Respiratory Emergencies Study Guide for the CEN

General Information

The Certified Emergency Nurse (CEN) exam places considerable emphasis on this area of emergency nursing, with about 12% of the test questions pertaining to respiratory emergencies. Every aspect of the respiratory system and the assessment and treatment of related emergencies is covered.

Aspiration

Aspiration is defined as inhaling a foreign object, such as food or liquid, into the trachea or lungs. It can be symptomatic or asymptomatic, the latter of which is commonly known as silent aspiration. In severe cases, aspiration can result in pneumonia. Aspiration occurs due to dysphagia, which is often secondary to a stroke, reflux, or an inability to protect the airway due to altered mental status.

Assessment

The symptoms of aspiration vary depending on which type of aspiration the patient is experiencing. No symptoms are present in silent aspiration, but silent aspiration might be suspected if a patient presents with repeated pneumonia or bronchitis. Patients experiencing symptomatic aspiration may choke or cough when eating, experience shortness of breath while eating, feel like food is lodged in their throat after eating, experience heartburn, have a wet-sounding voice, or have excess saliva.

Both silent and symptomatic aspiration is diagnosed using either a barium swallow test or a fiber-optic endoscopic evaluation of swallowing. Symptomatic aspiration can also be diagnosed through a swallow study administered by a speech-language pathologist.

Treatment

The treatments for silent and symptomatic aspiration are similar. A consultation with a speech language pathologist is key. Depending on the degree of aspiration, they may recommend:

• thickened liquids
• pureed foods/foods of different textures
• crushed pills
• liquid medications

The pathologist will also work with the patient to strengthen the swallowing muscles and develop safe swallowing techniques, such as chin tucking and eating in high Fowler’s position. A patient with pneumonia will require antibiotics and possible supplemental oxygen.

Asthma

Asthma is an acute spasm of the bronchioles that occurs in conjunction with swelling of the mucosa (mucous membrane) lining the respiratory tract and excess mucus production. It can affect patients of all ages but is most common in children ages five to 17. Potential causes of asthma include:

• allergies
• repeated exposure to chemical irritants
• history of severe respiratory infections
• family history of asthma

Assessment

Evaluate the patient for signs of wheezing, shortness of breath, and respiratory distress. Determine if they can maintain a conversation comfortably or if they only speak in short sentences or cannot speak at all due to their breathlessness. In severe cases, hypoxia will also be present and lung sounds will be absent because the obstruction of the bronchioles prevents the exchange of air altogether. While mild cases may appear normal on a diagnostic chest X-ray, severe cases may show hyperinflation of the lungs, focal atelectasis, and bronchial thickening.

Treatment

In the event of an asthma exacerbation, immediate intervention is key. The patient should have continuous respiratory and oxygen saturation monitoring using a pulse oximeter. If their oxygen saturation drops, they should receive supplemental oxygen. The patient will receive a nebulizer treatment, likely DuoNeb®, which combines ipratropium bromide (a long-acting bronchodilator) and albuterol (a short-acting bronchodilator), or another similar medication.

Any asthma triggers, such as perfume or other strong scents, should be removed from the patient’s room. In severe cases, the patient may need to be intubated and placed on a ventilator to help them to breathe. A respiratory therapist may also be consulted, depending on the healthcare facility.

Chronic Obstructive Pulmonary Disease (COPD)

COPD is a slow-onset respiratory disease in which a long-term bronchial obstruction dilates and damages the patient’s alveoli and airways and reduces the elasticity of the lung. It can be caused by smoking, frequent lung infections, and repeated exposure to other particulates, such as air pollution.

Assessment

Patients with COPD will have diminished and possibly wheezy lung sounds due to bronchial obstruction and a limited capacity to exchange air. They will experience frequent coughing and wheezing and frequently feel short of breath, especially with activity. The cough is usually productive with thick sputum. The patients are more prone to catching bronchitis, pneumonia, or other infectious respiratory diseases. In advanced cases, hypoxia can occur. COPD is diagnosed using chest X-rays, computed tomography (CT) of the chest, pulmonary function testing to measure lung capacity, and an arterial blood gas (ABG) test.

Treatment

The primary treatment for COPD is bronchodilators, both long-acting medications that are taken once or twice a day and a short-acting bronchodilator to use as needed. Patients with COPD can experience exacerbations of their underlying disease that require hospitalization and more intensive treatments. These intensive treatments include inhaled corticosteroids or antibiotics if an infection is present. Severe exacerbations may require intubation and use of a ventilator to assist with respiration.

Patients with advanced cases of COPD may require the use of supplemental oxygen and find it beneficial to participate in pulmonary rehabilitation.

Infections

There are a wide range of respiratory infections, from the common cold to pneumonia. These infections can be bacterial, viral, or fungal. While most individuals recover without an issue from respiratory infections, patients who are immunocompromised or very young or very old can experience more complications.

Assessment

Infection symptoms range from mild congestion to severe respiratory distress that requires hospitalization. The patient can experience the following symptoms:

• thick yellow or green nasal discharge
• cough
• fever
• coarse lung sounds
• hypoxia
• tachypnea
• stridor
• dyspnea

Dyspnea in a respiratory infection is always due to some sort of obstruction of the airways, whether from mucus (caused by a cold), swelling of the upper airway tissue due to croup, or impaired gas exchange in the alveoli due to pneumonia.

Diagnostic tests include throat swabs to check for infections such as strep throat; nasal swabs to check for COVID-19 or the flu; lab work like a complete blood count (CBC), comprehensive metabolic panel (CMP), or lactic acid level to check for signs of sepsis or organ dysfunction; and a chest X-ray to check for pneumonia.

Treatment

The treatment options vary depending on the type of infection that the patient has contracted. A patient with mild pneumonia may need only oral antibiotics, while a severe case of pneumonia and/or sepsis may require intravenous antibiotics. It is best practice to obtain a sputum culture or blood culture before initiating broad-spectrum antibiotics to determine which type of antibiotics the bacteria is most sensitive to.

Minor viral infections such as colds only require symptom management, rest, and plenty of fluids. More severe cases such as COVID-19 or the flu can be treated with antiviral drugs such as Paxlovid® (COVID-specific), Tamiflu®, or remdesivir. Racemic epinephrine is used to treat upper airway stridor.

Inhalation Injuries

Inhalation injuries result from breathing in a noxious substance, such as smoke from a fire or toxic fumes from a workplace accident. Another example of an inhalation injury is carbon monoxide poisoning. Tissue anoxia occurs when carbon monoxide joins with hemoglobin in the blood, forming carbonyl hemoglobin and preventing the normal transport of oxygen through the circulatory system. Tissue injury can also result in acute pulmonary edema, which is fluid accumulation in the lungs.

Assessment

The patient will likely experience dyspnea and tachypnea. Auscultation of their lungs will reveal diminished breath sounds, wheezing, or rales. They will have a harsh cough that produces sputum. Stridor and hypoxia may occur in severe cases. If the patient experiences severe pulmonary edema, frothy pink sputum may be noted around the mouth. Respiratory depression and loss of consciousness may occur in severe cases.

The tests used to diagnose an inhalation injury include a chest CT, carboxyhemoglobin measurements for carbon monoxide poisoning, fiberoptic bronchoscopy, and pulmonary function testing.

Treatment

The treatment for inhalation injuries consists of providing supplemental oxygen, respiratory support, and monitoring with pulse oximetry. In the case of carbon monoxide poisoning, supplemental oxygen should be provided using a tightly fitted facemask to reduce the half-life of carboxyhemoglobin. Bronchodilators like albuterol can help if bronchospasm occurs, while racemic epinephrine can treat stridor.

Therapeutic coughing, early ambulation, and chest physical therapy help to clear mucus from the lungs and prevent further complications. In severe cases, intubation, a ventilator, and deep airway suctioning may be necessary.

Obstruction

Airway obstruction is the complete or partial blocking of the airway, usually due to inhaling or partially swallowing a foreign object. This could be a toddler who chokes on a grape or an adult choking on a chicken bone.

Assessment

Complete or partial airway obstruction severely impairs or prevents breathing. If the airway is completely obstructed, the patient will be unable to speak, appear in acute distress, be cyanotic, and possibly grab at the throat. If the obstruction persists, the patient may lose consciousness.

Treatment

The treatment for airway obstruction is to remove the obstruction in the airway. The healthcare professional should perform the age-appropriate airway clearing technique (chest thrusts and back blows for infants less than one year old, and the Heimlich maneuver for patients greater than one year old) and provide supplemental oxygen to the patient. If the object cannot be removed, the patient should be urgently transported to the closest medical facility, where they may undergo a bronchoscopy to remove the object.