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Deteriorating Patient

Lung Auscultation


Breath Sounds

    • Interpretation

    • Vesicular breath sounds: soft, non-musical, heard in inspiration and early expiration
    • Bronchial breath sounds - hollow sounds similar to those normally heard over the trachea
    • Causes of Reduced Breath Sounds

    • Shallow breathing - e.g. due to anxiety or CNS depression
    • Obstruction - foreign body, tumour, asthma, COPD
    • Pleural effusion
    • Pneumothorax
    • Obesity


  • Stridor refers to musical, high-pitched heard in the upper airways or even without a stethoscope. This finding is suggestive of upper airway obstruction.
    • Causes

    • Soft tissue swelling - peritonsillar abscess, epiglottitis
    • Deformity - laryngomalacia, laryngeal mass / web, tracheomalacia
    • Foreign body aspiration (infants)
    • Laryngotracheobronchitis (croup)
    • Vocal cord lesion / paralysis
    • Psychogenic stridor


  • Wheeze refers to high-pitched musical sounds, which suggest small airway narrowing.
    • Causes

    • Asthma
    • Chronci obstructive pulmonary disease (COPD)
    • Viral bronchospasm
    • Bronchiectasis
    • Pulmonary oedema
    • Aspiration
    • Bronchial / tracheal obstruction - foreign body, tumour, stenosis
    • Churg-Strauss syndrome
    • Carcinoid syndrome
    • Allergic bronchopulmonary aspergillosis (ABPA)

Crackles / Crepitations

  • Crackles / crepitations are short, explosive sounds. These may be fine or coarse, and may be cleared by coughing (if due to secretions)
    • Causes

    • Coarse Crepitations

    • Pneumonia
    • Bronchiectasis
    • Chronic bronchitis
    • Pulmonary oedema - congestive cardiac failure, fluid overload
    • Fine Crepitations

    • Interstitial lung fibrosis

Pleural Rub

  • A pleural rub is a classical sign of pleural inflammation, or pleurisy.
    • Listen For

    • Non-musical, explosive sounds best heard at the lung bases
    • Causes of Pleurisy

    • Infection - viral, bacterial, tuberculosis, fungal
    • Malignancy - lung cancer, mesothelioma, lymphoma
    • Autoimmune - rheumatoid arthritis, SLE
    • Pulmonary embolism
    • Familial Mediterranean fever
    • Asbestosis
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