Pathological Lung Sounds

Pathological Lung Sounds

Learning Objectives

• Define tactile fremitus and egophony and explain their physiological basis in normal lung function.

• Describe how sound waves travel through different lung tissues and differentiate between normal and abnormal findings.

• Compare and contrast the expected findings of tactile fremitus and egophony in various pulmonary conditions (e.g., pneumonia, pleural effusion, pneumothorax, COPD).

Poll

In which condition is fremitus increased?

• Pleural Effusion

• Atelectasis

• Simple pneumothorax

• Consolidation

• Tension Pneumothorax

​Fremitus

• Sound vibrations that travel from the vocal cords through the bronchi and into the lungs

• Typically, sound vibrations get dampened between the lungs and where you feel it on the patient's back

​Consolidation

​Fluid/Air

​Answers to Question 1

• Pleural Effusion

  • Fluid in the pleural cavity increases the distance between the lungs and the chest wall

  • Fluid in the pleural cavity absorbs the sound vibrations and dampens the sound

• Atelectasis/Simple/Tension Pneumothorax

  • The collapsed lung increases the distance between the lungs and the chest wall

  • Air is a poor conductor of sound vibrations

• Consolidation

  • Dense tissue and fluid in the alveoli allow sound vibrations to be conducted to the chest wall

Poll

In which of the following condition(s) can egophony be present?

• Pleural Effusion

• Pneumothorax

• Consolidation

• COPD

Egophony

• Typically, E gets dampened between the lungs and where you hear it

AAA

EEE

AAA

EEE

​Answers to Question 2

• Pneumothorax

  • The increase in air in the pleural cavity disrupts the transmission and increases the dampening of sound through the lungs.

• COPD

  • The increase in alveolar volume leads to more air in the lung and an increase in sound dampening throughout the lung.

• Pleural Effusion

  • Egophony is not heard where the pleural effusion is but rather where the lung and the effusion meet.

  • Compression of the lung increases the density of the tissue and allows for better transmission of high-frequency sound more clearly , leading to an E to A change.

• Consolidation

  • The consolidation of fluid within the alveoli increases the transmission of high-frequency sound more clearly, leading to an E to A change.

Open Ended

Whats the difference between tactile fremitus and egophony?

​References

​1. Bender K. Loud, annoyed goat mistaken for human screaming for help by Oklahoma police - watch! People.com. May 10, 2023. Accessed February 19, 2025. https://people.com/pets/annoyed-goat-mistaken-for-human-screaming-for-help-police/.

2. Bohadana A, Izbicki G, Kraman SS. Fundamentals of lung auscultation. N Engl J Med. 2014;370(8):744-751. doi:10.1056/NEJMra1302901

3. Modi P. Egophony. StatPearls [Internet]. July 3, 2023. Accessed February 19, 2025. https://www.ncbi.nlm.nih.gov/books/NBK518991/.

4. Shellenberger RA, Balakrishnan B, Avula S, Ebel A, Shaik S. Diagnostic value of the physical examination in patients with dyspnea [published correction appears in Cleve Clin J Med. 2018 Apr;85(4):332.]. Cleve Clin J Med. 2017;84(12):943-950. doi:10.3949/ccjm.84a.16127

5. Modi P. Vocal Fremitus. StatPearls [Internet]. July 4, 2023. Accessed February 19, 2025. https://www.ncbi.nlm.nih.gov/books/NBK499838/.