Acute Asthma Flashcards
what do they present with in an attack?
acute breathlessness and wheeze
what history may they have?
Ask about usual and recent treatment; previous acute episodes and their severity and best peak expiratory flow rate (PEF). Have they been admitted to ICU?
what should the differential diagnosis be ?
- acute infective exacerbation of COPD
- Pulmonary oedema
- upper respiratory tract obstruction
- pulmonary embolus
- anaphylaxis
what investigations should be done ?
PEF but they may be too ill
- ABG if sats below 92%
- CXR if suspected pneumothorax, infection or life threatening attack
- FBC
- U and E
what are the features of a severe attack?
Unable to complete sentences
• Respiratory rate >25/min
• Pulse rate >110 beats/min
• Peak expiratory flow 33–50% of predicted or best
what are the features of a life-threatening attack?
Peak expiratory flow 4.6kPa (32mmHg) •
- PaO2
how is an attack treated immediately ?
- Salbutamol 5mg (or terbutaline 10mg) nebulized with O2
- If PEF remains below 75%, repeat salbutamol
- Hydrocortisone 100mg IV or prednisolone 40–50mg PO or both if very ill
- Start O2 if saturations
what must happen for discharge
Been stable on discharge medication for 24h.
- Had inhaler technique checked.
- Peak flow rate >75% predicted or best with diurnal variability
what are the side effects of salbutamol?
tachycardia, arrhythmias, tremor, K+ decreased
why are hydrocortisone and prednisolone given?
they are steroids to reduce inflammation
which factors may require a higher dose?
Smoking, drugs that shorten the half-life, eg
phenytoin, carbamazepine, barbiturates, rifampicin.
what treatment should be given if life threatening features present?
Inform ICU and seniors
- Give salbutamol nebulizers every 15min, or 10mg continuously per hour. Monitor ECG; watch for arrhythmias
- Add in ipratropium 0.5mg to nebulizers
- Give single dose of magnesium sulfate (MgSO4) 1.2–2g IV over 20 mins
