Fluids and Electrolytes Flashcards
Water is mostly where?
Intracellular fluid
Intravascular compartment is
fluid in the blood vessel
Interstitial fluid compartment
Between cells and blood vessels
Transcellular fluid compartment
All fluid in pleura, peritoneum and percardium
Starling Forces
Capillary hydraulic pressure (force that pushes fluid from blood to extracellular space
Colloid osmotic pressure (the pressure which counters hydraulic and pushes fluid back into blood)
Hypotonic vs isotonic vs hypertonic
Iso: same osmolality as our fluids
Hypo: Less osmolality than our fluid, so water moves into the cells (lyse)
Hyper: More, so water moves out of the cells (shrive)
Human body fluid osmolaity leads to changes in the osmoreceptors which does what
Activation of vasopressin (blood volume and pressure changes) and thirst which both lead to retention of water
2 locations for receptors
Renal V2 within the thick ascending limb of Henle Molecular effects (cAMP increases, PKA activation, ion reabsorption transport by the thick ascending limb)
Vasopressin + Water
Binds to V2R on principle cells and activates adenylyl cyclase to increase cAMP
Aquaporins allow the water to move more efficiently and can be added and removed from membranes
AVP is the
guard of vascular integrity which means it can preserve regular blood pressure even when we are losing water and tissue perfusion
What are the receptors that are highly expressed in the proximal tubules that are very important for HTN pathophysiology?
Angiotensin receptors. (distal nephron)
What activates proximal sodium and chloride reabsorption?
Ang II and adrenergic receptors
Dopamine does what?
Natriuretic effect
***Transudate
Fewer proteins
Nothing to do with inflammation
Hypovolemic shock
Hypotension, tachycardia, peripheral vasoconstriction, hypoperfusion
Acid/base issues and lactic acidosis
Hypovolemic labs
BUN and creatinine are up due to decreased GFR Liver function tests and cardiac biomarkers for severe hypoperfusion Bicarbonate loss (metabolic acidosis) Lactic acidosis
Defense of serum osmolality is
Water intake and circulating AVP
Major problem with loss is
the imbalance between Na and water (is more of one being excreted or kept?)
Hyponatremia can only occur if what volume status is achieved?
Any volume status; it doesn’t matter, hyponatremia can occur at any point
Euvolemia =
Normal sodium
High body water
Hypervolemia =
High water and sodium
More water
Hypovolemia =
Decreased water and sodium
If you are losing sodium renally, you would have sodium _____.
In the urine (a lot)
Hyponatremia consequence
cellular swelling
Hypernatremia =
> 145 mM of Na
Combined water and electrolyte deficit
Central diabetes insipidus
Pituitary gland problems
NOT ENOUGH AVP
Nephrogenic Diabetes Insipidus
Renal resistance to AVP
Through genetics or drugs
Hypernatremia consequences
Cellular shrinkage
Rhabdomyolysis
***Potassium levels
3.5-5.0
Potassium stuff
Healthy individuals excrete their entire daily intake of potassium
Changes in whole body potassium are mediated by the kidney
Problems with potassium usually stem from a change in intra or extracellular K and not an actual change in levels
Hypokalemia =
Less than 3.6
CAN CAUSE ARRHYTHMIAS
Hypokalemia causes
abnormal cardiac rhythm, BP and CV morbidity rate
Hyperkalemia =
> 5.5 mM
Decreased K excretion is the most common cause
Severe hyperkalemia can lead to
Cardiac arrest
Paralysis and respiratory failure
Affects how cations and anions are transferred through the membrane
