When auscultating breath sounds of an infant with respiratory syncytial virus, which assessment finding would the nurse immediately report?

Choice A rationale

Cystic fibrosis primarily affects exocrine glands, leading to thick, viscous secretions that obstruct the pancreatic ducts. This obstruction prevents the release of pancreatic enzymes (e.g., lipase, amylase, protease) into the small intestine, impairing the digestion of fats, carbohydrates, and proteins, thus requiring exogenous enzyme supplementation.

Choice B rationale

Water-soluble minerals like sodium, potassium, and chloride are generally absorbed through active transport or diffusion in the intestines. While fluid and electrolyte imbalances can occur in CF, the primary digestive issue is enzyme deficiency, not a direct lack of water-soluble mineral absorption, although some may be affected indirectly.

Choice C rationale

Fat-soluble vitamins (A, D, E, K) require pancreatic lipase for their absorption, as they are dissolved in dietary fats. Due to the impaired fat digestion in CF, malabsorption of these vitamins is common, necessitating supplementation, but the fundamental issue addressed by enzymes is overall nutrient digestion, not just vitamins.

Choice D rationale

Salt supplements are often required in cystic fibrosis due to excessive sodium and chloride loss in sweat, particularly during hot weather or exercise. However, salt supplements do not directly facilitate the digestion and absorption of macronutrients; their role is to maintain electrolyte balance and prevent dehydration.

Choice A rationale

A sputum culture for acid-fast bacillus (AFB) is considered the gold standard for confirming the diagnosis of active pulmonary tuberculosis. This test directly identifies the presence of Mycobacterium tuberculosis in respiratory secretions, providing definitive evidence of infection and allowing for drug susceptibility testing, which is crucial for guiding treatment.

Choice B rationale

A chest X-ray can show abnormalities suggestive of pulmonary tuberculosis, such as infiltrates, cavitations, or effusions, but it is not definitive. Other respiratory conditions can present similarly, and a chest X-ray alone cannot confirm the presence of active Mycobacterium tuberculosis. It serves as a supportive diagnostic tool.

Choice C rationale

A sputum smear for acid-fast bacilli provides rapid presumptive evidence of active tuberculosis by visualizing AFB under a microscope. While helpful for early detection and isolation precautions, it does not confirm the species of mycobacteria and has lower sensitivity than culture. A positive smear needs confirmation with culture.

Choice D rationale

The Mantoux test, or tuberculin skin test, indicates exposure to Mycobacterium tuberculosis and the development of a cell-mediated immune response. A positive test signifies either latent TB infection or active disease but cannot differentiate between the two. It does not confirm active pulmonary tuberculosis and is not reliable for confirming active disease.