2. Obstructive Airway Disease Flashcards
General respiratory disease symptoms (5)
Cough Wheeze (expiration) Stridor (inspiration) SoB (distress on effort) Pain (general/inspiration)
General respiratory disease signs (5)
Chest movement with respiration Rate of respiration Air entry (symmetrical, reduced) Vocal resonance Percussion notes (resonant, dull)
Normal rate of respiration
12-15 breaths/min
General respiratory disease investigations (5)
Sputum exam CXR Pulmonary function Bronchoscopy VQ scan
Pulmonary function tests (3)
PEFR - max. flow rate
FEV1 - forced expiratory volume/one second
FEV1/VC - measurement of respiratory function
Types of respiratory diseases (4)
Infections
Airflow obstructions
Gas exchange failure
Tumours
Types of respiratory infections
Pneumonia
Types of respiratory airflow obstructions (3)
Asthma
COPD
Restrictive pulmonary change
Types of respiratory gas exchange failure (3)
Reduced surface area
Fibrosis
Fluid
Chronic airflow obstruction definition and examples (2)
Reversible airway obstructions
Asthma
COPD
Chronic airflow obstruction exacerbations (3)
Infections
Exercise
Cold air
Asthma mechanism (3)
Airway smooth muscle constriction
Inflammation of mucosa
Increased mucus secretion
Asthma symptoms (3)
Cough
Wheeze
SoB
Asthma triggers (5)
Infections Environmental stimuli (dust, smoke, chemicals, asbestos) Cold air Exercise Atopy
First stage of asthma treatment
Occasional B-agonist only
Second stage of asthma treatment
Low-dose inhaled steroid (or Na chromoglycate)
Third stage of asthma treatment
High-dose inhaled steroid
Fourth stage of asthma treatment (3)
Long-acting B-agonist, theophylline, anti-muscarinic drugs
Fifth stage of asthma treatment
Oral steroid
Types of respiratory drugs (6)
B-adrenergic agonists Anticholinergic drugs Corticosteriods Leukotrine inhibitors Chromones Theophylline
Action of B-agonists
Relax smooth muscle by reducing bronchoconstriction and reducing resting bronchial tone
Action of anticholinergic drugs
Reduce basal tone
Action of theophylline (3)
Cause adenosine inhibition
May cause CNS stimulation, diuretics and arrhythmias
When are corticosteroids used
If B2-agonists are used >3 times each week
Corticosteroid side effects (2)
Adrenal suppression
Osteoporosis (potentially)
COPD is a combination of (3)
Chronic obstructive airway disease (asthma and emphysema)
Chronic bronchitis
Emphysema
What is COPD (2)
Mixed airway reversible obstruction
Destructive lung disease
Definition and outcome of emphysema (2)
Destruction of alveoli
Causes dilatation of others to fill the space
How can COPD progress to respiratory failure (2)
Reduced surface area for gas exchange
Thickening of alveolar mucosal barrier
COPD results in poor ventilation due to (2)
Airway narrowing (potentially reversible) Restrictive lung disease
Causes of COPD (3)
Smoking
Environmental lung damage
Hereditary (emphysema)
Occupational lung disease can lead to respiratory failure from (2)
Fibrosis (dust related) - coal, silicon, beryllium, asbestos, silica
Tumours - asbestos (mesothelioma)
COPD management (6)
Smoking cessation Long-acting bronchodilator Inhaled steroids (if FEV < 50%) Systemic steroids Oxygen support Pulmonary rehabilitation therapy
Types of respiratory failure (2)
Type 1
Type 2
What is type 1 respiratory failure
Hypoxaemia (low oxygen)
What is type 2 respiratory failure
Hypercapnia (ventilation failure)
Why does type 2 respiratory failure occur
Due to airway blockage or narrowing
What is respiratory failure due to (2)
Failure of oxygenation
Failure of ventilation
When does failure of oxygenation occur (2)
When PaO2 < 8kPa or
When SaO2 < 90%
What does failure of oxygenation result in (3)
Poor alveolar ventilation
Diffusion abnormality
VQ (ventilation perfusion) mismatch
When does failure of ventilation occur (2)
When PaCO2 > 6.7kPa
Only in acute respiratory failure
(20% reduction in ventilation required)
What does chronic ventilation failure result in
Renal compensation from acidosis
Chronic ventilation failure involves contributions from (3)
Reduced compliance
Airway obstruction
Muscle dysfunction
Normal breathing control (2)
CO2 drive controls ventilation
SaO2 usually fine
COPD breathing control (2)
Hypoxia drives ventilation
CO2 tolerance