Obstructive & Restrictive Lung Disease Flashcards
What is the normal tidal volume?
7ml/kg, depends on mass of individual
Which is bigger - expiratory reserve or inspiratory reserve?
Inspiratory reserve volume
Why is it better to breathe from the bottom of your lungs than the top of your lungs?
if you breathe from the bottom the alveoli are small to start with so you have more room to expand and there is more room for air to go in however if you breathe at the top there is not much more expansion available and so not much more room for air to go into the alevoli
What should vital capacity be for a young woman?
3.0-3.5L
Why are peak flow serial measurements useful?
Can use to assess the effectiveness of treatment - each morning and evening
What is TLC =?
TV + IRV + ERV + RV
What is FVC?
Forced vital capacity - the maximum volume of air you can exhale after taking the deepest possible inhalation
What is VC?
The same as FVC - Forced vital capacity - the maximum volume of air you can exhale after taking the deepest possible inhalation
What does a vitalograph show you?
The time course of breathing, alternative to spirometer
What happens to FEV1/FVC in obstructive diseases?
FEV1 is reduced as you cannot breathe out as quickly
FVC stays the same as the size of the lungs is not affected
Therefore FEV1/FVC ratio is reduced
What happens to FEV1/FVC ratio in restrictive diseases?
FVC is reduced as the lung size is restricted
FEV1 is low as there is also airway constriction so you cannot breathe out as easily
Both are reduced so FEV1/FVC is not affected
What should FEV1/FVC normally be?
80-90%
How would you classify mild, moderate and severe obstructive diseases?
Normal >70% FEV1/FVC
Mild 61-69%
Moderate 45-60%
Severe <45%
What are key features seen in obstructive disorder?
Reduced peak flow
Reduced FEV1/FVC
What effect does smoking have on obstructive disorders?
Steadily reduces FEV1 further
Damages elastin in airways
What other things apart from obstructive disorders reduce FEV1/FVC ratio?
age
smoking
Why is it important to stop smoking regardless of age?
Lung function will somewhat improve at any age
What is the definition of asthma?
An Episodic limitation of airflow, reversing either spontaneously or in response to treatment
What is asthma characterised by?
Reversible airway obstruction
Smaller airways
AHR (Airway Hyper- Responsiveness)
Often atopic (allergens)
What are the 3 essential features of asthma?
Bronchoconstriction
Secretion of mucus
Airway Inflammation
What are some symptoms of asthma?
Troublesome cough, particularly at night, may be awakened by coughing
Coughing or wheezing after physical activity
Breathing problems during particular seasons
Coughing, wheezing, or chest tightness after allergen exposure
Colds that last more than 10 days
Relief when medication is used
What are some signs of asthma?
Reduced Peak Expiratory Flow!!
normal airway reflexes are hyper-responsive and prolonged!!
Wheezing sounds during normal breathing
Hyperexpansion of the thorax
Increased nasal secretions or nasal polyps
Atopic dermatitis, eczema, or other allergic skin conditions
What is wheezing?
Turbulent air flow
Why asthmatics cough?
Oversecretion of mucus, want to remove it