Acute Renal Failure

Causes:

• Pre-renal- Hypovolemia, sepsis, hypercalcemia, drugs, hyperviscosity
• Renal- Interstitial nephritis due to infections/ infiltrations,  intratubular obstruction in myeloma, compression of renal vessels by tumor, radiation
• Chemotherapy toxicity- Cisplatin, carboplatin, methotrexate, Ifosfamide, Gemcitabine
• Post-renal- Obstruction in upper or lower urinary tract

Diagnosis:

• Oliguria
• Edema
• Hypertension
• Deranged RFT

Treatment:

• Correct reversible causes: Hypovolemia, hypotension
• Prevent additional injury: Avoid nephrotoxic drugs
• Strict input/output charge- Maintain maximum 500ml positive balance- Use Frusemide if required
• Diet- Restrict protein, salt, potassium, calcium, phosphate
• Monitor BP, RFT and electrolytes
• Treatment of complications: Hyperkalemia, acidosis etc
• Indications for hemodialysis:
  • Potassium >6.5mEq/L
  • Severe, persistent acidosis
  • Pulmonary edema
  • Uremic encephalopathy
  • Daily rise in creatinine>2, in the absence of catabolic states

Hemorrhagic Cystitis

Causes:

• High dose cyclophosphamide- 5-25% cases depending on preventive measures adopted
• Other chemotherapy agents include- Ifosfamide, busulfan, Etoposide
• Total body irradiation
• B K virus- Seen in 7-58 % cases of HSCT(depending on type of transplant lowest with RIC and highest with haplo/cord)

Clinical feature:

• Hematuria

Grading

• I – Microscopic
• II- Macroscopic
• III- With clots
• IV- Requiring instrumentation for clot evacuation or leading to urinary retention or requiring surgical intervention

Complications:

• Obstructive uropathy
• Hydronephrosis
• Tubulo interstitial nephritis
• Acute renal failure
• Bladder perforation

Prophylaxis: (Continuous irrigation is abandoned, due to high incidence of hematuria and infections. Some studies have shown, Mesna does not give additional protection if hydration and diuresis are adequate)

• Hydration – 3 lit/m²/day.It should be continued for 24hrs after the last cyclophosphamidedose
• Mesna- dose -1-1.5 x daily dose of cyclophosphamide, administered as bolus injections of 33 % of daily doses 0, 4 and 8 hrs, starting 10min beforecyclophosphamide. 

Treatment – 3 step approach

• Forced diuresis +  intensive platelet support
• Avoid use of aminocaproic acid, as it favors clot formation within bladder
• Continuous bladder irrigation
  • Done via transurethral or suprapubiccystostomy using saline
  • Several agents are tried for local instillation used such as
    • Formalin
    • Alum
    • Silver nitrate
    • Sodium hyalurunate
    • Prostaglandin E2
    • Fibrin glue
    • GMCSF
• Agents tried by systemic administration
  • Palifermin
  • Hyperbaric oxygen
  • Estrogen
  • Rec factor VII a
• Systemic / intra vesicle to reduce BK virus replication
  • Cidofovir
  • Ciprofloxacin
• Salvage approaches( If above techniques fail)
  • Selective embolization of bladder arteries
  • Catheterization of both ureters to rest the bladder
  • Hypogastric bond (May produce sexual impotence)
  • Cystectomy (Last resort)