Obstructive and Restrictive Lung Disease Flashcards
What are the two general categories for drugs that treat obstructive airway conditions?
- Relievers- bronchodilators
2. Preventers- ati- inflammatory
What is step 1 in asthma treatment?
SABA
Salbutamol
What is step 2 in asthma treatment?
SABA + ICS (200-800 micrograms)
What is step 3 in asthma treatment?
SABA + LABA + ICS
What is step 4 in asthma treatment?
Increase ICS dose from step 3
Add fourth drug e.g. theophylline or a leukotriene receptor antagonist
What is step 5 in asthma treatment?
Use daily steroid tablet ( prednisolone)
Maintain high dose ICS (2000 micrograms)
Which immune cells are corticosteroid effective against in the mucosa ?
Eosinophils
What is a downside to corticosteroid use in asthma or COPD?
It weakens the immune system, and impairs the mucociliary escalator.
This increases chance of infection
In COPD chances of pneumonia infection are boosted
ICS have a _____ therapeutic ratio and are ____ due to being delivered directly to the organ of interest
High
Topical
Oral corticosteroids have a ___ therapeutic ratio
Low
Why is a spacer useful for administering asthma medication?
- Reduces oropharyngeal and laryngeal side effects (gag reflex/ nausea)
- Reduces systemic absorption (no swallowing)
- Acts as a holding chamber aiding inhalation
- Reduces particle size and velocity allowing the particle to embed deeper in the lungs increasing effectivity
What are cromones and what is their function?
- Cromones are used in asthma and are proposed mast cell stabilisers
- This means they can prevent pro-inflammatory mediator release
How are leukotrienes formed during asthma?
They are produced due to processes involving the lipids in the cell membrane
The enzyme phospholipase A2 detaches fatty acids from the second carbon group of the glycerol molecule that makes up a lipid
One of these acids is arachinidonic fatty acids
When arachidonic acid is acted on by 5- lipoxygenase leukotrienes are formed
What happens when cycle-oxygenate acts on arachidonic acid?
Prostaglandins and thromboxanes are produced aiding inflammation and amplification
Which leukotriene is over produced in asthma?
LTD4
What is the effect of overproduction of leukotrienes in asthma?
- Trigger contraction and proliferation of smooth muscle
- Cause eosinophil influx (which release cationic proteins damaging epithelial cells)
- Increases mucus secretion, but decreased transport
- Oedema
Leukotriene receptor antagonists are used in asthma, name one that is used to bind to LTD4?
Montelukast
taken orally
What is anti- IgE and what is the name of one key form in relation to asthma called?
Monoclonal antibody
Omalizumab
OmalizumB has what effects?
Binds strongly to IgE inactivating it
Prevents pro-inflammatory mediators being released from basophils and mast cells
Boosted every 2-4 weeks via injection
Name two anti- IL5 drugs
- Mepolizumab
2. Reslizumab
How does anti- IL5 therapy work?
Th2 cells produce IL-5 in the immune response aiding eosinophilic inflammation in asthma
The use of anti- IL5 therapy is that eosinophilic inflammation is much reduced
Name 2 LABAs
- Formeterol
2. Salmeterol
What are the three different types of muscarinic receptors?
- M1 - enhance cholinergic reflex
- M2 -inhibit acetylcholine release
- M3 - mediate bronchoconstriction and mucus release
Muscarinic antagonists inhibit which type of muscarinic receptor ?
M3
Name a SAMA
Ipratropium
Name two LAMAs
- Tiotropium
2. Glycopyrronium
Methylxanthines act as ______ and also ______
Bronchodilators
Anti-inflammatory drugs
Name and example of a methylxanthine
Thophylline
What is the function of phosphodiesterase 4 enzymes?
Hydrolyse cAMP
What is the overall function of PDE4 inhibitors?
Prevent cAMP hydrolysis allowing high levels of cAMP in cells
Bronchial smooth muscle will become relaxed
PDE4 inhibitors are for use only in ____
COPD
Give an example of a PDE4 inhibitor
Roflumilast
Why are PDE4 inhibitors used infrequently ?
Side effects such as nausea, diarrhoea and headaches
What are mucolytics
Drugs which reduce the viscosity of mucous and reduce inflammation
Give two examples of mucolytics
- Carbocisteine
2. Erdosteine
Ina n acute asthma attack what treatment is given?
- Oral prednisolone (40mg)
- At least 60% oxygen aim for 94- 98% SpO2
- Nebulised salbutamol
What are some treatment methods for COPD?
- Smoking cessation
- Immunisation
- Pharmacotherapy
- Oxygen
- Increase exercise
Name two LAMAs
- Titanium
2. Aclidinium
Name two LABAs
- Olodaterol
- Formeterol
Name an ICS for COPD use
Beclometasone
Which antibiotic may be used for COPD?
Azithromycin
also amoxicillin and doxycycline
How is acute COPD treated?
- Nebulised high dose salbutamol and ipratropium
- Oral prednisolone
- Antibiotic (amoxicillin/ doxycycline) if infection
- 24-28% O2
- Non- invasive ventilation
Which external factors can cause lung restrictions?
- Skeletal causes ( broken ribs, kyphoscoliosis)
- Muscle Weakness (intercostal/ diaphragmatic)
- Obesity (due to compression)
What are the effects of lung compression from external sources?
- Reduced partial pressure of oxygen
- Reduced partial pressure of carbon dioxide
- Reduced lung volumes
- Hypoxia
What is DPLD?
Diffuse parenchymal Lung Diseas
Interstitial lung disease
An umbrella term for lung diseases affecting the interstitium
What is the interstitium of the lungs?
The space and tissues surrounding the alveoli
What are the three main categories for ILD( interstitial lung disease)?
- Those with a known cause
- Those with an unknown cause( isopathic)
- Those associated with systemic disease
Why may hypoxia occur at a thickened alveolar/ arteriolar barrier?
Carbon dioxide is ver soluble and easily diffuses across so can be blown off
Oxygen will not be able to pass the barrier into the blood as easily potentially leading to hypoxia
Give two different causes for ILD
- LVF- fluid in alveolar lumen due to a raised pulmonary venous pressure
- Sepsis, adult respiratory distress syndrome damage, altitude sickness- Non- cardiac pulmonary oedema
What is consolidation in the lungs?
Fluid within areas which there normally is not any fluid
What can cause consolidation on a CXR?
- Pneumonia
- PE
- Alveolitis
- cryptogenic pneumonia (not infectious)
What is alveolitis?
This is the infiltration of inflammatory fluid into the alveolar walls It can be caused by: - Drugs - Toxic gases - Fibrosing alveolitis - Autoimmune disease
What is pneumoconiosis?
Dust disease
Restrictive lung disease that can be either fibrogenic (asbestosis, silicosis) or non- fibrogenic (siderosis (due to iron), stenosis, baritosis (due to barium))
What is carcinomatosis?
Body-wide spread of cancer and can contribute to DPLD
How do eosinophils contribute to DPLD?
They occur alongside all sides of inflammation which is present in DPLD
Symptoms of DPLD?
- Breathlessness
- Cough (without wheeze- no obstruction)
- Finger clubbing
- Lung crackles (inspiration)
- Central cyanosis
- Pulmonary fibrosis (chronic inflammation)
How is FEV1 affected in DPLD?
It is reduced
How is FVC affected in DPLD?
It is reduced
What happens to the FEV1/ FVC ration in DPLD?
It remains normal as both variables decrease in proportion
Aside from FEV1 and FVC what are the three main checks which must be covered for diagnosing DPLD?
- Arterial oxygen saturation (should be lowered in DPLD)
- CXR (bilateral consolidation is common)
- Presence of antibodies (caused by infection)
How is DLPD treated?
- Cause is removed
- Inflammation is treated
- Oral prednisolone (systemic corticosteroids )
- ICS - if oral fails
- Oral azathioprine (immunosuppressor)
- Anti-fibrotic drugs (pirfenidone, ninetdanib)
- Oxygen (if hypoxic)
- Lung transplant- end stage disease
In asthma, FVC is ____ but FEV1 is _____
Normal
Reduced
What type of graph can help diagnose lung conditions?
Flow volume curve
How does peak expiratory flow rate differ between obstructive and restrictive when compared to a normal result?
Obstructive - reduced
Restrictive - normal
