Intrinsic Acute Renal Failure

Causes of Intrinsic Acute Renal Failure

Tubulointerstitial diseases

• • Hypersensitivity reactions to medications: PCN, sulfonamides, fluoroquinolones, chemotherapeutic agents, NSAIDs

  • Light chains in multiple myeloma

  • Autoimmune processes: Sarcoidosis, Sjogren's synd, lymphoma.

  • Associated with infections: Legionella, Toxoplasma, CMV, EBV

  • Exposure to organic solvents

  • Pyelonephritis

Glomerular diseases

• • Nephrotic syndrome: Most commonly occurs in children and results from significantly increased basement membrane permeability with heavy or nephrotic range proteinuria, >3.5 g/day. Nephrotic range proteinuria is often glomerular in nature. Excreted primarily as albumin. Hypoalbuminemia decreases oncotic pressure and may be expressed as fluid accumulation in interstitial tissues: periorbital and facial edema, peripheral edema, anasarca, pleural effusions, and ascites. BP is usually normal. HLP and lipiduria occur secondary to increased hepatic production and impaired clearance. Mild hematuria can occur, but often the basement membrane has enough integrity to trap RBCs. Nephrotic synd. is associated with hyperocoagulable state; the most common being thromboembolic complications including renal vein thrombosis.

    • Minimal change disease

      • does not progress to chronic renal failure

    • FSGS

      • Immunoglobulin and complement deposition detected by immunofluorescence

    • Membranous nephropathy

      • Rule of thirds for membranous GN: One third progress to CRF, one third have spontaneous remission, one third remain nephritic and do not progress.

      • Caused by immune complex deposition

      • Idiopathic, SLE, Hep-B

    • Diabetic nephropathy (diffuse glomerulosclerosis, nodular glomerulosclerosis)

  • Nephritic syndrome: clinical definition involves abrupt onset hematuria with RBC casts, mild proteinuria, often included HTN, edema, and azotemia. Nephritic synd represents inflammatory responses characterized by glomerular capillary damage and rupture leading to edema, hematuria with dysmorphic RBCs, mild to moderate proteinuria <3.5 g/day, HTN, and uremia. Variable renal insufficiency may develop with azotemia and oliguria. If RBCs are trapper in the urinary casts, bleeding probably originated in the nephron and nephritic synd is more likely; RBC casts are an indication of glomerulonephritis.

    • RPGN

      • Also called crescentic GN

      • Pauci-immune GN: 50% of RPGN where no immune

    • PSGN

      • Inf with nephritogenic strains of group A beta hemolytic streptococcus (usually associated with preceding pharyngitis or impetigo)

      • Immune complex deposition with complement (IgG, C3, C4) in a granular pattern

      • 10 - 30% adults and 1% children will develop RPGN

      • 24-h protein usually between 0.5 - 2 g/day

      • RBC casts in urine

      • ASO positive within 1 - 2 weeks in post pharyngitis PSGN

      • Hypocomplementemia of C3 and C4 during active phase, returning to normal within 6 weeks. If PSGN is membranoproliferative type, complement level will not return to normal.

    • IGA nephropathy

    • Membranoproliferative GN

    • Postinfectious glomerulonephritis

    • Focal glomerulosclerosis associated with AIDS

  • Secondary (multisystem associated) glomerular diseases

    • Collagen vascular disorders

      • PAN

      • SLE

      • Wegener's granulomatosis

      • Henoch-Shonlein purpura

    • Hematologic disorders:

      • TTP

      • HUS

      • serum sickness

    • Glomerular basement membrane disease

      • Alport's syndrome

      • Goodpasture's syndrome

      • Thin basement membrane disease

Acute tubular necrosis

• • Ischemia, hypotension, septicemia, postoperative patients

  • Direct drug toxicity:aminoglycosides, cisplatin, amphotericin, contrast agents, cyclosporine

  • Myoglobin or hemoglobin

  • Renal cortical necrosis

  • ATN in pregnancy

  • Hypercalcemia

Vascular disease

• • Renal artery occlusion

  • Acute vasculitis

  • Malignant HTN

  • Atheroembolic disease, multiple cholesterol emboli syndrome