Which of these is an example of postrenal acute kidney injury (AKI)?

Acute kidney injury (AKI) is categorized into prerenal, intrinsic, and postrenal causes. Postrenal AKI occurs due to an obstruction in the urinary tract downstream from the kidney, which impedes urine flow. This obstruction causes an increase in pressure within the urinary collecting system, leading to kidney damage. Benign prostatic hyperplasia (BPH) is a common cause of bladder outlet obstruction, where the enlarged prostate gland compresses the urethra. This blockage prevents urine from leaving the bladder, resulting in a classic example of postrenal AKI.

B. Heart failure causes prerenal AKI by reducing cardiac output and subsequent blood flow (perfusion) to the kidneys.
C. Dehydration is a cause of prerenal AKI, as volume depletion leads to decreased renal perfusion.
D. Renal vein thrombosis causes intrinsic AKI by inducing venous congestion and ischemic damage directly within the kidney tissue.

1. Saseen

J. J.

& MacLaughlin

E. J. (2020). Acute Kidney Injury. In J. T. DiPiro

G. C. Yee

L. M. Posey

S. T. Haines

T. D. Nolin

& V. Ellingrod (Eds.)

Pharmacotherapy: A Pathophysiologic Approach (11th ed.). McGraw-Hill. Chapter 42

Table 42-2 "Common Causes of Acute Kidney Injury

" classifies benign prostatic hyperplasia under "Postrenal AKI" and heart failure/dehydration under "Prerenal AKI."

2. Lameire

N.

Van Biesen

W.

& Vanholder

R. (2005). Acute renal failure. The Lancet

365(9457)

417–430. https://doi.org/10.1016/S0140-6736(05)17831-3. In Table 1

"Etiology of acute renal failure

" prostatic hypertrophy is listed as a cause of postrenal failure.

3. Levey

A. S.

& James

M. T. (2017). Acute Kidney Injury. Annals of Internal Medicine

167(9)

ITC66–ITC80. https://doi.org/10.7326/AITC201711070. The section "Etiology and Pathophysiology" states that postrenal AKI is caused by acute obstruction of the urinary tract

with prostatic disease being a common cause.