Comparing high versus low dose of nebulised salbutamol in acute adult asthmatics presenting to the Emergency Department.

INTERVENTION: 5mg salbutamol nebulisation every 20minutes over 1 hour. This will be directly observed by the investigator. CONDITION: Asthma PRIMARY OUTCOME: FEV1 using bedside handheld spirometry. SECONDARY OUTCOME: Adverse events: symptoms mirroring salbutamol toxicity, such as tremor, anxiety, uncharacteristic tachycardia or tachypnoea. These measures will be identified by the treating clinician and recorded by the investigator. FEV1 using bedside handheld spirometry. Length of stay in ED. This will be monitored by the investigator. Total dose of salbutamol administered at 120minutes post commencement of treatment protocol. This will be recorded by the attending clinician on the trial proforma. Treatment failure defined as the need for non‐invasive or invasive ventilation and IV salbutamol. This will be recorded by the investigator. INCLUSION CRITERIA: • Doctor diagnosis of asthma • Age 18 to 65 years • Presentation to ED with a severe asthma exacerbation • PEF < 50% of predicted • Concomitant asthma medication may include: none, ICS, ICS/LABA, theophylline, LTRA, oral steroids, sodium cromoglycate, nedocromil sodium