Auscultation sounds

Fine crackles: clinical causes

Atelectasis; inter-alveolar oedema; secretions in small airways

Fine crackles: atelectasis

Short, explosive; periphery of lung; reduces with deep breathing

Fine crackles: inter-alveolar oedema

Does not resolve with deep breath or cough; late inspiration (interstitial fibrosis)

Fine crackles: secretions in small airways

High pitched; peripheral; clears with cough

Coarse crackles: what they sound like

Pouring milk on Rice Krispies

Coarse crackles: cause

More proximal obstruction; tends to be larger airways with sputum

Coarse crackles: timing

May be inspiratory and expiratory

Coarse crackles: associated conditions

COPD, bronchiectasis, pneumonia, lung abscess, TB

Coarse crackles: early expiratory vs late expiratory

Early expiratory = central airways; late expiratory = more peripheral airways

Coarse crackles: how to differentiate the sound

Large, deep sound; changes/clears with coughing

Crackles: when are they heard?

Only if velocity of airflow is adequate and breath sounds are audible

Wheeze: definition

Musical sounds due to vibration of the wall of a narrowed airway

High-pitched wheeze: cause and relevance

Bronchospasm; potential increased work of breathing

Low-pitched wheeze: cause

Sputum

Low-pitched wheeze: how to differentiate

Disrupted turbulent flow; changes with coughing

Localized wheeze: causes

Tumour; foreign body

Localized wheeze: how to differentiate

Limited to a local area on auscultation

Pleural rub: what it sounds like

Creaking/rubbing (like boots on snow); localized or generalized; soft or loud; equal inspiration to expiration

Pleural rub: causes

Inflammation of pleura; infection; tumour

Stridor: what it sounds like

Constant pitch on inspiration and expiration; produced in upper airways

Stridor: causes

Croup; laryngeal tumour; upper airway obstruction

Stridor: clinical action

Alert medical staff, as the patient's airway is at great risk of compromise

Which added sound reduces with deep breathing?

Fine crackles from atelectasis

Which added sound is high pitched, peripheral and clears with cough?

Fine crackles from secretions in small airways

Which added sound is heard in late inspiration and does not clear with a deep breath or cough?

Fine crackles from inter-alveolar oedema (interstitial fibrosis)

Which added sound is caused by upper airway obstruction and is a medical emergency?

Stridor

Which added sound is described as boots on snow?

Pleural rub

Which wheeze is limited to one area on auscultation?

Localized wheeze (think tumour or foreign body)