Airway Resistance

DEFINITION:
-Blockage (obstruction) of air in the airway
-On mechanical ventilation, the degree of weight resistance mainly influenced by the size (diameter), length and airway patency, length of endotracheal tube and circuit

Factors affecting the airway resistance:
A. Resistance increases if the airway diameter decreases
B. Obstruction to airflow can be caused by changes in:
1. In the airway (sputum retention)
2. In the airway wall (tumor on the bronchial muscle structure)
3. Outside the airway (tumors that surround and suppress airway)
4. When these factors occur, the airway diameter will shrink so that the increased airway resistance
5. So if the airway diameter is reduced ½ of the normal, then the pressure required to incorporate as much air flow as normal time will increase 16 times
C. Of the few diseases that can increase airway resistance, COPD is the commonest
1. This type includes emphysema, chronic bronchitis, chronic asthma, and bronkletasis
2. Mechanical conditions that may also increase airway resistance is obstruction post-intubation and aspiration of foreign bodies
3. The process of infection include laringotrakeobronkitis, epiglottitis and bronchiolitis
D. Normal airway resistance ranged between 0.6 and 2.4 cmH20/liter/detik can stream flow (air flow) of 38 liters / minute (0.5 liters / sec)
1. Will increase the terintubasi apasien pad, and depending on the size of ETT
2. Airway resistance will change at any time and directly proportional to the length of ETT and inversely proportional to the diameter of the ETT
3. For that ETT is a good measure of the largest ETT according to patient's trachea
4. Nukus plaq in ETT was instrumental in increasing airway resistance
E. Ventilator Circuit also affect resistance to airflow from the ventilator, or play a role in increasing airway resistance
F. The important thing also is the amount of water (water), condensation in the ventilator circuit, if the number will increase quite a lot of resistance also