taking a careful history with the aid of the tools described by Schwartzstein will give clinicians a measure of functional impairment in relation to the magnitude of the task undertaken by the patient and the effort involved. The goal of such assessments is to improve the evaluation of changes in the degree of dyspnea from a baseline state — a badly needed objective resource.
The diagnosis of unexplained dyspnea must take into account cardiac deconditioning, or heart failure with systolic dysfunction, diastolic dysfunction, or both. As the chapter on this topic explains, such cardiac abnormalities are common in the elderly and easily missed if echocardiography is not performed. Vocal-cord dysfunction consisting of paradoxical adduction of the cords during inspiration can easily be mistaken for asthma, but standard rhinolaryngoscopy will spot the problem. Hyperventilation disorders are surprisingly common; patients report breathlessness and show signs of abnormal breathing patterns both at rest and during exercise.
The book's editors, Donald A. Mahler and Denis E. O'Donnell, have written a scholarly chapter on the effect of bronchodilators (with or without corticosteroids) on dyspnea in chronic obstructive pulmonary disease (COPD). They document that clinically significant improvements in dyspnea and exercise capacity can occur with only minimal improvements in forced expiratory volume in one second. They deplore the pervasive therapeutic nihilism concerning dyspnea in COPD, and they support their views with persuasive data. However, they admit that bronchodilators reduce the severity of dyspnea in COPD by only a small degree.
A chapter on pulmonary rehabilitation and its effect on dyspnea enumerates four essential components: education for understanding COPD; exercise for improving strength and endurance; nutritional therapy to counteract cachexia; and behavioral intervention to minimize anxiety and depression. Although there is no evidence of any clinically significant effect on the underlying pathophysiology of COPD, the authors propose that, at the very least, exercise training improves what they call "secondary morbidity" by improving peripheral and respiratory muscle performance, correcting obesity or muscle wasting, and alleviating anxiety, panic, and depression. How this comes about is a mystery, but patients who undergo pulmonary rehabilitation feel better.
The final chapter deals with the management of dyspnea at the end of life, and it is outstanding. The author, D. Dudgeon, reviews both pharmacologic and nonpharmacologic interventions. There is evidence to support the safe use of parenteral opioids in the control of dyspnea, provided that the detailed guidance in the chapter's appendix is followed. This guidance relates the dose of the opioid to the degree of dyspnea; all doses given are dependent on the previous dose. My only criticism of this excellent book is that it fails to review what little we know of the neurologic basis of the symptoms of dyspnea.
Abraham Guz, M.D.
Imperial College School of Medicine
London W6 8RF, United Kingdom
a.guz@imperial.ac.uk((Lung Biology in Health a)
In a remarkable chapter, "Language of Dyspnea," Richard M. Schwartzstein brings the reader up to date on the development of dyspnea questionnaires, clusters of dyspnea descriptions, and examples of phrases used by patients to describe their perceptions of dyspnea. The art of taking a careful history with the aid of the tools described by Schwartzstein will give clinicians a measure of functional impairment in relation to the magnitude of the task undertaken by the patient and the effort involved. The goal of such assessments is to improve the evaluation of changes in the degree of dyspnea from a baseline state — a badly needed objective resource.
The diagnosis of unexplained dyspnea must take into account cardiac deconditioning, or heart failure with systolic dysfunction, diastolic dysfunction, or both. As the chapter on this topic explains, such cardiac abnormalities are common in the elderly and easily missed if echocardiography is not performed. Vocal-cord dysfunction consisting of paradoxical adduction of the cords during inspiration can easily be mistaken for asthma, but standard rhinolaryngoscopy will spot the problem. Hyperventilation disorders are surprisingly common; patients report breathlessness and show signs of abnormal breathing patterns both at rest and during exercise.
The book's editors, Donald A. Mahler and Denis E. O'Donnell, have written a scholarly chapter on the effect of bronchodilators (with or without corticosteroids) on dyspnea in chronic obstructive pulmonary disease (COPD). They document that clinically significant improvements in dyspnea and exercise capacity can occur with only minimal improvements in forced expiratory volume in one second. They deplore the pervasive therapeutic nihilism concerning dyspnea in COPD, and they support their views with persuasive data. However, they admit that bronchodilators reduce the severity of dyspnea in COPD by only a small degree.
A chapter on pulmonary rehabilitation and its effect on dyspnea enumerates four essential components: education for understanding COPD; exercise for improving strength and endurance; nutritional therapy to counteract cachexia; and behavioral intervention to minimize anxiety and depression. Although there is no evidence of any clinically significant effect on the underlying pathophysiology of COPD, the authors propose that, at the very least, exercise training improves what they call "secondary morbidity" by improving peripheral and respiratory muscle performance, correcting obesity or muscle wasting, and alleviating anxiety, panic, and depression. How this comes about is a mystery, but patients who undergo pulmonary rehabilitation feel better.
The final chapter deals with the management of dyspnea at the end of life, and it is outstanding. The author, D. Dudgeon, reviews both pharmacologic and nonpharmacologic interventions. There is evidence to support the safe use of parenteral opioids in the control of dyspnea, provided that the detailed guidance in the chapter's appendix is followed. This guidance relates the dose of the opioid to the degree of dyspnea; all doses given are dependent on the previous dose. My only criticism of this excellent book is that it fails to review what little we know of the neurologic basis of the symptoms of dyspnea.
Abraham Guz, M.D.
Imperial College School of Medicine
London W6 8RF, United Kingdom
a.guz@imperial.ac.uk((Lung Biology in Health a)