Renal 3

Question 1

Renal hypoperfusion in AKI leads to a (increase/decrease) GFR and a consequent (increase/decrease) in creatinine.

Answer 1

Renal hypoperfusion&raquo_space; decreased GFR&raquo_space; ^ creatinine

** Note that in renal hypoperfusion you get an increased passive reabsorption of urea due to increase in renal tubular sodium and water reabsorption&raquo_space; BUN:Cr greater than 20:1.

Prevent AKI with volume resuscitation via IV normal saline.

Question 2

What is the best way to prevent recurrent renal calcium stones?

Answer 2

Restrict dietary Na+. Increased Na enhances Ca2+ excretion&raquo_space; worsening stones. Restriction of Na+ promotes Na+ (and subsequently Ca2+) reabsorption through CaSR [Ca2+ sensing receptor] in thick ascending limb of loop of Henle.

Question 3

In the case of recurrent renal calcium stones, why shouldn’t you restrict dietary Ca2+?

Answer 3

Because dietary Ca2+ binds oxalate to form inabsorbable calcium oxalate in the GI tract. Decreased dietary Ca2+&raquo_space; ^ free oxalate absorption leading to hyperoxaluria and urinary calcium oxalate stone formation.

** Increased Vit C also promotes hyperoxaluria.

Question 4

How do you prevent acute renal failure due to rhabdo?

Answer 4

Renal failure can occur with rhabdo due to ATN (acute tubular necrosis) from excessive filtered myoglobin. Risk of renal failure can be decreased with aggressive hydration, mannitol, and urine alkalinization.

Question 5

What’s the MCC of aseptic meningitis?

Answer 5

Coxsackie virus and echovirus

Question 6

What should you give to the patient to prevent contrast induced nephropathy?

Answer 6

Adequate pre-CT IV hydration via isotonic bicarb or normal saline. Give prior to procedure and for several hrs after procedure.

Question 7

How does Bartter syndrome result in hypokalemia?

Answer 7

Bartter syndrome is a state of chronic volume depletion due to a defect in salt reabsorption in TAL of Henle&raquo_space; hyperplasia of JGA&raquo_space; Increased Renin and secondary aldosterone elevation&raquo_space; k wasting and Na+ reabsorption via NaK2Cl transporter

Question 8

If a patient presented with gross hematuria with minimal proteinuria after having an URI, then what would be the most likely differential?

Answer 8

IgA nephropathy

Question 9

Thiazide diuretics are occasionally used in treatment of HTN. What is an unfavorable metabolic side effect of chlorthalidone?

Answer 9

Chlorthalidone can cause impaired insulin release from pancreas and can decrease glucose utilization in peripheral tissues. This can result in hyperglycemia, ^ LDL cholesterol and plasma triglycerides, and hyperuricemia.

Question 10

What are the electrolyte abnormalities that can result from thiazide use?

Answer 10

Hyponatremia, hypokalemia, hypomagnesemia, and hypercalcemia.

Question 11

How can hepatorenal syndrome worsen renal dysfunction?

Answer 11

Hepatorenal syndrome happens as cirrhosis progresses and patients undergo splanchnic arterial dilation&raquo_space; overall decrease in vascular resistance. This causes activation of renin-angiotensin system&raquo_space; local vasoconstriction with decreased perfusion and decreased glomerular filtration.

** Can use temporizing options like midodrine, Epi, and octreotide to cause splanchnic vasoconstriction&raquo_space; increased renal perfusion.

Question 12

How would you treat severe symptoms of SIADH due to SCLC?

Answer 12

Hypertonic (3%) saline admin but careful with rate of correction in order to prevent osmotic demyelination syndrome.