COPD Flashcards
What is the pathology of COPD?
Inflammation causes the mucosa to become engorged and causes obstruction
Circular smooth muscle constricts
Collapse of airway integrity
Emphysema
What are the features of COPD
Inflammation
Tissue damage
Mucocilliary dysfunction
What two conditions does COPD compromise of and what is their effect?
Chronic bronchitis:
Chronic neutrophil inflammation
Mucous hyper secretion
Smooth muscle spams
Emphysema: alveolar destruction impaired gas exchange Loss of bronchial support Irreversible
How does emphysema occur?
Protease is increased
Increased beyond the normal size of airspaces distal to the number of terminal bronchiole
Leads to destruction of acinial pouching in alveolar sacs
What pharmacological treatments are used for COPD?
LAMA - tiotropium LABA - salmeterol PDE41 - rofumilast Mucolytic - carbocisteine Antibiotics - azithromycin
What is the disease process of COPD?
Cigarette smokes causes alveolar macrophages to produce cytokines
This is detected by CD8+ cells that are activated and produce Proteases
Neutrophils are activated by chemotactic factors (IL8)
Proteases cause alveolar wall destruction and increase mucus secretions
Increase in macrophage population, increased release of metalloproteinases (e.g. Elastase)
Release of free radicals
What is the response to bronchodilators and corticosteroids in COPD?
Poor
What type of spirometry pattern is seen in COPD?
Obstructive spirometry pattern
What type of cell response is COPD?
CD8
What mucarinic antagonists are used in COPD and how do they function?
Ipratropium - M1, M2, M3 antagonist
Tiotropium - M3 specific antagonist
These drugs workday blocking the ACh on the M3 receptors which surpasses the cough reflex.
How are SAMA and LAMA’s given?
Orally - to reduce systemic effects
What type of chemical structure is ideal in drugs to prevent systemic effects?
Quaternary amine groups
Describe the cough reflex?
Irritant stimulant arrives in the airways
Causes depolarisation of the sensory nerve terminals
Action potentials go the brain stem via the vagus nerve
Action potentials arrise in the parasympathetic pre-ganglionic neurone which synapse via the post - works on the M3 receptor
How is a Muscarinic antagonist generally administered?
In combination with bronchodilators and steroids e.g. with Indaceterol
What is expressed by T cells and Macrophages which causes inflammation?
Phosphodiesterase 4 (PDE4) - cause inflammation
What drug is used to inhibit PDE4?
Rofumilast - supresses inflammation and emphysema
What is Chronic bronchitis?
A cough with productive sputum on most days for the last 3 months for at least 2 years
What are the types emphysema?
Centriacinar - around bronchioles
Panacinar - around lobes
Paraseptal
What is the pathology of emphysema?
High rate of emphysema in rare genetic conditions with alpha 1 antitrypsin deficiency
Elastic tissue is sensitive to damage by elastase
Alpha 1 anti-trypsin acts as an anti-elastase
Imbalance in either these causes damage
What is the effect of tobacco smoke?
Incase number of neutrophils and macrophages
Slow transit of cells
Promotes neutrophil degranulation
Inhibits aplha 1 anti-trypsin
What mucolytics are used in COPD?
Carbocisteine
Erfosteine
Reduce the viscosity of sputum
In acute exacerbations of COPD what bacteria typical are involved?
Pneumococcus
H influenzae
What is the first line of antibiotics in acute COPD exacerbation?
Doxycyline or Amoxycillin
What is the second line of antibiotics in acute COPD?
Azithromycin and Levoflaxacin
What is the non-pharmacoligcal treatment of COPD?
Smoking cessation Immunisation Physical activity Oxygen Venesection Lung volume reduction surgery Stenting
What is the treatment for acute COPD?
Nebulised salbutamol and Ipratropium
Prednisolone
Antibiotics - amoxycillin/doxycycline
Physiotherapist
What is meant by a pink puffer?
Dyspnoea
No cyanosis at rest
Type 1 respiratory failure
What is meant by a blue bloater?
Type 2 respiratory failure
Low O2
High CO2
What type of ABG is shown in COPD?
Respiratory acidosis with metabolic compensation. (Chronic COPD)
