B5.042 Prework 1: Pathophysiology of Renal Disease and Kidney Failure

Question 1

acute vs chronic kidney insufficiency

Answer 1

acute - developed in less than 3 months

chronic- ongoing for more than 3 months

Question 2

3 classes of diseases that lead to kidney insufficiency

Answer 2

prerenal
intrarenal
postrenal

Question 3

prerenal disease

Answer 3

reduced blood flow to kidney

usually due to stenosis

Question 4

intrarenal disease classes

Answer 4

glomerular- glomerulonephritis
tubular- tubular necrosis
vascular- vasculitis

Question 5

postrenal disease

Answer 5

obstruction of the urinary tract

Question 6

what are some results of longstanding stenosis

Answer 6

ischemic kidney, reduced in size
glomerular capillary tuft atrophy
thickening of Bowman's capsule
tubular sclerosis
interstitial fibrosis
inflammation

Question 7

what can lead to acute tubular injury?

Answer 7

ischemia

toxins (drugs, radiocontrast dyes, gentamicin, heavy metals)

Question 8

what is the course of progression of acute tubular necrosis (ATN)

Answer 8

initial phase with oliguria (<4 L urine production)

recovery phase with increase in urine but loss of electrolytes

Question 9

what is the result of inflammatory tubular injury?

Answer 9

tubulointerstitial nephritis or pyelonephritis
can be acute or chronic
leads to inability to concentrate urine, polyuria, salt wasting, and metabolic acidosis

Question 10

what is glomerulonephritis

Answer 10

glomerulus and components of the filtrating pathways can be altered

Question 11

criteria for nephrotic syndrome

Answer 11

heavy proteinuria (>3.5 g/day)
hypoalbuminemia
hyperlipidemia and hypercholesterolemia

Question 12

why do you get edema in nephrotic syndrome

Answer 12

decreased oncotic pressure due to hypoalbuminemia

Question 13

why do you get hyperlipidemia and hypercholesterolemia in nephrotic syndrome

Answer 13

increased lipoprotein production in liver due to decreased albumin

Question 14

criteria for nephritic syndrome

Answer 14

glomerular inflammation and bleeding/hematuria
oliguria and azotemia
variable salt retention and edema
red blood cell cast and dysmorphic red blood cells in urine
proteinuria below nephrotic range (<3.5 g/day)

Question 15

what abnormalities occur when kidneys aren’t functioning properly

Answer 15

volume overload
hypertension
acidosis
anemia
bone disease

Question 16

features of volume overload

Answer 16

decreased GFR
high serum creatinine, azotemia, uremia
oliguria
electrolyte imbalances
-less K+ secretion (hyperkalemia)
-hyperphosphatemia (risk for vascular calcification)
most important : sodium retention

Question 17

results of volume overload

Answer 17

peripheral edema
pulmonary edema
hypertension

Question 18

features of hypertension

Answer 18

increased intravascular volume
sodium retention (primary problem)
alteration of kidney regulatory mechanisms controlling ECF volume and osmolarity
renin-angiotensin-aldosterone is activated and worsens disease

Question 19

features of acidosis

Answer 19

low acid excretion

decreased release of acids derived from metabolism

Question 20

results of acidosis

Answer 20

acid accumulation leads to body bicarb consumption

Question 21

features of anemia

Answer 21

normocytic, normochromic

kidneys cant make EPO, altered oxygen sensing mechanism in kidney

Question 22

results of anemia

Answer 22

decreased delivery of oxygen to tissues
increased cardiac output
ventricular hypertrophy
congestive heart failure
decreased cognitive functioning
growth retardation in kids

Question 23

what is erythropoietin?

Answer 23

released by proximal tubule epithelial cells and cortical interstitial cells
acts on bone marrow to produce new RBCs

Question 24

features of bone disease

Answer 24

evident early in CKD
bone pain, increased risk of fracture, myopathy
osteomalacia, rickets

Question 25

pathophys of bone disease in kidney dysfunction

Answer 25

GFR declines as a result of underlying renal disease
due to decreased GFR, less inorganic phosphate excretion
decreased serum calcium and calcitriol stimulate PTH production
phosphate retention also stimulates PTH secretion

Question 26

what substance is used to estimate GFR

Answer 26

creatinine

Question 27

fractional excretion

Answer 27

(Us/Ps)/(Ucr/Pcr)

Question 28

normal fractional excretion of sodium

Answer 28

1-3%

Question 29

what happens to fractional excretion in tubular dysfunction

Answer 29

increases

not enough is reabsorbed

Question 30

normal BUN/Cr

Answer 30

15-20

Question 31

findings in prerenal failure

Answer 31

decreased GFR, azotemia, oliguria
increased BUN/Cr
normal FEna (1-3%)
normal urine osmolarity

Question 32

findings in intrarenal failure (tubular necrosis)

Answer 32

azotemia, oliguria with brown urine casts
decreased BUN/Cr (<15)
FEna > 3%, inability to concentrate urine (<500 mOsm/kg)

Question 33

findings in postrenal failure

Answer 33

decreased GFR, azotemia, oliguria
decreased BUN/Cr
FEna > 3%
inability to concentrate urine (<500 mOsm//kg)

Question 34

treatment of patients with renal insufficiency

Answer 34

control hypertension
control electrolytes
control body pH
control anemia