Chapter 12 Clin Chem
An urea N result of 9 mg/dl is obtained by a technologist. What is the urea concentration
19.3 mg/dl
Azotemia refers to
An increase in urea in blood
True or false? Indirect urea methods begin with the hydrolysis of urea to ammonia
True
True or false? Serum uric acid levels may be elevated in patients undergoing cancer chemotherapy.
True
which one of the listed conditions is not associated with elevated plasma uric acid concentration?
allopurinol overtreatment
Consider 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% What is the most likely cause of this patient's BUN?
Congestive heart failure
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
True or false? Serum urea levels are less affected by diet and metabolism than are serum creatinine levels
False
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
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
the abbreviated Modification of Diet in Renal Disease (MDRD) equation considers all of the following variables EXCEPT
Urine creatinine concentration
Which one of the following is not an NPN substance?
allantoin
Uric acid is the product of
allantoin metabolism
Prerenal azotemia is caused by
congestive heart failure
A MLT obtains a urea N value of 61 mg/dl and a serum creatinine value of 2.5 mg/dl on a patient. These results indicate
glomerular nephritis
Ammonia concentrations are usually measured to evaluate
hepatic encephalopathy
Urea:
Is synthesized from CO2 and ammonia
Which compound constitutes nearly half of the NPN substances in the blood?
urea