Crepts : An Overview

Hi everyone ! Just a short summary post on Crepts. Would like to thank Upasana for suggesting this topic ! 

Crepts

1 . Synonyms = Rales , Crepitations , Crackles

2 . Character = Rustling/  Bubbling type of sounds
Short , sharp, interrupted sounds.
(Wet Sounds)

3 . Types =

Fine and Coarse crepts -
Differentiation is clinical - fine crepts have a shorter amplitude while Coarse crepts have a higher amplitude and are usually louder with a lower frequency.

So ,  if you hear crepts of mellow tone (lighter quality) , with a very small gap between two crepts they are fine.
If they are very harsh and widely spaced they're likely to be Coarse crepts. 

As a thumb rule , fine crepts are generally Cardiac and Coarse are of Respiratory origin (with exceptions).

4 . Special types of Crepts :

Velcro crepts = Fine crepts of Interstitial Lung Disease

Coarse leathery crepts = Harsh Coarse crepts of Bronchiectasis

5 . Mechanism of Crepts :
- unclear but certain reasons are hypothesized.
- When an Alveolus is in a  collapsed state and then bursts open it produces a crept.
So for example -  in a pneumonia due to the exudates accumulated in the alveolus there is very little air in it and the alveolus is in a collapsed state at the end of expiration. Due to this, when a person inspires the collapsed alveolus and airway suddenly open with a snap and produce a sharp sound due to sudden pressure equalisation.
When many such alveoli open in a serial fashion from top to bottom we hear the typical bubbling sound of 'Crepts'.

- Older reasons - Air bubbling through exudative alveolus. But rejected as other forms of airway Obstruction like Bronchiectasis and Fibrosis causing collapsed airways also causes crepts.

6 . Causes of Crepts :

- Pneumonia / Consolidation
- Interstitial Lung Disease and Pulmonary Fibrosis
- Bronchiectasis
- Bronchitis
- Lung Abscess
- At times in COPD patients - Expiratory crepts may be heard.

Cardiac causes :
- Pulmonary edema due to Left Ventricular Failure.

7 . Cardiac vs Respiratory crepts :

Cardiac crepts are typically Basal and Bilateral , are fine crepts , associated with features of Heart Failure and may disappear on adminstering diuretics.
The opposite is true for Respiratory crepts.

Hope this was concise enough and helped !
Happy Studying!
Stay Awesome!

~ A.P.Burkholderia