UREMIA 

1️⃣ Definition

Uremia is the clinical syndrome resulting from severe reduction in glomerular filtration rate (GFR) leading to accumulation of:

• Nitrogenous waste (urea, creatinine)
• Middle molecules
• Protein-bound toxins
• Electrolyte & acid–base derangements
• Hormonal dysfunction

It is NOT just elevated urea, but a multi-system toxic state of advanced kidney failure.

Typically seen when:

• GFR < 15 mL/min/1.73 m²
• Advanced AKI or CKD (Stage 5)

2️⃣ Pathophysiology of Uremia

Uremia results from accumulation of:

A. Small Water-Soluble Molecules

• Urea
• Creatinine
• Guanidines
• Phosphate

B. Middle Molecules

• β2-microglobulin
• Parathyroid hormone fragments
• Advanced glycation end products

C. Protein-Bound Toxins

• Indoxyl sulfate
• p-Cresyl sulfate

These cause:

3️⃣ Etiology

Uremia develops in:

A. Acute Kidney Injury (AKI)

• Sepsis
• Hypovolemia
• Nephrotoxins
• Obstruction

B. Chronic Kidney Disease (CKD Stage 5)

• Diabetic nephropathy
• Hypertensive nephrosclerosis
• Glomerulonephritis
• Polycystic kidney disease

4️⃣ Clinical Manifestations (Multi-System)

 1. Neurological – Uremic Encephalopathy

Features:

• Fatigue
• Confusion
• Delirium
• Seizures
• Coma
• Asterixis
• Peripheral neuropathy
• Restless legs

EEG: Diffuse slowing

 Reversible with dialysis.

 2. Cardiovascular

A. Uremic Pericarditis

Features:

• Chest pain
• Pericardial rub
• Large effusion
• Tamponade

 Non classic ECG ST elevation pattern

Absolute indication for dialysis.

B. Hypertension

• Volume overload
• RAAS activation

C. Cardiomyopathy

• LVH
• Dilated cardiomyopathy

 3. Hematological

A. Normocytic Normochromic Anemia

Cause:

• ↓ Erythropoietin
• Iron deficiency
• Inflammation

B. Platelet Dysfunction

• Normal count
• Prolonged bleeding time
• Mucosal bleeding

Mechanism:

• Impaired platelet aggregation
• Abnormal vWF interaction

 4. Pulmonary

Uremic Lung

• Pulmonary edema
• Capillary leak
• Volume overload

 5. Gastrointestinal

• Nausea
• Vomiting
• Anorexia
• Metallic taste
• GI bleeding
• Uremic fetor (ammonia smell)

 6. Endocrine & Bone

CKD–Mineral Bone Disorder (CKD-MBD)

• Hyperphosphatemia
• Hypocalcemia
• Secondary hyperparathyroidism
• Renal osteodystrophy

 7. Dermatological

• Pruritus
• Hyperpigmentation
• Uremic frost (rare now)

5️⃣ Laboratory Findings

8️⃣ Indications for Dialysis in Uremia

Classic mnemonic: AEIOU

Uremic Symptoms include:

• Encephalopathy
• Pericarditis
• Severe bleeding
• Persistent nausea/vomiting

 These are absolute indications.