Harrison's Internal Medicine Part 2. Cardinal Manifestations and Presentation of Diseases Section 6. Alterations in Gastrointestinal
Function Chapter 33. Dyspnea and Pulmonary Edema
Dyspnea The American Thoracic Society defines dyspnea as a "subjective experience of breathing discomfort that consists of qualitatively distinct sensations that vary in intensity. The experience derives from interactions among multiple physiological, psychological, social, and environmental factors, and may induce secondary physiological and behavioral responses.
Integration: Efferent-Reafferent Mismatch A discrepancy or mismatch between the feed-forward message to the ventilatory muscles and the feedback from receptors that monitor the response of the ventilatory pump increases the intensity of dyspnea. This is particularly important when there is a mechanical derangement of the ventilatory pump, such as in asthma or chronic obstructive pulmonary disease (COPD).
Approach to the Patient: Dyspnea (Fig. 33-3) In obtaining a history, the patient should be asked to describe in his/her own words what the discomfort feels like, as well as the effect of position, infections, and environmental stimuli on the dyspnea. Orthopnea is a common indicator of congestive heart failure, mechanical impairment of the diaphragm associated with obesity, or asthma triggered by esophageal reflux. Nocturnal dyspnea suggests congestive heart failure or asthma.
Distinguishing Cardiovascular from Respiratory System Dyspnea If a patient has evidence of both pulmonary and cardiac disease, a cardiopulmonary exercise test should be carried out to determine which system is responsible for the exercise limitation. If, at peak exercise, the patient achieves predicted maximal ventilation, demonstrates an increase in dead space or hypoxemia (oxygen saturation below 90%), or develops bronchospasm, the respiratory system is probably the cause of the problem.
Differential Diagnosis Dyspnea is the consequence of deviations from normal function in the cardiopulmonary systems. Alterations in the respiratory system can be considered in the context of the controller (stimulation of breathing); the ventilatory pump (the bones and muscles that form the chest wall, the airways, and the pleura); and the gas exchanger (the alveoli, pulmonary vasculature, and surrounding lung parenchyma). Similarly, alterations in the cardiovascular system can be grouped into three categories: conditions associated with high, normal, and low cardiac output (Fig. 33-2).
Although dyspnea is a common symptom, there has been only limited investigation of
its prognostic significance among patients referred for cardiac evaluation.
We studied 17,991 patients undergoing myocardial-perfusion single-photon-emission
computed tomography during stress and at rest. Patients were divided into five categories
on the basis of symptoms at presentation (none, nonanginal chest pain, atypical angina,
typical angina, and dyspnea).
Mechanisms of Dyspnea Respiratory sensations are the consequence of interactions between the efferent, or outgoing, motor output from the brain to the ventilatory muscles (feed-forward) and the afferent, or incoming, sensory input from receptors throughout the body (feedback), as well as the integrative processing of this information that we infer must be occurring in the brain (Fig. 33-1). A given disease state may lead to dyspnea by one or more mechanisms, some of which may be operative under some circumstances but not others. ...
Distinguishing Cardiogenic from Noncardiogenic Pulmonary Edema
The history is essential for assessing the likelihood of underlying cardiac disease as well as for identification of one of the conditions associated with noncardiogenic pulmonary edema.
The physical examination in cardiogenic pulmonary edema is notable for evidence of increased intracardiac pressures (S3 gallop, elevated jugular venous pulse, peripheral edema), and rales and/or wheezes on auscultation of the chest.
Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học 'Respiratory Research cung cấp cho các bạn kiến thức về ngành y đề tài:Airflow limitation or static hyperinflation: which is more closely related to dyspnea with activities of daily living in patients with COPD...
Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học 'Respiratory Research cung cấp cho các bạn kiến thức về ngành y đề tài: " Gender and respiratory factors associated with dyspnea in chronic obstructive pulmonary disease...
Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học Critical Care giúp cho các bạn có thêm kiến thức về ngành y học đề tài: Perception of urge-to-cough and dyspnea in healthy smokers with decreased cough reflex sensitivity...
Health and Quality of Life Outcomes
Dyspnea and quality of life indicators in hospice patients and their caregivers
Linda E Moody* and Susan McMillan
Address: University of South Florida, College of Nursing,12901 Bruce B. Downs Blvd., MDC 22, Tampa, FL 33612 Email: Linda E Moody* - email@example.com; Susan McMillan - firstname.lastname@example.org * Corresponding author
Published: 17 April 2003 Health and Quality of Life Outcomes 2003, 1:9 This article is available from: http://www.hqlo.
Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học Critical Care giúp cho các bạn có thêm kiến thức về ngành y học đề tài: Cough and dyspnea during bronchoconstriction: comparison of different stimuli...
Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học Critical Care giúp cho các bạn có thêm kiến thức về ngành y học đề tài: Midregional pro-Adrenomedullin in addition to b-type natriuretic peptides in the risk stratification of patients with acute dyspnea: an observational study...
Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học Critical Care giúp cho các bạn có thêm kiến thức về ngành y học đề tài: Copeptin and risk stratification in patients with acute dyspnea...
Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học Critical Care giúp cho các bạn có thêm kiến thức về ngành y học đề tài: Combination of lung ultrasound (a comet-tail sign) and N-terminal pro-brain natriuretic peptide in differentiating acute heart failure from chronic obstructive pulmonary disease and asthma as cause of acute dyspnea in prehospital emergency setting...
(BQ) Part 2 book "Tips and tricks of bedside cardiology" presents the following contents: Exertional dyspnea, cyanosis and fainting, fever with chills and petechial spots; exertional dyspnea and sudden hemiparesis; retrosternal discomfort upon climbing stairs; recent increase in angina frequency;...
(BQ) Part 2 book "ECG rounds" presents the following contents: An asymptomatic 30-year-old woman, 53-year-old woman with long-standing mitral valve prolapse, an 89-year-old gentleman with hypertension, presenting for routine follow-up, 45-year-old gentleman presents with dyspnea,...
Pulmonary embolism is a serious, potentially life-threatening cardiopulmonary disease
that occurs due to partial or total obstruction of the pulmonary arterial bed. Pulmonary
embolism constitutes 5-25% of in-hospital deaths, and mortality is decreased from 30%
to 8% with early treatment. Therefore, risk factors should be identified and treatment
should be planned to decrease the risk of mortality. Clinical findings, routine laboratory
data, electrocardiogram, chest X-ray, and arterial blood gases are not sufficient to
diagnose or rule out pulmonary embolus.