Pathology - Edema

1. EDEMA, HYPEREMIA AND
CONGESTION

2. EDEMA

3. EDEMA : OUTLINES
WHAT IS EDEMA ?
HOW IT DEVELOPS ?
CAUSES OF EDEMA
MORPHOLOGY AND TYPES OF EDEMA
LABORATORY TESTS
TREATMENT

4. EDEMA : Definition and Introduction
• The health of body depends on the
circulation of blood which delivers oxygen
and nutrients and removes wastes.
• Under normal conditions, as blood passes
through capillary, the proteins in the
plasma are retained.

5. EDEMA : Definition and
Introduction
• Normally, outflow of fluid produced
by hydrostatic pressure at the
arteriolar end is balanced by inflow
at the venular end.
• This balance is may disturbed by
pathologic conditions which
promote edema.

6. EDEMA : Definition and
Introduction
 Edema is the accumulation of fluid in
tissues due to a net movement of
water into extravascular spaces.
 It is marked by swelling of tissues and
accumulation of fluid in body cavities,
commonly in subcutaneous tissues,
lungs and brain.

7. EDEMA : Definition and Introduction
• Approximately 60% of body weight is water, two thirds of which is
intracellular, and the remaining is found in interstitial spaces in the
form of interstitial fluid.
• Fluid (water) movement between the vascular and interstitial spaces
is governed mainly by two opposing forces:
1) The hydrostatic pressure and
2) The osmotic pressure.
• Either increased hydrostatic pressure or reduced osmotic pressure
causes increased movement of water into the interstitium.

8. EDEMA : CAUSES
Here is the list of the major causes of edema:
1. Increased Hydrostatic Pressure
2. Reduced Plasma Osmotic Pressure
3. Lymphatic Obstruction
4. Sodium and Water Retention

9. EDEMA » CAUSES » INCREASED HYDROSTATIC PRESSURE
• Increases in hydrostatic pressure are mainly caused by
disorders that spoil venous return.
• Local increases in intravascular pressure, for example, by
venous thrombosis in the lower extremity can cause edema
restricted to the distal portion of the affected leg.
• Generalized increases in venous pressure, with resultant
systemic edema, occur most commonly in heart failure.

10. • The reduced cardiac output leads to venous blocking and
resultant increase in capillary hydrostatic pressure.
• At the same time, it causes hypoperfusion of the kidneys,
inducing sodium and water retention.
• Unless cardiac output is restored or renal water retention
is reduced, this downward movement continues, and
excessive fluid starts to accumulate.
EDEMA » CAUSES » INCREASED HYDROSTATIC PRESSURE

11. • Reduction of plasma albumin concentrations leads to decreased
osmotic pressure of the blood and loss of fluid from the
circulation.
• The conditions (nephrotic syndrome, liver disease or protein
malnutrition) in which albumin is either lost from the circulation
or synthesized in inadequate amounts are common causes of
reduced plasma osmotic pressure.
• Regardless of cause, low albumin levels lead in a stepwise fashion
to edema.
EDEMA » CAUSES » REDUCED PLASMA OSMOTIC PRESSURE

12. EDEMA

13. EDEMA » CAUSES »
LYMPHATIC OBSTRUCTION
• Edema may result from
lymphatic obstruction that
compromises resorption of
fluid.
• Impaired lymphatic drainage
results from a localized
blockage caused by an
inflammatory condition.
• For example, obstruction of
superficial lymphatics by breast
cancer.

14. EDEMA » CAUSES » SODIUM AND WATER RETENTION
• Excessive retention of salt can lead to edema by
increasing hydrostatic pressure and by reducing plasma
osmotic pressure.
• Excessive salt and water retention are seen in a wide
variety of diseases that compromise renal function
including glomerulonephritis and acute renal failure.

15. EDEMA;
MORPHOLOGY

16. EDEMA : MORPHOLOGY
• Edema is easily recognized on gross inspection.
• Microscopic examination shows clearing and
separation of the extracellular matrix elements.
• Although any tissue can be involved, but edema
most commonly is encountered in subcutaneous
tissues, lungs, and brain.

17. EDEMA » MORPHOLOGY » SUBCUTANEOUS EDEMA
• Subcutaneous edema can be in
the parts of the body positioned
at great distance below the
heart, where hydrostatic
pressures are high.
• Finger pressure over affected
tissue displaces the interstitial
fluid, leaving a finger-shaped
depression; this appearance is
called pitting edema.
Fig: PITTING EDEMA; showing depression

18. SUBCUTANEOUS EDEMA

19. EDEMA » MORPHOLOGY » PULMONARY EDEMA
• With pulmonary edema, the
lungs often are two to three
times than their normal
weight.
• Sectioning shows frothy,
blood-tinted fluid consisting
of a mixture of air, fluid,
and extravasated red cells.
Fig: PULMONARY EDEMA

20. PULMONARY EDEMA

21. EDEMA » MORPHOLOGY » BRAIN EDEMA
• Brain edema can be localized or
generalized, depending on the
nature and extent of the
pathologic condition or injury.
• With generalized edema, the
sulci are narrowed as the gyri
swell and become flattened
against the skull.
Fig: BRAIN EDEMA

22. EDEMA;
CLINICAL FEATURES

23. • The effects of edema vary, ranging from merely annoying to
rapidly fatal.
• Subcutaneous edema is important to recognize, because it
signals underlying cardiac or renal disease.
• It also can damage wound healing and the clearance of
infections.
• Pulmonary edema is seen frequently in left ventricular failure,
renal failure and disorders of the lung.
EDEMA » CLINICAL FEATURES

24. • It can cause death by interfering with normal ventilatory function,
obstructing oxygen diffusion and creates a favorable environment
for infections.
• Brain edema is life threatening; if the swelling is severe, the brain
can herniate (extrude) through the foramen magnum. With
increased intracranial pressure, the brain vascular supply can be
compressed, leading to death due to injury to the medullary
centers controlling respiration and other vital functions.
EDEMA » CLINICAL FEATURES

25. EDEMA;
LABORATORY TESTS

26. • The following laboratory tests are useful for diagnosing systemic causes of
edema:
 Brain Natriuretic Peptide Measurement (for CHF)
 Creatinine Measurement (for Renal Disease)
 Urinalysis (for Renal Disease)
 Albumin Measurement (for Hepatic Disease)
 Hepatic enzyme and
• In patients who present with acute unilateral upper or lower extremity
swelling, a D-DIMER can be ordered.
EDEMA » LABORATORY TESTS

27. EDEMA;
TREATMENT

28. • Possible, treatment involves resolving the underlying cause.
• Many cases of heart or kidney disease, are treated with diuretics.
• Treatment may also involve positioning the affected body parts to
improve drainage, for example, swelling in feet or ankles may be
reduced by having the person lie down in bed or sit with the feet
propped up on cushions.
• Compression can be used to pressurize tissue in a limb, forcing fluids;
both blood and lymph, to flow out of the compressed area.
EDEMA » TREATMENT

29. HYPEREMIA
AND
CONGESTION
HYPEREMIA
CONGESTION

30. HYPEREMIA AND CONGESTION
WHAT ARE HYPEREMIA AND CONGESTION ?
WHAT IS THE DIFFERENCE BETWEEN THEM ?
WHAT ARE THE CAUSES ?
MORPHOLOGY
LABORATORY TESTS
TREATMENT

31. • Hyperemia and Congestion both refer to an increase in blood
volume within a tissue but have different underlying
mechanisms.
• Hyperemia is an active process resulting from arteriolar
dilation and increased blood inflow, as occurs at sites of
inflammation or in exercising skeletal muscle.
• Congestion is a passive process resulting from impaired outflow
of venous blood from a tissue.
HYPEREMIA AND CONGESTION

32. HYPEREMIA

33. CONGESTION

34. CAUSES
A. The causes of hyperemia include exercise, fever, hot
flashes, injury, infection, heart failure, and
thrombosis.
B. The causes of congestion include heart failure, mitral
stenosis (a type of heart disease), a blockage in a
blood vessel, pneumonia and thrombosis.

35. MORPHOLOGY
• Hyperemic tissues are redder than normal because of
engorgement with oxygenated blood.
• Congested tissues have an abnormal blue-red color
that is due to accumulation of deoxygenated blood in
the affected area.
• Cut surfaces of hyperemic or congested tissues feel
wet and typically ooze blood.

36. MORPHOLOGY
On microscopic examination,
acute pulmonary congestion
is marked by blood-inflamed
alveolar capillaries and intra
alveolar hemorrhage.

37. MORPHOLOGY
In chronic hepatic congestion, the central regions of
the hepatic lobules, viewed on gross examination,
are red-brown, slightly depressed and are highlighted
against the surroundings, sometimes called fatty
liver (nutmeg liver).

38. MORPHOLOGY
A: Liver with chronic passive congestion and hemorrhagic
necrosis.
B: Microscopic preparation shows centrilobular hepatic
necrosis with hemorrhage.

39. Liver Biopsy

40. CLINICAL FEATURES
• In chronic congestion, inadequate tissue perfusion and
hypoxia may lead to parenchymal cell death and
secondary tissue fibrosis.
• The elevated intravascular pressures may cause
edema or sometimes rupture capillaries, producing
focal hemorrhages.

41. LABORATORY TESTS
• The following laboratory tests are useful for
diagnosing purposes:
 Gross/Physical Examination
 Microscope Examination
 Pulse Rate

42. TREATMENT
• Hyperemia does not typically need to be treated, as it is a
physiological response to activities such as physical exercise and
will improve on its own.
• Congestion, however, is caused by conditions that will need to be
treated and the medication may include:
• Beta-blockers (to lower blood pressure)
• Digoxin (to strengthen the heartbeat)
• Blood Thinners

43. REFERENCES
1. (Vinay Kumar, 2018):
Vinay Kumar, A. K. (2018). Robbins Basic Pathology (Tenth ed.). (A. K.
Vinay Kumar, Ed.) Philadelphia, Canada: Elsevier - Copyright © 2018 by
Elsevier Inc. Retrieved December 14, 2021, from www.elsevier.com
2. (Alila Medical Media, 2019)
Alila Medical Media. “Capillary Exchange and Edema, Animation.”
YouTube, © Alila Medical Media, 30 Sept. 2019,
https://www.youtube.com/Capillary Exchange and Edema, Animation

44. QUESTION ??
Please raise your hand !
🙋

45. THE END
Thank You ☺️
*hatam, tata goodbye