Lung Auscultation

Objectives

• Understand lung anatomy for effective auscultation.
• Identify specific auscultation sites using anatomical landmarks.
• Differentiate between normal and abnormal breath sounds.

Lung Anatomy

Anterior Chest

• Predominantly upper lobes of the lungs.
• Landmarks: Clavicle, intercostal spaces.
• Right Lung:
  • Right Upper Lobe
  • Right Middle Lobe
  • Right Lower Lobe
  • Horizontal and Oblique Fissures
• Left Lung:
  • Left Upper Lobe
  • Left Lower Lobe

Posterior Chest

• Predominantly lower lobes of the lungs.
• Landmarks: Clavicle, scapula, C7 to T10.
• Right Lung:
  • Right Upper Lobe
  • Right Lower Lobe
• Left Lung:
  • Left Upper Lobe
  • Left Lower Lobe

Auscultation Tips

• Use stethoscope diaphragm directly on skin.
• Raise women’s breasts for better sound quality.
• Note full cycle of inspiration and expiration.
• Assess both anteriorly and posteriorly.
• Start from apex (top) and move downward, comparing sides.
• Seat patient upright for better access to posterior chest.
• Have patient breathe in and out of mouth slowly.

Auscultation Sites

Anterior Chest

• Apex of Lungs: Above the clavicle.
• Upper Lobes: 2nd Intercostal Space, mid-clavicular.
• Right Middle Lobe: 4th Intercostal Space, mid-clavicular.
• Lower Lobes: 6th Intercostal Space, mid-axillary.

Posterior Chest

• Upper Lobes: C7 to T3, between scapula and spine.
• Lower Lobes: T3 to T10, between scapula and spine.

Normal Breath Sounds

Types

1. Bronchial

   • Heard anteriorly over trachea.
   • High pitched, loud.
   • Expiration longer than inspiration.

2. Bronchovesicular

   • Heard anteriorly (1st and 2nd intercostal space) and posteriorly (between scapula at T3/T4).
   • Medium pitch.
   • Inspiration and expiration equal.

3. Vesicular

   • Heard throughout peripheral lung fields anteriorly and posteriorly.
   • Low pitch, soft.
   • Inspiration longer than expiration.

Abnormal Breath Sounds

Continuous Sounds (lasting >2 seconds)

1. High Pitch Polyphonic Wheeze

   • Mainly on expiration, high pitch, musical.

2. Low Pitch Monophonic Wheeze

   • Mainly on expiration, low pitch.

3. Stridor

   • Heard on inspiration, high pitch, harsh.

Discontinuous Sounds (lasting <2 seconds)

1. Coarse Crackles

   • Mainly on inspiration, low pitch, wet bubbling.

2. Fine Crackles

   • On inspiration, high pitch, does not clear with coughing.

3. Pleural Friction Rub

   • Both inspiration and expiration, low pitch, harsh grating.

• Note: Differentiate pleural from pericardial friction rub by listening to the heart while patient holds breath.

Conclusion

• Review lung auscultation and sounds using available quizzes and materials.
• Continue practice with a stethoscope to become familiar with sound differences.