Understanding High Urea Levels in Newborns: Causes & Explanations

1. Prerenal azotemia:

- occurs when there is inadequate perfusion to the kidneys, decreasing glomerular filtration rate.

- Causes:

- Severe dehydration

- Shock

- Renal artery stenosis

- Drugs (NSAIDs, ACE-I)

2. Renal azotemia:

- occurs when there is direct damage to the kidneys causing the tubules to have decreased ability to reabsorb solutes (like sodium and chloride), concentrating the urine.

- Causes:

- Acute tubular necrosis

- Renal cysts

- Obstructive uropathy

3. Postrenal azotemia:

- caused by obstruction of the flow of urine from the kidneys to the outside world, usually resulting in bilateral hydronephrosis.

- Causes:

- Posterior urethral valves

- Pyeloureteral junction (UPJ) obstruction

- Urethral atresia