Acute asthma attacks can be potentially life-threatening. It’s therefore important that you can recognise and manage this condition in an acute setting. This guide gives an overview of the recognition and immediate management of an asthmatic exacerbation (using an ABCDE approach).
Is the patient able to talk?
- If so the airway can be considered patent.
- In severe asthma, the patient may be unable to talk due to shortness of breath.
Noisy breathing suggests airway compromise
1. Perform head tilt, chin lift manoeuvre.
2. If noisy breathing persists try a jaw thrust.
3. If airway still appears compromised use an airway adjunct:
- Insert an oropharyngeal airway (Guedel) only if unconscious (as otherwise may gag/aspirate)
- Alternatively, use a nasopharyngeal airway (better tolerated if the patient is partially conscious)
Sit the patient upright.
Give high-flow oxygen (40–60%) with a tight-fitting mask. If pulse oximetry is available, adjust the flow rate to maintain an oxygen saturation of 94–98%.
Assess the patient
Oxygen saturation – aim for 94-98%
- Tachypnoea is concerning and suggestive of significant respiratory compromise.
- A falling or normal respiratory rate in the context of hypoxia is a sign of impending respiratory failure and need for urgent critical care review.
Auscultate both lungs:
- Assess air entry – reduced air entry suggests significant airway compromise and need for critical care input.
- Note the degree of wheezing – wheeze becomes less apparent with increasing airway obstruction
Use high-dose inhaled beta-2 agonists as first-line agents in acute asthma and administer as early as possible.2
- Mild to moderate asthma – use either pressurised multiple dose inhaler (pMDI) plus spacer or oxygen driven nebulisation to administer beta-2 agonists
- Severe asthma – use oxygen driven nebulisation to administer beta-2 agonist
- Life-threatening – continuous oxygen driven nebulised beta-2 agonist
Repeat doses of beta-2 agonists at 15-30 minute intervals or give continuous nebulised salbutamol at 5-10 mg/hour if there is an inadequate response to initial treatment.
Steroids reduce mortality, relapses, subsequent hospital admission and requirement for beta-2 agonist therapy. The earlier they are given in the acute attack the better the outcome.2
- Give steroids in adequate doses in all cases of acute asthma (40-50mg prednisolone orally).
- If the oral route is unavailable then hydrocortisone can be given IV as an alternative
- Continue prednisolone 40-50mg daily for at least five days or until recovery.
Combining nebulised ipratropium bromide with a nebulised beta-2 agonist produces significantly greater bronchodilation than a beta-2 agonist alone.2
- Add nebulised ipratropium bromide (0.5 mg 4-6 hourly) to beta-2 agonist treatment for patients with acute severe or life threatening asthma or those with a poor initial response to beta-2 agonist therapy.
There is some evidence that, in adults, magnesium sulphate has bronchodilator effects.2
Consider giving a single dose of IV magnesium sulphate for patients with:
- Acute severe asthma who have not had a good initial response to inhaled bronchodilator therapy
- Life-threatening or near-fatal asthma
IV Magnesium sulphate should only be used following consultation with senior medical staff.
In acute asthma, IV aminophylline is not likely to result in any additional bronchodilation compared to standard care with inhaled bronchodilators and steroids. Side effects such as arrhythmias and vomiting area increased if IV aminophylline is used.2
- IV aminophylline should only be administered by senior medical staff / in a critical care context
It is NOT recommended to routinely prescribe antibiotics in acute asthma.2
Peak expiratory flow rate (PEFR)
Can be useful to assess severity and response to treatment, however, it shouldn’t delay administration of oxygen and nebulised medications.
Asthma severity grading
The below table demonstrates how to grade asthma severity which can then inform your management.
Assess the patient
Blood pressure and pulse – rule out any evidence of haemodynamic shock
Capillary refill time – central – should be <2 seconds
Gain IV access
Gain IV access – large bore cannula
Take blood samples – FBC / U&E / LFT / Clotting / CRP
Take an arterial blood gas (ABG):
- PaO2 – is there evidence of respiratory failure?
- pH – alkalosis initially due to hyperventilation/acidosis is a poor prognostic sign
- PaCO2 – often low due to hyperventilation / if rising patient needs critical care input
Assess level of consciousness – AVPU / GCS
A falling level of consciousnesses is a sign of serious deterioration and will require critical care input for further support (e.g. ventilation).
Expose patient’s body looking for:
- Rash / Angioedema – seen in anaphylaxis
- Allergens’ – e.g. IV antibiotics
It is essential to continually reassess ABCDE and treat issues as you encounter them. This allows continual reassessment of the response to treatment and early recognition of deterioration.
If the patient does not respond to treatment or deteriorates, critical care input should be involved as soon as possible.