Thursday [18/8/22]

Question 1

parameters sodium

Answer 1

135-145

Question 2

how much extra cellular and intracellular fluid?

Answer 2

1/3 extracellular
2/3 intracellular

Question 3

most common anions/cations extracellular compartment

Answer 3

extracellular = Na and Cl

Question 4

most common anions/cations intracellular compartment

Answer 4

intracellular = K, Po4, Mg

Question 5

which electrolyte moves most across cell membranes?

Answer 5

sodium, which also moves sodium down osmfalirty gradient

Question 6

hyponatraemia causes patho

Answer 6

losing more sodium than water or gaining more water than sodium

Question 7

3 categories

Answer 7

hypervolaemic hyponatraemia

Question 8

conditions with hypervolaemic hyponatraemia [3]

Answer 8

fluid leaks from congestive heart failure, cirrhosis, nephrotic syndrome

• oedema, lower circulating volume though increase in water in body overall
• large increase H20, small increase Na
• lower circulating volume causes ADH retaining more H20, also increase in aldosterone causes increase in sodium by small amounts but is equaled by water flowing at almost the same rate as sodium

Question 9

conditions that cause hypovolaemic hyponatraemia

Answer 9

• small decrease water, large decrease hyponatraemia
• diarrhoea and vomiting -> sodium tossed from body
• medications like diuretics from renal tubule
• cerebral salt wasting when condition like meningitis causes disruption of sympathetic nervous system

Question 10

conditions that cause euvolemic hyponatraemia

Answer 10

• increase H20, normal sodium
• don’t have fluid into interstitial space, so no oedema, so no signs of hypovolaemia
• split into cases with dilute urine and concentrated urine

Question 11

conditions that cause dilute urine in euvolemic hyponatraemia

Answer 11

adrenal insufficiency, hypothyroidism, drinking too much… water -> polydipsia, beer -> potomania

Question 12

conditions that cause concentrated urine in euvolaemic hyponatraemia

Answer 12

SiADH -> H20 retention

Question 13

what is false hyponatraemia ?

Answer 13

• normal sodium, normal H20
• excess lipids, or proteins in MM
• affects instruments that measure sodium, saying it’s ctoo low

Question 14

Sx of hyponatraemia

Answer 14

nausea, cramps vomiting, muscle

Question 15

Sx severe hyponatraemia

Answer 15

cerebral oedema -> coma death, increased Ice [ischaemia], herniation causing and resp failure

Question 16

Dx of hyponatraemia

Answer 16

physical exam and lab findings

Question 17

what suggests true low sodium

Answer 17

normal serum osmolarity

Question 18

what suggests hypervolaemic hyponatraemia

Answer 18

oedema

Question 19

what suggests hypovolaemic hyponatraemia

Answer 19

dehydration

Question 20

what suggests SiADH

Answer 20

concentrated urien [over 100 mOsm/kg]

Question 21

what suggests too much fluid

Answer 21

dilute urine [<100mOsm/kg]

Question 22

Tx hyponatraemia SIADH

Answer 22

fluid restriction

Question 23

Tx hyponatraemia SIADH

Answer 23

more fluid

Question 24

Tx hyponatraemia severe

Answer 24

give hypersonic saline
- careful to avoid cerebral pontine myelinolysis -> loss of myelin in the pons
[I guess transfer slowly]

Question 25

Urine osmolarity results

Answer 25