oedema - pathophysiology, special forms, consequences

1. HEMODYNAMICS - I
DERANGEMENTS OF BODY FLUIDS - OEDEMA
Dr. Jyothi Reshma S
Tutor
Dept of Pathology

2. The mechanism by which the constancy
of the internal environment is maintained
and ensured is called the homeostasis.
Claude Bernarde (1949) – internal
environment or milieu interieur
Internal envt – water and electrolytes
HOMEOSTASIS

3. FLUID COMPARTMENTS

4. STARLING’S FORCES
 HYDROSTATIC PRESSURE - capillary blood
pressure - drives fluid through the capillary wall into
the interstitial space.
 COLLOID OSMOTIC PRESSURE - exerted by
proteins present in the ECF - tends to draw fluid
into the vessels.

6. NORMAL FLUID EXCHANGES
32 12

7. DISTURBANCES OF BODY FLUIDS
Oedema
Dehydration
Overhydration

8. OEDEMA
Abnormal and excessive
accumulation of “free
fluid” in the interstitial
tissue spaces and serous
cavities

9. NORMAL FLUID EXCHANGES

11. INCREASED HYDROSTATIC PRESSURE
 Impaired venous
return
 Congestive heart
failure
 Constrictive
pericarditis
 Ascites (liver cirrhosis)
 Venous obstruction or
compression
 Thrombosis
 External pressure
(e.g., mass)
 Lower extremity
inactivity with
prolonged
dependency
 Arteriolar dilation
 Heat
 Neurohumoral
dysregulation

12. REDUCED PLASMA OSMOTIC PRESSURE
(HYPOPROTEINEMIA)
Liver cirrhosis (ascites)
Malnutrition
Protein-losing glomerulopathies (nephrotic
syndrome)
Protein-losing gastroenteropathy

13. LYMPHATIC OBSTRUCTION
Inflammatory
Neoplastic
Postsurgical
Postirradiation
Milroy’s disease

14. INCREASED CAPILLARY PERMEABILITY
Acute inflammation
Chronic inflammation
Angiogenesis
Burns
ARDS

15. SODIUM RETENTION
Excessive salt intake with renal insufficiency
Increased tubular reabsorption of sodium
Renal hypoperfusion
Increased renin-angiotensin-aldosterone
secretion

17. PATHOGENESIS

18. TYPES
 limited to an organ
or limb
 e.g. lymphatic
oedema,
inflammatory
oedema,
allergic oedema
 Anasarca or dropsy
 systemic in
distribution
 subcutaneous
tissues
Localised Generalised

19. TRANSUDATE EXUDATE
Definition Filtrate of blood plasma
without changes in endothelial
permeability
Oedema of inflamed
tissue associated with
increased vascular
permeability
Character Non-inflammatory oedema Inflammatory oedema
Protein
content
Low (less than 1 gm/dl);
mainly albumin, low
fibrinogen; hence no tendency
to coagulate
High ( 2.5-3.5 gm/dl),
readily coagulates due
to high content of
fibrinogen and other
coagulation
factors
Glucose
content
Same as in plasma Low (less than 60
mg/dl)

20. TRANSUDATE EXUDATE
Specific gravity Low (less than 1.015) High (more than 1.018)
pH > 7.3 < 7.3
LDH Low High
Effusion LDH/ Serum
LDH ratio
< 0.6 > 0.6
Cells Few cells, mainly
mesothelial cells
Many cells, inflammatory
as well as parenchymal
and cellular debris
Examples Oedema in congestive
cardiac failure
Purulent exudate such as
pus

21. SPECIAL FORMS

22. RENAL OEDEMA
Renal dysfunction - all parts of the
body
 Initially manifests in tissues with loose
connective tissue matrix – eyelids
Periorbital edema - characteristic -
severe renal disease.

23. COMPARE & CONTRAST
Feature Nephrotic Nephritic
Cause Nephrotic syndrome Glomerulonephritis
(acute, rapidly
progressive)
Proteinuria Heavy Moderate
Mechanism ↓Plasma oncotic
pressure
Na+ and water
retention
Na+ and water
retention
Degree of oedema Severe, generalised Mild
Distribution Subcutaneous tissues
as well as visceral
organs
Loose tissues mainly
(face, eyes, ankles,
genitalia)

24. PULMONARY OEDEMA

25. CAUSES - left ventricular failure, renal
failure, acute respiratory distress
syndrome and pulmonary
inflammation or infection
CONSEQUENCES - impede oxygen
diffusion- hypoxia – hypercapnia -
favorable environment - bacterial
infection

26. HAPE
After an altitude of 2500 metres
Without acclimatisation
Appearance of oedema fluid -
lungs, congestion - widespread
minute haemorrhages

27. MORPHOLOGY
 Gross- the lungs are heavy
 Moist and subcrepitant.
 Cut surface exudes frothy fluid (mixture of air and
fluid).

28. M/S
 Interstitial
oedema -
alveolar oedema
 Congestion -
alveolar
capillaries
 Alveoli filled with
a homogeneous,
pink-staining
fluid permeated
by air bubbles
If pulmonary edema is caused by
alveolar damage, cell debris, fibrin and
proteins form films of proteinaceous
material in the alveoli - hyaline
membranes

29. X RAY
 Fluid accumulation - basal regions of lungs.
 Thickened interlobular septa + dilated lymphatics -
linear lines - perpendicular to the pleura - “Kerley B
lines”

30. CARDIOGENIC OEDEMA

31. CONSEQUENCES
Failure of the left ventricle - passive congestion - lungs
and pulmonary edema
When chronic - result in pulmonary hypertension
Right ventricular failure - generalized subcutaneous
edema - ascites and pleural effusions
The liver, spleen and other splanchnic organs - congested.

32.  Distribution is influenced by gravity - dependent
oedema (legs - standing, sacrum - recumbent).

33. CEREBRAL OEDEMA
 Brain edema -localized or generalized - nature extent -
pathologic process or injury.
 VASOGENIC OEDEMA : increased filtration pressure or
increased capillary permeability
 CYTOTOXIC OEDEMA : disturbance in the cellular
osmoregulation – response to cell injury
 INTERSTITIAL OEDEMA : hydrocephalus

35. Generalized edema - grossly swollen- narrowed sulci - distended gyri
- evidence of compression against the unyielding skull

36. M/S
 Separation of tissue elements - oedema fluid
 Swelling of astrocytes
 Widening - Perivascular (Virchow-Robin) space
 Clear halos - small blood vessels.

37.  CONSEQUENCES - life-threatening
 brain substance can herniate (extrude) through the
foramen magnum
 the brain stem vascular supply – compressed
 injure the medullary centers and cause death

38. HEPATIC OEDEMA
i) Hypoproteinaemia - impaired synthesis of
proteins
ii) Portal hypertension - increased venous pressure
in the abdomen - raised hydrostatic pressure.
iii) Failure of inactivation of aldosterone -
hyperaldosteronism.
iv) Secondary stimulation of RAAS- sodium and
water retention.

39. MISCELLANEOUS
 Kwashiorkor, prolonged
starvation, famine, fasting
 Vitamins (beri-beri due to
vitamin B1 deficiency)
 Chronic alcoholism
 Hypoproteinaemia
 Sodium-water retention
 Hypothyroidism -
nonpitting
 Skin of face - internal
organs
 Excessive deposition of
glycosaminoglycans in the
interstitium
 Microscopically -
basophilic
mucopolysaccharides.
Nutritional Oedema Myxoedema

40. PLEURAL SPACE
 Pleural effusion - straw- colored - transudate
- low specific gravity - few cells mainly
exfoliated mesothelial cells
 Nephrotic syndrome, cirrhosis of the liver
and congestive heart failure
 Pleural effusion response to an
inflammatory process or tumor in the lung or
on the pleural surface

41. PERICARDIUM
 Hemorrhage (hemopericardium) / injury (pericardial
effusion).
 Pericardial infections, metastatic neoplasms to the
pericardium, uremia , systemic lupus erythematosus
(postpericardiotomy syndrome) or radiation therapy for
cancer.
 Rapid accumulation of fluid - hemorrhage from a ruptured
myocardial infarct, dissecting aortic aneurysm or trauma -
pericardial cavity pressure rises & exceed the filling
pressure of the heart - cardiac tamponade

43. PERITONEUM
 Peritoneal effusion – ascites
 Cirrhosis of the liver, abdominal neoplasms,
pancreatitis, cardiac failure, the nephrotic
syndrome and hepatic venous obstruction (Budd-
Chiari syndrome).
 Obstruction of the thoracic duct - cancer - chylous
ascites - milky appearance - high fat content

45. GLOMERULONEPHRITIS
 A 6-year-old boy presents with a new onset of oliguria
and hematuria shortly after he has recovered from an
untreated sore throat. Additional workup finds
hypertension, periorbital edema, and impaired renal
function with slightly increased amounts of protein in the
urine.
COMPREHENSION QUESTIONS

46. A 27-year-old man presents to the outpatient clinic complaining of 2 days
of facial and hand swelling. He first noticed swelling around his eyes 2
days ago, along with difficulty putting on his wedding ring because of
swollen fingers. Additionally, he noticed that his urine appears reddish-
brown and that he has had less urine output over the last several days.
He has no significant medical history. His only medication is ibuprofen
that he took 2 weeks ago for fever and a sore throat, which have since
resolved. On examination, he is afebrile, with heart rate 85 bpm and
blood pressure 172/110 mm Hg. He has periorbital edema; his
funduscopic examination is normal without arteriovenous nicking or
papilledema. His chest is clear to auscultation, his heart rhythm is regular
with a nondisplaced point of maximal impulse (PMI), and he has no
abdominal masses or bruits. He does have edema of his feet, hands,
andface. A dipstick urinalysis in the clinic shows specific gravity of 1.025
with 3+ blood and 2+ protein, but it is otherwise negative.
PostStreptococcal GN

47.  Which of the following combinations of signs and symptoms
is most consistent with a diagnosis of nephrotic syndrome?
 A. Hematuria, hypertension, and proteinuria
 B. Massive proteinuria, edema, and hyperlipidemia
 C. Oliguria, hydronephrosis, and abdominal rebound
tenderness
 D. Painful hematuria, flank pain, and palpable abdominal
mass
 E. Painless hematuria, polycythemia, and increased skin
pigmentation

48. CONGESTIVE HEART FAILURE
 A55-year-old woman presents to your clinic complaining
of ankle swelling and increasing shortness of breath with
exertion. Upon directed questioning, she reveals that she
also experiences shortness of breath when she is lying
down. Physical examination reveals marked
hepatosplenomegaly, distended neck veins, and pedal
edema. A chest x-ray is suggestive of cardiomegaly. You
start the patient on an ACE inhibitor, diuretic, and a low-
sodium diet and you refer her to a cardiologist.

49.  Fluid is aspirated from the grossly distended abdomen of a
47-year-old chronic alcoholic man. The fluid is straw
colored and clear and is found to have a protein content
(largely albumin) of 2.5 g/dL. Which of the following is a
major contributor to the fluid accumulation in this patient?
 (A) Blockage of lymphatics
 (B) Decreased oncotic pressure
 (C) Decreased sodium retention
 (D) Increased capillary permeability
 (E) Inflammatory exudation

50. ARDS – PULMONARY OEDEMA
 A 63-year-old man is hospitalized for a severe case of
lobar pneumonia with sepsis. Within the first 24 hours of
his hospitalization, he develops worsening respiratory
failure and requires intubation. A chest x-ray reveals
bilateral patchy opacities. He becomes progressively
hypoxemic even with increased oxygen delivery via the
ventilator. You continue to treat the patient’s pneumonia,
but you worry that he will have up to a 40% mortality rate
given his current condition.

51. CARDIAC TAMPONADE
 A 75-year-old woman with a history of metastatic breast
cancer presents to the emergency department
complaining of weakness and difficulty breathing. On
physical examination, her blood pressure is 90/50 and
her heart sounds are distant and faint. You also note that
she has an increased JVP. When an ECG reveals a QRS
complex height that varies from one heart beat to the
next, you prepare for an immediate pericardiocentesis.

52. T
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