Renal failure

Pre-renal – disordered perfusion of a kidney which is structurally normal. Renal – damage to the renal parenchyma, sometimes secondary to pre-renal failure. Post-renal – disordered urinary drainage of both kidneys or of a single functioning kidney. Renal failure

Renal parenchymal failure Pre-glomerular disease: involving the small arteries and arterioles, eg. atheroembolism, malignant hypertension, vasculitis Glomerular disease: the most common cause of CRF; nephrotic vs. nephritic syndrome, the primary disease or part of a generalized systemic disease. Post-glomerular disease: involves the nephron beyond Bowman’s capsule and the interstitial tissue surrounding it, e.g. myeloma multiplex, tubular necrosis, interstitial nephrosis.

Post-renal failure Intraluminal obstruction Ureteric wall disease Extraluminal obstruction

Effects of renal failure Regulatory failure: volume regulation, acidosis, hyperkalemia, hyperphosphatemia. Excretory failure: uremia. Metabolic failure:  erythropoietin production,  vitamin D 3 hydroxylation,  renin production.

Time and renal failure Acute renal failure (ARF) Chronic renal failure (CRF):  end stage renal disease (ESRD) Acute-on-chronic renal failure Rapidly progressive renal failure

Acute renal failure Are there pre-renal factors? Are there post-renal factors? What is wrong in the kidney?

Pre-renal factors Pre-renal failure: Urine > 500mOsm/kg Urine [Na + ] < 20 mmol/L Renal failure: Urine < 500mOsm/kg Urine [Na + ] > 40 mmol/L

Post-renal factors