Resp Med Flashcards
Give three triggers of asthma
INfection, night time or early morning, exercise, animals, dust, strong emotions, cold/damp
When is asthma typically worse?
Diurnal variation - worse at night
What are the first-line investigations for asthma?
Fractional exhaled nitric oxide, spirometry with bronchodilator reversibility
Second-line incl keeping a diary of peak flow measurements several times per day
How do SABAs work?
Adrenalin acts on the smooth muscles of the airways to cause relaxation. This results in dilatation of the bronchioles and improves the bronchoconstriction present in asthma.
Give an example inhaled corticosteroid
Beclometasone
What are ICS’s used for?
Maintenance or preventer medications
Give an example LABA. When do we use them?
Long-acting beta 2 agonists (LABA), for example salmeterol. These work in the same way as short acting beta 2 agonists but have a much longer action.
Give an example LAMA
Tiotropium
How do LAMAs work?
These block the acetylcholine receptors. Acetylecholine receptors are stimulated by the parasympathetic nervous system and cause contraction of the bronchial smooth muscles. Blocking these receptors leads to bronchodilation.
Give an example leukotriene receptor antagonist. How do they work?
Leukotriene receptor antagonists, for example montelukast. Leukotrienes are produced by the immune system and cause inflammation, bronchoconstriction and mucus secretion in the airways. Leukotriene receptor antagonists work by blocking the effects of leukotrienes.
How does theophylline work?
This works by relaxing bronchial smooth muscle and reducing inflammation. Unfortunately it has a narrow therapeutic window and can be toxic in excess so monitoring plasma theophylline levels in the blood is required. This is done 5 days after starting treatment and 3 days after each dose changes.
What is MART?
Maintenance and Reliever Therapy (MART). This is a combination inhaler containing a low dose inhaled corticosteroid and a fast acting LABA. This replaces all other inhalers and the patient uses this single inhaler both regularly as a “preventer” and also as a “reliever” when they have symptoms.
What is a moderate acute asthma attack?
PEFR 50 – 75% predicted
What is a severe acute asthma attack?
PEFR 33-50% predicted
Resp rate >25
Heart rate >110
Unable to complete sentences
What is a life-threatening acute asthma attack?
PEFR <33%
Sats <92%
Becoming tired
No wheeze. This occurs when the airways are so tight that there is no air entry at all. This is ominously described as a “silent chest”.
Haemodynamic instability (i.e. shock)
What is the first-line treatment for acute moderate asthma attack?
Nebulised beta-2 agonists
Nebulised ipratropium bromide
Steroids - oral pred or IV hydrocortisone: continued for 5 days
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What would an ABG show in acute asthma?
Initially patients will have a respiratory alkalosis as tachypnoea causes a drop in CO2. A normal pCO2 or hypoxia is a concerning sign as it means they are tiring and indicates life threatening asthma. A respiratory acidosis due to high CO2 is a very bad sign in asthma.
What electrolyte abnormality can salbutamol cause?
Monitor serum potassium when on salbutamol as it causes potassium to be absorbed from the blood into the cells. Salbutamol also causes tachycardia (fast heart rate).
What is the difference between obstructive and restrictive disease?
Obstructive lung disease can be diagnosed when FEV1 is less than 75% of FVC (FEV1:FVC ratio < 75%).
If FEV1 and FVC are equally reduced and FEV1:FVC ratio > 75% this suggests restrictive lung disease.
What is the most common type of lung cancer?
Non-small cell lung cancer, most commonly adenocarcinoma (40%) or squamous cell carcinoma (20%)
Small cell lung cancers release neuroendocrine hormones are are responsible for 20% lung cancers)
What is Pemberton’s sign?
“Pemberton’s sign” is where raising the hands over the head causes facial congestion and cyanosis. This is a medical emergency.
Seen in SVC obstruction
Describe the MRC dyspnoea scale
Grade 1 – Breathless on strenuous exercise
Grade 2 – Breathless on walking up hill
Grade 3 – Breathless that slows walking on the flat
Grade 4 – Stop to catch their breath after walking 100 meters on the flat
Grade 5 – Unable to leave the house due to breathlessness
How do we determine the severity of airflow obstruction in COPD?
Stage 1: FEV1 >80% of predicted
Stage 2: FEV1 50-79% of predicted
Stage 3: FEV1 30-49% of predicted
Stage 4: FEV1 <30% of predicted
Which vaccines should COPD pts have yearly?
Annual flu and pneumococcal vaccines
