Urinalysis

Question 1

What can cause urine to appear red? How can you differentiate?

Answer 1

Red urine: blood, beets

Centrifuge will spin RBCs into a pellet, but if the color is due to beets the entire fluid will remain red.

Question 2

What are the urinalysis findings of AKI in the glomerulus vs. interstitium vs. tubules?

Answer 2

AKI Renal causes:
Glomerular: dysmorphic RBCs, RBC casts
Interstitial: WBCs and WBC casts
Tubular (ATN): granular casts

Question 3

If you see isomorphic RBCs where do you expect the blood to be coming from?

Answer 3

Isomorphic RBCs are strongly suggestive of lower urinary tract or post-glomerular bleeding

Question 4

A 58 year old male is referred with persistent hematuria. He complains of no other symptoms. He is an ex-smoker (40 year pack history). He is on no other medications. His GFR is 60 ml/min. Urine dip is otherwise unremarkable and microscopy indicates isomorphic RBCs. What is the likely diagnosis until proven otherwise?

Answer 4

Bladder cancer

Question 5

What are the urine microscopy findings in ATN?

Answer 5

Muddy brown, granular casts

Question 6

Match the following terms in 1 & 2:

1. Isomorphic blood, dysmorphic blood, active urine
2. Dysmorphic and/or RBC casts, lower tract or post glomerular, glomerular

Answer 6

Isomorphic blood = lower tract or post glomerular
Dysmorphic = glomerular
Active = dysmorphic and/or RBC casts

Question 7

What is your first thought when you see WBC casts?

Answer 7

Acute or chronic interstitial nephritis

Question 8

If you see granular casts what is your likely diagnosis?

Answer 8

ATN