Lecture on Tactile Fremitus by Dr. Sandra Adams

Introduction

• Speaker: Dr. Sandra Adams, Pulmonologist
• Topic: Demonstration of tactile fremitus in normal lung conditions and pathological states such as pneumonia, pleural effusions, and pneumothorax.

Tactile Fremitus

• Definition: Vibration felt on the patient's chest or back during low-frequency vocalization.
• Method: Patients are often asked to say "99" to feel vibrations over the thoracic cavity with the bony surfaces of hands.

Demonstration Using Cups and Straw

• Simulation Materials: Cups and straw representing lung structures.
  • Cup: Represents visceral and parietal pleura and chest wall.
  • Straw: Acts as an air tube or bronchus.
  • Air in the Cup: Represents air in the lungs.

Normal Lung

• Baseline Experiment: Vibrations felt through the straw, akin to normal lung conditions.

Pneumonia (Consolidation)

• Setup: Cup with water (representing pus or consolidation in lungs).
• Observation: Increased vibration felt as sound travels more easily through liquid.
  • Reason: Sound travels through air, then hits liquid, amplifying vibration.

Pleural Effusion

• Setup: Smaller empty cup placed in a larger cup with water (fluid).
  • Smaller Cup: Visceral pleura.
  • Larger Cup: Parietal pleura and chest wall.
• Observation: Markedly decreased or absent vibration.
  • Reason: No direct sound connection between straw (bronchus) and liquid; fluid cushions vibration.

Pneumothorax

• Setup: Two empty cups representing visceral and parietal pleura with air between them.
• Observation: Nearly no vibration or markedly decreased.
  • Reason: Air acts as a buffer, slowing sound vibration more than liquid.

Summary

• Consolidation (Pneumonia): Increased tactile fremitus due to direct conduction through bronchi and amplification by fluid.
• Pleural Effusion: Decreased tactile fremitus as fluid acts as a non-direct sound buffer.
• Pneumothorax: Decreased tactile fremitus due to air acting as a buffer, impeding sound conduction more than fluid.

Clinical Implications

• Understanding changes in tactile fremitus assists in diagnosing lung conditions such as pneumonia, pleural effusion, and pneumothorax.