Final answer:
Pre-renal azotemia involves elevated blood urea levels due to factors affecting blood flow to the kidneys. It commonly results from hypovolemia and is diagnosed by assessing serum creatinine and blood urea nitrogen levels along with symptoms such as oliguria.
Step-by-step explanation:
Features of Pre-renal Azotemia
The term pre-renal azotemia refers to a condition in which there is an increase in blood urea levels due to factors affecting the kidneys before disorders in the kidney tissue itself. It is a type of acute renal failure that occurs due to insufficient blood flow to the kidneys. Causes include situations that decrease blood volume, such as hypovolemia caused by shock, dehydration, fluid loss, or excessive use of diuretics. In pre-renal azotemia, the kidney function is not inherently defective but is impaired due to inadequate blood supply leading to reduced glomerular filtration rate (GFR) and increased urea concentration.
Diagnostics for renal failure typically include measuring serum creatinine and blood urea nitrogen levels, which are elevated in pre-renal azotemia. Oliguria, which is reduced urine output, is generally present and serves as an indicator of the condition along with clinical factors such as fluid overload, leading to an increased risk of developing hypertension and congestive heart failure. A detailed examination of a urine specimen and medical ultrasonography of the renal tract are essential components in diagnosing the cause of the acute renal failure.