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
