PA5.1-2 | Edema, Hyperemia, Congestion & Hemorrhage — Summary & Reflection

REFLECT

Think about the patient in the opening scenario — the 58-year-old with frothy pink sputum and swollen ankles.

1. Which pathogenic mechanism of oedema best explains his ankle swelling? Which explains the pulmonary symptoms?
2. If you sampled his pleural fluid, would you expect a transudate or exudate? Why?
3. If his autopsy liver showed nutmeg pattern and his lung showed brown induration with heart-failure cells — which side of his heart was most affected?
4. Could a small (80 mL) pericardial effusion be life-threatening in this patient? What would you look for clinically?

Discuss your reasoning with a peer or write it as a clinical encounter note before the next SGD session.

KEY TAKEAWAYS

Core take-aways from this module:

• Starling forces (capillary hydrostatic pressure, plasma oncotic pressure, lymphatic drainage) govern fluid balance; oedema forms when net filtration exceeds lymphatic return.

• Five oedema mechanisms: ↑ hydrostatic (CHF, venous obstruction), ↓ oncotic (nephrotic, cirrhosis, kwashiorkor), lymphatic obstruction (filariasis), sodium/water retention (renal), ↑ vascular permeability (inflammation).

• Transudate (protein-poor, low SG) = hydrostatic/oncotic cause. Exudate (protein-rich, high SG, cells) = inflammatory/permeable cause.

• Hyperaemia = active, arteriolar dilatation, warm, bright red. Congestion = passive, impaired outflow, cool, cyanotic.

• Chronic venous congestion → heart-failure cells in lung (haemosiderin-laden macrophages) and nutmeg liver (centrilobular congestion/atrophy, periportal fatty change).

• Haemorrhage significance determined by volume, site, and rate: even small bleeds in intracranial or pericardial spaces are immediately life-threatening.