Asthma Flashcards
What is the first step of treatment for asthma?
Consider monitored initiation of treatment with low-dose ICS
+
SABA
Omalizumab is a biological therapy targeting what?
Immunogobulin E
A patient with a history of asthma arrives in A&E struggling to breath, what is the initial first step?
Start treatment
Nebulised Salbutamol
Acute asthma severity is initially assessed by what?
Clinical examination
In terms of stable asthma you might look at peak flow and are useful in discharge consideration but not in acute setting
What are the features of a severe asthma attack?
Worsening dyspnoea, wheeze and cough that us not responding to salbutamol
What can trigger an acute asthma attack?
Respiratory tract infection
Exercise
What are the features of a moderate asthma attack?
PEFR (peak expiratory flow) 50-75% best or predicted
Speech normal
RR < 25/min
Pulse < 110 bpm
What are the features of a severe asthma attack?
PEFR 33-50 % best or predicted
Can’t complete sentences
RR >25/min
Pulse >100 bpm
What are the features of a life-threatening asthma attack?
PEFR < 33% best or predicted Oxygen sats < 92% Silent chest, cyanosis or feeble respiratory effort Bradycardia, dysrhythmia or hypotension Exhaustion, confusion or coma
(A patient having any one of the life-threatening features should be classified as a life-threatening attack
What does a normal pCO2 indicate in an acute asthma attack?
Exhaustion,
Should be classified as life threatening
What further assessment, aside from clinical observations and sats can be done in an acute asthma attack and when might this be required?
Only in life threatening asthma.
ABG if sats <92%
Chest x-ray if life threatening, suspected pneumothorax or failure to respond to treatment.
What patients with acute asthma should be admitted to hospital?
All patients with life threatening asthma
Patients with severe asthma if they fail to respond to initial treatment
(+ prev near-fatal attack, pregnancy, attack despite using oral corticosteroid, presentation at night)
What oxygen treatment is appropriate for patients with an acute asthma attack?
All hypoxaemic patients
If acutely unwell, 15L non-rebreath mask, titrated down till SpO2 94-98%
What medications should be used to treat a patient with an acute asthma attack?
- Short-acting beta2-agonist (SABA) - salbutamol, terbutaline
(not life-threatening = standard pressurised metered-dose inhaler or oxygen-driven nebulizer
life-threatening = nebulised SABA) - Corticosteroids
All patients should be given 40-50mg of prednisoloine PO daily, 5 days or until recovery - during this time continue normal routine of ICS (normal) - Ipratropium bromide: severe/life-threatening/not-responded to above, give nebulised ipratropium bromide a short-acting muscarinin antagonist (SAMA)
- IV Magnesium Sulphate
Senior discussion - IV aminophylline
Senior discussion - ITU, intubation and ventilation, extracorporeal membrane oxygenation
What are the criteria for discharge following an acute asthma attack?
Been stable on discharge medicatio (no nebs or O2) for 12-48 hours
Inhaler technique checked and recorded
PEF >75% of best or predicted
What is the prevalence of asthma?
10% of children
5-10% of adults
Prevalance is increasing
What is asthma?
A chronic inflammatory disorder of the airways secondary to type 1 hypersensitivity.
Symptoms are variable and recurring and manifest as reversible bronchospasm resulting in airway obstruction.
What are the risk factors of asthma?
- Personal or family history of atopy,
- Antenatal factors: maternal smoking, viral infection during pregnancy (RSV)
- Low birth weight
- Not being breastfed
- Maternal smoking around child.
- Exposure to high concentrations of allergens (e.g. house dust mite)
- Air pollution
- ‘Hygiene hypothesis’ *
- studies show an increased risk of asthma and other allergic conditions in developed countries. Reduced exposure to infectious agents in childhood prevents normal development of the immune system resulting in a Th2 predominant response.
What other IgE mediated conditions may be seen in a patient suffering from asthma?
Atopic dermatitis (eczema) Allergic rhinitis (hay fever)
What nasal sign may be seen in patients with asthma?
Nasal polyps
What is the definition of occupational asthma?
Asthma related to allergens in the workplace, usually diagnosed by observing reduced peak flows during the working week with normal readings when not at work.
What are the symptoms of asthma?
Cough: often worse at night
Dyspnoea
Wheeze
Chest Tightness
What are the signs of asthma?
Expiratory wheeze on auscultation
Reduced peak expiratory flow rate (PEFR)
What are the investigations for asthma? (3)
Spirometry
Fractional exhaled nitric oxide (raised - in infallatory cells (eosinophols))
Chest x-ray (history dependent)
What does spirometry measure?
The amount (volume) and speed (flow) of air during exhalation and inhalation.
What is FEV1?
Forced expiratory volume - volume that has been exhaled at the end of the first second of forced expiration
What is FVC?
Forced vital capacity - volume that has been exhaled after a maximal expiration following a full inspiration
In what conditions is an obstructive picture seen?
Where there is obstruction to airflow:
Asthma
In what condition is a restrictive pattern seen?
Where there is restriction to the lungs:
Lung fibrosis
What spirometry results are typically seen in asthma?
FEV1: significantly reduced
FVC: normal
FEV1% (FEV/FVC): <70%
What are the classes of drug used is asthma management?
Short-acting beta2-agonists (SABA)
Inhaled corticosteroids (ICS)
Long-acting beta-agonists (LABA)
Leukotriene receptor antagonists
Give an example of a SABA?
Salbutamol
Give somes examples of ICS?
Beclometasone dipropionate
Fluticasone propionate
Give an example of a LABA?
Salmeterol
Give an example of a LRA?
Monteleukast
What is a SABA used for?
- First line drug
Typically used if patient develops symptoms - blue inhaler
Relax smooth muscle airways
Side-effects include tremor
What is a ICS used for?
- Used in patients whose asthma is not controlled by SABA alone
Taken everyday, regardless of whether the patient has symptoms ‘ the preventer’
What are side effects of ICS?
Oral candidiasis
Stunted growth in children
What are LABAs used for?
Taken everyday, like ICS, regardless of whether there are symtoms
(No longer 3rd line, LRA is, 2017)
What are LRAs used for?
3rd line oral mediation for asthma not controlled by SABA and ICS
What is MART Therapy?
Maintenance and reliever therapy
A form of combined ICS and LABA treatment with a single inhaler
Can be used for daily maintenance and the relief of symptoms as required
Suitable for poorly controlled asthma
How should patients aged 17 + be diagnosed with asthma?
Spirometry with a bronchodilator reversibility test
FeNO
(if symptoms better away from work, refer to occupational asthma specialist)
How should patients aged 5-16 + be diagnosed with asthma?
Spirometry with a broncodilator reversibility (BDR) test
FeNO test requested if there is normal spirometry or obstructive spirometry with negative bronchodilator reversibility test.
How should patients aged <5 be diagnosed with asthma?
Clinical diagnosis
What is considered a positive FeNO test?
> 40 ppb
>35 ppb in children
What spirometry score is considered an obstructive pattern?
FEV1/FVC (FEV1%) <0.7 or 70% is considered obstructive
What is considered a positive bronchodilator reversibility test?
Improvement in FEV1 of 12% or more and increase in volume of 200 ml or more
(Children FEV1 12% increase only)
Give the stepwise treatment pathway for asthma in adults?
- SABA
- SABA + low-dose ICS
- SABA + low-dose ICS + LTRA
- SABA + low-dose ICS + LABA +/- LTRA (response depended)
- SABA +/- LTRA + MART
(Switch ICS + LABA for MART which includes both)
6. SABA +/- LTRA + One of: change ICS to high-dose a trial of additional drug (theophylline, mag. sulf) seek senior advice
Should a patients asthma treatment be changed to adhere to new guidelines?
NICE do not advocate the changing of treatment in patients who have well-controlled asthma simply to adhere to new guidelines
Exposure to what chemicals is associated with occupational asthma?
Isocyanates (spray painting and foam moulding) Platinum salts Soldering flux resin Glutaraldehyde Flour Epoxy resins Proteolytic enzymes
How often should the ‘stepping down’ of asthma treatment be considered?
Every 3 months ~
Take into account duration of treatment, side-effects and patient preference.
Reduce dose of ICS by 25-50% at a time