Primary care provider orders cefazolin (Kefrol) 30 mg/kg in two divided doses per day for a child with pneumonia. Child weighs 20 lb. If the available oral suspension is 125 mg/5ml how many mls per dose should the child receive?

A. Pulmonary function test:

Pulmonary function tests (PFTs) assess lung function by measuring airflow, lung volume, and gas exchange. While PFTs can provide valuable information about respiratory function, they are not specific to cystic fibrosis and may show abnormalities consistent with various respiratory conditions. However, PFTs are often performed in individuals with cystic fibrosis to monitor lung function over time and assess response to treatment. They are not considered the most definitive test for diagnosing cystic fibrosis.

B. Sweat chloride test:

This option is correct. The sweat chloride test is considered the most definitive diagnostic test for cystic fibrosis. It measures the concentration of chloride in sweat, which is typically elevated in individuals with cystic fibrosis due to defective chloride transport in sweat glands. A sweat chloride concentration above a certain threshold (usually ≥60 mmol/L) is diagnostic of cystic fibrosis, particularly when confirmed with repeat testing.

C. Stool fat content analysis:

Stool fat content analysis evaluates fat absorption and fecal fat excretion, which may be impaired in individuals with cystic fibrosis due to pancreatic insufficiency. However, while stool fat content analysis can provide supportive evidence of malabsorption in cystic fibrosis, it is not considered the most definitive test for diagnosing the condition. Stool fat content analysis is often used in conjunction with other diagnostic tests to assess pancreatic function and nutritional status in individuals with cystic fibrosis.

D. Sputum culture:

Sputum culture involves culturing respiratory secretions to identify bacterial pathogens, which can be useful for diagnosing respiratory infections in individuals with cystic fibrosis. However, sputum culture is not specific to cystic fibrosis and may show similar findings in other respiratory conditions. While respiratory cultures are important for guiding treatment in cystic fibrosis, they are not considered the most definitive test for diagnosing the condition.

Convert the child's weight from pounds (lb) to kilograms (kg):

20 lb × (1 kg / 2.20462 lb) ≈ 9.07 kg

Calculate the total daily dose of cefazolin:

Total daily dose = 30 mg/kg/day × 9.07 kg = 272.1 mg/day

Divide the total daily dose into two equal doses:

Each dose = 272.1 mg / 2 ≈ 136.05 mg

Determine the dose per ml using the available oral suspension concentration:

125 mg/5 ml = 25 mg/ml

Calculate the volume of oral suspension needed for each dose:

Volume per dose = Dose per dose / Concentration per ml

≈ 136.05 mg / 25 mg/ml

≈ 5.44 ml

So, the child should receive approximately 5.44 ml per dose of cefazolin oral suspension.