MBBS Block 2: Edema

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Questions and Answers

What percentage of body weight is made up of water?

80%

50%

70%

60% (correct)

Where is the majority of extracellular fluid located?

Bloodstream

Interstitium (correct)

Lymphatic vessels

Plasma

What is one of the causes of edema?

Decrease in lymphatic flow

Increase in plasma osmotic pressure

Increase in intravascular hydrostatic pressure (correct)

Decrease in salt and water retention

What is the normal balance between hydrostatic and osmotic forces in vessels?

They are nearly balanced Signup and view all the answers

What is the result of an imbalance between hydrostatic and osmotic forces?

Extravasation of fluid into tissues Signup and view all the answers

What is the consequence of a decrease in plasma osmotic pressure?

Edema formation Signup and view all the answers

What is the role of lymphatics in the body?

Regulation of fluid balance Signup and view all the answers

What is the consequence of an impairment in lymph flow?

Edema formation Signup and view all the answers

What is the consequence of renal retention of salt and water?

Edema formation Signup and view all the answers

What happens when the capacity for lymphatic drainage is exceeded?

Tissue edema results Signup and view all the answers

Which of the following is a cause of increased hydrostatic pressure?

Congestive heart failure Signup and view all the answers

What is a cause of reduced plasma osmotic pressure?

Protein-losing glomerulopathies Signup and view all the answers

Which of the following is a cause of lymphatic obstruction?

Neoplastic lymphatic obstruction Signup and view all the answers

What is a consequence of excessive sodium retention?

Tissue edema Signup and view all the answers

Which of the following is a cause of edema?

Increased renin-angiotensin-aldosterone secretion Signup and view all the answers

What is a consequence of impaired venous return?

Increased hydrostatic pressure Signup and view all the answers

Which of the following is a cause of increased hydrostatic pressure?

Constrictive pericarditis Signup and view all the answers

What is a consequence of lymphatic obstruction?

Tissue edema Signup and view all the answers

What is the definition of edema?

Abnormal accumulation of fluid in the tissue spaces or body cavities Signup and view all the answers

What type of edema is caused by venous obstruction?

Edema of venous obstruction Signup and view all the answers

What is cardiac edema an example of?

Generalized edema Signup and view all the answers

Which of the following is not a type of generalized edema?

Acute inflammatory edema Signup and view all the answers

What is myxoedema an example of?

Generalized edema Signup and view all the answers

What is the main difference between transudate and exudate?

The protein content Signup and view all the answers

Which of the following is a serious complication of edema?

All of the above Signup and view all the answers

What is the term for fluid accumulation in body cavities?

Effusion Signup and view all the answers

What is the classification of edema caused by protein losing enteropathy?

Nutritional edema Signup and view all the answers

What is the term for generalized edema producing marked swelling of subcutaneous tissue?

Anasarca Signup and view all the answers

What is the primary cause of cardiac edema?

Congestive cardiac failure Signup and view all the answers

What is the term for the abnormal accumulation of fluid in the pericardial cavity?

Hydropericardium Signup and view all the answers

What is the characteristic of pulmonary edema on gross examination?

Lungs are 2-3 times larger than normal Signup and view all the answers

What is the term for the swelling of the part of the optic nerve inside the eye?

Papilloedema Signup and view all the answers

What is the effect of brain edema on the brain substance?

All of the above Signup and view all the answers

What is the significance of papilloedema in clinical practice?

It is a sign of increased intracranial pressure Signup and view all the answers

What is the effect of pulmonary edema on normal ventilatory function?

It impairs oxygen diffusion Signup and view all the answers

What is the significance of subcutaneous edema in cardiac and renal failure?

It is a sign of underlying disease Signup and view all the answers

What may be the initial vision problems in certain individuals?

Short flickers of gray vision Signup and view all the answers

What is the main characteristic of exudate?

High protein content Signup and view all the answers

What is the definition of transudate?

Filtrate of blood or plasma with no increased vascular permeability Signup and view all the answers

What is the nature of exudate?

Inflammatory edema Signup and view all the answers

What is the protein content of transudate?

Low (less than 3 g/dl) Signup and view all the answers

What is the fluid LDH/serum LDH ratio in exudate?

>0.6 Signup and view all the answers

What is the specific gravity of exudate?

More than 1.018 Signup and view all the answers

What is the characteristic of exudate in terms of fibrinogen?

High fibrinogen Signup and view all the answers

What is the LDH level in transudate?

Low Signup and view all the answers

What is the main cause of edema in cardiac failure?

Renal retention of salt and water Signup and view all the answers

What is the primary mechanism of edema formation in renal disease?

Renal retention of salt and water Signup and view all the answers

What is the underlying cause of edema in lymphatic obstruction?

Impairment in lymph flow Signup and view all the answers

What is the result of an imbalance between hydrostatic and osmotic forces in vessels?

Extravasation of fluid into tissues Signup and view all the answers

What is the consequence of a decrease in plasma osmotic pressure?

Extravasation of fluid into tissues Signup and view all the answers

What is the role of lymphatics in edema formation?

To drain excess fluid from tissues Signup and view all the answers

What is the consequence of an impairment in lymph flow?

Edema formation Signup and view all the answers

What is the underlying cause of edema in hepatic disease?

Decreased plasma oncotic pressure Signup and view all the answers

What is the primary cause of cardiac edema?

Impaired venous return Signup and view all the answers

What is the primary mechanism of edema formation in hypersensitivity reactions?

Increased capillary permeability Signup and view all the answers

Which of the following can cause renal edema?

All of the above Signup and view all the answers

What is the underlying mechanism of hepatic edema?

Reduced plasma osmotic pressure Signup and view all the answers

Which of the following is a characteristic of lymphatic edema?

Impaired lymphatic drainage Signup and view all the answers

What is a common cause of edema in patients with liver cirrhosis?

Reduced plasma osmotic pressure Signup and view all the answers

Which of the following can cause hypersensitivity edema?

Allergic reaction Signup and view all the answers

What is the consequence of an imbalance between hydrostatic and osmotic forces in vessels?

Edema Signup and view all the answers

What is the role of lymphatic vessels in the body?

To remove excess fluid Signup and view all the answers

Which of the following can cause edema in patients with cardiac disease?

All of the above Signup and view all the answers

What is the main characteristic of vision problems in certain individuals?

All of the above Signup and view all the answers

What is the nature of transudate?

Non-inflammatory edema Signup and view all the answers

What is the protein content of exudate?

More than 4g/dl Signup and view all the answers

What is the specific gravity of transudate?

Less than 1.015 Signup and view all the answers

What is the fluid LDH/serum LDH ratio in exudate?

More than 0.6 Signup and view all the answers

What is the characteristic of exudate in terms of fibrinogen?

High fibrinogen Signup and view all the answers

What is the definition of transudate?

Filtrate of blood or plasma; no increased in permeability Signup and view all the answers

What is the nature of exudate?

Inflammatory edema Signup and view all the answers

What is the LDH level in exudate?

High Signup and view all the answers

What is the main cause of cardiac edema?

Increased hydrostatic pressure Signup and view all the answers

Which type of edema is associated with allergic reactions?

Hypersensitivity edema Signup and view all the answers

What is the main characteristic of renal edema?

Sodium and water retention Signup and view all the answers

Which type of edema is caused by impaired lymphatic drainage?

Lymphatic edema Signup and view all the answers

What is the main cause of hepatic edema?

Liver cirrhosis Signup and view all the answers

Which type of edema is associated with protein-losing enteropathy?

Nutritional edema Signup and view all the answers

What is the main difference between cardiac edema and renal edema?

Cause of edema Signup and view all the answers

Which type of edema is more likely to cause respiratory distress?

Cardiac edema Signup and view all the answers

What is the common characteristic of cardiac edema, renal edema, and hepatic edema?

Generalized edema Signup and view all the answers

What is the main cause of cardiac edema?

Congestive cardiac failure Signup and view all the answers

Which type of edema is characterized by periorbital edema and pitting edema?

Renal edema Signup and view all the answers

What is the term for the abnormal accumulation of fluid in the pleural cavity?

Hydrothorax Signup and view all the answers

What is the effect of pulmonary edema on normal ventilatory function?

Impaired oxygen diffusion Signup and view all the answers

What is the characteristic of brain edema?

Generalized swelling of the brain Signup and view all the answers

What is the term for the swelling of the part of the optic nerve inside the eye?

Papilloedema Signup and view all the answers

What is the clinical significance of papilloedema?

Precious clinical sign of increased intracranial pressure Signup and view all the answers

What is the effect of subcutaneous edema in cardiac and renal failure?

Impairs wound healing and clearance of infection Signup and view all the answers

What is the gross characteristic of pulmonary edema?

The lungs are 2-3 times larger Signup and view all the answers

What is a type of generalized edema that is caused by liver disease?

Hepatic edema Signup and view all the answers

Which of the following types of edema is caused by obstruction of the lymphatic vessels?

Lymphatic edema Signup and view all the answers

What is the cause of hypersensitivity edema?

Allergic reaction Signup and view all the answers

Which of the following types of edema is caused by kidney disease?

Renal edema Signup and view all the answers

What is the primary cause of cardiac edema?

Increased hydrostatic pressure Signup and view all the answers

What type of edema is caused by protein losing enteropathy?

Generalized edema Signup and view all the answers

What is the characteristic of edema caused by hypersensitivity?

Allergic reaction Signup and view all the answers

Which of the following types of edema is caused by venous obstruction?

Edema of venous obstruction Signup and view all the answers

What is the classification of edema caused by liver disease?

Generalized edema Signup and view all the answers

What is the primary cause of edema in cardiac failure?

Increased hydrostatic pressure Signup and view all the answers

What is the underlying cause of edema in lymphatic obstruction?

Impaired lymphatic flow Signup and view all the answers

What is the primary mechanism of edema formation in renal disease?

Renal retention of salt and water Signup and view all the answers

What is the term for the abnormal accumulation of fluid in the pleural cavity?

Hydrothorax Signup and view all the answers

What is the consequence of an increase in capillary hydrostatic pressure?

Increased fluid movement out of vessels Signup and view all the answers

What is the primary cause of cardiac edema?

Congestive cardiac failure Signup and view all the answers

What is the result of a decrease in plasma osmotic pressure?

Increased fluid movement out of vessels Signup and view all the answers

What is the characteristic of Renal edema?

Periorbital edema and pitting edema Signup and view all the answers

What is the primary mechanism of edema formation in hepatic disease?

Decreased plasma osmotic pressure Signup and view all the answers

What is the consequence of an impairment in lymphatic flow?

Accumulation of fluid in the interstitium Signup and view all the answers

What is the term for the swelling of the part of the optic nerve inside the eye?

Papilloedema Signup and view all the answers

What is the result of an imbalance between hydrostatic and osmotic forces in vessels?

Increased fluid movement out of vessels Signup and view all the answers

What is the effect of pulmonary edema on normal ventilatory function?

Impairs normal ventilatory function Signup and view all the answers

What is the significance of subcutaneous edema in cardiac and renal failure?

Signals the underlying disease Signup and view all the answers

What is the primary cause of edema in hypersensitivity reactions?

Increased capillary permeability Signup and view all the answers

What is the characteristic of edema fluid in alveolar spaces in pulmonary edema?

Frothy and serosanguinous Signup and view all the answers

What is the effect of brain edema on the brain substance?

Herniates through the foramen magnum Signup and view all the answers

What is the significance of papilloedema in clinical practice?

It is a sign of increased intracranial pressure Signup and view all the answers

What is the consequence of impaired venous return in the body?

Edema Signup and view all the answers

Which of the following is a cause of reduced plasma osmotic pressure?

Protein-losing glomerulopathies Signup and view all the answers

What is the result of lymphatic obstruction?

Edema Signup and view all the answers

Which of the following is a cause of renal edema?

Excessive salt intake with renal insufficiency Signup and view all the answers

What is the consequence of cardiac failure?

Edema Signup and view all the answers

Which of the following is a cause of hepatic edema?

Liver cirrhosis Signup and view all the answers

What is the result of excessive sodium retention?

Edema Signup and view all the answers

Which of the following is a cause of lymphatic edema?

Lymphatic obstruction Signup and view all the answers

What is the consequence of increased hydrostatic pressure?

Edema Signup and view all the answers

What is the characteristic of exudate in terms of protein content?

High (more than 4g/dl) Signup and view all the answers

What is the main difference between transudate and exudate?

Nature of edema (inflammatory or non-inflammatory) Signup and view all the answers

What is the characteristic of transudate in terms of specific gravity?

Low (less than 1.015) Signup and view all the answers

What is the fluid LDH/serum LDH ratio in exudate?

More than 0.6 Signup and view all the answers

What is the characteristic of transudate in terms of fibrinogen?

Low fibrinogen content Signup and view all the answers

What is the initial vision problem in certain individuals?

Short flickers of gray vision Signup and view all the answers

What is the nature of exudate?

Inflammatory edema Signup and view all the answers

What is the definition of transudate?

Filtrate of blood or plasma; no increased permeability Signup and view all the answers

What is the protein content of exudate?

High (more than 4g/dl) Signup and view all the answers

Study Notes

Edema

Edema is an abnormal accumulation of fluid in tissue spaces or body cavities (effusion).

Classification

Edema can be classified into two types: Generalized edema and Local edema
Generalized edema includes:
- Cardiac edema
- Renal edema
- Nutritional edema
- Protein-losing enteropathy
- Hepatic edema
- Myxoedema
- Unexplained edema
Local edema includes:
- Acute inflammatory edema
- Hypersensitivity (allergic) edema
- Edema of venous obstruction
- Lymphatic edema

Pathogenesis

Edema occurs due to:
- Increase in intravascular hydrostatic pressure
- A fall in colloid oncotic pressure in plasma
- An impairment in the flow of lymph
- Renal retention of salt and water

Pathogenesis of Different Types of Edema

Increased hydrostatic pressure:
- Impaired venous return
- Arteriolar dilation
Reduced plasma osmotic pressure (hypoproteinemia):
- Protein-losing glomerulopathies (nephrotic syndrome)
- Liver cirrhosis (ascites)
- Malnutrition
- Protein-losing gastroenteropathy
Lymphatic obstruction:
- Inflammatory
- Neoplastic
- Postsurgical
- Post-irradiation
Sodium retention:
- Excessive salt intake with renal insufficiency
- Increased tubular reabsorption of sodium
- Renal hypoperfusion
- Increased renin-angiotensin-aldosterone secretion
Inflammation:
- Acute inflammation
- Chronic inflammation
- Angiogenesis

Terminology

Anasarca: generalized edema producing marked swelling of subcutaneous tissue
Hydrothorax: abnormal accumulation of fluid in pleural cavity (pleural effusion)
Hydropericardium: abnormal accumulation of fluid in pericardial cavity (pericardial effusion)
Hydroperitoneum: abnormal accumulation of fluid in peritoneal cavity (ascites)

Morphology of Edema

Cardiac edema:
- Mainly due to congestive cardiac failure
- Dependent edema: subcutaneous edema of lower parts of the body or sacral edema
Renal edema:
- Acute glomerulonephritis
- Nephrotic syndrome
- Chronic glomerulonephritis
- Periorbital edema and pitting edema

Clinical Significance of Serious Complications of Edema

Pulmonary edema:
- Causes: left ventricular failure, renal failure, adult respiratory distress syndrome, pulmonary infections, hypersensitivity reactions
- Gross: lungs are 2-3 times larger, edema is confined to lower lobes, all lobes may be involved in advanced cases
- Histology: edema fluid first accumulates about septal arteries with widening of septa, then proteinaceous fluid escapes into alveolar spaces
Papilloedema:
- Swelling of the part of the optic nerve inside the eye (optic disc) due to raised intracranial pressure
- Typically presents as bilateral disc edema
Brain edema (Cerebral edema):
- Localized: at sites of injury, abscess, or neoplasm
- Generalized: encephalitis, hypertensive crisis, obstruction to venous flow
- Gross: brain is swollen with narrowing of sulci and flattening of gyri, white matter may appear soft and gelatinous
- Clinical significance: impaired normal ventilatory function, increased ICP, vision problems

Transudate and Exudate

Transudate:
- Filtrate of blood or plasma
- No increased permeability
- Low protein content (less than 3g/dl)
- Low specific gravity (less than 1.015)
- Low LDH
Exudate:
- Oedema associated with increased vascular permeability
- High protein content (more than 4g/dl)
- High specific gravity (more than 1.018)
- High LDH

Edema

Definition: Abnormal accumulation of fluid in the tissue spaces (edema) or body cavities (effusion)
Classification:
- Generalized edema
- Local edema
- Types of edema:
  - Cardiac edema
  - Renal edema
  - Nutritional edema
  - Edema of venous obstruction
  - Lymphatic edema
  - Hepatic edema
  - Myxoedema

Body Composition

60% of body weight is water
2/3 of water is intracellular
Remainder is in extracellular compartments, mostly in the interstitium

Pathogenesis of Edema

Increase in intravascular hydrostatic pressure
Fall in colloid oncotic pressure in plasma
Impairment in the flow of lymph
Renal retention of salt and water

Lymphatics

Lymphatic vessels remove excess fluid from tissues
If lymphatic capacity is exceeded, tissue edema results

Causes of Edema

Increased hydrostatic pressure:
- Impaired venous return
- Arteriolar dilation
Reduced plasma osmotic pressure (hypoproteinemia):
- Protein-losing glomerulopathies
- Liver cirrhosis
- Malnutrition
- Protein-losing gastroenteropathy
Lymphatic obstruction:
- Inflammatory
- Neoplastic
- Postsurgical
- Post-irradiation
Sodium retention:
- Excessive salt intake with renal insufficiency
- Increased tubular reabsorption of sodium
- Renal hypoperfusion
- Increased renin-angiotensin-aldosterone secretion
Inflammation:
- Acute inflammation
- Chronic inflammation
- Angiogenesis

Types of Edema

Anasarca: generalized edema producing marked swelling of subcutaneous tissue
Hydrothorax: abnormal accumulation of fluid in the pleural cavity
Hydropericardium: abnormal accumulation of fluid in the pericardial cavity
Hydroperitoneum: abnormal accumulation of fluid in the peritoneal cavity

Morphology of Edema

Cardiac edema: mainly due to congestive cardiac failure
Renal edema:
- Periorbital edema and pitting edema
- Acute glomerulonephritis
- Nephrotic syndrome
- Chronic glomerulonephritis

Clinical Significance of Edema

Pulmonary edema:
- Causes: left ventricular failure, renal failure, adult respiratory distress syndrome, pulmonary infections, hypersensitivity reactions
- Gross: lungs are 2-3 times larger, edema is confined to lower lobes
- Histology: edema fluid first accumulates about septal arteries, then escapes into alveolar spaces
Papilloedema:
- Swelling of the optic nerve inside the eye due to raised intracranial pressure
- Bilateral disc edema
- Optic nerve is typically swollen and hyperemic
Brain edema:
- Localized: at sites of injury, abscess, or neoplasm
- Generalized: encephalitis, hypertensive crisis, obstruction to venous flow
- Gross: brain is swollen with narrowing of sulci and flattening of gyri
- Histology: white matter may appear soft and gelatinous, peripheral gray matter is widened, ventricles are compressed

Effects of Edema

Subcutaneous edema:
- Impairs wound healing and clearance of infection
- Signals underlying disease in cardiac and renal failure
Pulmonary edema:
- Impaired normal ventilatory function
- Fluid collects in alveolar septa around capillaries, impeding oxygen diffusion
- Edema fluid in alveolar spaces creates a favorable environment for bacterial infections
Edema of brain:
- Increased intracranial pressure, leading to headache, projectile vomiting, and convulsive seizure
- Serious and rapidly fatal, brain substance can herniate through the foramen magnum, brain stem vascular supply can be compressed, and can injure medullary centers and death

Differences between Transudate and Exudate

Definition:
- Exudate: oedema associated with increased vascular permeability
- Transudate: filtrate of blood or plasma; no increased permeability
Nature:
- Exudate: inflammatory edema
- Transudate: non-inflammatory edema
Protein content:
- Exudate: high (> 4g/dl)
- Transudate: low (< 3g/dl)
Specific gravity:
- Exudate: high (> 1.018)
- Transudate: low (< 1.015)
LDH:
- Exudate: high
- Transudate: low
- Fluid LDH/serum LDH ratio:
 - Exudate: > 0.6
 - Transudate: < 0.6

Inflammation

Inflammation can be acute or chronic
Angiogenesis is a process related to inflammation

Edema

Definition: Abnormal accumulation of fluid in tissue spaces or body cavities
Classification:
- Generalized edema
- Local edema
- Types of edema:
  - Cardiac edema
  - Renal edema
  - Nutritional edema
  - Protein losing enteropathy
  - Hepatic edema
  - Myxoedema
  - Unexplained edema

Pathogenesis of Edema

Edema occurs due to:
- Increase in intravascular hydrostatic pressure
- A fall in colloid oncotic pressure in plasma
- An impairment in the flow of lymph
- Renal retention of salt and water

Factors Affecting Edema

Increased hydrostatic pressure:
- Impaired venous return
- Congestive heart failure
- Constrictive pericarditis
- Ascites (liver cirrhosis)
- Venous obstruction or compression
- Arteriolar dilation
- Heat
- Neurohumoral dysregulation
Reduced plasma osmotic pressure (hypoproteinemia):
- Protein-losing glomerulopathies (nephrotic syndrome)
- Liver cirrhosis (ascites)
- Malnutrition
- Protein-losing gastroenteropathy
Lymphatic obstruction:
- Inflammatory
- Neoplastic
- Postsurgical
- Post-irradiation
Sodium retention:
- Excessive salt intake with renal insufficiency
- Increased tubular reabsorption of sodium
- Renal hypoperfusion
- Increased renin-angiotensin-aldosterone secretion

Types of Edema

Anasarca: generalized edema producing marked swelling of subcutaneous tissue
Hydrothorax: abnormal accumulation of fluid in pleural cavity
Hydropericardium: abnormal accumulation of fluid in pericardial cavity
Hydroperitoneum: abnormal accumulation of fluid in peritoneal cavity (ascites)

Morphology of Edema

Cardiac edema:
- Mainly due to congestive cardiac failure
- Dependent edema: subcutaneous edema of lower parts of the body or sacral edema
Renal edema:
- Acute glomerulonephritis
- Nephrotic syndrome
- Chronic glomerulonephritis
- Periorbital edema and pitting edema

Pulmonary Edema

Causes:
- Left ventricular failure
- Renal failure
- Adult respiratory distress syndrome
- Pulmonary infections
- Hypersensitivity reactions
Gross:
- Lungs are 2-3 times larger
- Edema is confined to lower lobes
- For advanced cases, all lobes may be involved
- On section, free escape of frothy serosanguinous fluid presenting a mixture of air, edema fluid, and extravasated red cells
Histology:
- Edema fluid first accumulates about septal arteries with widening of septa
- Then, proteinaceous fluid escapes into alveolar spaces, marked by a granular pink coagulate within spaces

Papilloedema

Swelling of the part of the optic nerve inside the eye (optic disc) due to raised intracranial pressure
Typically in bilateral disc edema
Optic nerve is typically swollen and hyperemic

Brain Edema (Cerebral Edema)

Localized: at sites of injury, abscess, or neoplasm
Generalized: encephalitis, hypertensive crisis, obstruction to venous flow
Gross:
- Brain is swollen with narrowing of sulci and flattening of gyri
- On section, white matter may appear soft and gelatinous
- Peripheral gray matter is widened
- Ventricles are compressed

Clinical Significance of Edema

Subcutaneous edema:
- Signals underlying disease
- Impairs wound healing
- Impairs clearance of infection
Pulmonary edema:
- Impairs normal ventilatory function
- Fluid collects in alveolar septa around capillaries and impedes oxygen diffusion
- Edema fluid in alveolar spaces creates a favorable environment for bacterial infections
Edema of brain:
- Increased ICP: headache, projectile vomiting, and convulsive seizure
- Serious and rapidly fatal, brain substance can herniate through the foramen magnum, brain stem vascular supply can be compressed, can injure the medullary centers and death

Differences between Transudate and Exudate

Features:
- Exudate:
  - Oedema associated with increased vascular permeability
  - High protein content (more than 4g/dl)
  - High fibrinogen
  - Specific gravity: high (more than 1.018)
  - LDH: high
- Transudate:
  - Filtrate of blood or plasma; no increased in permeability
  - Low protein content (less than 3g/dl)
  - Mainly albumin, low fibrinogen
  - Specific gravity: low (less than 1.015)
  - LDH: low

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Description

This quiz covers the definition, classification, and pathogenesis of edema, as well as its clinical significance and complications, including pulmonary, papilloedema, and cerebral edema.