Urea and Creatinine Analysis: Recognizing and Managing Renal Failure

Urea and Creatinine Analysis: Recognizing and Managing Renal Failure

1. Pre-renal Renal Failure:

• Symptoms: Increased urea and creatinine.

• Cause: Decreased fluid volume, reducing glomerular filtration rate (GFR).

• Management: Fluid replacement to raise blood pressure and increase GFR.

• Note: Pre-renal failure is functional renal failure, where the kidneys are not actually damaged.

2. Intrinsic Renal Failure:

• Symptoms: Increased urea and creatinine, but Ure/Cre ratio < 50, BUN/Cre < 10.

• Cause: Physical damage to the kidneys, for example: acute tubular necrosis, drug-induced nephrotoxicity (aminoglycosides), etc.

• Management: Fluid restriction, even diuretics, avoid excessive fluid replacement that can cause acute pulmonary edema.

• Note: Intrinsic renal failure is actual renal failure, where the kidneys are damaged.

3. Recognizing the type of renal failure through Ure/Cre and BUN/Cre ratio:

• Pre-renal failure: Ure/Cre > 100, BUN/Cre > 20.

• Intrinsic renal failure: Ure/Cre < 50, BUN/Cre < 10.

4. Assessing renal failure based on FENa:

• FENa < 1%: Pre-renal failure.

• FENa > 2%: Intrinsic renal failure.

5. Hormones that cause hyperglycemia:

• Cortisol

• Catecholamine

• Glucagon

6. Osmotic Diuresis:

• Hyperglycemia increases blood osmotic pressure, urine excretes more glucose, increasing urinary osmotic pressure.

• Symptoms: Increased urination, thirst, can lead to severe dehydration.

7. Principles of managing increased osmotic pressure:

• Fluid replacement to increase blood volume.

• Insulin to lower blood sugar.

• Potassium correction.

8. Calculating blood osmotic pressure:

• Osm = 2Na + Glucose.

• Increased blood osmotic pressure: Osm > 320.

9. Evaluating glomerular filtration function:

• Urea is reabsorbed in the proximal convoluted tubule, making it inaccurate for GFR assessment.

• Creatinine is secreted slightly in the renal tubules, making it more accurate than urea.

10. Renal failure due to Aminoglycoside use:

• Aminoglycosides are toxic to the renal tubules, causing glomerular-tubular dissociation, leading to non-oliguric acute renal failure.

Note:

• The above information is for reference only and cannot replace medical advice.

• If you suspect you have renal failure, please see a doctor for diagnosis and timely treatment.