Asthma Flashcards
Asthma is the most common chronic respiratory disorder encountered in clinical practice
true
What % affected children and adults?
10% of children and around 5-10% of adults
Asthma definition?
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.
Risk factors?
personal or family history of atopy antenatal factors: maternal smoking, viral infection during pregnancy (especially 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':
A number of patients with asthma are sensitive to?
aspirin
atients who are most sensitive to asthma often suffer from?
nasal polyps
Signs & symptoms?
cough: often worse at night dyspnoea 'wheeze', 'chest tightness' expiratory wheeze on auscultation reduced peak expiratory flow rate (PEFR)
Is asthma obstructive or restrictive?
Obstructive
What are the typical spirometry results in asthma?
FEV1 - significantly reduced
FVC - normal
FEV1% (FEV1/FVC) < 70%
How should adults be diagnosed with asthma?
Exclude occupational asthma
all patients should have spirometry with a bronchodilator reversibility (BDR) test
all patients should have a FeNO test
How should patients aged 5-16 years be diagnosed with asthma?
all patients should have spirometry with a bronchodilator reversibility (BDR) test
a FeNO test should be requested IF:
- There is normal spirometry or
- Obstructive spirometry with a negative bronchodilator reversibility (BDR) test
How should patients aged< 5 years be diagnosed with asthma?
diagnosis should be made on clinical judgement
What is a FeNo positive test?
in adults level of >= 40 parts per billion (ppb)
in children a level of >= 35 parts per billion (ppb
What does a reversbility test measure?
FEV1
What is a positive reversibility test?
Adults: improvement in FEV1 of 12% or more and increase in volume of 200 ml or more
Children: FEV1 of 12% or more
How does FeNO work?
nitric oxide is produced by 3 types of nitric oxide synthases (NOS).
one of the types is inducible (iNOS) and levels tend to rise in inflammatory cells, particularly eosinophils
levels of NO therefore typically correlate with levels of inflammation.
What are steps 1-4 in asthma management for adults?
- Short-acting beta agonist (SABA)
- SABA + low-dose inhaled corticosteroid (ICS)
- SABA + low-dose ICS + leukotriene receptor antagonist (LTRA)
- SABA + low-dose ICS + long-acting beta agonist (LABA)
Continue LTRA depending on patient’s response to LTRA
When should you skip to step 2 in a new diagnosis of asthma for adults?
Newly-diagnosed asthma with symptoms >= 3 / week or night-time waking
What is step 5 in asthma management for adults?
- SABA +/- LTRA
Switch ICS/LABA for a maintenance and reliever therapy (MART), that includes a low-dose ICS
What is step 6 in asthma management for adults?
- SABA +/- LTRA + medium-dose ICS MART
OR consider changing back to a fixed-dose of a moderate-dose ICS and a separate LABA
What is step 7 in asthma management for adults?
- SABA +/- LTRA + one of the following options:
increase ICS to high-dose (only as part of a fixed-dose regime, not as a MART)
a trial of an additional drug (for example, a long-acting muscarinic receptor antagonist or theophylline)
seeking advice from a healthcare professional with expertise in asthma
What is Maintenance and reliever therapy MART?
a form of combined ICS and LABA treatment in which a single inhaler, containing both ICS and a fast-acting LABA, is used for both daily maintenance therapy and the relief of symptoms as required
MART is only available for ICS and LABA combinations in which the LABA has a fast-acting component
true
for example, formoterol
Describe low, moderate and high doses of ICS
<= 400 micrograms budesonide or equivalent = low dose
400 micrograms - 800 micrograms budesonide or equivalent = moderate dose
> 800 micrograms budesonide or equivalent= high dose
paeds 200/ 200-400/ >400
What are the differences between paediatric 5-16 and adult management of asthma?
In contrast to the adult guidance, NICE recommend stopping the LTRA at step 4 if it hasn’t helped and not using it after this.
Theophyline is the first choice of trial additional drug at step 2 (in addition to SABA & ICS/MART)
What are steps 1-4 in asthma management for CHILDREN AGED <5?
- Short-acting beta agonist (SABA)
- SABA + an 8-week trial of paediatric MODERATE-dose inhaled corticosteroid (ICS)
- SABA + paediatric low-dose ICS + leukotriene receptor antagonist (LTRA)
- Stop the LTRA and refer to an paediatric asthma specialist
When should we consider stepping down asthma treatment?
every 3 months or so
take into account duration of treatment, side-effects and patient preference
When reducing the dose of inhaled steroids the BTS advise us to do this by what increments?
25-50%
What are the features of ACUTE asthma?
worsening dyspnoea, wheeze and cough that is not responding to salbutamol
maybe triggered by a respiratory tract infection
How is acute asthma classified?
moderate, severe or life-threatening
Features of moderate acute asthma?
PEFR 50-75% best or predicted
Speech normal
RR < 25 / min
Pulse < 110 bpm
Features of Severe acute asthma?
PEFR 33 - 50% best or predicted
Can’t complete sentences
RR > 25/min
Pulse > 110 bpm
Features of Life-threatening acute asthma?
PEFR < 33% best or predicted Oxygen sats < 92% Silent chest, cyanosis or feeble respiratory effort Bradycardia, dysrhythmia or hypotension Exhaustion, confusion or coma
normal pCO2 in an acute asthma attack is a good sign
FALSE
indicates exhaustion and should, therefore, be classified as life-threatening.
What is Near-fatal asthma?
fourth category
characterised by a raised pC02 and/or requiring mechanical ventilation with raised inflation pressures
What is an important step in further assessment of acute asthma?
the BTS guidelines recommend arterial blood gases for patients with oxygen sats < 92%
CXR is routinely performed in acute asthma attacks
false a chest x-ray is not routinely recommended, unless: life-threatening asthma suspected pneumothorax failure to respond to treatment
When should patients be admitted to hopsital?
life-threatening asthma
severe acute asthma should also be admitted if they fail to respond to initial treatment
previous near-fatal asthma attack, pregnancy, an attack occurring despite already using oral corticosteroid and presentation at night
What is reccomended oxygen therapy for acute asthma attack?
15L of supplemental via a non-rebreathe mask, which can then be titrated down to a flow rate where they are able to maintain a SpO₂ 94-98%.
Medical management of acute asthma attack?
bronchodilation with short-acting beta₂-agonists (SABA)
40-50mg of prednisolone orally (PO) daily, which should be continued for at least five days
ipratropium bromide: in patients with severe or life-threatening asthma, or in patients who have not responded to above
IV magnesium sulphate
IV aminophylline may be considered
ITU/HDU
Criteria for discharge following acute asthma attack?
been stable on their discharge medication (i.e. no nebulisers or oxygen) for 12–24 hours
inhaler technique checked and recorded
PEF >75% of best or predicted
Asthma in children: how do you assess acute attacks?
Severe attack or Life-threatening attack
What is a severe asthma attack in kids?
SpO2 < 92% PEF 33-50% best or predicted Too breathless to talk or feed Heart rate >125 (>5 years) >140 (1-5 years) Respiratory rate >30 breaths/min (>5 years) >40 (1-5 years) Use of accessory neck muscles
What is a life threatening asthma attack in kids?
SpO2 <92% PEF <33% best or predicted Silent chest Poor respiratory effort Agitation Altered consciousness Cyanosis
What chemicals are associated with occupational asthma?
isocyanates - the most common cause. Example occupations include spray painting and foam moulding using adhesives platinum salts soldering flux resin glutaraldehyde flour epoxy resins proteolytic enzymes
