Asthma Management

For patients undergoing an acute asthma attack, assessment must be focused on determining the severity of the attack and the nature of treatment required. All patients presenting to ED with any feature of a severe asthma attack persisting after initial treatment or any feature of a life-threatening or near-fatal asthma attack should be admitted for further treatment.

  • Hypoxaemia is a common feature of acute severe asthma. As such, supplementary oxygen should be given urgently for any hypoxaemic asthma patient with flow rates adjusted as necessary to maintain SpO2 of 94–98%.

  • Importantly, asthmatic bronchoconstriction can be reversed using inhaled B2 bronchodilators (e.g Salbutamol), which cause relaxation of airway smooth muscles and dilatation of airways through stimulation of sympathetic lung pathways. Oxygen-driven B2 bronchodilators are the preferred method of delivery and should be administered to patients with acute-severe or life-threatening asthma.

    If a patient responds poorly to an initial B2 bronchodilators bolus, then repeat doses (at 15-30 minute intervals) or continuous nebulised doses of B2 bronchodilators should be administered.

    Intravenous B2 bronchodilators may be prescribed in those where nebulised/inhaled B2 bronchodilators cannot be reliably administered.

  • Oral steroids (prednisolone 40-50mg daily) should be administered to all patients with an acute asthma attack. Steroids can be given; IV (hydrocortisone 100mg 6-hourly) or intra-muscular (methylprednisolone 160mg IM) if oral tablets are not tolerated.

  • Patients with severe or life-threatening asthma should be prescribed Ipratropium bromide (0.5mg 4-6 hourly) combined with nebulised β2 agonist therapy.

  • A single dose of IV MgSO4 can be prescribed for severe acute asthma that has not responded well to initial inhaled therapy. Continuous IV MgSO4 should only be prescribed following consultation with senior medical personnel.

    • IV Aminophylline: only prescribed after consultation with senior medical personnel.

    • Antibiotics: not prescribed routinely in acute asthma events as infective causes are usually viral.

    • IV fluids: use is limited to correcting electrolyte imbalance, β2 agonist-induced hypokalaemia or hypotension

Monitoring

  • Measure PEFR every 15-30 minutes following initial treatment to measure response.

  • Record oxygen saturation and maintain SpO2 at 94-98%.

  • Repeated measurements of blood gases within an hour of initial treatment if initial blood gases reveal abnormal measures (e.g PaO2, PaCO2).

Escalation

If patients do not respond to initial treatment they should be escalated to the Medical SpR/ Consultant and the intensive care team. They may require ventilatory support and admission to an HDU/ ICU. Signs and symptoms that indicate need for ventilatory support include: 

  • Deteriorating peak expiratory flow

  • Persisting or worsening hypoxia

  • Hypercapnia

  • ABG analysis showing ↓pH

  • Exhaustion, feeble respiration

  • Altered conscious state

  • Respiratory arrest

Stop and think!

Signs of life threatening asthma is a medical emergency and needs prompt treatment.