A 64-year-old man with a history of chronic obstructive pulmonary disease (COPD) is evaluated in the emergency department for increased dyspnea over the past 48 hours. There is no change in his baseline production of white sputum but he has increased nasal congestion and sore throat. His medications include inhaled tiotropium, combination fluticasone and salmeterol, and albuterol.
The patient is alert but in mild respiratory distress. The temperature is 38.6°C (101.5°F), blood pressure is 150/90 mm Hg, pulse rate is 108/min, and respiration rate is 30/min. Oxygen saturation with the patient breathing ambient air is 90%. Breath sounds are diffusely decreased with bilateral expiratory wheezes; he is using accessory muscles to breathe. He does not have any peripheral edema or elevated jugular venous distension (JVD). With the patient breathing oxygen, 2 L/min by nasal cannula, arterial blood gases (ABGs) are pH 7.27, PCO2 60 mm Hg, and PO2 62 mm Hg; oxygen saturation is 91%. His CBC shows leukocytosis of 11,000 and chest x-ray does not show any new infiltrates or pneumothorax.
1. What is your diagnosis?
2. How would you approach this patient?
This is a 64-year-old man with a known history of COPD who is on maintenance therapy. He has respiratory failure likely due to a COPD exacerbation precipitated by an upper respiratory tract infection.
Diagnosis: COPD exacerbation.
Next step in therapy: The patient is already on supplemental oxygen and his oxyhemoglobin saturation (SaO2) is >90%. Next, you should start the patient on a short-acting inhaled bronchodilator such as albuterol as well as an anticholinergic such as ipratropium bromide, IV corticosteroids, and empiric IV antibiotics. You should also consider placing the patient on noninvasive positive-pressure ventilation (NPPV).
Acute exacerbations of COPD are common. When a patient with known COPD presents with respiratory failure, the first step is to differentiate it from other causes that may present similarly. Exacerbations of COPD must be distinguished from pneumonia, pneumothorax, pulmonary embolism (PE), and congestive heart failure (CHF). Pneumonia and pneumothorax usually can be diagnosed by the chest radiograph. PE can be difficult to diagnose in patients with COPD, and spiral CT angiography should be used if embolic disease is suspected. Your suspicion of PE should be high in those patients who have risk factors such as prolonged immobilization, a history of cancer, recent trauma, or a history of clotting disorders. PE should also be expected if the patient is in hypoxic respiratory failure rather than hypercarbic respiratory failure and in those patients who do not respond to appropriate treatment for COPD exacerbation. Patients with respiratory failure due to heart failure usually have a history of systolic or diastolic heart failure. On physical examination, they have bibasilar crackles, elevated JVD, and peripheral edema of their lower extremities. Their CXRs will show pulmonary vascular congestion ...