Kidney Disease Intro and Lab Flashcards
Urinalysis
- Microorganisms
Microscopic Analysis
- Urine should be free from any microorganisms, RBC, WBC, or any cells
3 Processes in Nephron
Glomerular Filtration
Reabsorption
Secretion
Oliguria
Low urine output
- 100-400 mL in last 24 hours
Urinalysis
- Urine Dipstick
Chemical Analysis
- Measure how concentrated the urine is
–> Low Value = Dilute urine
–> High Value = Concentrated urine
Urinalysis
- Foamy Appearance
Macroscopic Analysis
- Presence of proteins or bile acid
Creatinine Clearance vs Glomerular Filtration Rate
Creatinine Clearance
- Determine drug dosing
- Only a surrogate marker of renal function
Estimated GFR
- Diagnosis stage of CKD
Where do the kidneys receive blood from
Renal Arteries
Pyuria
Presence of white blood cells in urine
- Indicator of inflammation
Calculating Creatinine Clearance
(140 - Age x Weight) / (SCr)
Multiply by 1.2 if male
Blood Urea Nitrogen
- What
The nitrogen (as urea) in the serum
- Represents urea production
- Not used for assessing renal function
- Used for monitoring hydration, protein tolerance, renal function
Azotemia
Accumulation of nitrogenous waste products in the blood
Blood Urea Nitrogen
- High Lab Values meaning
- High protein diet
- Upper GI bleeding
- Dehydration
- AKI or CKD
Main Functions of Kidney
Regulation
- BP, Osmolarity, Acid/Base, Fluid volume, electrolyte
Excretion
- Metabolic end products, urea, drugs
Synthesis
- Renin, Erythropoietin, Vitamin D3
AKI and CKD
- Risks
Patients with AKI are at risk of developing CKD
Patients who have CKD are at risk of AKI
Urine Protein/Albumin
- What
- Use
- How to measure
Glomerulus is normally impermeable to large proteins like albumin
24 hour urine collection
4 hour time collection to estimate 24 hour
Urine dipstick
Useful biomarkers to assess progression of CKD
Anuria
Lack of urine output
- Less than 100 mL in last 24 hours
Urinalysis
- Colour
Macroscopic Analysis
- Darker colour the more concentrated the urine is
AKI vs CKD
AKI (Acute decrease in kidney function)
- Over hours, days, or weeks
- Expressed through GFR
- Expressed through accumulation of waste products and volume
CKD (Progressive loss of kidney function)
- Over months, years
Proteinuria
Protein in urine (Albuminuria)
- Lack of glomerular filtration
Urinalysis
- Turbidity
Macroscopic Analysis
- More cloudy if RBC or WBC present in urine
- Urates and Phosphatases precipitate in urine
How to measure GFR
Can not measure directly, have to use an ideal marker
- Stable in plasma
- Physiologically inert
- Freely filtered at glomerulus
- Not secreted, reabsorbed, synthesized, metabolized at the kidneys
- Amount secreted at glomerulus is equal to amount excreted in urine
Hematuria
Presence of blood in urine
Blood Urea Nitrogen
- Low Lab Values meaning
No pathophysiological consequences
- May be fluid overload, malnutrition, liver damage
Function of Nephron
Functional unit of the nephron
- Filters blood and produces urine
Serum Creatinine
- What
- Eliminated
- Kidney Function
Determine by muscle mass
- Metabolic byproduct of muscle
Eliminated mostly by glomerular filtration
Inverse relation to kidney function
- Low serum creatinine means good kidney function
Serum Creatinine Reference Rangee
50-110 umol/L
What Decreases Creatinine
- Paralysis, Low activity levels
- Elderly
- Decreased Muscle Mass
- Cirrhosis
What Increases Creatinine
- Renal Causes
- Large Protein Intake
- Vigorous Exercise
- Increased Muscle Mass
