CKD I

Question 1

GFR

Answer 1

glomerular filtration rate. Volume of blood filtered by the glomerulus each minute

Question 2

what is the normal adult GFR range?

Answer 2

100-125 mL/min

Question 3

How can we estimate the GFR?

Answer 3

Using different equations such as creatinine clearance

Question 4

what is the equation for creatinine clearance?

Answer 4

= [(140-age)x88.4x(0.85 if female)]/serum creatinine (sCr)

Question 5

why is creatinine clearance important?

Answer 5

Since it is freely filtered by the glomerulus, it can be used as a marker of glomerular filtration rate (GFR)

Question 6

What happen to serum creatine levels when renal functioning is impaired?

Answer 6

become elevated

Question 7

what drugs can cause acute kidney injury by inhibiting vasodilation of the afferent arteriole?

Answer 7

1. NSAIDS
2. Cox-2 inhibitors
3. Cyclosporine

Question 8

what drugs can cause acute kidney injury by inhibiting vasoconstriction of the efferent arterioles?

Answer 8

1. angiotensin converting enzyme inhibitors (ACE-I)

2. angiotensin II receptor blockers (ARB)

Question 9

T or F: We want to constrict the afferent and dilate the efferent

Answer 9

FALSE; we want to DILATE the afferent and CONSTRICT the efferent

Question 10

what is reabsorbed at the proximal tubule?

Answer 10

1. Nutrients
   (a) glucose
   (b) amino acids
2. Electrolytes
   (a) Na+
   (b) K+
   (c) Cl-
   (d) bicarbonate (HCO3-)
   (e) Ca2+
   (f) phosphorous (PO4-)

Question 11

What is secreted at the proximal tubule?

Answer 11

• creatinine
• uric acid
• certain drugs

Question 12

What is the role of the Loop of Henle?

Answer 12

reabsorption of Na+, Cl-, water and Mg

Question 13

What does the distal convoluted tubule reabsorb?

Answer 13

• Na+ and water

Question 14

What does the distal convoluted tubule secrete?

Answer 14

K+, H+ and phosphorus

Question 15

what does the collecting duct reabsorb?

Answer 15

Na

Question 16

What does the collecting duct secrete?

Answer 16

K+ , which is dependent on aldosterone

Question 17

which is a more sensitive marker of kidney function, Urea or creatinine ?

Answer 17

creatinine

Question 18

Why is concentration of Urea clinically important?

Answer 18

serum urea to creatinine ratio > 70 may indicate dehydration

Question 19

What happens to electrolytes in patients with chronic kidney disease?

Answer 19

1. sodium/water –> edema and swelling due to inability to decrease reabsorption
2. K+ increases in the blood due to inability to increase excretion from distal tubule
3. Phosphorus increases in blood because not able to decrease reabsorption in proximal tubule and increase excretion from distal tubule
4. Magnesium increases in the blood because not able to decrease reabsorption in the loop of henle

Question 20

what do the kidneys do when it is experiencing acidosis?

Answer 20

reabsorb all the filtered bicarbonate into the extracellular fluid

Question 21

what do the kidneys do when it is experiencing alkalosis?

Answer 21

the kidneys cannot reabsorb bicarbonate so it is excreted instead

Question 22

when is renin released?

Answer 22

when the juxtaglomerular cells - located in the walls of the arterioles are stimulated (responding to changes in circulating blood volume and pressure)

Question 23

hyperkalemia

Answer 23

increased K in the blood

Question 24

hyperphosphatemia

Answer 24

increased phosphorous in the blood

Question 25

erythropoietin (EPO)

Answer 25

stimulates the production of red blood cells in the bone marrow

Question 26

How does the kidney know to secrete EPO?

Answer 26

when the oxygen levels fall below a certain level the kidneys respond by secreting EPO

Question 27

What happens in CKD in regards to EPO?

Answer 27

EPO production goes down and the patient's RBCs/hemoglobin decrease = anemia

Question 28

What are the types of renal failure?

Answer 28

1. Pseudo 2. pre-renal 3. intrinsic 4. post renal

Question 29

Pseudo renal failure

Answer 29

serum creatinine levels increase due to blocking of renal tubular secretion of creatinine. This is not "true" renal failure because drugs are blocking the secretion of creatinine

Question 30

pre-renal renal failure

Answer 30

due to a decreased blood flow to the kidneys and hence a decreased glomerular filtration rate

Question 31

intrinsic renal failure

Answer 31

due to structural damage to the kidney affecting either the glomerulus or the tubules; damage to the kidney itself

Question 32

post-renal renal failure

Answer 32

obstruction to urine flow beyond the kidneys; something happening in bladder or ureter

Question 33

what is the most common cause of renal failure ?

Answer 33

pre-renal failure which is 50-60% of all cases

Question 34

what are some reasons why pre-renal failure can occur?

Answer 34

1. intravascular volume depletion 2. decline in effective blood volume 3. decreased pressure in glomerulus due to drugs that vasoconstrict the afferent arteriole and vasodilate the efferent arteriole

Question 35

what is Acute Tubular Necrosis (ATN)?

Answer 35

ischemia in the kidney producing cell damage to the tubules; leads to intrinsic renal failure. Due to medication induced causes

Question 36

What is Acute Interstitial Nephritis?

Answer 36

inflammatory disorder of the renal interstitium ("allergic reaction") . Caused by drugs

Question 37

What is glomerulonephritis?

Answer 37

results from the stimulation of the immune system leading to inflammation of the glomerulus

Question 38

What are 3 causes of Intrinsic AKI

Answer 38

1. Acute tubular Necrosis 2. Acute interstitial Nephritis 3. glomerulonephritis

Question 39

what is the cause of Post-renal AKI?

Answer 39

1. Kidney stones 2. bladder timor or obstruction 3. urethral stricture/tumor 4. crystal deposition in renal tubules (which can occur from certain drugs)