Asthma Flashcards
What are the signs of a severe asthma attack? (4 things)
- Inability to complete sentences
- Pulse over 110bpm
- Resp rate over 25 / min
- Peak Expiratory Flow (PEF) 33-50%
What are the signs of a life threatening asthma attack? (6 things)
- PEF below 33%
- Normal PCO2
- Bradycardia
- Silent chest
- Cyanosis
- Confused / exhausted
What is Asthma? (3 things)
- Chronic inflamm condition of airways
- Secondary to Type 1 Hypersensitivity
- Causes episodic bronchoconstriction
What are the triggers for Asthma? (9 things)
- Cold / damp air
- Allergens: Dust / Animals / Pollen
- NSAIDs
- Beta blockers
- Exercise
- Night / early morning
- Infections
- Smoking
- Strong emotions
CAN BE NISS
When is asthma worse?
@ sleep
(diurnal variation)
What factors contribute to the reversible airway obstruction in asthma? (3 things)
- Bronchial muscle contraction
- Mucosal swelling / inflamm
- Increased mucus production
What is the mucosal swelling / inflamm in asthma caused by?
Mast cell and basophil degranulation –> release of inflamm mediators
What is asthma characterised by? (3 things)
- Breathless
- Tight chest
- Wheezy cough
What are the Signs of asthma? (4 things)
- Tachypnoea
- Audible polyphonic wheeze
- Hyperinflated chest
- Hyper-resonant percussion note
What is the wheeze in asthma caused by?
Reversible airway obstruction
What extra things should you ask for in Asthma pt? (4 things)
- Disturbed sleep? (quantify bc can be sign of severe Asthma)
- Exercise tolerance? (quantify)
- Acid reflux (40-60%)
- Other diseases: Eczema, hay fever, allergy?
What investigations should you do for sus Asthma? (NICE) (4 things)
First Line:
- Fractional Exhaled Nitric Oxide (FENO)
- Spirometry
If diagnosis still unclear:
- Peak Flow (keep diary few times per day for 2-4 wks)
- Direct Bronchial Challenge Test w histamine or methacholine
What is the Fractional Exhaled Nitric Oxide test for Asthma? (2 things)
- Measures how much Nitric Oxide is in breath
- 40+ ppb of NO = airways inflammed –> probs asthma
What investigations should you do for an ACUTE Asthma ATTACK? (6 things)
- Peak Flow
- Sputum Culture
- Blood Culture
- FBC
- CRP
- ABG
What may a FBC show in an ACUTE Asthma ATTACK?
What does this suggest?
High Eosinophils (type of WBC)
Suggests atopic asthma (ashma triggered by allergens)
What does an ABG show in ACUTE Asthma Attacks? (3 things)
What does this mean?
- Normal / Slightly low PaO2
- Low PaCO2
- High pH
Hyperventilation
What does an ABG show in Resp Failure? (3 things)
- Low PaO2
- High PaCO2
- Low pH (resp acidosis)
What inevestigations should you do for CHRONIC Asthma? (5 things)
- Peak Flow
- Spirometry (low FEV1/FVC ratio)
- CXR
- Skin prick test (to identify allergens)
- Direct Bronchial Challenge test w histamine or methacholine
What will Spirometry tests show in Asthma?
Low FEV1/FVC ratio = obstructive disease
What will a CXR show in Asthma?
Hyperinflation
(flattened diaphragm = hyperinflation)
What are some differentials that present similarly to Asthma? (8 things)
- Pulmonary oedema
- COPD (can co-exist)
- Large airway obst (foreign body / tumour)
- Superior Vena Cava obst (wheeze / dyspnoea but NOT episodic)
- Pneumothorax
- PE
- Bronchiectasis
- Obliterative bronchiolitis (sus in elderly)
How are the CF of COPD similar to Asthma? (3 things)
- Dyspnoea
- Cough
- Wheezing
How are the CF of COPD DIFFERENT to Asthma? (6 things)
- COPD = Progressively worsening airway obst // Asthma = Episodic airway obst
- COPD NOT improved by bronchodilators / steroids (Asthma is)
- COPD inflamm = MAC + Neut // Asthma = Eusinophils + Mast Cells + T Cells
- COPD = NO airway remodelling (Asthma has)
- COPD = Frequent emphysema (none in Asthma)
- COPD = More common in 50+ yrs
How are the CF of Large Airway Obst (foreign body) similar to Asthma? (2 things)
- Wheeze (in foreign body)
- CXR hyperinflation (in foreign body)
How are the CF of Large Airway Obst (tumour) different to Asthma? (2 things)
- Stridor instead of Wheeze (in tumour)
- Flow-Volume Loop shows flow limited in BOTH insp + exp curves (see Fiixed obst in pic)
How is a diagnosis of a Large Airway Obst (foreign body / tumour) confirmed?
Bronchoscopy (can use it to remove foreign body as well)
What is the Step-wise management guidelines for Asthma? (7 steps)
Step 1: Short Acting B2 Agonist (SABA) (Salbutamol) (PRN)
Step 2: Low Dose Inhaled Corticosteroid (ICS) (Fluticasone)
Step 3: Maintence And Reliever Therapy (MART) (ICS + LABA)
Step 4: Medium Dose ICS / Oral Leukotriene Receptor Antagonist (LTRA) (Montelukast / Zafirlukast)
Step 5: High Dose ICS / Oral Theophylline / Long Acting Muscarinic Receptor Antagonist (LAMA) (Tiotropium)
(When you go up a step, ADD what’s written, not replace)
What is Maintence And Reliever Therapy (MART)?
ICS + LABA in a single inhaler
(LABA has to be fast acting, e.g Formoterol)
What is the use of Beta Agonists in Asthma?
Relax bronchial smooth muscle
(by increasing cAMP levels)
What are the Side Fx of Salbutamol (SABA)? (4 things)
- Tachyarrhythmias
- Tremor
- Anxiety
- Hypokalaemia
TTAH
Why are Corticosteroids better to be inhaled?
To minimize Systemic fx
What is the use of Corticosteroids in Asthma?
Reduce bronchial mucosal inflamm
What should you advise patients to do after taking ICS (Inhaled Corticosteroids)?
Rinse mouth to prevent Oral Candidiasis (thrush)
What is the use of Theophylline in Asthma?
Reduces bronchoconstriction
(by inhibiting phosphodiesterase –> increases cAMP levels)
What is the use of LAMA (Tiotropium) in Asthma?
Reduce muscle spasm together w Beta Agonists
What is the use of Leukotriene Receptor Antagonists (LTRA)(Montelukast / Zafirlukast) in Asthma?
Block fx of Cysteinyl leukotrienes on airways
(i.e dey cause dilation of airway)
