Skip to Main Content

Chapter 46: Cystic Fibrosis

JN is a 2-year-old (8 kg) with repeat visits to her physician for pneumonia. There is a positive family history for CF. What test should be ordered in this patient to diagnose CF?

a. Chest x-ray

b. Sputum culture

c. Sweat test

d. DNA test

Answer c is correct. With repeat pneumonias and a positive family history for CF, this patient should receive a sweat test.

Answers a and b are incorrect. They are tests that would be ordered to diagnose pneumonia.

Answer d is incorrect. Most patients with CF can be diagnosed with the less expensive sweat test. If the sweat test is inconclusive, then DNA testing can be used for diagnosis.

JN is diagnosed with CF and treatment for her pneumonia needs to be initiated. Which test should be ordered to guide the antibiotic selection?

a. Sputum culture and sensitivity

b. Chest x-ray

c. Chest MRI

d. Chest CAT scan

Answer a is correct. The sputum culture and sensitivity will identify the organism(s) in the lungs and will show the organism’s sensitivity to antibiotics.

Answer b is incorrect. The chest x-ray and clinical symptoms are used to diagnose pneumonia in children. This test will not help guide antibiotic selection.

Answers c and d are incorrect. These tests are used to distinguish pathologic tissue, such as a tumor, from normal tissue in the body. These tests will not help guide antibiotic selection.

Which organism would you empirically treat for in this patient with CF?

a. Burkholderia cepacia

b. Pseudomonas aeruginosa

c. Stenotrophomonas maltophilia

d. Haemophilus influenzae

Answer b is correct. Empiric antibiotic therapy is usually aimed at P. aeruginosa in CF patients.

Answers a and c are incorrect. Burkholderia cepaciaand S. maltophilia are resistant organisms seen in CF patients later in life after exposure to many broad-spectrum antibiotics.

Answer d is incorrect. This organism may be a copathogen but CF exacerbations are correlated with P. aeruginosa density in the airways. Antibiotic treatment should be aimed at sensitivities of P. aeruginosa.

Which combination of antibiotics would be appropriate to treat ...

Pop-up div Successfully Displayed

This div only appears when the trigger link is hovered over. Otherwise it is hidden from view.