B5.058 Prework 1 Electrolyte Abrnormalities

Question 1

sources of electrolyte disbalances

Answer 1

glomerulus
tubules
mechanisms of regulation (RAA, ADH, ANP)

Question 2

alterations in filtration with electrolytes and water accumulation

Answer 2

glomerular defects

-renal insufficiency from any origin

Question 3

alteration in reabsorption and secretion of electrolytes and water

Answer 3

tubular defects

1. acquired- injury or inflammatory processes
2. genetic- mutation of renal transport systems in both dominant and recessive manner

Question 4

precursors of renal insufficiency/glomerular damage

Answer 4

DM
hypertensive nephropathy
glomerulonephritis
renal artery stenosis
polycystic kidney disease

Question 5

symptoms of glomerular damage

Answer 5

electrolyte retention

• hypernatremia
• hyperkalemia
• calcium/phosphate imbalance
• acidosis

Question 6

reasons for acquired tubular injury

Answer 6

ischemic (interrupted blood flow)
toxic (drugs, dyes, gentamicin, heavy metals)
inflammatory

Question 7

result of acute/chronic renal tubular injury

Answer 7

inability to concentrate urine
salt wasting
metabolic acidosis

Question 8

variants of Bartters

Answer 8

1. neonatal (NKCC)
2. neonatal (ROMK1)
3. classic (mutated Cl- channel)

Question 9

pathophysiology of Bartter’s

Answer 9

malfunctions of NKCC, ROMK1, and Cl channels > solute diuresis and wasting of Na+, K+, and Cl-
malfunction of countercurrent mechanisms > polyuria and polydipsia, inability to concentrate urine
malfunction of juxtaglomerular apparatus > hyperreninemia, high aldosterone, alkalosis

Question 10

why do you get alkalosis in Bartters

Answer 10

high aldosterone stimulates H+ secretion in the collecting ducts/distal tubules

Question 11

clinical presentation of Bartters

Answer 11

tendency to volume depletion
excitability alterations
electrolyte disbalance
renin up regulation
pH problems

Question 12

electrolyte disbalances in Bartters

Answer 12

hyponatremia
hypokalemia
hypochloremia
ECF volume contraction
hypercalciuria

Question 13

what causes hypercalciuria in Bartters

Answer 13

reduced reabsorption of Cl-, Ca2+ and Mg2+ absorption is reduced

Question 14

Bartters prognosis

Answer 14

non curable
variable outcome depending on mutation
significant morbidity and mortality

Question 15

Bartters complications

Answer 15

cardiac arrhythmia and sudden death due to electrolyte disbalance
failure to thrive and developmental delay

Question 16

diagnosis of Bartters

Answer 16

blood analysis of lytes, renin, and aldosterone

urine tests for lytes and PGE2

Question 17

why is PGE2 elevated in Bartters

Answer 17

intermediate for products of juxtaglomerular apparatus which is hyperactive

Question 18

treatment of BArtters

Answer 18

potassium supplements and liberal salt intake
aldosterone antagonists (spironolactone)
ACE inhibitors to counteract effects of angiotensin II and aldosterone
NSAIDs (indomethacin) to decrease PGE2
calcium a nd magnesium supplements

Question 19

extrarenal causes of hypokalemia

Answer 19

GI
skin
redistribution (insulin, B2 activity alkalosis)
neuromuscular symptoms

Question 20

renal causes of hypokalemia with metabolic acidosis

Answer 20

renal tubular acidosis (type 1 or 2)
diabetic ketoacidosis
carbonic anhydrase inhibitor therapy

Question 21

renal causes of hypokalemia with metabolic alkalosis

Answer 21

diuretics
mineralcorticoid excess
Gitelman and Bartters

Question 22

renal cause of hypokalemia without acid base disorder

Answer 22

osmotic diuresis