Asthma Flashcards
what is asthma?
chronic inflammatory airway disease charcterised by intermittent airway obstruction and hyper-reactivity. the airflow obstruction is reversible
what are the symptoms in asthma?
intermittent SOB wheeze (expiratory) Cough Sputum production Acid reflux (40-60%)
what are the signs of asthma?
tachypnoea wheeze hyperinflated chest hyperresonant percussion decreased A/E
what are the important points in an asthma history?
precipitants e.g cold air, exercise, allergens
Diurnal variation - in symptoms or peak flow. often worse in morning
Disturbed sleep
Effect on school/job/life
what are the investgations in asthma?
PEF
- diurnal variations of >20% on >3 days per week for 2 weeks. lower than normal for age and height
Spirometry
- FEV1/FVC of <80% predicated
- > 15% improvement in FEV1 after salbutamol
CXR
- hyperinflation. can be normal
FBC
- raised eosinophils and/or neutrophilia
skin prick allergy testing
what are the treatment steps in asthma?
step 1 = SABA PRN. If used more than once a day or nightime then move to step 2
Step 2 = add inhaled corticosteroid e.g beclometasone or budesonide
Step 3 = LABA e.g salmeterol. Increase steroid dose to max of 800ug a day before;
Step 4 = increase beclometasone to 2000ug/day. Then add theophylline, Leukoriene receptor antagonist (montelukast) or anti-IgE MAB (omalizumab)
Step 5 = oral prednisolone
how do B2 receptor agonist work in asthma? what are SEs?
increase cAMP leading to broncial SM relaxation
tremor, hypokalaemia, tachyarrhythmias
what are the S&S of acute asthma exacerbation?
cough, wheeze, SOB
progressive chest tightness tachycardia RR >25 silent chest - loss of wheeze accessory muscle use
how is acute asthma treated?
oxygen
5mg salbutamol nebs and 0.5mg ipatropium bromide nebs
oral prednisolone 40mg or IV hydrocortisone 100mg
IV magnesium sulphate
ICU referral after that
what are the signs of a moderate asthma attack?
- Increasing symptoms;
- Peak flow > 50-75% best or predicted;
- No features of acute severe asthma.
what are the features of severe acute asthma ?
Any one of the following:
- Peak flow 33-50% best or predicted;
- Respiratory rate ≥ 25/min;
- Heart rate ≥ 110/min;
- Inability to complete sentences in one breath.
what are the features of life threatening asthma?
any 1 of in patient with severe asthma
PEF <33% best or predicted SpO2 < 92% PaO2 < 8 kPa Normal PaCO2 (4.6–6.0 kPa) Silent chest Cyanosis Feeble respiratory effort Bradycardia Dysrrhythmia Hypotension Exhaustion Confusion Coma