Question

TWO CLINICAL CHEMISTRY EQUATIONS:

1. A 12-hour urine sample contained 750mL of urine and had a creatinine concentration of 85mg/dL. Find the total amount of creatinine excreted by this patient. How many grams of creatinine did this patient excrete in one day?

2. In an 8-hour period 500mL of urine was collected from a patient. It was found to have a protein concentration of 35mg/dL. Find the total amount of protein excreted and find the 24-hour protein value in terms of milligrams per day.

Answer 1

1) 1 dL = 100 mL

then 85 mg/dL = 85 mg/100mL

thus creatinine concentration is 85 mg in 100mL of urine sample then 750 ml contain 750 85/100 = 637.5

in 750 mL of urine contain 637.5 mg creatinine

It is 12 hour sample

12 hour sample contain 637.5 mg creatinine then 24 hour sample contain 637.5 2 = 1275mg of creatinine

1275mg of creatinine = 1.275 gm of creatinine

In one day patient excrete 1.275 gm of creatinine

2)

1 dL = 100 mL

then 35 mg/dL = 35 mg/100mL

thus protein concentration is 35 mg in 100mL of urine sample then 500 ml contain 500 35/100 = 175 mg

in 500 mL of urine contain 175 mg protein

175 mg protein excreted in 8 hour.

It is 8 hour sample

8 hour sample contain 175 mg protein then 24 hour sample contain 175 3 = 525mg of protein

In 24 hour patient excrete 525 mg of protein.