Disorders Of The Renal And Urinary System Notes

Disorders of the Renal and Urinary System

1. Renal failure

Some key terms used in renal failure are listed below:

• Azotaemia: azotaemia refers to biochemical evidence of increase in the blood concentrations of non-protein nitrogenous waste, i.e. urea and creatinine.

• Uraemia: the constellation of adverse clinical signs caused by advanced renal failure or occasionally other causes of severe azotaemia .

• Isothenuria: isosthenuria refers to the excretion of urine with a specific gravity (concentration) is neither greater (more concentrated) nor less (more dilute) than that of protein-free plasma.

• Hyposthenuria: excretion of urine of low specific gravity (dilute) due to an inability of the tubules of the kidneys to produce concentrated urine.

• Hypersthenuria: excretion of urine of unusually high specific gravity and concentration of solutes, resulting usually from loss or deprivation of water.

• Oliguria: oliguria is the low output of urine.

• Anuria: anuria is the non-passage of urine.

• Polyuria: the excessive production or passage of urine.

• Polydipsia: excessive thirst and drinking.

Renal failure can be classed as pre-renal, renal or pot-renal. Pre-renal failure is a result of poor kidney perfusion, and may be as a result of cardiac failure or hypovolaemia. Renal failure is when the kidney itself is damaged and not functioning normally. Post-renal failure is due to an inability to void urine. This may be due to urinary obstructions or bladder rupture.

GFR and so renal clearance can be measured using inulin or creatinine. It is important to note that endogenous creatinine levels increase in renal failure, so creatinine excretion will not give an accurate representation of GFR.

Renal failure may also be acute or chronic. Acute renal failure is rare, and involves rapid deterioration of renal function. In some cases this may be reversible, but prognosis is poor. Acute renal failure is characterised by large, painful kidneys, lethargy, vomiting, dehydration and anuria.

Chronic renal failure is much more common. Progressive chronic renal failure is also called chronic interstitial nephritis. Chronic renal failure is irreversible, and clinical signs often aren’t apparent until there is significant loss of renal tissue. Clinical signs include polyuria and polydipsia, weight loss and non-regenerative anaemia. Non-regenerate anaemia occurs as erythropoietin normally...

Buy the full version of these notes or essay plans and more in our Urinary 1 Notes.