A 54-year-old man is admitted to the hospital with an acute myocardial infarction and goes into cardiac arrest. The patient is successfully resuscitated and transferred to the cardiac intensive care unit, where he is hemodynamically stable. On the second day of his hospitalization, however, his urine flow drops to 400 mL/day. The blood pressure is 115/68 mm Hg, and the pulse rate is 78 beats per minute. Laboratory results are as follows: Urine sediment microscopy reveals muddy brown casts. Which of the following renal structures are most likely to demonstrate signs of ischemic injury?

Question

A 54-year-old man is admitted to the hospital with an acute myocardial infarction and goes into cardiac arrest. The patient is successfully resuscitated and transferred to the cardiac intensive care unit, where he is hemodynamically stable. On the second day of his hospitalization, however, his urine flow drops to 400 mL/day. The blood pressure is 115/68 mm Hg, and the pulse rate is 78 beats per minute. Laboratory results are as follows:  Urine sediment microscopy reveals muddy brown casts.  Which of the following renal structures are most likely to demonstrate signs of ischemic injury?

Quizplus · Accepted Answer

Eductional Objective: Oliguria, increased serum creatinine, and muddy brown casts are symptoms of acute tubular necrosis, which can be caused by renal ischemia. Ischemic injury primarily affects the renal medulla, which has a poor blood supply. The most commonly involved parts of the nephron are the proximal tubules and the thick ascending limb of the loop of Henle.

A 54-Year-Old Man Is Admitted to the Hospital with an Acute