Master Specialist Nephrology (NEP5991)
for DHA Speciality

Core Concepts

Nephrology encompasses the study of normal kidney function and kidney diseases, their diagnosis, and treatment. Key areas include acute kidney injury (AKI), chronic kidney disease (CKD), glomerular diseases (nephrotic and nephritic syndromes), hypertension (especially renovascular), electrolyte and acid-base disorders, inherited kidney diseases, and renal replacement therapy (dialysis and transplantation). Understanding GFR estimation, albuminuria, and the progression of kidney disease is fundamental.

Clinical Presentation

• Acute Kidney Injury (AKI): Rapid decline in kidney function. Presents with oliguria/anuria, peripheral/pulmonary edema, nausea, vomiting, fatigue, altered mental status (uremia).
• Chronic Kidney Disease (CKD): Often asymptomatic until advanced stages. Symptoms include fatigue, weakness, pruritus, anorexia, nocturia, peripheral edema, muscle cramps, bone pain (renal osteodystrophy), neuropathy.
• Nephrotic Syndrome: Characterized by heavy proteinuria (>3.5g/day), hypoalbuminemia, generalized edema (anasarca), hyperlipidemia, and thrombotic tendency.
• Nephritic Syndrome: Presents with hematuria (often microscopic, but can be macroscopic/coca-cola urine), hypertension, mild proteinuria, oliguria, and often AKI (rapidly progressive glomerulonephritis, RPGN).
• Electrolyte/Acid-Base Disorders:
  • Hyperkalemia: Palpitations, muscle weakness, arrhythmias (peaked T waves, wide QRS).
  • Hypokalemia: Muscle cramps, weakness, fatigue, arrhythmias (U waves).
  • Hyponatremia: Headache, nausea, confusion, seizures.
  • Hypernatremia: Thirst, lethargy, seizures, coma.
  • Metabolic Acidosis: Kussmaul breathing, fatigue, confusion.
• Hypertension: Often asymptomatic. May present with headache, visual changes, epistaxis, or symptoms of end-organ damage (e.g., flash pulmonary edema in renal artery stenosis).

Diagnosis (Gold Standard)

• AKI: Defined by KDIGO criteria: increase in serum creatinine by ≥0.3 mg/dL within 48 hours, or ≥1.5 times baseline within 7 days, or urine volume <0.5 mL/kg/h for 6 hours.
• CKD: GFR <60 mL/min/1.73m² for ≥3 months, or markers of kidney damage (e.g., albuminuria, hematuria, structural abnormalities) for ≥3 months, irrespective of GFR.
• Glomerular Diseases (Nephrotic/Nephritic Syndromes, RPGN): Renal biopsy is the gold standard for definitive diagnosis and classification, guiding specific therapy.
• Renovascular Hypertension: Renal angiography is the gold standard; non-invasive tests include duplex ultrasound, CT angiography, and MRA.
• Electrolyte/Acid-Base Disorders: Serum electrolyte panel, arterial blood gas (ABG) analysis.
• Urinary Tract Obstruction: Renal ultrasound, CT KUB.

Management (First Line)

• AKI:
  • Address underlying cause (e.g., stop nephrotoxic drugs, rehydrate in prerenal, relieve obstruction in postrenal).
  • Optimize hemodynamics and fluid balance.
  • Manage electrolyte abnormalities (e.g., hyperkalemia).
  • Renal Replacement Therapy (RRT) if indicated (AEIOU: Acidosis, Electrolytes, Intoxications, Overload, Uremia).
• CKD:
  • Blood pressure control: Target <130/80 mmHg; ACEi/ARB are first-line, especially with albuminuria (caution in advanced CKD/AKI).
  • Glycemic control: HbA1c target 6.5-7.5% in diabetics; SGLT2 inhibitors (e.g., empagliflozin, dapagliflozin) are now standard for kidney and cardiovascular protection in eligible patients.
  • Lifestyle modifications: Diet (low salt, protein moderation), exercise, smoking cessation.
  • Manage complications: Anemia (iron supplementation, ESAs), CKD-MBD (phosphate binders, vitamin D analogs), acidosis (sodium bicarbonate).
  • Delay progression: SGLT2i, finerenone (for CKD with T2DM and albuminuria).
• Glomerular Diseases:
  • Symptomatic relief: Diuretics for edema, ACEi/ARB for proteinuria/BP.
  • Immunosuppression: Tailored to specific biopsy diagnosis (e.g., corticosteroids, cyclophosphamide, mycophenolate mofetil, rituximab).
• Hypertension:
  • Lifestyle modification.
  • Pharmacotherapy: ACEi/ARB, CCB, thiazide diuretics. Alpha-blockers, beta-blockers as add-on.
  • Target BP <130/80 mmHg for most CKD patients.
• End-Stage Kidney Disease (ESKD): Prepare for RRT (hemodialysis, peritoneal dialysis) or kidney transplantation.