Lab Approach to a Patient with Renal Disease Flashcards
What is reabsorbed at the PCT?
Na+, Cl-, HCO3-, K+, H20, glucose, AA
What is secreted at the PCT?
H+, organic acids, bases
What is reabsorbed at the Descending Loop of Henle?
Nothing
What is secreted at the Descending Loop of Henle?
H2O
What is reabsorbed at the Ascending Loop of Henle?
Na+, Cl-, K+, Ca++, HCO3-, Mg++
What is secreted at the Ascending Loop of Henle?
H+
What is reabsorbed at the DCT?
Na+, Cl-, Ca++, Mg++, HCO3-, K+, H2O (w/ ADH)
What is secreted at the DCT?
K+, H+
What is Azotemia? Uremia?
Azotemia: ↑ BUN w/o symptoms
Uremia: ↑ BUN & Cr w/ symptoms
If you decrease GFR by 50%, what will happen to your plasma creatinine levels?
Plasma creatinine will increase to twice the normal value (if creatinine production by the body remains the same)
What is the formula for Fractional Na and what is the reference range?
FENa = (Na excretion / total filtered load) x 100
Na excretion = (Urine Na) / (Serum Na)
Total Load = (Urine Creatinine) / (Serum Creatinine)
Reference Range: [Urine Na] < 20 mEq/L & FENa < 1.0
What is the reference range for Specific Gravity?
1.003 - 1.035
What are some causes of pseudohematuria?
- Excessive consumption of beets, berries, or rhubarb
- Food coloring
- Certain laxatives
- Pain Medications
What do RBC in cellular casts suggest? WBC in cellular casts? Granular casts? Muddy-brown casts?
RBC: glomerulonephritis
WBC: acute/chronic pyelonephritis
Granular: nonspecific, acute, chronic disease
Muddy-Brown: Tubular Damage (ATN)
What is the use of a Plain Radiograph of the Abdomen (KUB)
Kidney size and shape
Detection of nephrolithiasis
(radiopaque) and nephrocalcinosis
