TBL topic - leg swelling

(although topic is LEG swelling, i will discuss swelling in general)
referring to Harrison 17th ed.

·         Pathogenesis

o   

o    Pathogenesis depends on the cause of edema

o    Cardiac causes

§  Ventricular impairment promotes accumulation of blood in the venous bed

·         Increased capillary pressure

·         Increased transudation

·         Decreased plasma volume

§  Cardiac output decrease

·         Decreasesd arterial blood volume

§  All leading to interstitial volume increase causeing edema

o    Lymphatic causes

§  Leishmeniasis

o    Capillary damage

§  Drugs, viral or bacterial agents

§  Themal, mechanical trauma

§  Hypersensitivity recation

§  Inflammatory edema

·         Non pitting

·         Localized

·         Inflammatory signs

·         Differential diagnosis

o    Localized edema

§  Hypersensitivity

§  Inflammation

§  Venous obstruction

§  Lymphatic obstruction

§  E.g.

·         Lymphangitis

·         Thromboplebitis

·         Resection of regional lymphnodes

·         filariasis

o    Generalized edema

§  Cardiac

·         Characterized by

o    Gallop rhythm

o    Orthopnea

o    PND

o    Evidence of Cardiac Failure

§  Dyspnea

§  Basilar rales

§  Venous distension

§  Hepatomegaly

o    JVP up

o    Displaced apical pulse

o    Peripheral cyanosis

o    Cool extremities

o    Small pulse pressure when severe

o    Indicated investigations

§  Echocardiography

§  CXR

§  Urea nitrogen - creatinine ratio

§  Uric acid level

§  Sodium level (low in CF)

§  Liver enzyme?

§  Hepatic

·         Cirrhosis

o    Characteristics

§  Ascites

§  Clinical evidence of hepatic disease

·         Collateral venous channels

·         Jaundice

·         Spider nevi

§  History of alcohol abuse

§  JVP normal or low

§  BP lower than in Cardiac / renal cause

o    Why ascites?

§  Obstruction of hepatic lymph drain

§  Portal HTN

§  Hypoalbuminemia

§  Large ascites cause increased intraabdominal pressure leading to lower extremity edema

o    Indication of investigations

§  Serum albumin

§  Cholesterol

§  Hepatic proteins

§  Liver enzymes

§  Hypokalemia?

§  Respiratory alkalosis

§  Folate level

§  renal

·         Nephrotic $

o    Characteristics

§  Proteinuria (>3.5g/d)

§  Hypoalbuminuria (<35g/L)

§  Hypercholesterolemia

§  Usually chronic

§  Uremic signs and symptoms

·         Decreased apetite

·         Altered taste

·         Altered sleep pattern

·         Difficulty concentrating

·         Restless legs

·         Myoclonus

·         Dypnea (less so than CCF)

o    Seen in

§  Diabetic GN

§  Hypersentitivity reactions

§  Previous renal disease

§  GN

·         Acute GN and other renal failure

o    Characteristics

§  Hematuria

§  Proteinuria

§  Hypertension

§  Normal Cardiac output

§  Normal arterial mixed venous oxygen difference

§  Arterial HTN

§  Pulmonary congestion

§  May / may not orthopnea

o    Why edema?

§  Increased capillary permeability

§  Primary retention of NaCl and H2O by kidney

·         Investigation

o    Albuminuria

o    Hypoalbuminemia

o    Creatinine

o    Hyperkalemia

o    Metabolic acidosis

o    Hyperphosphatemia

o    Hypocalcemia

o    Anemia (normocytic)

o    Edema of nutritional origin

§  Diet grossly deficient in protein causing hypoproteinemia and edema

o    Other causes

§  Hypothyroidsm

§  Pregnancy

§  Admin of estrogens

§  Vasodilators

§  Nifedipine

§  NSAIDs

§  TZTs

·         Points in DX

o    Local colour

§  Red, tender and warm - possibly inflammatory

§  Cold and blue - venous obstruction

o    Local skin thickness

§  Thicker in prolonged edema

§  Indurated and red

o    JVP

§  Raised in Cardiac causes

§  Normal in Liver, renal causes

o    Serum albumin

§  Edema due to low intravascular plasma oncotic pressure

§  If albumin very low, not likely to be cardiac

Case presentation (trigger) J

·         Mr. Li 82

·         Shortness of breath while sleeping lasting for an hour

·         Also fatigue on both legs

·         SOB on and off going on for 7 8 years

·         Worsening on past 2 weeks

·         Cough

·         PND

·         Orthopnea

·         Signs of leg swelling - 2 weeks

·         SOB worsening on exertion

One more trigger

·         Mr. Abang

·         43 yrs old

·         ICU admit due to SOB

·         3 yrs chest pain on right upper side

·         Construction site worker

·         Bilateral Leg swelling up to the knees for one year

Mechanisms

·         Plasma pressure increase -

o    Vessel blockage

§  DVT

§  ascites

·         Plasma oncotic pressure decrease

o    Liver not producing Albumin

o    Albumin loss

§  Renal

§  GI

o    Lack of protein intake

§  Prolonged severe malnutrition

History taking

·         Nature of job

o    Waiter

o    Nurses

·         Both legs swelling? One leg only?

·         Associated conditions

o    Diarrhea

o    Blood in urine

·         Alcoholism (may lead to liver cirrhosis)

·         Varicose veins

·         Diarrhea, oily stool (protein wasting enteropathy)

·         Frothy urine (protein loss through urine)

·          

What to do to distinguish

·         CVS examination

o    Check for rales (LHF)

o    Apical displacement (cardiomegaly)

o    JVP (high in Cardiac cause, not high in others)

o    Valvular heart disease (murmurs)

o    Parasternal heave (RVH)

·         GI, liver and Renal

o    jaundice

o    Palmar erythyma (liver failure)

o    Dupeyton’s contracture (alcoholic)

o    Flapping tremor (liver failure)

o    Uremic frost and scratchmarks (renal)

o    Uremic fetor (renal)

o    Axillary hair (Liver cirrhosis)

o    Leukonekia (Chronic Liver fail)

o    Spider naevi (liver failure)

o    Liver tenderness

o    Fetor hepaticus (liver failure)

o    Gynacomastia

o    Caput medusa

o    Striae (ascites)

o    Shifting dullness

o    Fluid thrill

o    Liver span

o    Distended veins ( portal HTN due to liver cirrhosis)

o    Facial swelling (renal)

o    Anemia (kidney failure)

o    Emaciation (protein-losing enteropathy)

o    dehydration

·         Investigations

o    CXR (size of heart, see heart failure signs pulmonary edema)

o    ECG (rule out AF, ACS)

o    Echocardiography (ejection fraction)

o    Urine tests (proteinurea)

o    Liver enzymes (ALT)

Albumin (any oncotic causes) normal in CVS causes