Acute asthma needs to be recognised quickly and managed appropriately. This guide gives an overview of the recognition and immediate management of an acute asthmatic exacerbation (using an ABCDE approach).
This guide has been created to assist students in preparing for emergency simulation sessions as part of their training, it is not intended to be relied upon for patient care.
Clinical features of asthma
Asthma is characterised by paroxysmal and reversible obstruction of the airways.
The disease involves both bronchospasm and excessive production of secretions.
Acute asthma can be life-threatening and therefore an ability to recognise the condition, start appropriate therapies and involve appropriate specialities is of paramount importance.
Typical symptoms and signs of acute asthma include:
- Shortness of breath
Tips before you begin
- Treat all problems as you find them
- Re-assess regularly and after every intervention to see if your management is effective
- Make use of the team around you to delegate tasks where appropriate – is another clinical member of staff available to help you?
- All critically unwell patients should have continuous monitoring equipment attached for accurate observations (e.g. pulse oximetry)
- If you need senior input for your patient, call for help early using an appropriate SBARR handover structure (check out the guide here)
- Review results (e.g. laboratory investigations) as they become available
- Make use of medical school/hospital guidelines and algorithms in managing specific situations such as asthma
- Any medications or fluids will need to be prescribed
- Your assessment and management should be documented in the notes (however this should not delay clinical management)
You are likely to see this patient after a brief handover from another member of staff.
Introduce yourself to whoever has requested a review of the patient.
Perform a quick general inspection of the patient to get a sense of how unwell they are:
- Check consciousness level using AVPU
- How do they look?
- How is their breathing?
- What is around the bedside? (look for inhalers, oxygen, IV lines, monitoring equipment etc).
- Introduce yourself to the patient
- Ask the patient how they are feeling
- Pay attention to their ability to speak in full sentences (an inability to do this suggests significant shortness of breath)
- Make sure the patient’s notes, observation chart and prescription chart are on hand (however this should not delay initial clinical assessment and management)
- Ask for another clinical member of staff to assist you if possible
If the patient is unconscious or unresponsive, start the basic life support (BLS) algorithm as per resuscitation guidelines.
Can the patient talk?
- Airway is patent; move on to Breathing assessment
- Look for signs of airway compromise (e.g. see-saw breathing, use of accessory muscles, diminished breath sounds, added sounds)
- Is the patient cyanosed?
- Open the mouth and inspect: is there anything obviously compromising the airway (e.g. secretions)?
In any case of airway obstruction, seek immediate expert help from an anaesthetist. You may need the crash team. In the meantime, you can perform some basic airway manoeuvres to help maintain the airway.
Maintain the airway whilst awaiting senior input
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)
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
- 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
- Sit the patient upright
- Administer oxygen 15L via a non-rebreathe mask
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
Peak expiratory flow rate (PEFR)
Can be used to assess severity and response to treatment, however, it shouldn’t delay administration of oxygen and nebulised medications.
A portable chest x-ray may be useful in ruling out other respiratory diagnoses if shortness of breath is the primary issue (e.g. pneumothorax/pneumonia/pulmonary oedema). Chest x-ray should not delay emergency management of acute asthma.
Blood pressure and pulse – rule out any evidence of haemodynamic shock
Capillary refill time – central – should be <2 seconds
Gain IV access – large bore cannula
Take blood samples – FBC / U&E / LFT / Clotting / CRP
There is some evidence that magnesium sulphate has bronchodilator effects in adults. 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 are 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
Arterial blood gas (ABG)
Take an arterial blood gas (ABG):
- PaO2 – look for evidence of type 1 respiratory failure (PaO2 <8 kPa)
- pH – alkalosis is often present initially due to hyperventilation (acidosis is a poor prognostic sign)
- PaCO2 – often low due to hyperventilation / if normal or rising patient likely needs critical care input (poor prognostic sign)
Assess level of consciousness – AVPU
A falling level of consciousnesses suggests severe hypoxia and requires urgent critical care input for further support (e.g. ventilation).
- Rash/angioedema – allergic reaction (or possibly anaphylaxis)
- Potential 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.
Asthma severity grading
It is important to have a good understanding of asthma severity grading as this will allow you to apply it in clinically to inform management decisions.
Moderate asthma exacerbation
- Increasing asthma symptoms. PEFR >50-70% of best or predicted.
- No features of severe asthma.
Severe asthma exacerbation
Any one of the following (in individuals > 12 years old):
- PEFR 33-50% of best or predicted
- Respiratory rate greater or equal to 25 breaths/min
- Pulse greater or equal to 110 beats/min
- Inability to complete sentences in one breath
Life-threatening asthma exacerbation
Any one of the following in someone with severe asthma:
- PEFR <33% of best or predicted
- Oxygen saturation <92%
- Silent chest
- Poor respiratory effort
Well done! You’ve stabilised the patient and they’re doing much better. Just a few more things to do…
Take a history
Take a more detailed history of what has happened and how the patient has been. Involve staff or family members as appropriate.
Check out our history taking guides here
Review the patient’s notes, observations, fluid charts, and any investigation findings. Double check the medications you have just prescribed, and any routine medications the patient is taking.
Document your ABCDE assessment clearly, including examination, observations, investigations, interventions, and patient response/changing condition. Write down any pertinent details from your history-taking.
If a senior doctor hasn’t already been involved, it is important to contact them and make them aware of the unwell patient. As a junior doctor, it would be appropriate to give an SBARR handover outlining your assessment and actions, and to discuss the following:
- Are any further assessments or interventions required?
- Does the patient need a referral to HDU/ICU?
- Should they be referred for a review by a speciality doctor?
- Should any changes be implemented to the management of any underlying conditions?
The next team of doctors on shift should be made aware of any patient in their department who has become acutely unwell.