L7 - Edema Flashcards
What law dictates fluid movement at the capillaries?
Starling’s Law
By what 3 forces/mechanisms can edema be caused?
Increases hydrostatic pressure –> more force pushes fluid out of the
Decrease protein in blood –> less oncotic/osmotic force for fluid to return to circulation
Increased capillary permeability
Increased hydrostatic pressure where is most closely correlated with edema?
Venous side of capillary
If have isolated high pressure in arterial side, it tends to just increase flow not cause edema
Generally speaking what are the main causes of decreased oncotic pressure?
Kidney, GI or liver diseases (only if excreting protein)
How does heart failure cause edema?
Failure to pump enough –> fluid backs up into venous system –> increases venous hydrostatic pressure –> edema
What are the heart failure classifications?
L vs. R
Ischemic vs. non-ischemic
Systolic vs. diastolic
Where does fluid back up during L sided heart failure?
Lungs –> pulmonary edema –> crackles
Where does fluid back up during R sided heart failure?
Periphery
If see peripheral edema, what assumptions can be made about the classification of the underlying heart failure with regards to being L or R sided?
R sided is the cause of the peripheral edema, but the most common cause of R sided heart failure is L sided heart failure so it isn’t ruled out either
What are the causes of isolated R sided heart failure?
Usually pulmonary HTN due to COPD, Pulmonary embolism, pulmonary fibrosis, familial respiratory disease or obstructive sleep apnea
Can also have isolated R sided MI or R sided valvular problem but this is rare
What is the main ischemic cause of heart failure?
MI
What are the non-ischemic causes of heart failure?
Valvular problem
Pericardial effusion (fluid in pericardial sack)
Constrictive Pericarditis (thick fibrosed inflamed pericardium doesn’t allow heart to expand)
Cardiomyopathy (tachycardia induced, restrictive, dilated or hypertrophic)
What is systolic heart failure? How does it correlate to the other classifications of heart failure?
Can’t pump enough
Can be R or L sided (or both), ischemic or non-ischemic
How is systolic heart failure mainly diagnosed?
Low EF on echo
What type of heart failure is very sensitive to increases in HR or BP?
Diastolic
What is diastolic heart failure? How does it correlate to the other classifications of heart failure?
Can’t fill –> cant relax or is too rigid/thick
L or R sided. Generally, non-ischemic
Causes of diastolic heart failure?
Long standing HTN –> thicker ventricle
Aortic stenosis
Constrictive pericarditis
Restrictive cardiomyopathy
What is Anasarca? What is suggested by it?
Full body edema
Liver, GI or kidney origin (decreased oncotic)
What is suggested by full body edema?
= Anasarca
Liver, GI or kidney origin (decreased oncotic)
What GI disorders can cause edema? How do they cause edema?
Not enough protein eaten/absorbed or too much excreted due to diarrhea –> low oncotic pressure
IBD/Chrons/UC or infection –> diarrhea
Malnutrition (low protein intake)
Celiac disease –> malabsorption
How do liver diseases cause edema?
Not making enough proteins (including albumin) –> low oncotic
What renal disorders cause edema?
Chronic renal failure
Nephrotic syndrome
How do pulmonary problems cause edema? What pulmonary problems cause edema?
Somehow inhibit flow to lungs –> blood backs up –> R sided heart failure –> blood backs up into periphery
Pulmonary HTN due to COPD, Pulmonary embolism, pulmonary fibrosis, familial respiratory disease and obstructive sleep apnea
What pulmonary cause of edema is most common?
obstructive sleep apnea
What vascular problems can cause edema?
DVT
Intrinsic/extrinsic obstruction (compress vessels)
Venous Insufficiency (valvular problem)
What is suspected with non-pitting edema?
Lymphadema
Hypothyroid
What is angioedema? What causes it?
Swelling of the face
allergic or autoimmune reaction to ACEI or NSAID –> increases capillary permeability
What is suggested by swelling of the face?
= Angioedema
Most likely ACEI, but could also be NSAID
Acute symptoms can come on even in somebody who has been on the medication for years
What causes of edema work by all 3 mechanisms?
Pregnancy
Hypothyroid
Mechanism of pregnancy induced edema?
all 3
Mechanism of hypothyroid induced edema?
all 3
What causes edema by increasing fluid pressure?
Heart failure
Pulmonary HTN
Vessel/Lymphatic obstruction/compression
Renal failure –> not excreting Na –> water follows –> increased in blood volume –> increase in venous pressure
What causes edema by lowering oncotic pressure?
Liver & GI problems
Not listed but if kidney disease involves nephrotic syndrome will lose protein and cause low oncotic pressure
What causes edema by increasing capillary permeability?
ACEI
CCB
Idiopathic cyclic edema
What is idiopathic cyclic edema? Mechanism?
Normal bloating associated with menstrual cycle
Capillary permeability
What is suspected for edema and dyspnea? Tests?
L sided heart failure (dyspnea) causing R sided heart failure (peripheral edema)
Echo & CXR
What is suspected for edema and orthopnea? Tests?
L sided heart failure (dyspnea) causing R sided heart failure (peripheral edema)
Echo & CXR
What is suspected with edema and crackles on auscultation of lungs?
Pulmonary edema = L sided heart failure
What blood test is used to test for suspected heart failure?
NT-proBNP
high during heart failure
What must be done for a patient with new onset edema and LV dysfunction?
MI workup
What 2 things can combine to predispose somebody to liver cirrhosis?
Alcoholism and hepatitis C
What is suspected for lower limb edema & abdominal distention? Tests?
Liver problem –> ascites
CMP, PT/INR, RUQ ultrasound
What is suspected for edema and fluid wave, shifting dullness, caput medusa, gynecomastia or spider angioma?
Liver problem and ascites
What is suspected for normal AST/ALT?
Could be healthy or the liver could be so bad it isn’t even making the proteins anymore in high enough levels to give a high reading. Look at rest of Liver function test
What is suspected for edema & small nodular liver on ultrasound?
Liver cirrhosis
What is suspected for edema and splenomegaly?
Liver problem –> portal hypertension –> backs up into spleen
What type of liver disease causes edema?
Usually chronic
Only very severe forms of acute liver disease like fulminant Hep B, toxins or drug overdose can cause edema
Ascites can be difficult to determine in what type of patients?
Obese
What is suspected for edema with mild hepatosplenomegaly & fatty liver change?
Probably not cirrhosis, keep looking for cause
What is the gold standard for definitive diagnosis of R sided heart failure?
Right heart catheterization to measure pulmonary artery pressure
How do you test for obstructive sleep apnea?
Sleep study
Does DVT usually present bilat or unilat?
Usually unilat
But can have separate DVTs in both legs or a blockage of IVC –> bilat
What is the mechanism of edema in Obstructive Sleep Apnea?
During the night become hypoxic –> low levels of O2 cause vasoconstriction of the alveolar vessels –> increase pulmonary arterial pressure –> pulmonary hypertension –> blood backs up into R heart & then periphery
Kidney diseases can cause edema by what mechanism(s)?
Nephrotic –> protein loss –> decreased oncotic
Kidney Disease –> lower excretion on Na –> increased blood volume –> increased venous hydrostatic pressrue
What is orthopnea? Its presence in somebody with edema suggests what etiology?
SOB when lay down cuz increase venous return. Less effect of gravity on blood flow means less in legs and more blood to congested lungs
Often need to sleep on more than 2 pillows
Probably related to L sided heart failure –> pulmonary edema
How does the echo present in diastolic heart failure?
Normal
How does heart failure present on CXR?
Cardiomegaly
Pul edema
Cephalization
May have effusion
How does liver function panel present during cirrhosis?
Low proteins
High Alk phos
High Bilirubin
ALT/AST can be normal
