Urine Microscopy

Question 1

urine analysis is composed of two major parts

Answer 1

1. urine dip
2. urine microscopy

Question 2

urine dip detects “blood” from three sources

Answer 2

• actual blood RBC
• hemoglobin
• myoglobin

if its in the pellet, it’s blood. if its in the supernatant, it’s just red pigment like Hb, Mb, or beet

Question 3

Type of protein that can be detected by urine dip

Answer 3

albumin.

• generally turns positive at 300mg/day of albumin. ONLY POSITIVE AT SUPER HIGH LEVELS. Not a good way to reliably quantify proteinuria.

Question 4

T/F a urine dipstick is good to see if someone has proteinuria

Answer 4

false. - generally turns positive at 300mg/day of albumin. ONLY POSITIVE AT SUPER HIGH LEVELS.

need to do an ACR and UTPCR

Question 5

WBCs can be detected on urine dip, but can be suggestive of multitude of things such as inflammation or infection or interstitila nephritis (NSAIDS, alllopurinol, PPI, Infection or inflammation). What is more telling to further support infection?

Answer 5

NITRATES further support infection.

• positive culture of 10CFU or freater.

symptoms are most important differentiator. (dysuria, fever, flank pain)

Question 6

for urine microscopy, if the supernatant is red vs if the pellet is red

Answer 6

Question 7

Answer 7

The more dehydrated you are, the more hyaline casts

normal finding in everyone

Question 8

Answer 8

Isomorphic Blood

This is strongly suggestive of lower urinary tract or post-
glomerular blood

Question 9

 58 M referred for persistent hematuria
 No other symptoms
 Ex-smoker – 40 pack year history
 No meds
 GFR 60 ml/min
 Urine dips positive for blood and protein

Answer 9

dysmorphic RBC!

suggestive of aglomerular nephritis

TIA, PIG, ATN

T= thin basement membrane disease

I= IgA neph

A= allports

P= pauci-immune

I= immune complexes like Iga, lupus, strep

G= anti-GBM/goodpastures

M= MPGN

P= post infectious again with strep, legionella or CMV

L= LUPUS, sarocid, schrogrens

Question 10

Should you give this person steroids

Answer 10

no This is not a dysmorphic red blood cell. This is segmenting yeast. If there’s yeast in their urine you shouldn’t give them steroids.

Question 11

 58 M
 Complains of a 3 week history of a sore throat
 Started on oral Keflex  Doesn’t improve
 Admitted to ICU with septic shock and found to have
bacteremia with a cephalosporin resistant Streptococcus

whats going on

Answer 11

ATN! Acute tubular necrosis AKI due to the kephlex. Toxin

Question 12

classic triad of AIN

Answer 12

Rash, peripheral eosinophilia and white blood cell casts in urine –> classic triad of acute interstitial nephritis. Needs predinosine.

Question 13

Answer 13

Needle shaped monohydrate calcium oxalate crystals seen only in Ethylene Glycol overdose

Question 14

most common stones

Answer 14

Calcium oxalate stones are the most common stones.

COC can also be spherical

Question 15

treatment of calcium oxalate stones

Answer 15

water

diet- sodium restriction, with calcium– do not restrict.

• restrict oxalate
• alkalinization or urine
• thiazide

Question 16

Answer 16

Looks like a coffin– struvite. Due to chronic infection in urinary tract. Hard to treat. Can get HUGE.

 Stones
 Calcium oxalate = envelopes, dumb bells or needles
 Uric acid = rhomboid
 Struvite = Coffin shaped