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22 Cards in this Set
- Front
- Back
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Definition of asthma |
recurrent episodes of cough, dyspnoea and wheeze caused by reversible airway obstrution |
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3 factors that contribute to airway narrowing? |
bronchial muscle contraction, mucosal swelling/inflammation, increased mucous production |
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4 signs of severe asthma |
Can't complete full sentence, RR>25, PR>110, PFR<50% |
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7 signs of life threatening asthma |
PFR<33%, O2 sat <92%, Cyanosis, Hypotension, Exustion, Silent chest, Tachycardia/bradycardia |
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Signs of asthma (6) |
tachycardia, wheeze, hyperinflated chest, hyperresonant percussion note, decreased airentry, polyphonic wheeze |
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What to ask patient? |
Precipitation factors (cold air, exercise, smoke, allergies NSAIDs, B-blockers, diurnal variation, disturbed sleep, acid reflux, eczema, hay fever, fam hx, occupation hazards |
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Tests acute asthma |
PEF, sputum culture, FBC, U+E, blood cultures, ABG, CXR |
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What does ABG show in acute asthma |
decreased PaO2 and PaCO2 - hyperinflation. If PaCO2 is normal or raised transfer pt to high dependency unit or ITU for ventilation |
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Tests for chronic asthma |
PEF monitoring, spirometry, CXR, skin-prick tests for allergens, Histamine or methacholine challenge. Aspergillus serology |
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Management of acute severe asthma |
1.Assess severity of attack 2. Immediate treatment: Salbutamol 5mg nebulised with O2. Hydrocortisone 100mg IV of prednisolone 40-50mg PO or both if very ill. Start O2 if sats <92% (check ABG), aim for 94-98%. 3. If life-threatening asthma: inform ICU and seniors. Give Salbutamol nebs every 15 mins or 10mg continuously per hr. Monitor ECG watch for arrhythmias. Add ipratroprium 0.5mg to neb. Give signal dose magnesium sulfate (MgSO4) 1.2-2g IV over 20 mins If not improving - ICU for ventilation, aminophylline , IV salbutamol. If improving - neb salbutamol every 4hr, prednisolone 45-50mg PO OD for 5-7 days, monitor peak flow and O2 sats |
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Management of chronic asthma (Behaviour) |
Behaviour: stop smoking, inhalor technique, monitor themselves with peak flow monitor twice a day, advice what to do in an emergency, relaxed breathing |
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Management of chronic asthma (drugs) |
BritishThroacicSociety guidelines: Step1: short acting B2-agonist a required. 100-200microgram Step2: add inhaled steroid beclomethasone 200-800microg/day Step3: add long acting B2-agonist salmeterol 50microg BD, can increase dose of beclometasone to 800micog/day. Leukotriene receptor antagonist or oral theophylline can be tried. Step4: Beclomethasone up to 2000micog OD. Modified release B2-agonist, oral leukotriene receptor antagonist Step5: add regular oral prednisolone. Continue with high-dose inhaled steroids |
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beta2-adrenoceptor agonists MOA |
relax bronchial smooth muscle by increasing cAMP |
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beta2-adrenoceptor agonists side effects |
tachyarrhythmias, hypokalceamia, tremor, anxiety |
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Corticosteroid MOA |
act over days to decrease bronchial mucosal inflammation |
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Corticosteroid S/E |
oral candidiasis (rinse out mouth after use of inhalor) |
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Aminophylline (metabolised to theophylline) MOA |
inhibits phosphodiesterase and therefore decreases bronchoconstriction by increasing cAMP levels.
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Aminophylline S/E |
has a narrow therapeutic window. Arrhythmias, GI upset, fits. Monitor ECG. |
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Anticholenergics - ipatropium, tiotropium MOA |
reduce muscle spasm in combination with beta2 agonists. May be more benefit in COPD |
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Leukotriene receptor antagonists (montelukast) MOA |
block cysteinyl leukotriene receptor preventing bronchoconstriction |
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Leukotriene receptor antagoinist S/E |
Gi upset, headache
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SIGN guidelines on how to escalate care of acute severe asthma: |
1. Oxygen 2. Salbutamol nebs 3. Ipatropium bromide nebs 4. Hydrocortisone IV or oral prednisolone 5. Magnesium Sulfate IV 6. Aminophylline/IV salbutamol |
