W8/L3: Airway obstruction Flashcards
At rest, what is WOB?
Low - about 3% of oxygen usage
What does WOB stand for?
Work of breathing
What can cause an increase is resistive WOB?
Airway obstruction
What are the consequences increased restrictive WOB?
- Recruitment of accessory muscles
- Increased oxygen consumption by resp muscles
- Risk of resp muscle fatigue
How does intra-alveolar pressure compare to atmospheric during inspiration?
Intra-alveolar pressure is less
How does intra-alveolar pressure compare to atmospheric during expiration?
Intra-alveolar pressure is greater
How does intra-alveolar pressure compare to atmospheric at the end of inspiration?
They’re equal
How does intra-alveolar pressure compare to atmospheric at the end of expiration?
They’re equal
In general, what is the breathing of people with airflow obstruction?
Deep, slow breaths
In a healthy person, what system limits exercise tolerance?
Cardiovascular - they reach their max HR
When does gas trapping occur?
In severe airflow obstruciton
What is Type 2 resp failure aka?
Ventilatory failure
What are the features of ventilatory failure?
Hypoxia
Hypercapnea
What level of hypoxia & hypercapnea define ventilatory failure?
PaO2 < 60mmHg
PaCO2 > 50mmHg
What’s the traditional treatment for ventilatory failure?
Mechanical ventilation via intubation
