It is a term of a Greek root: Dys = painfull, difficult Pnea = breathing *Definition: It is an abnormally uncomfortable awareness of breathing (witch is subjective). *Causes: -Cardiac -Psychogenic - Obesity -Respiratory -Anaemia -****bolic -Fever *Mechanism &Physiological basis: Any increase in respiratory work or load due to: ↑ Ventilatory rate or ↓ Ventilatory capacity → DYSPNEA This is through stimulation of: 1-intrathoracic (J) receptors (via vagus). 2-afferent nerves in respiratory muscles, chest wall, skeletal muscles and joints. 3-chemoreceptors in the brain, aortic arch and carotid bodies. 4-higher centers. 5-phrenic nerves (some afferent fibers). *Patterns of dyspnea: Orthopnea: dyspnea in supine position. Platypnea: dyspnea in upright position. Trepopnea: dyspnea in lateral position. *Respiratory causes: -Laryngeal: spasm or oedema -Tracheobronchial: F.B, secretions, tumours, C.O.P.D. -Parynchematous lung diseases: consolidation, fibrosis or collapse. -Pleural: effusion, pneumothorax. -Chest wall: kyphoscoliosis, obesity or trauma. *Cardiac causes: Left ventricular failure Mitral stenosis *****bolic causes: -D.K.A. -Lactic acidosis. -Uremia. -Salicelate toxicity. *GRADING&QUANTITATION: Dyspnea on exertion: Mild →on severe exertion Moderate →on moderate exertion Severe →on mild exertion Dyspnea on rest: Orthopnea P.N.D Cardiac asthma *An approach to the differential diagnosis of the patient with chronic exertional dyspnea: *C.O.P.D: History: -history of exertional dyspnea over months or years. -↓ exercise capacity by time. -chronic cough & expectoration. -recurrent attacks of acute bronchitis. -wheezes especially with exercise. -if patient developed core pulmonale→ orthopnea, nocturnal dyspnea, ankle swelling. On examination: Cyanosis,wheezes,pursing of lips,indrawing of I.C muscles, barell chest. C.X.R→hyperinflation, bullae A.B.G→hypoxia, hyercapnea spirometry→↓ FEV1 *HEART DISEASES: -history of hypertension (headache, blurring of vision,…). -anginal pain (retrosternal, radiating to shoulder.jaw,..). -family history of heart diseases. On examination: Cardiomegaly ↑J.V.P Murmurs C.X.R→cardiomegaly *INTERSTITIAL LUNG DISEASES: -History of exposure to dust, silica, birds, occupational asthma On examination: ↓ Vital capacity C.X.R→fibrosis *An approach to the patient with acute severe dyspnea: -It is a medical emergency – dramatic presentation -rapid history&examination -investigations include: CXR, ECG, ABG, and ECHO. History: -similar attacks, previous diseases. -associated symptoms: Cardiovascular→chest pain, palpitation, orthopnea, sweating. Respiratory→cough, haemoptysis, wheezes, stridor. Provocating factors: Infection Drug intake Smoking Allergens: dust, pullens, birds. Examination: Assessment of the severity of the case by: -level of consciousness. -air way potency. -ability to speake. -pulse, ABP. -cyanosis, clubbing, polythycemia. -urticaria, angioedema (anaphylaxis). -respiratory rate, pattern of breathing. -wheezes, crepitation, ↓breath sound. -hyperresonence, dullness.
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