edema Flashcards
edema
palpable swelling produced by expansion of the interstitial fluid volume. can be diffuse or localized.
how much does the interstitial fluid have to be expanded before it is clinically relevant?
2.5-3 liters
what are the two basic steps for the formation of edema?
- ) alteration in the capillary hemodynamics that favors the movement of fluid into the interstitial space.
- ) retention of dietary sodium and water by the kidneys.
why is there no hemoconcentration or shock in edema/
because the vascular plasma volume is kept at close enough levels to restore tissue perfusion
what is the normal situation for hemodynamics within the body, as far as hydrostatic pressure, etc?
there is normally a net pressure for the filtration of the plasma. this is taken care of by the lymphatics.
what are the five basic causes of edema?
increased capillary hydraulic pressure, decreased plasma oncotic pressure, increased capillary permeability, lymphatic obstruction, myxedema
increased capillary hydraulic pressure?
increased venous pressure by blood volume expansion or venous obstruction. HF, renal disease, cirrhosis, pregnancy. DVT or cirrhosis.
decreased plasma oncotic pressure
hypoalbuminemia/malnutrition, nephrotic syndrome, decreased hepatic albumin synthesis in liver failure
lymphatic obstruction
lymphedema
myxedema
hypothyroidism leads to accumulation of interstitial albumin and low lymphatic flow
how does lymphatic flow compensate for edematous scenarios
flow and contractility will increase with tissue edema and remove some excess filtrate
how does fluid flow itself contribute to edema compensation
fluid entry into the interstitium raises the hydraulic pressure, reducing the pressure gradient favoring filtration. this also lowers the interstitial oncotic pressure.
what are the most common causes of generalized edema
HF, cirrhosis, nephrotic syndrome and other renal diseases, premenstrual edema and pregnancy. anemia.
what is peripheral edema only suggestive of?
right sided HF, pericardial disease, renal disease, local venous or lymphatic disease
what does intermittent edema in a female patient indicate?
common premenstrual symptom.
what is anasarca?
whole body edema
what does periorbital or specific localized edema indicate?
hereditary angioedema
what do we look for on abdominal exam?
ascites, hepatojugular reflux, cirrhosis, signs of portal HTN, splenomegaly.
what does palmer flush indicate?
this is indicative of liver failure
what does non-pitting edema indicate?
this is usually indicative of lymphatic obstruction or lymphedema.
what is the differential for localized edema?
angioedema, urticaria, cellulitis, erysipelas
if localized edema is the entire limb?
need to perform duplex ultrasound. if DVT then start anticoagulants.
if localized edema is the entire limb and no DVT?
consider cellulitis, obstruction from neoplasm, radiation, lymphedema
for bilateral/generalized edema with no cardiac, hepatic, renal or anemia is found then what?
look for venous insufficiency -if yes then start leg elevation and compression stockings. If no look for meds that would cause this.
for bilateral/generalized edema with cardiac, hepatic, renal or anemia is found then what
establish cause, start diuretics
treatment of edema?
reversal of underlying causes. sodium restriction, compression stockings, diuretic meds
what is the only life threatening edema?
pulmonary edema.
what is a common therapy for edema?
slowly reducing edema through use of diuretics such as furosemide.
