OEDEMA AND CONGESTION

Define oedema

. Abnormal excess accumulation of fluid in the intercellular tissue spaces (interstitial) or body cavities.

Classification of oedema

1. Based on pathophysiology

• Non inflammatory oedema—> due to imbalance of hemodynamic force

• Inflammatory oedema—> due to increased vessel permeability

2. Based on distribution

• Localized- inflammation

• Generalized- renal, hepatic, cardiac

3. Organ specific oedema

• Renal

• Hepatic’

• Cardiac

• Cerebral

• Papilloedema

Pathogenesis of oedema

1. Increased hydrostatic pressure

• Venous blockage

• Portal hypertension

• Cardiac failure

2. Decreased oncotic pressure

• Liver cirrhosis

• Malnutrition

• Nephrotic syndrome

3. Lymphatic obstruction

• malignancies

• Post surgery

• Radiotherapy

4. Sodium and water retention

• venous obstruction

• Increase RAAS activation

5. Vascular permeability

• increase permeability in acute and chronic inflammation

complications of oedema

1. Cerebral oedema

• increase ICP within rigid skull

• Due to tumor, ICH, Intracranial lesion

• Generalized and localized oedema

• Clinical consequences: headache, nausea, vomit

• Type of herniation syndrome:

• Sufalcine- ant. Cerebral artery

• Transtentorial - lead to motor deficit, Duret syndrome and pupil dilation

• Tonsillar - cerebral tonsil , medulla herniation —> respiratory failure

2. Papilloedema

• oedema of optic disc due to increased vessel permeability ICP

• ICP is transmitted along the aptic nerve, axoplasmic stasis

• Indication of tumor , ICH

3. Cardiac oedema

• due to left heart failure

• Dec CO, dec renal perfusion

• Activation of RAAS

• Increase sodium and water retention

• Inc venous pressure—> oedema

• Dependent oedema

• Pitting oedema, leg when standing, sacrum whe laying

4. Renal oedema

• Generalized oedema

• Periorbital oedema

TRANSUDATE VS EXUDATE

Pathophysiological basis of congestion

1. Systemic congestion

• in right cardiac failure

• Venous can’t back up to its venous system

• Increase venous pressure

2. Localized congestion

• in thrombosis

• Lead to impedes venous drainage

Define congestion

passive process of accumulation of venous in tissue due to impaired venous outflow

Pulmonary oedema

• definition—> accumulation of fluid in interstitial and alveoli

• Cardiogenic type: due to left heart failure—> increase hydrostatic pressure in pulmonary vein—> transudate fluid into alveoli

• Non cardiogenic type : diffuse alveoli damage infection —>accumulation of fluid in alveoli —> prevent diffusion of O2 from alveoli and capillary blood

• Clinical features - dyspnea, frothy sputum with blood tinged, crackles sound

• Acute oedema—> respiratory failure

• Chronic oedema—> dec lung compliance