Heart and Lung Sounds Reference Guide

Crackles - Fine (Rales) Auscultation Reference

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Lesson

For heart sounds listen to the synthetic sound while reviewing this lesson.

Fine crackles are brief, discontinuous, popping lung sounds that are high-pitched. Fine crackles are also similar to the sound of wood burning in a fireplace, or hook and loop fasteners being pulled apart or cellophane being crumpled.

Crackles, previously termed rales, can be heard in both phases of respiration. Early inspiratory and expiratory crackles are the hallmark of chronic bronchitis. Late inspiratory crackles may mean pneumonia, CHF, or atelectasis.

The waveform(s) seen above are a chart of sound amplitude (loudness) on the vertical axis against time on the horizontal axis.

Listening Tips

A summary of the key aspects of this heart or lung sound.
Rales are brief, discontinuous, popping sounds that are high-pitched. Similar to wood burning in a fireplace. More commonly heard during inspiration.

Auscultation Method

The recommended patient position is seated

For this sound, use stethoscope's diaphragm The recommended auscultation position for the stethoscope is anterior-3l

Relevant Courses

If you wish to review a complete mobile concerning Crackles - Fine (Rales) Auscultation Reference and related heart sounds, the modules(s) listed below may be useful. Each lesson includes text that explains the auscultatory sound and its clinical significance. The lesson also includes an audio track for playback. A waveform provides a great way to visualize the sounds. Finally, we also include an animation video. For heart sounds, the video illustrates heart muscle and valve movements along with blood flow. For lung sounds, the primary source of the sounds can be seen. Each module also includes a quiz.

Basics of Lung Sounds

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Crackles - Fine (Rales) Auscultation Reference