Renal

Question 1

The functional unit of the kidney whose structure is complex

Answer 1

Nephron
*Each kidney has approximately 1 million nephrons and each has a vascular system (with two arterioles - efferent & afferent) and tubular system

Question 2

What does the afferent arteriole do when perfusion is decreased?

Answer 2

DILATES to increase flow to the glomerular capillaries

Question 3

What does the efferent arteriole do when perfusion is decreased?

Answer 3

CONSTRICTS to decrease flow from the glomerular capillaries

Question 4

Measures the amount of nitrogen in the blood that comes from the waste product urea (formed in the liver)

Answer 4

Blood urea nitrogen

-Elevated with dehydration and shock

Question 5

A non-protein waste product of creatine phosphate metabolism by skeletal muscle tissue.

Answer 5

Creatinine

Question 6

What is the best indicator of glomerular filtration rate?

Answer 6

24-hour urine creatinine clearance test

-Variables needed are creatinine and volume of urine

Question 7

The volume of plasma filtered from the glomerular capillaries into Bowman’s capsule per minute

Answer 7

Glomerular filtration rate

• Inversely related to creatinine not the BUN
• Affected by a persons age, sex, size, and serum creatinine.
• If large molecules (protein) are in urine if indicated glomerular damage. It can be used to detect early diabetic nephropathy.

Question 8

An increase in serum creatinine by 1.5 or > of baseline within 7 days

Answer 8

AKI

Question 9

What is RIFLE

Answer 9

Criteria used to stage renal failure
Risk
Injury 
Failure
Loss
End-stage kidney disease

Question 10

How does NSAIDs effect kidneys?

Answer 10

Block production of prostaglandins in afferent arteriole resulting in constriction

Question 11

How do ACE inhibitors effect kidneys?

Answer 11

Prevent production of angiotensin II so efferent arteriole will remain in dilated state.

Question 12

Causes of infrarenal cortical failure:

Answer 12

• Post-infectious (strep, hepatitis, varicella)
• Systemic lupus
• Vasculitis

Question 13

Causes of infrarenal medullary (ATN) failure:

Answer 13

Nephrotoxic:

• Contrast die
• Drug (antibiotics, NSAIDs)
• Rhabdomyolysis
• Organic solvents

Ischemic:

• All causes of pre-renal, post-renal failure
• Surgery (CABG, valves, vascular)
• HoTN

Question 14

Release of myoglobin, creatinine phosphokinase (CK), and potassium into the extracellular and intravascular spaces due to damaged muscles.
-Myoglobin and CK obstruct renal tubules.

Answer 14

Rhabdomyolysis

Question 15

Common clinical s/s for rhabdo:

Answer 15

• Dark, tea colored urine
• Positive hon on dipstick but no RBC on UA
• Myoglobin in urine (treatment is usually done until myoglobin is cleared from urine)
• CK >10,000

Question 16

Used to treat chronic anemia in renal patients

Answer 16

Epogen

*Note: platelet count may be normal but renal failure can cause them to be dysfunctional.

Question 17

What’s the highest cause of mortality in renal failure?

Answer 17

Infection

Question 18

What do you not want to restrict in renal failure?

Answer 18

Protein

Question 19

Who is most likely a candidate for dialysis?

Answer 19

A: acidemia
E: electrolyte disorders (high K)
I: intoxication (methanol, aspirin, lithium)
O: overload (heart failure)
U: uremia (elevated BUN with mental status changes)

Question 20

What is the BUN:creat for pre-renal failure?

Answer 20

20-40:1

Question 21

What is the BUN:creat for intra-renal failure?

Answer 21

10-15:1

Question 22

Caused by any obstruction in the flow of urine from the collecting ducts in the kidneys to the external urethral orifice.

Answer 22

Post-renal failure

-Ex: renal stones, enlarged prostate, neurogenic bladder, tumor