Management
The initial management of adults with acute asthma is summarised in Table 3. For information on the assessment of severity, see Table 2. Initial assessment of acute asthma in adults.
| Table 3. Initial management of adults with acute asthma |
| Treatment |
Mild episode |
Moderate episode |
Severe episode |
| Hospital admission |
Probably not necessary |
Admit |
Admit. Consider admission to intensive care unit. |
| Oxygen |
Flow rate adjusted to achieve SaO2 > 90%. Frequent measurement of arterial blood gases is indicated in severe asthma and those not responding to treatment. |
| SABA via MDI + spacer |
8-12 puffs salbutamol |
8-12 puffs salbutamol every 1-4 hours |
8-12 puffs salbutamol every 15-30 minutes |
|
or
|
*SABA nebulised, e.g. salbutamol or terbutaline,
with O2 8 L/min |
One salbutamol 5 mg/2.5 mL nebule
or
One terbutaline 5 mg/2 mL respule)
or
Salbutamol 1 mL of 5 mg/mL solution + 3 mL saline |
One salbutamol 5 mg/2.5 mL nebule
or
One terbutaline 5 mg/2 mL respule
or
Salbutamol 1 mL of 5 mg/mL solution + 3 mL saline 1-4 hourly |
Salbutamol 1 mL of 5 mg/mL solution + 3 mL saline every 15-30 mins
If no response, give salbutamol 250 mcg (0.5 mL of 500 mcg/mL solution) IV bolus over one minute then IV 5-10 mcg/kg/hour
|
| Nebulised ipratropium bromide |
Not necessary |
Optional |
Ipratropium bromide 2 mL 0.05% (500 mcg) with salbutamol 2 hourly
|
Oral corticosteroids
e.g. prednisolone |
Yes (consider) |
Yes
0.5-1.0 mg/kg initially |
Yes
0.5-1.0 mg/kg initially |
Intravenous steroids
e.g. hydrocortisone (or equivalent) |
Not necessary |
†Hydrocortisone 250 mg (or equivalent) |
‡Hydrocortisone 250 mg 6 hourly for 24 hours then review |
Theophylline/
aminophylline |
-
|
-
|
#Aminophylline 25 mg/mL: give 6 mg/kg slow IV injection then 0.3-0.6 mg/kg/hour IV infusion |
| Adrenaline |
Not indicated |
Not indicated |
5 mL of 1:10,000 solution slowly IV if anaphylaxis present |
| Chest X-ray |
Not necessary unless focal signs present |
Not necessary unless focal signs present, or no improvement to initial treatment |
Necessary if no response to initial therapy or pneumothorax suspected |
| Observations |
Regular |
Continuous |
Continuous |
| Other |
|
|
Treat for hypokalaemia if present |
*SABA via MDI and spacer is as effective as nebulisation in patients with moderate-to-severe acute asthma, other than those with life-threatening asthma (e.g. patients requiring ventilation).1
†Use IV corticosteroids in moderate acute asthma if oral route not convenient
‡ Either oral or IV corticosteroids can be given initially. Follow with oral course.
# Alternative to IV salbutamol |
Patients with moderate-to-severe acute asthma require admission to hospital (consider intensive care) and continuous observation.
In adults with mild acute asthma, admission to hospital is usually not necessary. Observe patients for 1 hour after the episode is controlled to ensure full recovery. For information on community-based management of acute or subacute deterioration in symptom control and lung function, see Managing exacerbations.
Give SABA via MDI plus spacer immediately
Initially give 8-12 puffs salbutamol (100 mcg/dose) via MDI and spacer. Repeat as necessary (e.g. repeat every 15-30 minutes in a severe episode, 1-4 hours after the first dose in a moderately severe episode).
The use of SABAs by intermittent inhalation via MDI plus spacer is now recommended in the management of acute asthma, whether mild, moderate or severe.
- Delivery of SABA via MDI and spacer is equally effective as nebulisation in patients with moderate-to-severe acute asthma, other than those with life-threatening asthma (e.g. patients requiring ventilation).1 In patients who can inhale well enough to use an MDI, the use of IV SABA gives no advantage over inhaled treatment.
- Continuous nebulisation and intravenous therapy are alternatives in severe asthma. However, adverse events are more frequent.2,3,4
- Use a nebuliser instead if the person cannot inhale adequately: a 5 mg nebule of salbutamol with 2 mL saline or 1 mL of salbutamol solution (5 mg/mL) with 3 mL saline as needed. If available give wall oxygen at a flow of 8-10 L/min. A mouthpiece delivers considerably more drug to the lung than a facemask.5
- If no response to SABA via inhaler or nebuliser, give salbutamol 250 mcg IV bolus then 5-10 mcg/kg/hour by IV infusion.
 |
Salbutamol 8-12 puffs via MDI (100 mcg/dose) is equivalent to 5 mg via nebuliser. Alternatives are:
- terbutaline (Bricanyl) 500 mcg/dose 4-6 puffs
- eformoterol (Oxis Turbuhaler) 6 or 12 mcg/dose can be used. Up to 48 mcg in divided doses over 30 mins has been shown to be safe and effective.6
|
|
Start systemic corticosteroids
All patients with moderate-severe acute asthma will require a course of systemic corticosteroids in addition to inhaled corticosteroids (ICS).
- Commence a short course of oral corticosteroids (e.g. prednisolone 0.5-1.0 mg/kg for 7-10 days)
- Alternatively, corticosteroids can be given IV: hydrocortisone 100 mg 6 hourly or 40-120 mg methylprednisolone once daily or 4-12 mg dexamethasone once daily. There is no significant advantage to using more than 400 mg hydrocortisone per day (200 mg per day is adequate for most patients.7 Oral corticosteroids can be substituted when oral intake resumes.
ICS should be continued, but it is not clear whether this provides any additional benefit over systemic corticosteroids alone.8
The roles of other agents in acute asthma care in adults
- Nebulised ipratropium bromide given in addition to SABA may improve bronchodilation.9 If using nebulised SABA, add ipratropium bromide 2 mL 0.05% (1 mg) with salbutamol 2 hourly.
- Aminophylline 25 mg/mL IV (6 mg/kg IV slow injection then 0.3-0.6 mg/kg/hour infusion) can be used as an alternative to IV salbutamol when an acute episode does not respond to inhaled SABA. However, the use of intravenous aminophylline is unlikely provide a significant benefit in addition to therapeutically effective SABAs (i.e. where not compromised by concurrent use of beta blockers), and may increase adverse effects including nausea and vomiting.10 Injection rate should not exceed 25 mg/minute to reduce the risk of hypotension, seizures and arrhythmia. Serum levels should be monitored for both maximal effect and toxicity.
- Magnesium sulphate (via nebuliser or IV, as available) can be added to improve airflow, although the evidence to support this is not strong.11,12 Suggested doses are 1.2-2 g of MgSO4 IV over 20 min or 2.5 mL isotonic MgSO4 (250 mmol/L) by nebuliser
- Adrenaline is required for respiratory arrest or exhaustion suggesting impending respiratory arrest. Give 5 mL of 1:10,000 solution slowly IV. An alternative is 0.5 mL of 1:1,000 (0.5 mg) solution IM, but IV is the preferred route due to unpredictable absorption and the possible need for another injection with IM administration.
Other investigations
Arrange chest X-ray if there is no response to initial therapy, if focal signs are present or if pneumothorax is suspected.
Check for hypokalaemia and correct if present.
Content Updated (Wednesday, 02 January 2008)
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