Which is a laboratory feature of Prerenal azotemia?

In prerenal azotemia, hemoconcentration results in elevation of the hematocrit and total protein/albumin, calcium, bicarbonate, and uric acid levels from baseline values. Urinary findings include the following: Oliguria (urine volume < 500 mL/day) or anuria (< 100 mL/day) High specific gravity (> 1.015)

What happens to creatinine in Prerenal azotemia?

Pre-renal failure, also called pre-renal azotemia (PRA), is described as a reversible increase in serum creatinine and urea concentrations resulting from decreased renal perfusion, which leads to a reduction in the glomerular filtration rate (GFR) [6].

Which test may be used to diagnose azotemia?

Azotemia is usually diagnosed by using urine and blood tests. These tests will check your blood urea nitrogen (BUN) and creatinine levels.

Why is BUN creatinine ratio high in Prerenal azotemia?

Prerenal azotemia refers to elevations in BUN and creatinine levels resulting from problems in the systemic circulation that decrease flow to the kidneys. The decreased renal flow stimulates salt and water retention to restore volume and pressure.

Why is urine osmolality high in Prerenal azotemia?

In contrast, a urine osmolality above 500 mosmol/kg is highly suggestive of prerenal AKI because it usually reflects both a hypovolemic stimulus to the secretion of antidiuretic hormone and the maintenance of normal tubular function.

Why is urine sodium low in Prerenal failure?

The urine sodium concentration tends to be low in prerenal AKI (<20 mmol/l) as the kidney appropriately attempts to conserve sodium and high in intrarenal AKI (>40 mmol/l) due in part to the adverse effects of the tubular injury on sodium reabsorption.

Why does BUN increase in Prerenal azotemia?

The BUN:Cr in prerenal azotemia is greater than 20. The reason for this lies in the mechanism of filtration of BUN and creatinine. Renal Plasma Flow (RPF) is decreased due to hypoperfusion which results in a proportional decrease in GFR.

Why is Bun Cr ratio high in Prerenal?

The BUN/Cr ratio is normal at 10 to 15:1 in ATN (intrarenal), but is often greater than 20:1 in prerenal disease due to the increase in the passive reabsorption of urea that follows the enhanced proximal reabsorption of sodium and water .

Why is BUN creatinine ratio high in Prerenal AKI?

The ratio is predictive of prerenal injury when BUN:Cr exceeds 20 or when urea:Cr exceeds 100. In prerenal injury, urea increases disproportionately to creatinine due to enhanced proximal tubular reabsorption that follows the enhanced transport of sodium and water.

How do you differentiate pre renal renal and post renal azotemia?

Prerenal azotemia can usually be distinguished from renal azotemia by clinical signs (evidence of dehydration or hypovolemia), urinalysis (urine should be “adequately” concentrated i.e. > 1.030 in the dog, > 1.040 in the cat, > 1.025 in large animals; usually with no evidence of renal tubule dysfunction such as …

What is elevated in azotemia?

Azotemia is a biochemical abnormality, defined as elevation, or buildup of, nitrogenous products (BUN-usually ranging 7 to 21 mg/dL), creatinine in the blood, and other secondary waste products within the body.