Emergency Management of Asthma

What is emergency management of asthma?

Emergency management is the management plan for acute exacerbation of asthma. Severe acute asthma should always be dealt on emergency basis. Acute exacerbation of asthma may appear in any class or variant of asthma.

What are the protocols of emergency management ?

Emergency management consists of the following protocols:

1. Management at Home
2. Management at Physicians chamber
3. Management at Emergency department
4. Management at Hospital and ICU

What are the components of management of acute exacerbation?

There are four important components of management of asthma exacerbation, these are :

1. Initial and periodic observations
2. b2-agonist inhalation
3. O2 inhalation
4. Systemic corticosteroid

All these should be followed in emergency management of asthma at home, at physician's chamber, at emergency department or at hospital - wherever the patient is.

What is meant by Initial and Periodic observation?

Initial observation will be helpful to identity whether exacerbation is mild, moderate or severe and periodic observation will help to see the nature of response following treatment and whether patient needs hospital admission or can be managed at home.

Initial and periodic observation can be done from symptoms signs, pulmonary function and arterial oxygen saturation. Table I shows mild, moderate and severe exacerbation that can be assessed from initial and periodic observation.

ASSESSMENT OF SEVERITY OF ACUTE ASTHMA IN ADULTS

ASSESSMENT OF SEVERITY OF ACUTE ASTHMA IN CHILDREN

What is the role of drugs?

How b2-agonists is used in emergency management?

b2-agonist inhalation is an important basic component of management of asthma exacerbation. It can be given by nebulizer or from metered dose inhaler. From nebulizer b2-agonist given 2.5-5 mg salbutamol mixed with 2 ml normal saline. It is given as stat dose and at an interval of 20 minute. Two such doses can be given initially. Then it can be given 1-4 hour interval as per need. Sometimes b2-agonists are given by continuous nebulization as 10-15mg/hour or 0.5 mg/kg/hour.

If nebulizer is not available :

b2-agonists can be given through meter dose inhaler via spacer. Here 4-8 puffs given initially then at 5-20 minutes interval upto 4 hours, then it is given 1-4 hourly. If no improvement is observed, transfer to hospital should be considered.

What is the role of anti-cholinergic drugs?

In addition to b2-agonist inhalation, anticholinergic drugs such as ipratropium bromide may be added in nebulizer to get relief from asthma exacerbation. Not all asthma exacerbation get benefit from ipratropium bromide. Ipratropium bromide is found to be helpful in following situation :

1. Age of the patient <2 years</li>
2. H/O smoking >10 pack years
3. Severe attack with poor response to nebulized salbutamol (after 2 doses)
4. Refractory asthma

Why and how Oxygen inhalation is given?

All patients with acute severe asthma are hypoxaemic and require oxygen. This should be given via a face mask in a concentration high enough to maintain an adequate arterial oxygen saturation. The risk of significant carbon-di-oxide retention is low except in life threatening attacks. Inspired oxygen concentrations of 35% to 40% should be given rather the lower 24% to 28% which is often recommended. Goal of O2 administration is to achieve arterial O2 saturation > 90%.

How steroid is used?

Systemic steroids are recommended in the treatment of patients with acute asthma who do not respond rapidly and substantially to bronchodilator therapy. Intravenous hydrocortisone or methylprednisolone may be used, but in most cases extremely large doses are unnecessary. A dose of hydrocortisone (or methylprednisolone) which produces such a blood level that exceeds the level produced by stress condition has been suggested. This desired level is achieved by giving hydrocortisone 3-4 mg/kg followed by the same dose 6-hourly (an empirical regimen of 200 mg followed by 200 mg 4-6 hourly is simpler and more frequently used). Methylprednisolone in a dose of 50-100 mg 12 hourly has also been recommended. Intravenous corticosteroids may be replaced by oral prednisolone in doses of 30-60 mg in most patients within 24-48 hours.

As patient recovers, reduction in the dose of systemic/oral steroids should be associated with the early introduction of inhaled steroids.

How to assess and follow-up the patient?

We should carefully look at the response of the patient getting emergency management. Response to the treatment may be of following types.

Good response:

Criteria :

Improvement almost complete

No distress

Physical examination - normal

PEF > 70% of predicted or best

In case of good response, patient will go home with rescue steroid and step care management.

Incomplete response:

Criteria :

Improvement partial

Mild to moderate distress

Rhonchi present

PEFR >50% -

Poor response:

Criteria :

No improvement

Severe symptom persists

Extensive rhonchi/ silent chest

PEF < 50%

In case of poor response patient is to be admitted in ICU for further management. If necessary, intubation and artificial ventilation is to be employed.

What is the role of Methyl xanthines?

Aminophylline has been given by slow intravenous injection in the treatment of severe acute asthma for many years. b2-agonists are tending to replace methylxanthines as the initial treatment for severe asthma. Methylxanthines may increase side effects following high dose b2-agonist therapy. However, in the severely ill patient or the patient who is responding poorly to inhaled b2-agonist therapy, Aminophylline may be recommended a slow intravenous injection over at least 20 minutes (5 mg/kg x body weight) followed by continuous infusion (0.5mg/kg/hour).

What is the role of antibiotics?

Antibiotics are rarely indicated in the treatment of asthma exacerbations. Mucus hypersecretion and a productive cough are frequent manifestation of asthma. Discoloured sputum may be due to allergic inflammation and should not be interpreted as an indication of infection in the the absence of other symptoms or signs. Antibiotics should be reserved for specific infections, e.g. Pneumonia, Sinusitis.

Can sedatives be prescribed during acute attack?

No, sedatives are contraindicated during an acute attack. Agitation during an attack may be due to bronchospasm and hypoxaemia and is better treated with b2 agonists and oxygen. Most sedatives, including benzodiazepines, will suppress respiratory drive.

When to hospitalize a patient?

If following features are acknowledged by a physician, the patient should immediately be transferred to hospital and emergency management to be started:

• Patient is breathless at rest, unable to complete a sentence in one breath and talks in words and is hunched forward. Infants stop feeding
• Wheeze is very loud or chest is silent on auscultation
• Use of accessory muscles of respiration is marked
• Respiratory rate > 25/min
• Pulse rate > 120/min (>160/min for infants)
• PEFR <40% of predicted value or personal best; or <200 lit/min</li>
• Inspiratory fall of systolic BP<10 mm of Hg (Pulsus Paradoxus)</li>
• Patient is cyanosed, confused, and may be unconscious

When artificial ventilation is indicated?

Artificial ventilation is required in upto 2% of asthma admissions and may be a life saving procedure. Indication of artificial ventilation includes :

• PaCO2 more than 50 mmHg and rising
• PaO2 less than 60 mmHg and falling
• pH 7.4 or less and falling.
• SaO2 less than 90% even after 40% O2 inhalation.

Therapies not recommended during acute attack

• Sedatives (strictly avoid)
• Mucolytic drugs (may worsen cough)
• Chest physical therapy (may increase patient discomfort)
• Hydration with large volumes of fluid for adults and older children (may be necessary for younger children and infants)
• Antibiotics (do not treat attacks but are indicated for patients who also have pneumonia or bacterial infection such as sinusitis).
• Antihistamines (has no helpful effect on asthma itself, but can be given to prevent allergic rhinitis).

What is emergency management of asthma?

Emergency management is the management plan for acute exacerbation of asthma. Severe acute asthma should always be dealt on emergency basis. Acute exacerbation of asthma may appear in any class or variant of asthma.

What are the protocols of emergency management ?

Emergency management consists of the following protocols:

1. Management at Home
2. Management at Physicians chamber
3. Management at Emergency department
4. Management at Hospital and ICU

What are the components of management of acute exacerbation?

There are four important components of management of asthma exacerbation, these are :

1. Initial and periodic observations
2. b2-agonist inhalation
3. O2 inhalation
4. Systemic corticosteroid

All these should be followed in emergency management of asthma at home, at physician's chamber, at emergency department or at hospital - wherever the patient is.

What is meant by Initial and Periodic observation?

Initial observation will be helpful to identity whether exacerbation is mild, moderate or severe and periodic observation will help to see the nature of response following treatment and whether patient needs hospital admission or can be managed at home.

Initial and periodic observation can be done from symptoms signs, pulmonary function and arterial oxygen saturation. Table I shows mild, moderate and severe exacerbation that can be assessed from initial and periodic observation.

ASSESSMENT OF SEVERITY OF ACUTE ASTHMA IN ADULTS

ASSESSMENT OF SEVERITY OF ACUTE ASTHMA IN CHILDREN

What is the role of drugs?

How b2-agonists is used in emergency management?

b2-agonist inhalation is an important basic component of management of asthma exacerbation. It can be given by nebulizer or from metered dose inhaler. From nebulizer b2-agonist given 2.5-5 mg salbutamol mixed with 2 ml normal saline. It is given as stat dose and at an interval of 20 minute. Two such doses can be given initially. Then it can be given 1-4 hour interval as per need. Sometimes b2-agonists are given by continuous nebulization as 10-15mg/hour or 0.5 mg/kg/hour.

If nebulizer is not available :

b2-agonists can be given through meter dose inhaler via spacer. Here 4-8 puffs given initially then at 5-20 minutes interval upto 4 hours, then it is given 1-4 hourly. If no improvement is observed, transfer to hospital should be considered.

What is the role of anti-cholinergic drugs?

In addition to b2-agonist inhalation, anticholinergic drugs such as ipratropium bromide may be added in nebulizer to get relief from asthma exacerbation. Not all asthma exacerbation get benefit from ipratropium bromide. Ipratropium bromide is found to be helpful in following situation :

1. Age of the patient <2 years</li>
2. H/O smoking >10 pack years
3. Severe attack with poor response to nebulized salbutamol (after 2 doses)
4. Refractory asthma

Why and how Oxygen inhalation is given?

All patients with acute severe asthma are hypoxaemic and require oxygen. This should be given via a face mask in a concentration high enough to maintain an adequate arterial oxygen saturation. The risk of significant carbon-di-oxide retention is low except in life threatening attacks. Inspired oxygen concentrations of 35% to 40% should be given rather the lower 24% to 28% which is often recommended. Goal of O2 administration is to achieve arterial O2 saturation > 90%.

How steroid is used?

Systemic steroids are recommended in the treatment of patients with acute asthma who do not respond rapidly and substantially to bronchodilator therapy. Intravenous hydrocortisone or methylprednisolone may be used, but in most cases extremely large doses are unnecessary. A dose of hydrocortisone (or methylprednisolone) which produces such a blood level that exceeds the level produced by stress condition has been suggested. This desired level is achieved by giving hydrocortisone 3-4 mg/kg followed by the same dose 6-hourly (an empirical regimen of 200 mg followed by 200 mg 4-6 hourly is simpler and more frequently used). Methylprednisolone in a dose of 50-100 mg 12 hourly has also been recommended. Intravenous corticosteroids may be replaced by oral prednisolone in doses of 30-60 mg in most patients within 24-48 hours.

As patient recovers, reduction in the dose of systemic/oral steroids should be associated with the early introduction of inhaled steroids.

How to assess and follow-up the patient?

We should carefully look at the response of the patient getting emergency management. Response to the treatment may be of following types.

Good response:

Criteria :

Improvement almost complete

No distress

Physical examination - normal

PEF > 70% of predicted or best

In case of good response, patient will go home with rescue steroid and step care management.

Incomplete response:

Criteria :

Improvement partial

Mild to moderate distress

Rhonchi present

PEFR >50% -

Poor response:

Criteria :

No improvement

Severe symptom persists

Extensive rhonchi/ silent chest

PEF < 50%

In case of poor response patient is to be admitted in ICU for further management. If necessary, intubation and artificial ventilation is to be employed.

What is the role of Methyl xanthines?

Aminophylline has been given by slow intravenous injection in the treatment of severe acute asthma for many years. b2-agonists are tending to replace methylxanthines as the initial treatment for severe asthma. Methylxanthines may increase side effects following high dose b2-agonist therapy. However, in the severely ill patient or the patient who is responding poorly to inhaled b2-agonist therapy, Aminophylline may be recommended a slow intravenous injection over at least 20 minutes (5 mg/kg x body weight) followed by continuous infusion (0.5mg/kg/hour).

What is the role of antibiotics?

Antibiotics are rarely indicated in the treatment of asthma exacerbations. Mucus hypersecretion and a productive cough are frequent manifestation of asthma. Discoloured sputum may be due to allergic inflammation and should not be interpreted as an indication of infection in the the absence of other symptoms or signs. Antibiotics should be reserved for specific infections, e.g. Pneumonia, Sinusitis.

Can sedatives be prescribed during acute attack?

No, sedatives are contraindicated during an acute attack. Agitation during an attack may be due to bronchospasm and hypoxaemia and is better treated with b2 agonists and oxygen. Most sedatives, including benzodiazepines, will suppress respiratory drive.

When to hospitalize a patient?

If following features are acknowledged by a physician, the patient should immediately be transferred to hospital and emergency management to be started:

• Patient is breathless at rest, unable to complete a sentence in one breath and talks in words and is hunched forward. Infants stop feeding
• Wheeze is very loud or chest is silent on auscultation
• Use of accessory muscles of respiration is marked
• Respiratory rate > 25/min
• Pulse rate > 120/min (>160/min for infants)
• PEFR <40% of predicted value or personal best; or <200 lit/min</li>
• Inspiratory fall of systolic BP<10 mm of Hg (Pulsus Paradoxus)</li>
• Patient is cyanosed, confused, and may be unconscious

When artificial ventilation is indicated?

Artificial ventilation is required in upto 2% of asthma admissions and may be a life saving procedure.

Indication of artificial ventilation includes :

• PaCO2 more than 50 mmHg and rising
• PaO2 less than 60 mmHg and falling
• pH 7.4 or less and falling.
• SaO2 less than 90% even after 40% O2 inhalation.

Therapies not recommended during acute attack

• Sedatives (strictly avoid)
• Mucolytic drugs (may worsen cough)
• Chest physical therapy (may increase patient discomfort)
• Hydration with large volumes of fluid for adults and older children (may be necessary for younger children and infants)
• Antibiotics (do not treat attacks but are indicated for patients who also have pneumonia or bacterial infection such as sinusitis).
• Antihistamines (has no helpful effect on asthma itself, but can be given to prevent allergic rhinitis).

See Also:

Home Management of Asthma

Step Care Management of Asthma

Hospital Based Care of Asthma

Concomitant Disease management of Asthma

Pitfalls of Asthma Management