Chapter 44 - Renal complications

Question 1

Nephrons in a kidney

Answer 1

1 million

Question 2

Two types of nephrons

Answer 2

1) short loops of Henle 2) long loops of Henle

Question 3

Renal artery course

Answer 3

1) Renal artery 2) Interlobar arteries (enter cortex) 3) arcuate arteries (junction of cortex and medulla) 4) cortical radial arteries (ascend through cortex) 5) afferent arterioles 6) glomeruli 7) efferent arteriole 8) vasa recta 9) medullary plexus 10) capillary plexus of outer stripes 11) ascending vasa recta 12) arcuate veins

Question 4

Kidney’s basic processes

Answer 4

1) glomerular filtration 2) selective tubular secretion 3) selective tubular reabsorption

Question 5

Cardiac output that goes to normal kidney

Answer 5

25% around 900L/d

Question 6

Percentage of serum filtered by glomeruli and amount reabsorped

Answer 6

20% filtered 99% reabsorbed

Question 7

Descending loop of Henle movements

Answer 7

Permeable to water minimally permeable to sodium and chloride

Question 8

Ascending loop of Henle movement

Answer 8

Not permeable to water active transport to chloride and passive transport of sodium

Question 9

Aldosterone effect

Answer 9

increases reabsorption of sodium from distal tubule and proximal collecting duct

Question 10

Potassium absorption in the loop

Answer 10

Proximal convoluted tubule Thick ascending limb

Question 11

Potassium secretion in the loop

Answer 11

Connecting cells in late distal tubule cortical collecting duct

Question 12

Neuroendocrine modulators of renal function

Answer 12

1) baroreceptors in atrium 2) renal sympathetic nerve stimulation

Question 13

How does sympathetic nerve reduce renal sodium excretion

Answer 13

1) constriction of afferent and efferent arteriole 2) reabsoption of sodium in proximal tubule and thick ascending loop of henle 3) stimulate renin secretion

Question 14

Angiotensin II effects

Answer 14

1) arteriole construction 2) stimulate renal sodium reabsorption in proximal tubule 3) increase secretion of aldosterone

Question 15

Aldosterone release from

Answer 15

zona glomerulosa of adrenal cortex

Question 16

Aldosterone effect

Answer 16

sodium reabsorption in distal tubule and collecting duct

Question 17

Major renal eicosanoids and their effect

Answer 17

PGE2, PGI2 vasodilator inhibit sodium reabsorption from thick ascending loop

Question 18

Effect of COX-2 inhibition on renal function

Answer 18

1) decrease release of renin 2) reduce medullary blood flow 3) cause apoptosis of medullary intestitial cells therefore NSAID bad for kidney

Question 19

Paracrine and endocrine modulators of renal function

Answer 19

1) eicosanoids 2) NO (medulla and cortex) 3) endothelin (efferent and afferent arterioles) 4) purines

Question 20

Most common cause of post-op prerenal AKI

Answer 20

1) contracted intravascular volume due to inadequate fluid replacement 2) secondary to primary reduction in cardiac performance –> neurohormonal reflex to enhance intravascular volume by increasing tubular reabsorption of sodium and water

Question 21

Ischemic nephropathy

Answer 21

Renal artery stenosis

Question 22

Post-renal causes of AKI

Answer 22

1) hematuria traumatic catheter insertion obstruction 2) iatrogenic injury 3) epidural effect (should wait 6-12 hours) 4) prostatitis

Question 23

Parenchymal cause of AKI

Answer 23

Acute tubular necrosis decrease ATP –> loss of actin cytoskeleton –> loss of renal tubular cell membrane polarity –> loss of intercellular tight junction

Question 24

Causes of ATN

Answer 24

1) ischemic injury (shock, renal artery occlusion, multiorgan failure, atheroemboli) 2) toxic injury (myoglobinuria, antibiotics, contrast)

Question 25

Two fold pathophysiology of acute ischemic renal injury

Answer 25

1) Tubular cell swelling after reperfusion –> tubular obstruction 2) interstitial edema –> tubular cell death and loss of basement membrane –> slough into tubule

Question 26

Abciximab

Answer 26

Platelet glycoprotein IIb/IIIa inhibitor

Question 27

Lab finding that is suggestive of atheroembolism

Answer 27

Eosinophilia 71%

Question 28

5 year survival in patient with bilateral chronic ischemic nephropathy starting HD

Answer 28

12%

Question 29

Aminoglycoside effecdt on kidney

Answer 29

1) tubular cell mitochondrial damage 2) cell membrane destruction 3) phospholipase activation 4) lysosome alteration

Question 30

Treatment of myoglobinuria

Answer 30

1) IV fluid 2) diuretic (mannitol) 3) alkalinizing urine

Question 31

Algorithm to prevent contrast-induced nephropathy

Answer 31

FIGURE 44.4

Question 32

Fluid shifts in surgery

Answer 32

1) inflammatory mediators cause increased membrane permeability to albumin 2) flux of albumin into interstitium 3) decrease water reabsorption into intravascular space

Question 33

Rate of AKI after TAAA and AAA repair

Answer 33

TAAA 18% infrarenal AAA 1-13%

Question 34

Factors that predict renal dysfunction post-op

Answer 34

1) Cr > 133 2) cross time > 100 min