Lecture 64 - Edema & Diuretics Flashcards
interstitial edema
accumulation of fluid within ECF due to altered Starling forces
Intracellular edema
accumulation of fluid within cells due to altered osmolality
hydrostatic pressure
changes in BP/congestion
oncotic pressure
changes in albumin concentration
lymphatic edema
disruption, overwhelmed, obstruction
vascular barrier edema
disruption/inflammation of capillary wall
hypovolemia response
- decrease Na+ and water loss
- increased SNS
- Increased RAAS
- stimulation of ADH
- inhibition of ANP
hypervolemia response
- increase Na+ and water excretion
- increased ANP
- decreased SNS
- inhibition of ADH
- decreased RAAS
summarize kidney response to edema
- fluid moves into interstitial space (edema)
- relative hypovolemia and decreased BP
- baroreceptors detect decrease in intravasc. volume
- kidneys retain NaCl and water
- replenish intravascular volume and BP by increasing hydrostatic pressure
how to treat kidney edema
- NaCl restriction in diet
- inhibit kidney’s ability to retain NaCl
- inhibit RAAS
- treat underlying cause if possible
which of the following would promote interstitial edema?
a. decreased capillary hydrostatic pressure
b. increased capillary oncotic pressure
c. decreased vascular permeability
d. lymphatic obstruction
d. lymphatic obstruction
diuretic drugs
increase the rate of urine output by decreasing sodium reabsorption from filtrate
natriuretic = increase sodium
diuresis = increase water output
diuretic drugs are used to treat
- edema
- hypervolemia
- congestive heart failure
- exercise-induced pulmonary hemorrhage
T/F: diuretic drugs can be used to treat exercise-induced pulmonary hemorrhage in HORSES only
TRUE
what is the site of action for diuretic drugs
luminal side of the tubule
loop diuretics
*most commonly used
inhibit Na/K/2Cl co-transporter at ascending loop of henle
why are loop diuretic so effective
multiple MOA = more Na+ in the filtrate to decrease interstitial osmotic gradient and blocks ATP which increases GFR
osmotic diuretics
highly osmotic molecules in filtrate causes water to move towards it and freely filtered at the glomerulus
mannitol
thiazide diuretics
inhibit Na/Cl symporter in distal tubule
used in conjunction with loop diuretics
potassium-sparing diuretics
- aldosterone antagonists - blocks aldosterone receptors to increase Na+ loss and decrease K+ loss
- Na+ channel inhibitor - directly block Na+ channels in principal cells
carbonic anhydrase inhibitors
inhibits CA in the proximal tubule - prevents reabsorption of bicarbonate. not effective systemic diuretic, tx for glaucoma
ADH inhibitor
blocks ADH receptors in collecting ducts - inhibits ability to concentrate urine, but uncommon in vet med
