clinical chemistry, disordered fluid and electrolyte balance Flashcards
amount of fluid ... 1 intravascular 2 in the body 3 extracellular 4 interstitial 5 intracellular
5L 45L 15L 10L 30L
intracellular na and k
na - 9mmol/L
k = 150 mmol/L
extracellular na and k
na 140 mmol/L
k 5 mmol/L
what determines ECF fluid volume
total body sodium
name 3 factors that determine the distribution of fluid between plasma and interstitial fluid
hydrostatic P
colloid osmotic P
capillary P
how do we maintain fluid and electrolyte homeostasis
THIRST - hypothalamus sensitive to changes in osmol in blood ADH (changes in osmolality) and RAAS (renal blood flow, blood volume)
causes of dehydration
decreased intake - coma, unavailability, impaired thirst mechanism, dysphagia
increased fluid loss - haemorrhage, GI(vom diarohhea) skin (sweating), lungs, urine (diuretics diabetes)
Name some clinical features of dehydration
tachycardia, hypotension, thirst, weight loss, oliguria ( loss urine), loss of skin elasticity….
coma, confusion death
what can cause fluid overload
excessive fluid intake
impaired excretion - syndrome of inapropriate antidiuresis. primary hyperaldosteronism, renal impairment
clinical features of fluid overload
rapid weight gain, incresed venous pressure, oedema, pulmonary oedema
+hyponatraemia + sodium retention
treatment of fluid overload
fluid restriction and diuretics and treat underlying cause
where is hyponatremia common
intensive care unit
what causes true hyponatremia and hypertonic hyponataemia
true hyponatraemia - medication side effect? hydration?
hypertonic hyponataemi - fluid overload. hyperglycaemia
cause of hypernatremia
not enough water ! to old young sick GIT renal (to much salt)
what can hyponatremia cause
twitching, seizures, coma, neusea, vom, drowsiness, lethargy, convusions
how do you treat hyponatremia
diuretics, antidepressant, anticonvulsant, ace inhibitor
SIAGH causes
malignancy(bronchial carcinoma) cerebral(infection) pulmonary(pneumonia) drugs(antidepressants)
