1. Management of asthma exacerbations in adults
Ala’Eldin Hassan Ahmed, MD, FRCP, FCCP
Faculty of Medicine, University of Khartoum

2. Acute Asthma Exacerbations in Adults
Definition:
Asthma is an inflammatory disorder of the airways associated with reversible airflow
obstruction. Airflow obstruction is assessed by measuring peak expiratory flow (PEF).
Clinically asthma presents as cough, and/or shortness of breath, and/or wheeziness.
and/or chest tightness. The symptoms of asthma tend to be variable, intermittent, worse
at night, and provoked by triggers including exercise.
Differential diagnosis:
 Congestive heart failure.
 Pulmonary embolism.
 Chronic obstructive pulmonary disease.
 Mechanical airway obstruction.
 Vocal cord dysfunction (rare).
Directed Approach to Acute Asthma Exacerbations:
History:
Determine how good or bad is the patient’s asthma control in the chronic stable state
 Symptoms especially the presence of nocturnal symptoms
 Range of home peak expiratory flow rates (PEFs), if available
 Frequency of emergency department visits and ICU admissions.
 Long term medications including oral steroid dependence
Evaluate the following concerning the current exacerbation:
 duration
 severity (see next)
 potential precipitants
 medications taken in response
Physical examination:
 Asses asthma severity: Features of severe asthma are: PEF < 50% best or
predicted; respirations >/= 25/min; pulse rate >/= 110 beats/min; can’t complete
sentences in one breath.
 Features of life threatening asthma are: SpO2 < 92%; silent chest; cyanosis; poor
respiratory effort; bradycardia; arrhythmia; hypotension; exhaustion; confusion;
coma.
 These findings are not sensitive indicators of severe attacks; up to 50 percent of
patients with severe airflow obstruction will not manifest many of these
abnormalities.
 Look for signs of pneumothorax or pneumomediastinum.
Diagnostic studies:
1. PEF measurement:
 This is the best test for assessing the severity of an asthma attack.
 It is easy to perform and when repeated over time can be used to monitor a
patient's response to treatment.

3.  Predicted values for an individual differ with size, age, gender, and ethnicity,
but a peak flow rate below 200 L/min indicates severe obstruction for all but
unusually small adults.
2. Arterial blood gas (ABG) analysis:
 This is generally indicated only among patients with persistent dyspnea
(despite initial bronchodilator therapy) whose PEF remains below 33 percent
of predicted or those with signs of life threatening asthma.
3. Chest x-ray:
 Generally not recommended for all patients.
 It can be limited to those patients with suspected complications such as
pneumothorax, pneumomediastinum, or consolidation. Those with Life
threatening asthma and those who fail to respond to treatment satisfactorily.
For a stepwise approach for treating acute asthma exacerbations please
refer to the attached flowchart.
Notes:
 Give high flow oxygen to all patients with acute severe asthma.
 Ipratropium bromide provides greater bronchodilation for patients not rapidly
responding to initial beta agonist therapy.
 Avoid I.V. aminophylline if salbutamol is available. The combination of
salbutamol and itravenous aminophylline results in no further bronchodilation
than that achieved with nebulized beta agonists alone and may lead to
increased risk of toxicity.
 Rarely, however, some patients with near fatal asthma or life threatening
asthma with poor response to inhaled therapy may gain additional benefit
from IV aminophylline 5 mg/kg loading dose over 20 minutes unless on
maintenance oral therapy then give infusion of 0.5 – 0.7 mg/kg/h.
 If PEF is < 50% on presentation prescribe prednisolone 40 – 50 mg/day.
Continue prednisolone 40 – 50 mg daily for at least five days or until
recovery. This should be followed by treatment with regular inhaled
corticosteroids.
 In the absence of vomiting, oral administration of corticosteroids can be
substituted for intravenous administration. Oral formulations are rapidly
absorbed and exhibit comparable efficacy.
 If a nebulizer is unavailable, salbutamol may be delivered via a metered dose
inhaler (MDI) with a spacer. The equivalent dose has not been precisely
defined, but four to six carefully administered inhalations from an MDI with
spacer have generally been found to equal one nebulizer treatment.
 Routine prescription of antibiotics is not indicated for acute asthma.

4. Drugs used in this section:
Drug Main
indication
Recommended dose
Prednisolone Acute
asthma
 Oral: prednisolone 40 – 50 mg per day as single
dose. Continue for at least five days or until
recovery
Hydrocortisone Acute
asthma
 I.V. 100 mg 6 hourly is as effective as higher
doses
Salbutamol (via a
nebulizer OR a
metered dose
inhaler with a
spacer)
Acute
asthma
 Inhalation: 90 mcg/puff: 4 - 6 puffs every 20
minutes for up to 4 hours, then every 1 - 4 hours
as needed.
 Nebulization: 5 mg continuous flow nebulization
every 20 minutes for three doses. May also give
via continuous nebulization, administering
approximately 10 mg over one hour.
Ipratropium bromide Acute
asthma
 Nebulization: 500 mcg 4 times/day.
 Metered dose inhaler: 2 inhalations 4 times/day,
Aminophylline Acute
asthma
 I.V. loading dose (in patients not currently
receiving oral aminophylline or theophylline): 5
mg/kg over 20 minutes (given in normal saline or
5% dextrose); administration rate should not
exceed 25 mg/minute
 I.V. maintenance dosage continuous infusions in
normal saline: 0.5 – 0.7 mg/kg/hour. Dosage
should be adjusted according to serum level
measurement (if available)
Magnesium
sulphate
Acute
asthma
 IV. 1.2 – 2 grams infusion in normal saline or 5%
dextrose over 20 minutes (single dose)

5. Management of acute severe asthma in adults in emergency department
Measure Peak Expiratory Flow and Arterial Saturations
PEF>75% best or predicted
Mild
PEF 33-75% best or predicted
Moderate - severe
PEF < 33& best or predicted
Or any life threatening
features
Give usual bronchodilator Give salbutamol 5 mg by
oxygen driven nebuliser
Obtain senior ICU help
High concentration oxygen
> 60%
Salbutamol 5 mg plus
ipratropium0.5 mg via
oxygen driven nebulizer
Prednisolone 40 – 50 mg
orally or IV hydrocortisone
100 mg
Measure arterial blood gases
Markers of severity
PaOCO2 > 4.6 kPa
PaO2 < 8 kPa
Low pH
Give/repeat Salbutamol 5
mg plus ipratropium0.5 mg
via oxygen driven nebulizer
after 15 minutes
Consider continous
salbutamol nebuliser 5-10
mg/hr
Consider IV magnesium 1.2
– 2 grams over 20 minutes
Correct fluid/electrolytes
disturbances
Chest X ray
Life threatening
features
Or PEF < 50%
No life threatening
features
And PEF 50 –75%
Clinically
Stable and
PEF<75%
Clinically
Stable and
PEF>75%
Repeat salbutamol 5 mg nebuliser.
Give prednisolone
40 – 50 mg orally
Admit ICU accompanied by
doctor
Signs of severe
asthma or PEF
< 50%
No signs of severe
asthma and PEF
50 -75%
Patient
recovering and
PEF > 75%
Monitor SpO2,
heart and
respiratory rates
Signs of severe asthma
or PEF < 50%
Patient stable and
PEF > 50%
Potential discharge

6. Management of acute severe asthma in adults in emergency department
Measure Peak Expiratory Flow and Arterial Saturations
PEF>75% best or predicted
Mild
PEF 33-75% best or predicted
Moderate - severe
PEF < 33& best or predicted
Or any life threatening
features
Give usual bronchodilator Give salbutamol 5 mg by
oxygen driven nebuliser
Obtain senior ICU help
High concentration oxygen
> 60%
Salbutamol 5 mg plus
ipratropium0.5 mg via
oxygen driven nebulizer
Prednisolone 40 – 50 mg
orally or IV hydrocortisone
100 mg
Measure arterial blood gases
Markers of severity
PaOCO2 > 4.6 kPa
PaO2 < 8 kPa
Low pH
Give/repeat Salbutamol 5
mg plus ipratropium0.5 mg
via oxygen driven nebulizer
after 15 minutes
Consider continous
salbutamol nebuliser 5-10
mg/hr
Consider IV magnesium 1.2
– 2 grams over 20 minutes
Correct fluid/electrolytes
disturbances
Chest X ray
Life threatening
features
Or PEF < 50%
No life threatening
features
And PEF 50 –75%
Clinically
Stable and
PEF<75%
Clinically
Stable and
PEF>75%
Repeat salbutamol 5 mg nebuliser.
Give prednisolone
40 – 50 mg orally
Admit ICU accompanied by
doctor
Signs of severe
asthma or PEF
< 50%
No signs of severe
asthma and PEF
50 -75%
Patient
recovering and
PEF > 75%
Monitor SpO2,
heart and
respiratory rates
Signs of severe asthma
or PEF < 50%
Patient stable and
PEF > 50%
Potential discharge