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Flashcards in U and Es Deck (33):
1

what is diabetes insipidus

inability to produce or respond to ADH resulting in excessive urine production or thirst

2

what conditions may cause electrolyte disturbance

haemorrhage
d and v
intake
pyrexia- increased loss
diabetes mellitus or insipidus
diuretic therapy
endocrine disorder

3

what is the concentration of extracellular sodium

140 mmol/L

4

what is the extracellular K concentration

5 mmol/L

5

what physiological mechanisms compensate for electrolyte disturbance

thirst
ADH
renin

6

what part of the brain produces ADH

median eminence of posterior pituitary gland

7

in what conditions is urea raised

congestive heart failure
shock
MI
severe burns

8

what is creatinine

breakdown product of protein and muscle
higher in males usually

9

what electrolytes can be measured

sodium
potassium
chloride
bicarb
urea
creatinine

10

why is electrolyte balance important

cellular homeostasis
cardiovascular
renal
electrophysiology

11

what is the intracellular sodium concentration

10 mmol/L

12

name some isotonic fluids in the body

blood, fistula fluid

13

how much hypotonic fluid loss would be insensible

3 L

14

how might hypotonic fluid loss occur

diarrhoea and vomiting

15

what can cause activation of the RAAS system

na depletion
haemorrhage

16

how do you determine ADH status

if urine is a lot more concentrated than plasma then ADH is activated

17

how do you determine RAAS status

measure plasma and urine sodium concentration

if urine sodium is less than 10 mmol/L then RAAS is active

18

why should fluid loss of 2L be replaced with isotonic fluid rather than hypotonic fluid

will not cause a fall in sodium and will not cause fluid redistribution

19

what tow substances are used as markers of renal function

urea and creatinine

20

what factors influence GFR

renal perfusion pressure
renal vascular resistance
glomerular damage
post glomerular resistance

21

what is normal GFR

90- 150 mL/min
bigger people have higher rate
older people have lower rate

22

what is nephrosis

aka nephrotic syndrome
oedema
protein loss
increased glomerular permeability

23

what can cause hyponatraemia

diuretics
addison's
Na losing nephritis
nephrosis
vomiting and diarrhoea
burns
oedema (increased fluid compartment)
drugs
hypothyroidism
Kidney failure

24

what is SIADH

syndrome of inapropriate antidiuretic hormone

hormone is produced in the wrong place

25

what is osmotic diuresis

too much urine production caused by retention of a substance in the nephron e.g. glucose causing inability to reabsorb enough water

26

what is normal potassium range

3.6 - 5

disorders are often iatrogenic

27

what change in pH can cause hyperkalaemia

acidosis causing potassium to move out of cells

28

what change in pH can cause hypokalaemia

alkalosis which causes potassium to move inside the cells

29

what can cause hyperkalaemia

artifactual
haemolysis
drug therapy
renal failure
acidosis
mineralcorticoid dysfunction
cell death

30

how can hyperkalaemia be treated

correct acidosis
give glucose and insulin
ion exchange resins
dialysis

31

what can cause hypokalaemia

low intake
increased urine loss
tubular dysfunction
vomiting and diarrhoea
fistulae
alkalosis
insulin and glucose therapy

32

what are the symptoms of potassium depletion

lethargy
muscle weakness
arrhythmia
polyuria
alkalosis

33

how is potassium depletion treated

supplementation
oral/ iv
monitor