Renal Investigations

Question 1

Clues to renal disease upon history?

Answer 1

Hematuria
Dysuria
Fluid overload
Flank pain
Nocturia
Foamy urine
Symptoms of uremia
Systemic symptoms

Question 2

What is anasarca?

Answer 2

Extreme generalized edema

Question 3

What are symptoms of uremia?

Answer 3

Pale conjunctiva
Pruritis
Pericardial friction rub
Confusion
Clonus

Question 4

What sign on physical exam would indicate renal artery stenosis?

Answer 4

Abdominal bruit

Question 5

What is the single best screening tool for renal disease?

Answer 5

Urinalysis

Question 6

What is measured in urinalysis?

Answer 6

Color, clarity, turbidity
pH
Specific gravity
Glucose
Ketones
Blood
Protein
Microscopic examination of cells, casts, crystals

Question 7

Which protein is urinalysis most sensitive for?

Answer 7

Albumin

Question 8

What are two methods of quantifying protein in urine?

Answer 8

1. 24 hour urine for protein (Gold Standard)

2. Spot urine sample

Question 9

What is a urinary cast?

Answer 9

Matrix of Tamm-Horsfall protein

Question 10

What casts would be suspected in a healthy individual?

Answer 10

Hyaline & fine granular casts

Question 11

What casts indicate a non-specific abnormality?

Answer 11

Coarse granular casts, waxy casts, fatty casts

Question 12

What type of cast indicates proliferative glomerulonephritis?

Answer 12

RBC cast

Question 13

What type of cast would indicate acute tubular necrosis or glomerulonephritis?

Answer 13

Hemegranular casts

Question 14

What type of cast would indicated an infective/inflammatory process?

Answer 14

WBC cast

Question 15

What is the most common type of urinary crystal?

Answer 15

Calcium oxalate

Question 16

What three factors accelerate age-related loss of kidney function?

Answer 16

1. Hypertension
2. Smoking
3. Abnormal glucose metabolism

Question 17

What is creatinine?

Answer 17

Product of normal muscle metabolism cleared by filtration (95%) and secretion (5%)

Question 18

What is creatinine clearance?

Answer 18

Estimate of glomerular filtration rate

Question 19

What is the Cockcroft-Gault formula?

Answer 19

Measurement of creatinine clearance

CrCl (mL/min) = [(140-age) x IBW (kg)]/ serum creatinine (micromol/L)

Question 20

What is the correction factor for males in the Cockcroft-Gault formula?

Answer 20

Multiply by 1.2

Question 21

When is the MDRD (Modification of Diet in Renal Disease) formula helpful?

Answer 21

When GFR < 60ml/min

Question 22

How is kidney biopsy performed?

Answer 22

Percutaneously through the back +/- direct visualization with ultrasound or CT

Question 23

What is the biggest risk of kidney biopsy?

Answer 23

Hematuria

Question 24

When would you expect a false positive urine dipstick for protein?

Answer 24

Highly concentrated urine samples

Question 25

Hematuria, RBC casts, dysmorphic RBCs, proteinuria - Diagnosis?

Answer 25

Proliferative glomerulonephritis

Question 26

Isolated proteinuria - Diagnosis?

Answer 26

>500mg/24hours = renal disease
>3g/24hours = non-proliferative glomerulonephritis

Question 27

Heme or coarse granular/epithelial casts with free epithelial cells - Diagnosis?

Answer 27

Acute tubular necrosis

Question 28

Isolated hematuria - Diagnosis?

Answer 28

Mild glomerular damage or urologic cause

Question 29

Isolated pyuria - Diagnosis?

Answer 29

Interstitial infection or nephritis

Question 30

Negative urinalysis in setting of renal failure - Diagnosis?

Answer 30

Pre-renal or post-renal disease

Question 31

What charge of protein is is the urine dipstick good at detecting?

Answer 31

Negatively charged proteins

Question 32

List the three types of proteinuria

Answer 32

1. Glomerular
2. Tubular
3. Overflow

Question 33

What is the rule of thumb about serum creatinine and GFR?

Answer 33

Every time serum creatinine doubles, GFR drops by 50%