COUGH and Huff

COUGH

Definition :

It is sudden audible expulsion of air from lung to move secretion from lung bronchus & trachea to out 

may be voluntary or reflexive .

Aiming for clearance of lung air way from secretions or prevention of aspiration of foreign body into the lung .

Cough	Huff
Voluntary or reflexive	Voluntary
Done through CNS stimulation	No CNS stimulation
Productive	Not or less productive
Doesn’t stimulate huffing	Used as preparation & stimulate cough
Remove secretions from proximal airways ( 7th generation)  to out	Remove secretions from the distal 23th generation toward proximal airways
Deep inspiration with closed glottis	No deep inspiration with no closed glottis
The increase in intrathoracic & intraabdominal pressure is more so cause forced expiration	Less pressure so less power of expiration

Cough reflex : ( SRACEER) 

• Stimulus : foreign body 
• Receptors : cough receptors 
• Afferent : glossopharyngeal , vagus , trigeminal , recurrent pharyngeal nerve . 
• Centre : respiratory center  in medulla 
• Efferent : phrenic nerve 
• Effector : contraction of diaphragm 
• Response : cough & expulsion of secretion 

Cough mechanism :

Order the patient to do the following : 

• Deep breathing

• Closure of glottis(to prepare abdominal and inter costal muscles to produce (+ve) intra thoracic pressure)

• Contraction of abdominal muscles ( to increase intra abdominal pressure which leads to pushing the diaphragm upward leading to decrease the volume of the cavity &then lead to increase intra thoracic pressure). 

• Opening of the glottis so sudden expulsion of air due to increased intra alveolar pressure .

Types of cough mechanism : 

1.Controlled cough :

• Used as a preparation for patient 

• First educate patient diaphragmatic breathing and explain pattern of cough to him 

Patient position : 

• Sitting with lean forward ( better position ) 

• Pillow on lower limbs & hands rested on these pillows. 

Order : 

1. Ask pt. to do 3 huffs 

1. Take deep breath 2 times ( to prevent atelectasis ) 

1. Ask pt. to take deep breath for 3rd time and close glottis then contract abdominal muscles & then open mouth and then cough 

2. Splinted cough :

• Same as controlled cough 

• But pt. supports the incisional site by pillow, by his hand or  belt .

3) Manual assisted cough :

There are 2 types of manual assisted cough which are :
1. By therapist assist :

• Pt. position : supine, sitting OR long sitting

• Grasp from supine position : hands over each other on epigastric area. 

• Order : 

1. 3 huffs 
2. Deep breath 2 times 
3. Deep breath for 3rd time and close epiglottis then contract abdominal M.s ( apply assistance once pt. contract abdominal muscles by pushing inward & upward to help expiration ) 
4. Open mouth and then cough . 

2. By self assist :

Pt. position: same 
Order :  same & push inward and upward by his hands 

4. Tracheal trickle :

• Insert your index & middle finger in supra sternal notch and press downward with circular motion 

• Used with old age , disoriented pt ( ICU) & pediatrics . 

what are the factors that affect cough?

• Anesthesia which inhibit cilia movement 
• Incisional pain which inhibit cough.
• Inability of patient to take deep inspiration due to (fracture of rib, chest incision).
• Inability of patient to make forced expiration (myopathy, spinal cord injury above T10)
• Injury of phrenic nerve .
• Thick secretions.

Measurement of an effective cough:

Depends on the number of coughs per each expiration:

1. Functional cough:   👉   2cough / 1 expiration.
2. Sub functional :   👉   1 cough /1 expiration.
3. Zero:    👉    sigh