Fluid Balance


What is the treatment for ascities?


sodium restrictionalbumin infusion (keeps the water inside of the cells instead of in the peritoneal space)diuretics such as Spironolactone (Aldactone) to block aldosterone in distal tubal


What are the 3 major places that your total body water is distributed?


Intracellular fluid (65%)Interstitial fluid (25%)Plasma (8%)


A heart failure patient will have a ______ fluid balance


Positive (input > output)


Define filtration


Net fluid movement into or out of the capillaryIs determined by the difference between the forces favoring filtration and those opposing it (tug of war)


Interstitial hydrostatic pressure


Pushes water into the capillary


Interstitial oncotic pressure


Pulls water out of the capillary (this is very low pressure- little movement of water)


Capillary hydrostatic pressure


Pushing water out of the capillary


Capillary oncotic pressure


Pulling water into the capillary


Osmosis


Movement of water across cell membranes from less concentrated to more concentrated


Osmolarity


The concentration of solute in a fluid (mostly sodium) per kg of water OR per L of solution (more clinically interpretable)


Diffusion


Movement of molecules from higher concentration to lower concentration.


Filtration


Fluid and solutes move together across a membrane from an area of higher pressure to one of lower pressure


Active Transport


Substance moves across cell membranes from less concentrated solution to more concentrated; requires a carrier, and energy


What is the normal serum osmolarity?


275 to 295 milliosmoles/liter (mOsm/L)


What is the function of ADH?


�Stimulates water conservation and the thirst center


What is the function of aldosterone?


Controls Na+ absorption and K+ loss along the descending convoluted tubules and collecting duct


What is the function of the natriuretic peptides (ANP/BNP)?


Reduce thirst and block the release of ADH and aldosterone


Where are barorecptors and osmoreceptors found?


Baroreceptors: in the aorta and carotidsOsmoreceptors: in the head and kidney inside the nephron


What are the major functions of the kidney?


�Fluid balanceSolute concentration and dilutionAcid-base balanceWaste excretion


Describe autoregulation in terms of the kidney


The kidney controls the amount of blood that goes in and out of the organ; if the kidney detects a need for more blood it dilates its vessels, vasoconstricts if has too much blood inside of the kidney


What is the major measure of kidney function?


Glomerular filtration rate (GFR); based on creatine clearance. If the creatinine is high, then it means that the kidney is not functioning correctly


What does the Blood urea nitrogen (BUN) test for?


Tests for hydration status. The higher the BUN,the more dehydrated the function


What two tests together can diagnose kidney disease?


GFR and BUN


GFR increases as arterial pressure _________


Increases *Hypertension if prolonged can cause kidney failure (esp. in African Americans)


What is a normal amount of daily urine output?


1-2 L


What does urine contain?


ElectrolytesGlucoseBicarbonateUreaCreatine


What is the normal pH of urine?


4.6-8.0 (slightly acidic)


What is the function of the juxta-glomerular apparatus (JGA)?


Releases renin