EDEMAEDEMAEDEMAEDEMA

Fluid extravasation and Fluid extravasation and

accumulation in the interstitial accumulation in the interstitial

spaces spaces

EDEMA• Localized Localized ( a limb) or ( a limb) or systemicsystemic

• InflammatoryInflammatory or or non inflammatorynon inflammatory

• Massive edema is called AnasarcaAnasarca

• Fluid may also accumulate in body body

cavities:cavities:

HydrothoraxHydrothorax

Hydro pericardiumHydro pericardium

Hydro peritoneum is also called Hydro peritoneum is also called AscitesAscites

Edema Fluid

• A TRANSUDATETRANSUDATE is protein-poor (specific

gravity <1.012)(non inflammatory)

• An EXUDATEEXUDATE is protein-rich (specific

gravity >1.020) (inflammatory edema)(inflammatory edema)

Pathophysiologic Categories of Edema

I.Increased Hydrostatic PressureII.Reduced Plasma Oncotic PressureIII.Sodium retentionIV.Lymphatic obstruction

•EDEMA - Summary

•INCREASED•HYDROSTATIC•PRESSURE• Congestive Heart Failure• Ascites• Venous Obstruction

•DECREASED •ONCOTIC•PRESSURE• Nephrotic Syndrome• Cirrhosis• Protein Malnutrition

•LYMPHATIC•OBSTRUCTION• Inflammatory• Neoplastic

• HEART• LIVER• KIDNEY

EdemaMorphology

•Edema of the subcutaneous tissue is most

easily detected GrosslyGrossly (not microscopically)

•Push your finger into it

•and a depression remains

Compare between:Hyperemia & Congestion

HYPEREMIA:HYPEREMIA:

• is an active process

• resulting from increase

blood inflow into tissue

• due to arteriolar dilation

• (e.g. acute inflammation)

Congestion Congestion

• is a passive process

• resulting from

impaired outflows

from a tissue

• Impaired venous

return

• (e.g. cardiac failure or

venous obstruction)

Cross Section of a Nutmeg

“Nutmeg” Liver

Liver - Chronic Passive Congestion

HemorrhageHemorrhageHemorrhageHemorrhage

Extravasation of bloodExtravasation of blood

due to rupture of blood vesselsdue to rupture of blood vessels

Hemorrhage

Causes:Causes:– Rupture of a large vessel:

– Trauma

– Atherosclerosis

– Inflammatory

– Neoplastic Erosion

– Rupture of small vessels:

» hemorrhagic

diathesis

Forms:Forms:

May be:

– external

– into a body cavity

– into a tissue

Hemorrhage: into tissue

1) Haematoma: 1) Haematoma:

accumulation of blood accumulation of blood ENCLOSED OR CONFINED WITHIN ENCLOSED OR CONFINED WITHIN

TISSUETISSUE

e.g.

- Bruise (insignificant)

- retroperitoneal haematomaretroperitoneal haematoma

due to ruptured aortic aneurysm

fatal

Hemorrhage

2) Petechiae:2) Petechiae:

minute hemorrhages into

skin, mucous membranes, or

serosal surfaces (1-2 MM) • Associated with:Associated with:

– Local increase hydrostatic

pressure– Thrombocytopenia

Hemorrhage

3) Purpura:3) Purpura:

– Slightly larger hemorrhages than Petechiae (3-5

MM)– Causes:Causes:

• Causes as Petechiae• Trauma• Vasculitis• Increased vascular fragility

Hemorrhage4) Ecchymoses:4) Ecchymoses:

– Subcutaneous haematoma ‘bruise’ OVER 1-2

CM

Q: Why do bruisesbruises changechange colorcolor as they Resolve?

• The RBC’s in a hemorrhage are broken down:

– hemoglobin (red) – bilirubin (blue-green) – hemosiderin (golden-brown)

Hemorrhage: Accumulation of blood Accumulation of blood in a body cavityin a body cavity::

– Hemothorax

– Hemopericardium

– Hemoperitoneum

– Hemarthrosis

HemorrhageCerebral hemorrhage