Asthma Flashcards
What FEV1: FVC ratio gives an obstructive picture
> 80%
How can bronchodilator spirometry be used to diagnose asthma
- FEV1 pre and post beta agonist
- Shows a 12% and 200ml improvement for FEV1
What is direct challenge testing
Drop in FEV1 by 20% when patient exposed to a provoking substance
How can peak flow be diagnostic of asthma
20% variability
Twice daily readings for 2 weeks
When, within asthma, should the anaesthetist be called
33-92 CHEST peak flow: <33 Sp02: <92 C- cyanosis H- hypotension E- exhaustion S- silent chest T- tachy or brady cardia
What are the 5 categories of BTS severity
- Brittle asthma (type 1 and 2)
- Moderate asthma exacerbation
- Acute severe
- Life threatening asthma
- Near fatal
Type 1 Brittle Asthma?
Wide PEF variability (>40% diurnal variability for 50% of the time over 150 days) despite intense therapy
What is type 2 brittle asthma?
Sudden severe attack on background of well controlled asthma
Criteria for moderate severe asthma?
- Increasing symptoms
- PEF> 50-75% best or predicted
- No features of acute severe asthma
Critera for acute severe asthma?
- PEF 33-50%
- Resp rate 25/min
- HR 110
- Inability to complete sentence in one breath
Criteria for life threatening asthma
- PEF<33%
- SpO2 <92%
- PaO2 <8kPa
- Silent chest, cyanosis, feeble resp effort, confusion, coma`
Critera for near fatal asthma
- Increased paCO2
- Mechanical ventilation
From which level of severity should you admit a patient?
Acute severe
MoA of short and long acting beta agonist?
Activation of sympathetic nervous system
Bronchodilation and mucociliary clearance
Relaxes smooth muscle, relieves bronchospasm
SE of beta agonists
Tremor
Tachycardia
Sweats
Agitation
SE of inhaled corticosteroids
Oral candidiasise
MoA of leukotriene antagonist
reduces bronchoconstriction by blocking leukotriene receptors
SE of Leukotriene antagonist
Nausea and headaches
SE of anti-Ige
aching, headache, nausea, joint pain
What is the mneumonic for emergency management of asthma
O- oxygen S- salbutamol H- hydrocortisone I- Ipratroprium bromide T- theophylline !- Magnesium sulphate
How is salbutamol adminstered in an asthmatic emergency
Nebulised with oxygen
2.5mg-5mg every 10 minutes
How is hydrocortisone administered in an asthmatic emergency
IV 100mg-200mg QDS
How is ipatropim bromide administered in an asthmatic emergency
Nebulised with oxygen
500mg every 4-6 hours
How is magnesium sulphate administered in an asthmatic emergency
1.2-2g over 20 mins IV
