Pathophysiology of congestion and oedema Flashcards
What is congestive heart failure (CHF)?
CHF is a chronic condition where the heart fails to pump efficiently, leading to fluid buildup (congestion) in the lungs, liver, and extremities.
What are the main types of heart failure?
1️⃣ Left-sided heart failure → Pulmonary congestion (dyspnea, orthopnea)
2️⃣ Right-sided heart failure → Systemic congestion (peripheral oedema, ascites)
3️⃣ Biventricular heart failure → Combination of both
What are the main causes of vascular congestion?
🫀 Heart failure (left or right)
🩸 Venous obstruction (DVT, portal hypertension)
🫁 Lung disease (chronic pulmonary congestion)
🦠 Infections or inflammation
What is the difference between exudate and transudate?
📌 Exudate → Protein-rich, caused by inflammation (e.g., pneumonia, malignancy)
📌 Transudate → Protein-poor, caused by hydrostatic or oncotic pressure changes (e.g., heart failure, cirrhosis)
What are Starling forces, and how do they affect fluid movement across capillaries?
🔹 Capillary hydrostatic pressure (Pc) – Pushes fluid out of capillary
🔹 Interstitial hydrostatic pressure (Pi) – Pushes fluid into capillary
🔹 Capillary oncotic pressure (πc) – Pulls fluid into capillary (from albumin)
🔹 Interstitial oncotic pressure (πi) – Pulls fluid out of capillary
💡 Fluid balance is determined by the net Starling equation.
How do disturbances in Starling forces cause oedema?
✅ Increased capillary hydrostatic pressure (heart failure, venous obstruction)
✅ Decreased capillary oncotic pressure (low albumin in liver disease, nephrotic syndrome)
✅ Increased capillary permeability (inflammation, sepsis)
✅ Lymphatic obstruction (tumors, lymphatic damage)
Mnemonic for Oedema Causes
“CHIL” – Causes of Oedema
C – Capillary hydrostatic pressure ↑ (Heart failure, DVT)
H – Hypoalbuminemia ↓ oncotic pressure (Cirrhosis, Nephrotic syndrome)
I – Increased capillary permeability (Inflammation, Sepsis)
L – Lymphatic obstruction (Tumors, Lymphedema)
