Topic 9 non -protein nitrogens

Flashcards covering key vocabulary and concepts related to urea, creatinine, uric acid, and ammonia in clinical chemistry.

Blood Urea Nitrogen (BUN)

A vital measure in clinical chemistry used to assess renal function, liver health, and protein metabolism.

Urea Cycle

A series of enzymatic reactions in the liver that converts ammonia to urea, the primary end product of protein catabolism.

Pre-Renal Azotemia

Elevated BUN caused by conditions that reduce blood flow to the kidneys without intrinsic renal damage.

Renal Azotemia

Increased BUN and creatinine levels due to intrinsic kidney damage affecting filtration.

Post-Renal Azotemia

Elevated BUN levels caused by urinary tract obstructions that impede urine flow.

Enzymatic Methods using Urease

Common methodology for measuring urea nitrogen, where urease catalyzes the hydrolysis of urea to ammonia.

Quality Control (QC)

Procedures ensuring accuracy and reliability of laboratory results by validating assay performance with control samples.

Creatinine Clearance

A measure of the volume of plasma cleared of creatinine per unit time, used to estimate glomerular filtration rate (GFR).

Estimated Glomerular Filtration Rate (eGFR)

A calculated measure of kidney function that estimates the GFR based on serum creatinine and other factors.

Uric Acid

The end product of purine metabolism, elevated levels are associated with gout and renal impairment.

Hyperammonemia

Elevated ammonia levels in the blood, often indicating liver dysfunction or inherited metabolic disorders.

Nesslerization

A colorimetric method that measures ammonia concentration by forming a colored complex with Nessler's reagent.

Isotope Dilution Mass Spectrometry (IDMS)

A highly specific reference method for quantifying urea or creatinine levels, ensuring assay calibration.

Reference Interval for Urea Nitrogen

Normal plasma urea nitrogen levels generally range from 6 to 20 mg/dL in adults.

BUN/Creatinine Ratio

A diagnostic tool used to differentiate between pre-renal, renal, and post-renal causes of azotemia.

Acute Kidney Injury (AKI)

A rapid decline in kidney function resulting in increased serum creatinine and decreased urine output.

End-Stage Renal Disease (ESRD)

The final stage of chronic kidney disease where kidney function is severely impaired, requiring dialysis or transplantation.