Emergency Management of Acute Asthma

Introduction:

A common cause of emergency visits to the emergency department is due to acute exacerbation of asthma, a chronic disease of the lung. Asthma is a known cause of morbidity and mortality and results in 4,000 deaths yearly in the United States (US). Asthma is a chronic disease that causes diffuse inflammation of the airway muscles (muscles surrounding the passage to the lungs). In asthma, breathing difficulty, breathlessness, cough, tightness in the chest, and wheezing are caused by various triggers due to reversible constriction of the airway (bronchoconstriction). Asthma is diagnosed with a thorough history, examination, and various lung function tests. It can be controlled and managed with drug therapy and by preventing exposure to triggers. However, when asthma is poorly controlled, it can result in life-threatening acute asthma attacks that require emergency medical care.

What Are the Triggers of Asthma?

The following triggers can cause asthma:

1. Infections of the respiratory tract (flu or common cold).

2. Cold air.

3. Exercise.

4. Emotions such as laughing or crying hard.

5. Chemicals.

6. Smoke.

7. Pollution.

8. Perfume.

9. Air fresheners.

10. Inhaled allergens such as pollen, dust, and mold.

11. Drugs such as Aspirin and other non-steroidal anti-inflammatory drugs.

What Are the Key Symptoms of Asthma?

The symptoms of asthma can range from mild to severe among individuals. Asthma causes inflammatory swelling and irritation of the airways and tightens the muscles around the airway (bronchoconstriction). As a result, the airway or the passage to the lungs shrinks, making breathing difficult. It often worsens at night. The four main symptoms of asthma include the following:

1. Breathing difficulty (ranging from mild to severe).

2. Chest tightness (due to the constriction of the muscles around the airway).

3. Cough.

4. High-pitched whistling sound during breathing or wheezing.

What Are the Signs of Poorly Controlled Asthma?

The warning signs of poorly controlled asthma that are often missed include the following:

• Disrupted sleep at night due to cough and wheezing.

• Using an inhaler that offers quick relief more than two times a week.

• Missing school or work due to asthma symptoms.

• Difficulty in performing everyday activities.

• Inability to breathe properly, requiring emergency medical care.

When Should We Seek Emergency Help to Manage Asthma?

If the asthma episodes have increased in frequency or severity, one must visit the doctor or specialist (pulmonologist or allergist) for a consultation. Severe or acute asthma that does not respond to the patient’s prescribed medications requires emergency care. If the asthma attack is severe and is accompanied by signs of shock (a marked drop in blood pressure), it is known as status asthmaticus or a potentially fatal asthma attack. In addition, it is important is seek immediate medical attention if the patient has the following symptoms of respiratory system failure:

1. Persistent breathing difficulty or breathlessness, even while lying in bed.

2. Asthma symptoms that do not respond to the prescribed inhalers.

3. Bluish or grayish discoloration of the fingernails and lips.

4. Unable to speak without pausing for breath (straining to breathe).

5. Chest tightness.

6. Confusion.

7. Inability to concentrate.

8. Straining the neck and abdomen muscles, hunching shoulders, and altering positions to breathe more easily.

9. Agitation.

10. Signs of shock include severe sweating, nausea, faintness, rapid pulse, panting, and pale and clammy moist skin.

An acute asthma attack can also quickly occur without many warning signs and lead to death (due to asphyxiation or oxygen deprivation). These are more common among patients with poorly controlled asthma, repeatedly exposed to the triggers, and using their medications infrequently. In addition, coughing and wheezing may not be seen in some severe asthma attacks, as the airways are severely restricted (insufficient air passes through the airway to cause cough or wheeze).

How Are Acute Asthma Attacks Treated?

The aim of emergency management is to relieve severe symptoms and to help the patients to have normal lung function. Oxygen, inhaled medications to free the narrow airway (bronchodilators such as Albuterol), and medications to decrease the inflammatory response, such as corticosteroids, are usually provided in the emergency department to treat potentially fatal acute asthma attacks:

• Inhaled Bronchodilators:

Bronchodilators are drugs that act on the muscles surrounding the passage to the lungs to widen the constricted airway. This makes it easier for the air to pass through to and from the lungs, making breathing easier. Beta-2 agonists and Anticholinergics are the commonly used bronchodilators to treat acute asthma and are the mainstay of emergency care. These include:

1. Systemic Beta-2 Agonists:

   • Epinephrine: 0.2 to 0.5 milligrams (1:1000) is administered subcutaneously every 20 minutes (for a maximum of three doses) or every two hours as needed.

   • Terbutaline: 0.25 milligrams is administered subcutaneously once and may be repeated in 15 to 30 minutes (maximum dose of 0.5 mg over four hours can be administered)

2. Short-Acting Beta-Agonists:

   • Albuterol: Four to ten puffs every 20 minutes for three doses or a nebulized solution of 2.5 to five milligrams every 20 minutes for three doses are administered as emergency management initially. Alternatively, continuous nebulization is also administered.

   • Levalbuterol: Initially administered four to eight puffs every 20 minutes for three doses or a nebulized solution of 1.25 to two milligrams every 20 minutes for three doses as emergency management. Alternatively, continuous nebulization is also administered.

• Anticholinergic Drugs: An anticholinergic drug, Ipratropium, is added to beta-2 agonists to treat asthma attacks. These are not used as first-line therapy. It may be mixed in the same nebulizer as albuterol. A dose of 0.5 milligrams is given every 20 minutes for three doses, then every two to four hours as needed.
• Combination Drugs: The drugs used in combination include the following:

1. Ipratropium and Albuterol.

2. Mometasone (corticosteroid) and Formoterol (beta-2 agonist).

3. Budesonide (corticosteroid) and Formoterol.

• Systemic Corticosteroids: These drugs help to reduce the inflammatory response and the swelling and irritation in the airway, thus making it easier to breathe. Oral or intravenous administration of these drugs is administered in acute asthma. These include:

1. Methylprednisolone.

2. Prednisolone.

3. Prednisone.

• Antibiotics: These are administered only in case of bacterial infections.
• Oxygen Supplementation: Oxygen is given if the patient has low oxygen levels in their blood. These are usually given through nasal cannula (tube) or face masks to increase the oxygen levels in the body.

• Hospitalization: If the patient’s condition has not improved or has a relapse after hours of emergency care in the emergency department, they are usually hospitalized to continue treatment. If the oxygen levels continue to decrease and the carbon dioxide levels increase, it indicates respiratory failure, and the following treatment is done:

1. Oxygen is given to improve the oxygen levels in the blood using the following methods:

   • Bag-Mask Ventilation: Oxygen is pumped through a bag attached to the mask.

   • Noninvasive Positive Pressure Ventilation (NPPV): Mild air is blown into the airway to keep it open using tubes or masks.

   • Ventilator: A machine that helps to support breathing and provides oxygen to the lungs.

   • Tracheostomy: Oxygen is supplied through a hole (surgically made) in the windpipe.

   • Extracorporeal Membrane Oxygenation (ECMO): Artificial lung that can be used for several days to weeks till the lung recovers.

2. Various medicines are prescribed to treat respiratory failure. These include bronchodilators (medicines that help keep the airways open), antibiotics (to treat infections), and corticosteroids (to reduce inflammation)

3. Lung procedures and surgery.

4. Procedures to help recovery - fluids, feeding tubes, physiotherapy, and lung exercises. In case of severe conditions, the patient is asked to lie facing down to increase oxygen uptake.

Conclusion:

An acute asthma attack can quickly occur with or without warning signs and lead to death (due to asphyxiation or oxygen deprivation). These are more common among patients with poorly controlled asthma. The key to preventing these life-threatening acute asthma attacks is to control them with proper medical care and medications and avoid the triggering agents. Oxygen, inhaled medications to free the narrow airway (bronchodilators), and medications to decrease the inflammatory response, such as corticosteroids, are usually provided in the emergency department to treat potentially fatal acute asthma attacks.