Chronic Obstructive Pulmonary Disease (COPD) and Emphysema in Emergency Medicine Treatment & Management

The mainstays of therapy for acute exacerbations of chronic obstructive pulmonary disease (COPD) are oxygen, bronchodilators, and definitive airway management.

Oxygen

Adequate oxygen should be given to relieve hypoxia. A belief (ingrained from medical school) is held widely that too much oxygen causes significant respiratory depression. Multiple studies in the literature dispute this view. With administration of oxygen, PO₂ and PCO₂ rise but not in proportion to the very minor changes in respiratory drive. However, a prehospital study of patients with acute exacerbations of chronic obstructive pulmonary disease by Austin et al documented lower morbidity and mortality with titrated versus standard high-flow oxygen treatment. In a cluster randomized, controlled parallel group trial in 405 patients, titrated oxygen treatment significantly reduced mortality, hypercapnia, and respiratory acidosis. ^[6]

The need for intubation can be established quickly at the bedside by asking the patient to hold the nebulizer in his or her hand. If the patient becomes so sleepy that the nebulizer starts to fall away, consider intubation regardless of PCO₂ level. The cause of increased CO₂ production is not decreased respiratory drive but probably reversal of hypoxic arterial vasoconstriction in areas of less-ventilated lung tissue, which increases the extent of ventilation/perfusion defects and thus CO₂. "Stated another way, there is probably no single value for arterial PCO₂, pH, or PO₂ that by itself constitutes an indication for [intermittent positive pressure ventilation (IPPV)]." ^[7]

Occasionally, large increases in CO₂ can lead to deterioration of mental status, causing stupor and obtundation. In such cases, decreasing O₂ delivery is the wrong action. The CO₂ narcosis inhibits respiratory drive to the point that decreasing O₂ delivery leads only to worsening of hypoxia. The correct action is immediate intubation and oxygenation.

Supply the patient with enough oxygen to maintain a near normal saturation (above 90%) and do not be concerned about oxygen supplementation leading to clinical deterioration. If the patient's condition is that tenuous, intubation most likely is needed anyway.

Bronchodilator

In the prehospital setting, administer short-acting beta-agonist nebulizer therapy, which should be given as needed. In addition, short-acting anticholinergics, such as ipratropium, can be given.

If necessary and available, continuous positive airway pressure (CPAP) may be used.

Of course, in times of respiratory failure, patients may need intubation in the field.

In addition to oxygen, proper ED care may comprise bronchodilators, antibiotics, magnesium, CPAP or biphasic positive airway pressure (BiPAP), Heliox (ie, mixture of helium and oxygen), and definitive airway management via intubation. ^[2] All of these should be considered in the context of the individual patient's condition. 

Not all chronic obstructive pulmonary disease (COPD) exacerbations have a reversible (bronchospastic) component to their process, but predicting which ones will and which ones will not is an exercise in futility. Some evidence even shows that the amount of bronchospasm and response to bronchodilators may vary with the same patient from exacerbation to exacerbation.

Keep in mind that altered level of consciousness is a contraindication for BiPAP, so carefully examine patients to determine appropriateness of its use.

For more information, please see Medication.

Consult a pulmonologist.

Continuous positive airway pressure (CPAP) and bilevel positive airway pressure (BiPAP)

These devices help to decrease the work of breathing and maintain positive end-expiratory pressure (PEEP). In patients with chronic obstructive pulmonary disease (COPD) who are in extremis, CPAP or BiPAP may be attempted prior to intubation. This can be started in the ED and continued for several hours in the hospital. Usual recommended settings are an inspiratory positive airway pressure (IPAP) of 10 cm water and an expiratory positive airway pressure (EPAP) of 2 cm water, with further adjustments based on the individual. This is contingent on the patient's ability to withstand the mask. This treatment is not a substitute for intubation; rather, it is a means of trying to avoid intubation. Keep in mind that altered level of consciousness is a contraindication for BiPAP, so carefully examine patients to determine appropriateness of its use.

Heliox is an additional strategy that can be attempted prior to intubation. Whether Heliox or CPAP is used will depend on the individual patient and local hospital availability. Again, like several other therapies mentioned in this article, study results both for and against Heliox have been published. The current summation of that literature indicates that Heliox may actually decrease the work of breathing while the patient is breathing the mixture, but its effects are not long lasting once it is removed. The proper mixture of the gases and the ability to deliver enough oxygen to the patient are also issues.

Inhaled nitric oxide has been suggested, but at this point does not seem to have a role in acute treatment.

Lung volume reduction surgery has also been touted as effective, but most recent studies demonstrate varying levels of success.

For the vast majority of patients, cessation of smoking is the only true means of prevention.

Disposition from the ED depends on the clinical picture for each patient more than any single laboratory value or test. In general, the longer the exacerbation, the more airway edema and debris are present, making resolution in the ED increasingly more difficult. Patients who state that they "feel back to normal" and have no overt reason for admission can reasonably be discharged home with follow-up arrangements. The corollary to this is that patients who state they "do not feel comfortable," regardless of the numbers, are the best predictors of outcome and probably should be admitted. Data on risk factors for relapse and need for admission are limited at present.

For patients who are sent home, nearly all should receive a short steroid burst and an increase in the frequency of inhaler therapy. Close follow-up should be arranged with the patient's regular care provider. Other therapies should be considered on a case-by-case basis.

Patients with severe or unstable disease should be seen monthly.

When their condition is stable, patients may be seen biannually.

Check theophylline level with each dose adjustment, then every 6-12 months.

For patients on home oxygen, check ABGs yearly or with any change in condition. Monitor oxygen saturation more frequently than ABGs.