Chemistry chap 12True

Urea can be measured in all of the following ways EXCEPT: A

A) The Caraway method B) Ammonium ions generated by the urease reaction leading to a detectable pH change C) Electrode to measure the rate of increase in conductivity as ammonium ions D) Isotope-dilution mass spectrometry

The abbreviated Modification of Diet in Renal Disease (MDRD) equation considers all of the following variables EXCEPT: A

A) Urine creatinine concentration B) Serum creatinine concentration C) Age D) Gender E) Ethnicity

Of the following drug therapies, which is MOST likely to interfere with the Jaffe chemistry for measuring creatinine?

Cephalosporin

Which of the following best describes the correct collection and handling conditions for a blood ammonia measurement?

Draw sodium heparin tube, place in ice bath immediately, separate cells and plasma in refrigerated centrifuge, immediately remove plasma and freeze if analytical testing is delayed

The major causes of decreased plasma urea concentration include:

Low protein intake and sever liver disease

Monitoring of _______ in patients on chemotherapy due to leukemia, lymphoma or multiple myeloma is necessary to avoid nephrotoxicity.

Serum uric acid

In the commonly used ("Caraway") colorimetric method for uric acid in serum, interference from other reducing substances such as ascorbic acid is minimized by the addition of:

Sodium carbonate

True or false? Indirect urea methods begin with the hydrolysis of urea to ammonia.

True

Azotemia refers to:

An increase in urea in blood

Given the following lab results, what is the most likely cause of this patient's BUN? BUN 45 mg/dL Creatinine 1.8 mg/dL Uric Acid 7 mg/dL pH 7.22 pCO2 74.4 mm Hg pO2 32.8 mm Hg O2 sat. 51.3%

Congestive heart failure

True or false? Serum urea levels are less affected by diet and metabolism than are serum creatinine levels.

False

Urea:

Is synthesized from CO2 and ammonia

True or false? An enzymatic method for creatinine on the Vitros (Kodak Ektachem) analyzer uses the reagent enzyme creatinine amidohydrolase.

True

True or false? Serum uric acid levels may be elevated in patients undergoing cancer chemotherapy.

True

A toxic condition involving a very high serum level of urea and creatinine accompanied by failure of the three main functions of the renal system is referred to as:

Uremia