Nephro

Question 1

5 causes of renal mass in newborn

Answer 1

1. Hydronephrosis (I think #1?)
2. MCDK
3. ARPKD
4. Wilms tumor
5. Renal vein thrombosis

Question 2

Long term risk for MCDK

Answer 2

malignancy - wilm’s tumour

HTN

Question 3

Inheritance of MCDK

Answer 3

not inherited! trick!

Question 4

AR vs AD PCKD

Answer 4

AR more rare, more severe, presents earlier progresses more quickly
Can cause HTN in newborn
AD associated with cerebral aneurysm (10%)

Question 5

Ddx for recurrent hematuria 1-2 days after viral illness

Answer 5

1. IgA nephropathy: most common, normocomplementemic
2. Alports: normocomplementemic
3. Thin GBM disease (Benign familial hematuria)

Question 6

Bartter syndrome

Answer 6

Growth and mental retardation, hypokalemia, metabolic alkalosis, polyuria and polydipsia due to decreased urinary concentrating ability

Question 7

Ddx for hypoK hypoCl metabolic alkalosis (3) and how to differentiate

Answer 7

1. Chronic vomiting (Pyloric stenosis)
2. Renal: Bartter, Gitelman
3. Loop diuretic (Lasix) abuse
   Differentiated by Urinary Chloride: high in Bartter and diuretic abuse, low in chronic vomiting (losing from vomit not kidney)

Question 8

Distal vs proximal RTA

Answer 8

Confirm non–anion gap metabolic acidosis
–> urine pH distinguishes distal from proximal causes.
urine pH <5.5 in the presence of acidosis suggests proximal RTA (losing bicarb prox, distal tries to absorb HCO3, but still excretes H+ into urine), whereas patients with distal RTA typically have a urine pH >6.0 (able to resorb bicarb prox, but distal not excreting H+ so relatively basic urine)
K low in proximal
K normal/low in distal (less helpful)
Proximal = fanconi = no stones, acidosis not as severe as distal

Question 9

reasons for emergency urology consult for ANH

Answer 9

– Severe bilateral hydronephrosis.
– Severe hydronephrosis in a solitary kidney.
– Bilateral or unilateral hydronephrosis with dilated bladder consistent with PUV.
– Severe unilateral or bilateral hydronephrosis leading to pulmonary compromise from mass effect.

Question 10

Antinatal grade 1-2 hydro (6-7mm) - when do you image/consult?

Answer 10

Consult urology prior to DC if bilateral (or solitary kidney)!
imaging at 3-6 weeks if unilateral

Question 11

Tests to assess renal scarring/function vs. obstruction

Answer 11

scarring/pyelo = DMSA + Mag3
obstruction = Mag 3 + DTPA

DMSA = tubular binding isotope -in interstitium. Abnormal kidney won’t take it up. Will be photopenic area = scarring or pyelonephritis.
Mag 3 = 90% tubular agent, 10% glomerular agent = also secreted in urine; can also be used for scarring and flow of the dye through urine = see obstruction.
DTPA -mainly glomerular agent = assess obstruction but cannot use for photopenic area i.e. scarring/pyelo.

Question 12

Formula for calculating free water decific (hypernatremia)

Answer 12

simple: 4 cc/kg * wt * delta Na
(4cc/kg of free water will change your Na by 1 mEq/L)
Replace free water deficit + maintenance over 48 hours

Question 13

Causes for false + and - proteinuria on dipstick

Answer 13

false + = concentrated with alkaline urine (dehydrated), immersed too long, with gross hematuria, pus/semen/vaginal secretions
false - = dilute and acidic urine

Question 14

Rx for hypertensive emergency and mode of action

Answer 14

Hydralazine (IV): direct vasodilator, worry about lupus-like syndrome
Esmolol (infusion) or Labetalol (IV bolus): beta blocker, worry about brady + asthma
Nicardipine (IV infusion): Ca channel blocker, worry about rapid drop, reflex tachy
Na nitroprusside (infusion): vasodilator, worry about cyanide toxicity

Question 15

HSP criteria

Answer 15

2 of following:
- palpable purpura with normal Plt, INR/PTT
- bowel angina (post-prandial abdo pain, bloody stool)
- biopsy showing intramural granulocytes in small arterioles/venules with IgA deposition
Renal involvement: hematuria, proteinuria, RBC casts