The following cases and commentary, which involve chronic obstructive pulmonary disease (COPD), are excerpted from ACP's Medical Knowledge Self-Assessment Program (MKSAP 15).
Case 1: Adding medications to existing regimen
A 69-year-old man is evaluated in the hospital for fever, progressive cough productive of purulent sputum, and increasing dyspnea. The patient was diagnosed with severe (GOLD stage III) chronic obstructive pulmonary disease 3 years ago. He smokes a pack of cigarettes a day. His medical history also includes hypertension and hypercholesterolemia, and his medications are albuterol as needed, tiotropium, simvastatin, hydrochlorothiazide, and aspirin.
On physical examination, the patient is in mild respiratory distress and is sitting up in bed. The temperature is 38.2°C (101.0°F), the blood pressure is 110/70 mm Hg, the pulse rate is 104/min, and the respiration rate is 20/min; BMI is 25. The oxygen saturation is 88% with the patient breathing ambient air and 93% on oxygen, 2 L/min by nasal cannula. There are bilateral expiratory wheezes but no digital clubbing or peripheral edema.
Chest radiograph shows hyperinflation without infiltrates. Arterial blood gases while the patient was breathing ambient air are pH 7.40, PCO2 41 mm Hg, and PO2 53 mm Hg. Spirometry done 2 months ago showed an FEV1 of 45% of predicted and an FEV1/FVC ratio of 52%. Therapy with nebulized albuterol and ipratropium is begun.
Which of the following additional therapy would be most appropriate for this patient?
A. Inhaled corticosteroids
B. Inhaled salmeterol
C. Intravenous theophylline and antibiotics
D. Intravenous corticosteroids and antibiotics
E. Noninvasive positive-pressure ventilation
Case 2: Increased dyspnea in last 48 hours
A 64-year-old man with a history of chronic obstructive pulmonary disease 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. Therapy with methylprednisolone, 60 mg intravenously, and inhaled albuterol and ipratropium bromide is started.
The patient is alert but in mild respiratory distress. The temperature is 38.6°C (101.5°F), the blood pressure is 150/90 mm Hg, the pulse rate is 108/min, and the 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. With the patient breathing oxygen, 2 L/min by nasal cannula, arterial blood gases are pH 7.27, PCO2 60 mm Hg, and PO2 62 mm Hg; oxygen saturation is 91%.
Which of the following is the most appropriate next step in the management of this patient?
A. Increase supplemental oxygen to 5 L/min
B. Intubate and begin mechanical ventilation
C. Start aminophylline infusion
D. Start noninvasive positive-pressure ventilation
Case 3: COPD and cardiac problems
A 72-year-old man is evaluated in the emergency department for dyspnea. One week ago, an episode of severe dyspnea awoke him from sleep. His wife described audible wheezing. Over the next several days, he felt easily fatigued, but his dyspnea stabilized. On the morning of admission, the patient noted a sudden increase in dyspnea and called emergency medical services. His medical history is significant for hypertension, hyperlipidemia, and chronic obstructive pulmonary disease. He currently takes simvastatin, aspirin, lisinopril, and ipratropium and salmeterol metered-dose inhalers.
On physical examination, he is afebrile, blood pressure is 86/52 mm Hg, pulse is regular at 110/min, and respiration rate is 24/min. Oxygen saturation is 92% on 6 L of oxygen. The patient appears uncomfortable, sitting up with labored breathing. Estimated central venous pressure is 14 cm H2O. Cardiac examination reveals a grade 2/6 holosystolic murmur at the cardiac apex radiating toward the left axilla. Bibasilar crackles are present. There is trace pitting pedal edema.
An electrocardiogram is shown.
Transthoracic echocardiogram reveals hypokinesis of the inferior wall and a left ventricular ejection fraction of 50%. There is severe mitral regurgitation due to posteromedial papillary muscle rupture. The pulmonary arterial systolic pressure is 55 mm Hg. A chest radiograph shows pulmonary vascular congestion.
Which of the following is the best management option?
A. Chest CT
B. Percutaneous coronary intervention
C. Transesophageal echocardiography
D. Urgent mitral valve surgery
Case 4: Evaluating mental status after weaning from mechanical ventilation
A 68-year-old man with chronic obstructive pulmonary disease, hypertension, and hyperlipidemia is being weaned from mechanical ventilation after an exacerbation. The patient's current medications are ipratropium bromide and albuterol (both by metered-dose inhaler through the ventilator), prednisone, lisinopril, and atorvastatin.
He is started on a spontaneous breathing trial, which he initially tolerates well but later shows evidence of oxygen desaturation and agitation. He is given increasing doses of lorazepam to cause sedation, and assist-control ventilation is resumed. The following day he is calm but is not focused and fails to follow commands consistently.
Which of the following is the best test to assess the patient's mental status?
A. Beck Depression Inventory
B. Confusion Assessment Method for the Intensive Care Unit (CAM-ICU)
C. CT scan of the head
D. Metabolic profile
E. Mini-Mental State Examination
Case 5: Adding to medications after discharge for exacerbation
A 55-year-old man with a 7-year history of severe chronic obstructive pulmonary disease is evaluated after being discharged from the hospital following an acute exacerbation; he has had three exacerbations over the previous 18 months. He is a long-term smoker who stopped smoking 1 year ago. He adheres to therapy with albuterol as needed and inhaled salmeterol and tiotropium and has demonstrated proper inhaler technique.
On physical examination, vital signs are normal. Breath sounds are decreased bilaterally; there is no edema or cyanosis. Oxygen saturation after exertion is 92% on ambient air. Spirometry shows an FEV1 of 32% of predicted and an FEV1/FVC ratio of 40%. Chest radiograph done in the hospital 3 weeks ago showed no active disease.
Which of the following should be added to this patient's therapeutic regimen?
A. An inhaled corticosteroid
D. Oral prednisone
Answers and Commentary
Correct answer: D. Intravenous corticosteroids and antibiotics.
In moderate to severe exacerbations of chronic obstructive pulmonary disease (COPD), inhaled short-acting bronchodilators (β2-agonists and anticholinergic agents) and systemic corticosteroids, antibiotics, and supplemental oxygen are the mainstays of treatment. In one trial of 100 patients with COPD, 16 responded to albuterol only; 17 responded to ipratropium only; and 47 responded to both. Corticosteroids improve lung function, reduce hospital stay, and lower rates of relapse and treatment failure. Antibiotic therapy has been shown to significantly reduce mortality, treatment failure, and sputum purulence in patients with exacerbations of COPD.
Noninvasive positive-pressure ventilation should be considered if patients have persistent hypoxemia and/or hypercapnia with a pH less than 7.35 and a PCO2 greater than 45 mm Hg and a respiration rate greater than 25/min despite maximal medical therapy. Exclusion criteria include respiratory arrest, cardiovascular instability, somnolence, impaired mental status, lack of cooperation, high risk of aspiration, recent facial or gastrointestinal surgery, craniofacial trauma, and extreme obesity. Patients who are hypoxemic need supplemental oxygen to achieve an oxygen saturation of 88% or greater.
The role of theophylline in COPD exacerbations is controversial. The conclusion from four trials with 169 patients was that theophylline therapy did not affect FEV1 at 2 hours but slightly improved FEV1 at 3 days. There were also increased rates of relapse and occurrence of tremor, palpitations, and arrhythmias. Long-acting β2-agonists, such as salmeterol, have no role in the therapy of acute exacerbations of COPD.
- Inhaled short-acting bronchodilators β2-agonists and anticholinergic agents), systemic corticosteroids, and antibiotics are the mainstay of treatment of exacerbations of chronic obstructive pulmonary disease in hospitalized patients.
Correct answer: D. Start noninvasive positive-pressure ventilation.
The patient is having a moderate to severe exacerbation of chronic obstructive pulmonary disease (COPD) and should be placed on noninvasive positive-pressure ventilation (NPPV). A landmark study found that NPPV reduced the need for intubation, the length of hospital stay, and the mortality rate in such patients. Suitable candidates for NPPV include patients with moderate to severe dyspnea, use of accessory respiratory muscles, respiration rate greater than 25/min, and pH less than 7.35 with PCO2 greater than 45 mm Hg. Contraindications to NPPV include impending respiratory arrest, cardiovascular instability, altered mental status, high aspiration risk, production of copious secretions, and extreme obesity, as well as surgery, trauma, or deformity of the face or upper airway.
Intubation is inappropriate because the patient is not in respiratory arrest and is a suitable candidate for NPPV. However, if the patient's condition deteriorates or does not improve after 1 to 2 hours of NPPV, intubation should be considered. Most patients with exacerbations of COPD are usually easily oxygenated on low levels of inspired oxygen. Excessive oxygen supplementation can worsen carbon dioxide retention during a COPD exacerbation. Therefore, oxygen should be titrated to maintain a saturation of approximately 90%; increasing the nasal oxygen to 5 L/min is not indicated at this time.
Methylxanthines are generally not recommended for the treatment of acute exacerbations of COPD because they are not more effective than inhaled bronchodilators and corticosteroid therapy but can cause nausea and vomiting.
- Noninvasive positive-pressure ventilation should be initiated early in the course of moderate or severe exacerbations of chronic obstructive pulmonary disease unless there is a specific contraindication to use of non-invasive ventilation.
Correct answer: D. Urgent mitral valve surgery.
Although this patient does not have a known history of coronary artery disease, the electrocardiogram suggests an inferior wall myocardial infarction, with Q waves in leads II, III, and aVF. Clinical presentation is consistent with cardiogenic shock, with posteromedial papillary muscle rupture causing acute severe mitral regurgitation. The echocardiogram demonstrates hypokinesis of the inferior wall and significant mitral regurgitation. Acute, severe mitral regurgitation is associated with high mortality and is a surgical emergency. In the SHOCK Trial Registry, although patients with cardiogenic shock who underwent urgent mitral valve surgery had significant in-hospital mortality (40%), those who did not receive surgery fared worse, with mortality above 70%.
Clinical presentation for papillary muscle rupture is generally several days after the infarct event (in this case, 1 week later), once infarcted tissue has had time to necrose. Posteromedial papillary muscle rupture is more common than anteromedial papillary muscle rupture because of its single coronary artery supply, as opposed to the dual coronary supply of the anteromedial papillary muscle. As a consequence, acute severe mitral regurgitation complicating an acute myocardial infarct is more common with inferior versus anterior infarcts and should be suspected in patients with pulmonary edema and respiratory distress in that setting. The murmur of mitral regurgitation may not be prominent because of the acutely elevated left atrial pressure and relatively lower transmitral systolic pressure gradient. Echocardiography is diagnostic, and early clinical recognition with aggressive support (intra-aortic balloon pump and/or afterload reduction if blood pressure allows) is essential. This condition is often misdiagnosed as respiratory decompensation due to pneumonia, acute respiratory distress syndrome, or endocarditis.
CT of the chest aids in assessment of the aorta and great vessels to assess for aortic aneurysm and/or dissection, and allows for evaluation of the lung parenchyma. Chest CT is not indicated in this patient, however, as echocardiography was diagnostic for severe mitral regurgitation as the etiology of his respiratory distress.
This patient should undergo emergent diagnostic coronary angiography to identify targets for bypass grafting to be performed at the time of mitral valve replacement. Although percutaneous intervention would address any residual intracoronary lesions identified at angiography, papillary muscle rupture with severe mitral regurgitation can only be treated surgically.
Compared with transthoracic imaging, transesophageal imaging may provide improved visualization of cardiac anatomy and function, particularly of posterior cardiac structures such as the mitral valve. However, in this patient, the regional wall motion abnormalities, mitral regurgitation, and ruptured papillary muscle were adequately identified by transthoracic echocardiography, and the more invasive transesophageal imaging is not necessary.
- The treatment for acute ischemic mitral regurgitation and cardiogenic shock is mitral valve replacement.
Correct answer: B. Confusion Assessment Method for the Intensive Care Unit (CAM-ICU).
The Confusion Assessment Method for the Intensive Care Unit (CAM-ICU) is an instrument for nurses and physicians to use in evaluating a patient for delirium; the assessment takes less than 1 minute and is recommended for routine monitoring of all mechanically ventilated patients. The CAM-ICU, a well-validated and highly reliable method now translated into more than 10 languages, is widely used for monitoring delirium in ICU patients. The prevalence of delirium in most studies of mechanically ventilated patients is between 50% and 80%. ICU delirium has been shown to be an independent predictor of ICU and hospital length of stay, cost of care, cognitive status at hospital discharge, and 6-month mortality. The agitated, hyperactive subtype of delirium is much less common than the “quiet,” hypoactive subtype, which is generally associated with a lower likelihood of survival.
The Beck Depression Inventory II consists of 21 items to assess the intensity of depression in clinical and normal patients. The Mini-Mental State Examination (MMSE) is a 30-point questionnaire that is used to screen for cognitive impairment. It is commonly used to screen for dementia. It is also used to estimate the severity of cognitive impairment at a given time and to follow the course of cognitive changes in a patient over time.
The diagnosis of delirium is a clinical one, and there are no laboratory tests, imaging studies, or other tests that can provide greater accuracy than the CAM-ICU algorithm. Specifically, a head CT scan and metabolic profile will not establish the diagnosis of delirium as effectively as CAM-ICU.
- The Confusion Assessment Method for the Intensive Care Unit (CAM-ICU), a clinical instrument for use in evaluating a patient in the intensive care unit for delirium, takes less than 1 minute and is recommended for all mechanically ventilated patients.
Correct answer: A. An inhaled corticosteroid.
Regular use of inhaled corticosteroids in patients with chronic obstructive pulmonary disease (COPD) is associated with a reduction in the rate of exacerbations from 1.3 to 0.9 per year, and patients who have frequent exacerbations with more severe COPD benefit most. In six placebo-controlled trials in 1741 patients over 6 months, inhaled corticosteroids reduced exacerbations by 24%. Therefore, the GOLD guidelines recommend consideration of inhaled corticosteroids in patients whose lung function is less than 50% and those who have exacerbations. When inhaled corticosteroids are combined with a long-acting β2-agonist, the rate of decline in quality of life and health status is significantly reduced and acute exacerbations are reduced by 25%; lung function is also improved and dyspnea is alleviated. There does not appear to be a dose response to inhaled corticosteroids in COPD, and the effects of combination therapy on mortality are uncertain.
Anticholinergic agents in COPD are especially useful when combined with short-acting or long-acting β2-agonists. Tiotropium is effective in patients with stable COPD for up to 24 hours and should not be combined with short-acting anticholinergic agents, such as ipratropium. Mucolytic agents have little effect on lung function. The antioxidant N-acetylcysteine, a drug with both mucolytic and antioxidant action, did not reduce the number of exacerbations of COPD in a large prospective 3-year trial. Oral corticosteroids are not recommended for regular use in a long-term maintenance program because their use is not associated with superior outcomes compared with standard therapy and is associated with increased side effects.
- Inhaled corticosteroids may offer significant benefit in patients with severe chronic obstructive pulmonary disease, with the benefit generally greater when an inhaled corticosteroid is combined with a long-acting β2-agonist.