Acute Severe Asthma

Management of Status Asthmaticus

1. ACUTE SEVERE ASTHMA
Status Asthmaticus

2. Introduction
Status asthmaticus is an acute exacerbation of asthma that
remains unresponsive to initial treatment with
bronchodilators.
Status asthmaticus can vary from a mild form to a severe
form with bronchospasm, airway inflammation, and mucus
plugging that can cause difficulty breathing, carbon
dioxide retention, hypoxemia, and respiratory failure.
Patients report chest tightness, rapidly progressive shortness
of breath, dry cough, and wheezing and may have
increased their beta-agonist intake (either inhaled or
nebulized) to as often as every few minutes.

3. Pathophysiology
The airway obstruction is due to a combination
of factors that include
spasm of airway smooth muscle,
edema of airway mucosa,
increased mucus secretion,
cellular (eosinophilic and lymphocytic)
infiltration of the airway walls, and
injury and desquamation of the airway
epithelium.

4. Risk factors
Genetic predisposition
GERD
Viral infections
Air pollutants - Such as dust, cigarette smoke, and
industrial pollutants
Medications - Including beta-blockers, aspirin, and
nonsteroidal anti-inflammatory drugs (NSAIDs)
Cold temperature
Exercise

5. Asthma is one of the most common chronic diseases
worldwide with an estimated 300 million affected
individuals
Prevalence is increasing in many countries, especially in
children
Asthma is a major cause of school and work absence
Health care expenditure on asthma is very high
Developed economies might expect to spend 1-2 percent of
total health care expenditures on asthma.
Developing economies likely to face increased demand due to
increasing prevalence of asthma
Poorly controlled asthma is expensive
However, investment in prevention medication is likely to yield
cost savings in emergency care
The prevalence in Tanzania is 1-8%
Burden of asthma
GINA 2015

6. Clinical Presentation - History
Presence of current illness, such as upper respiratory tract infection or
pneumonia
History of chronic respiratory diseases (eg, bronchopulmonary dysplasia,
chronic lung disease of infancy)
History of allergies
Family history of asthma
Known triggering factors – smoke, pets
Home medications - Obtain a detailed list of medications being taken at
home and, if possible, their timing and dosage
History of increased use of home bronchodilator treatment without
improvement or effect
History of previous intensive care unit (ICU) admissions, with or without
intubation and mechanical ventilatory support
Asthma exacerbation despite recent or current use of corticosteroids
Frequent emergency department visits and/or hospitalization (implies poor
control)
History of syncope or seizures during acute exacerbation

7. Physical examination
Tachypneic with significant wheezing
Hyperexpanded chest with use of accessory muscles
(intercostal and subcostal retratctions)
Pulsus paradoxus
Inability to complete a sentence, sits hunched forward
Tachycardia and hypertension (PR >120 bpm)
O
2 saturation (on air) < 90%
PEF ≤50% predicted or best
level of consciousness may progress from lethargy to
agitation, air hunger, and even syncope and seizures
Life threatening features – inability to speak,
bradycardia, silent chest, normal or reduced respiratory
rate, cyanosis, PEF ≤33% predicted or best

8. Laboratory studies
The selection of laboratory studies depends on historical
data and patient condition. Tests that should be
performed in patients with status asthmaticus include
the following:
Complete blood count (CBC)
Arterial blood gas (ABG)
Serum electrolyte levels
Serum glucose levels
Peak expiratory flow measurement
Chest radiographs
Electrocardiogram (in older patients)

9. Management
After confirming the diagnosis and
assessing the severity of an asthma
attack, direct treatment toward
controlling bronchoconstriction and
inflammation.
Beta-agonists, corticosteroids, and
theophylline are mainstays in the
treatment of status asthmaticus

10. The first line of therapy is bronchodilator treatment with a beta2-
agonist. Handheld nebulizer treatments may be administered either
continuously (10-15 mg/h) or by frequent timing (eg, q5-20min),
depending on the severity of the bronchospasm.
Salbutamol solution 0.5% or 5 mg/mL nebulized by compressed
oxygen or Salbutamol via a spacer 2 puffs repeated every 20-30
minutes
Oxygen, via a mask or nasal prongs, oxygen therapy can be easily
titrated to maintain the patient's oxygen saturation above 92%
(>95% in pregnant patients or those with cardiac disease)
Set up an IV line for rehydration and possible IV medication,
Hydration, with intravenous normal saline at a reasonable rate, is
essential. Special attention to the patient's electrolyte status is
important.
Determine hydration status for amount of fluids required (not <2L/24hrs)
Steroids: Prednisolone orally 40-60mg daily or IV hydrocortisone 200mg
6hry (nebulized: controversial)
DO NOT give drugs that sedate the patient e.g. valium

11. Add nebulized ipratropium bromide (500mcg) to B 2 agonist
treatment for patients with acute severe or life-threatening asthma
or those with a poor initial response to B 2 agonist therapy.
Consider a single dose of IV magnesium sulphate (1.2–2g IVI over
20min) after consultation with senior medical staff, for patients with
acute severe asthma without a good initial response to inhaled
bronchodilator therapy or for those with life-threatening or near-fatal
asthma.
Use IV aminophylline only after consultation with senior medical staff.
Some individual patients with near-fatal or life-threatening asthma
with a poor response to initial therapy may gain additional benefit.
The loading dose of IVI aminophylline is 5mg/kg over 20min unless on
maintenance therapy, in which case check blood theophylline level
and start IVI of aminophylline at 0.5–0.7mg/kg/hr.
IV salbutamol is an alternative in severe asthma, after consultation
with senior staff. Draw up 5mg salbutamol into 500mL 5 % dextrose
and run at a rate of 30–60mL/hr.
Avoid ‘routine’ antibiotics.

12. ICU admission criteria
Indications for ICU admission include the following:
Altered sensorium
Use of continuous inhaled beta-agonist therapy
Exhaustion
Markedly decreased air entry
Rising PCO 
2
 despite treatment
Presence of high-risk factors for a severe attack
Failure to improve despite adequate therapy

13. Prevention
Compliance with medications
Avoid triggers