8- CKD

• Chronic kidney disease


  Previously called chronic renal failure
• Impaired renal function


  For >3 months based on abnormal structure or function (persistent proteinuria for >3 months), OR GFR <60mL/min/1.73m2 for >3 months with or without evidence of kidney damage
• Causes of chronic kidney disease


  • Diabetes (commonest cause worldwide, type II >> type I)
  • Glomerulonephritis (commonly IgA nephropathy)
  • Hypertension or renovascular disease
  • Obstructive uropathy
  • Others (unknown cause, chronic interstitial nephritis, adult polycystic kidney disease, Alport's syndrome, etc.)
• Stages of chronic kidney disease

  • Stage 1 (GFR > 90 ml/min with structural glomerular abnormalities (proteinuria or hematuria))
  • Stage 2 (GFR 60 - 89 ml/min)
  • Stage 3 (GFR 30 – 59 ml/min)
  • Stage 4 (GFR 15 – 29 ml / min, manifestations of renal failure are prominent (azotemia))
  • Stage 5 (GFR < 15 ml / min, manifestations of renal failure are prominent à uremia: metabolic acidosis, fluid overload, encephalopathy, hyperkalemia, pericarditis, end-stage renal disease, only option is dialysis or transplant)
• Conservative management of chronic renal failure


  1. Nutrition (ensure adequate calorie intake, avoid excessive K+ in hyperkalemic patients, avoid excessive fluids in edematous patients to prevent fluid overload)

  2. Hypertension (treat with appropriate antihypertensive, restrict salt to < 40 gm / day)

  3. Renal osteodystrophy (due to failure to activate Vitamin D in addition to inability to reabsorb calcium and excrete phosphate by the kidney, diagnosis: bone density test, treatment: calcium supplementation, 1-α-vitamin D supplementation, non-calcium phosphate binders, calcimimetics, parathyroidectomy if not controlled)

  4. Anemia (due to failure of the kidney to produce erythropoietin, treatment is by erythropoietin therapy and iron, vitamin B12, folate replacement, target Hb is 11-12 g/dl)
• Drug prescription in chronic renal failure


  • Use with caution with dose adjustment (aminoglycosides, cephalosporines, fluroquinolones, Tamiflu)
  • No dose adjustment (macrolides like clarithromycin)
• Causes of death in renal failure


  • Fluid overload
  • Hyperkalemia
  • Uremia
• Renal replacement therapy


  • Dialysis
  • Transplantation
• Chronic dialysis is initiated if


  • GFR < 10 [<15 in DM]
  • Uremia
  • Fluid overload
• Hemodialysis


  • Blood from a vascular access is passed over a semi-permeable membrane against dialysis fluid
  • Done in center
  • Cardiovascular stress
  • Need for blood access
  • Need anticoagulation
  • May have complications of vascular access
  • IHD is the most likely cause of death. Can't be done if elderly or severe IHD or hemorrhagic complications
• Peritoneal dialysis


  • Uses the peritoneum as a semi-permeable membrane
  • Done at home
  • Constant steady state
  • Protein loss across peritoneum
  • No need for anticoagulation
  • Peritonitis
  • Well-motivated patient
  • Preferred over hemodialysis if a patient is elderly or severe IHD or has hemorrhagic complications (ex: cerebral hemorrhage or bleeding PUD)
  • Not used if the patient is blind or has no one to help at home
• Recipient criteria for renal transplantation


  • Fit for surgery
  • No acute infection
  • No active hepatitis (will develop cirrhosis with immunosuppression)
  • No malignancy
  • HIV –ve
  • No active renal disease at time of transplantation (ex: Good pasture's)
• Donor criteria for renal transplantation


  • Fit for surgery
  • No acute infection
  • Free of hepatitis (unless same serotype as patient)
  • No malignancy (except for CNS)
  • HIV –ve
  • No chronic disease affecting kidney (ex: DM, BP, renal stones)
• Recipient - donor matching for renal transplantation


  • Blood group compatibility (at least ABO compatible)
  • Negative cross match (if positive the patient will get hyperacute rejection)
• The old kidney shouldn't be removed
• Transplantation is preferred only for selected fit patients
• Patients with severe IHD should not be transplant candidates unless their IHD is fixed (stenting or bypass surgery)
• Immunosuppression for transplantation


  1. Induction (intravenous pulse solumedrol, ALG (or ATG): 3 – 5 mg / kg daily for 7 – 10 day, or OKT 3 (5 mg iv daily))

  2. Maintenance (steroids, azathioprine (or mycophenolate), cyclosporine (or FK 506 / rapamycin))
• Complications of transplantation


  • Rejection (acute, chronic)
  • Specific related to the drugs (ex: cushinoid features, hemolytic anemia)
  • Infection (varicella zoster [chickenpox] could be deadly)
  • Malignancy
  • Accelerated cardiovascular disease