hyponatremia

Question 1

mild hyponatremia

Answer 1

130-134

Question 2

moderate hyponatremia

Answer 2

120-129

Question 3

severe hyponatremia

Answer 3

<120

Question 4

ADH dependent pathophsis

Answer 4

ADH activated -> H2O retain + no na retained -> increased H2O in blood + decrease na -> lower osmolarity -> hyponatremia
Increase thirst -> increased H2O intake -> increased H2O absorption
Increase urine osm
ADH -> vasoconstriction

Question 5

ADH stimulation

Answer 5

hypovolemic, decreased CO, RAAS

Question 6

ADH dependent causes of hyponatremia

Answer 6

v/d, bleeding, pancreatitis, diuretics, CSW, Adison’s disease, CHF, cirrhosis, nephrotic syndrome

Question 7

ADH independent cause

Answer 7

psychogenic polydipsia, tea + toast diet, beer potananea, CKD

Question 8

types of pseudohyponaturameia

Answer 8

high serum osmo, normal serum osmo

Question 9

ADH independent cause

Answer 9

psychogenic polydipsia, tea + toast diet, beer potomania, CKD

Question 10

types of pseudohyponatremia

Answer 10

high serum osmo, normal serum osmo

Question 11

high serum osmo pseudohyponatremia

Answer 11

hyperglycaemia, mannitol/glycerol from TURP

Question 12

isotonic serum osmo pseudohyponatremia

Answer 12

hyperlipidaemia/hyperproteinurea, mannitol

Question 13

hypervolaemia causes

Answer 13

HF (decreased CO -> ADH), liver cirrhosis (NO -> splanchnic vasodilation -> decreased renal perfusion - RAAS), nephrotic syndrome (hypoalbuminemia -> hypervolemic -> RAAS)

Question 14

hypervolemia pathophysis

Answer 14

H2O 3rd spacing + low effective arterial blood volume

kidney still working -> low urine na

Question 15

euvolemia causes

Answer 15

low cortisol (low na absorption in PCT + stimulates CRH release -> ADH), SIADH

Question 16

euvolemia pathophysis

Answer 16

decrease in H2O in urine -> increased na in urine

Question 17

hypovolaemia renal causes

Answer 17

diuretic (k + H+ loss -> metabolic alkalosis)

low aldosterone/Addison/cerebral salt wasting (increased k + H+ -> metabolic acidosis)

Question 18

hypovolaemia renal pathophysis

Answer 18

na not absorbed -> high urine na

Question 19

hypovolaemia extrarenal causes

Answer 19

bleeding

burns/sweating

vomiting (HCO3 + na excreted -> metabolic alkalosis)

diarrhoea (metabolic acidosis)

pancreatitis

Question 20

hypovolaemia extrarenal pathopysis

Answer 20

kidney fine = na reabsorbed but lost elsewhere = low urine na

Question 21

tea + toast diet/beer protonema pathophysis

Answer 21

poor diet (low solute intake) -> low urine output -> high fluid intake -> low plasma osmo -> no ADH -> hyponatremia + hypervolemic

low urine osmo

Question 22

symptoms of hyponatremia

Answer 22

coma, cerebral oedema -> headaches, n/v, focal deficits, herniating, AMS, seizures

Question 23

symptoms of chronic hyponatremia

Answer 23

gait instability, falls, cognitive decline

Question 24

treatment for severe symptomatic acute hyponatremia

Answer 24

3% hypertonic saline 100ml over 15min x3 - keep increased <8 units over 24 hours, bloods every 4 hours, fluids + desmopressin to keep na down

Question 25

treatment of hypovolemic normal saline

Answer 25

normal saline

Question 26

treatment of ADH independent

Answer 26

fludrocortisone

Question 27

treatment of hypervolemic saline

Answer 27

fluid restriction, loop diuretic, no thiazide diuretic, ADH antagonist

Question 28

osmotic demyelination syndrome risk factors

Answer 28

overcorrection, chronic hyponatremia, cirrhosis, malnourished, alcoholic, hypokalaemia

Question 29

osmotic demyelination syndrome pathophysis

Answer 29

osmotic molecules released into extracellular space to compensate against low na -> controlled cell shrinkage

rapid rise in na -> draws out h2o -> cell death