ACUTE EXACERBATION OF COPD

Patients with COPD have little or no ventilatory reserve, and a further compromise of their respiratory system can send them into hypoxemia. The normal wear and tear of daily life puts respiratory compromises in everyone’s path periodically. People with COPD respond poorly to these respiratory problems and often experience an increase in dyspnea, cough, and sputum production. Such episodes of suddenly worsening symptoms are called acute exacerbations. Acute exacerbations usually last 7–10 days, but 20% of COPD patients may still be experiencing increased symptoms for up to 8 weeks.

The significance to healthcare personnel of patients’ exacerbations is their deleterious effect on patients’ health, the healthcare economy, increased hospital readmissions, accelerated rate of disease progression, future exacerbation risk, and mortality (GOLD, 2021; Harding et al., 2020).

Causes of Acute Exacerbations

Acute exacerbations of COPD can be brought on by a variety of factors. Infections, especially respiratory infections from colds to pneumonias, are common triggers. Smoking, passive smoking, reactivity of airways, occupational factors, and air pollution are the risk factors of COPD and can be the cause of an acute exacerbation.

Acute exacerbations can also be triggered by other medical conditions, especially when these conditions impinge on the cardiovascular or respiratory systems. Pneumothorax, pulmonary emboli, congestive heart failure, heart arrhythmias, chest trauma, lung atelectasis, and pleural effusions will all worsen a patient’s COPD. At the same time, however, many acute exacerbations cannot be easily explained.

Signs and Symptoms of an Acute Exacerbation

During an acute exacerbation, patients become more breathless than usual. They may have chest tightness, begin to wheeze or cough, and find it difficult to talk. In addition, their airways can become clogged with sputum, which may be yellowish or greenish and filled with white blood cells.

A sudden decrease in the ability to breathe efficiently makes patients tachycardic and sweaty, and their percentage of oxygenated hemoglobin (measured by pulse oximetry) decreases. In serious cases, patients become hypercapnic because they cannot get rid of sufficient carbon dioxide, making them acidotic and lethargic.

Treatment of an Acute Exacerbation

A patient’s regularly scheduled medications will not reverse an acute exacerbation. Instead, extra rescue medicines (a short-acting bronchodilator) and systemic corticosteroids are needed. To prevent ventilatory decompensation from worsening, further medical assistance, including hospitalization and mechanical ventilation, can be needed to treat an acute exacerbation and its cause (Harding et al., 2020).

Unlike asthma exacerbations, which can usually be reversed quickly, acute exacerbations of COPD improve slowly even when the patient receives prompt medical care. On average, it will take a week for a person to recover from an exacerbation of COPD, and recovery from 1 out of 4 acute exacerbations takes more than a month. For patients with severe COPD, an acute exacerbation can be fatal.

RESCUE MEDICATIONS

As a first step in counteracting the sudden worsening of their lung functions, patients are usually advised to take a predetermined “rescue dose” of a short-acting bronchodilator. Typically, it is a beta-2 agonist (albuterol, pirbuterol, or terbutaline), ipratropium, or the combination of albuterol and ipratropium (GOLD, 2021; Harding et al., 2020). Patients with COPD are advised to always keep their quick-relief inhaler with them.

EMERGENCY EVALUATION

When a sudden worsening of the ability to breathe is not improved by rescue therapy, the patient must be seen quickly by a primary care provider. Besides their COPD, the patient could be experiencing a medical emergency such as pneumothorax, pulmonary embolism, anaphylaxis, airway obstruction, or myocardial infarction. When the person with COPD does not improve with the usual rescue medications or home oxygen (if available), the patient or family should call the physician or 911 or report to the emergency department, depending on the severity of symptoms.

Anyone with the sudden onset of severe dyspnea is evaluated as a medical emergency. First, it must be ascertained that the patient has a clear airway. Diagnostic tests may include chest X-ray, electrocardiography, arterial blood gasses, complete blood count, electrolytes, cardiac enzymes, peak flow measurement, pulse oximetry, and pulmonary function testing (GOLD, 2021).

At the same time, an intravenous line is established and a cardiac monitor connected. If the patient’s pulse oximetry shows an oxygen saturation of <88%, supplemental oxygen is given, with a target oxygen saturation of 88%–92% (GOLD, 2021). The possibility of a pulmonary embolus is always considered when there is a sudden increase in dyspnea and hypoxia.

The patient should be medically stabilized. Patients with a serious instability or decompensation are admitted to an intensive care unit and the workup continues there. In this case, there is serious consideration of ventilatory support. This is a decision made in conjunction with the patient, if possible, or the patient’s family, since there is a strong possibility that the patient may not be able to be weaned from the ventilator and extubated.

MEDICAL MANAGEMENT

For patients experiencing an acute exacerbation of COPD, the immediate goals are to maintain an adequate level of blood oxygen and an appropriate blood pH.

For some patients with COPD, their exacerbation will be sufficiently mild that bronchodilators, steroids, and oxygen will lead to a rapid improvement. Other pharmacologic treatments may include a short-acting beta agonist, a short-acting inhaled anticholinergic, corticosteroids, and antibiotics. If no treatable trigger is found for this episode, the patients can often be sent home and followed outside the hospital (Harding et al., 2020).

Other patients’ lung functioning will have deteriorated sufficiently that these persons must be supported in a hospital. COPD leads to chronic respiratory failure, and acute exacerbations can lead to the superposition of acute respiratory failure. The result is called acute-on-chronic respiratory failure. In acute-on-chronic respiratory failure, patients have increasing dyspnea and may eventually develop an altered mental state or even respiratory arrest. Acute-on-chronic respiratory failure typically produces an acidosis, with pH <7.35 (normal pH is 7.35–7.45).

For acute-on-chronic respiratory failure patients, hospital therapy includes bronchodilator treatments, systemic steroids, controlled oxygen, and often, intravenous antibiotics. When necessary, steps are taken to maintain the patient’s ventilation and circulation. Supplemental oxygen for hypoxemia in patients with COPD is given to keep blood oxygenation levels of 88%–92%. Meanwhile, attempts are made to identify and reverse the precipitating factors; if a specific infection has not been identified, antibiotics are sometimes given prophylactically (GOLD, 2021; Harding et al., 2020).

In severe cases, noninvasive positive pressure mechanical ventilation (also called noninvasive ventilatory support, or NIVS) with a facemask or nasal cannula will often improve gas exchange without having to intubate the patient. Noninvasive ventilation leads to fewer secondary pneumonias and is easier to wean than endotracheal intubation (GOLD, 2021).