Acute Renal Failure, Urinary Obstruction, and Elevated Psa: Slam Dunk Diagnosis?

1Wake Forest University School of Medicine, Winston Salem, NC

Meeting: Hospital Medicine 2013, May 16-19, National Harbor, Md.

Abstract number: 360

Case Presentation:

A 64‐year‐old man presented with a 4‐week history of abdominal fullness and urinary retention. He was recently seen at an urgent care clinic where he was diagnosed and treated for a UTI. He returned after symptoms persisted. Lab work at this visit showed significant acute renal failure. He was instructed to report to our hospital at this time. Patient had not been to a physician his entire life and had no reported medical history. He had mild abdominal fullness without tenderness but otherwise unremarkable physical exam. Vital signs were stable. Hemoglobin was 10.7 g/dL, platelets 77,000/μL, BUN 85, creatinine 7.86 mg/dL, Urine analysis was consistent with a UTI and PSA was 36.81. CT scan of the abdomen and pelvis revealed marked prostatomegaly. Patient had placement of a Foley catheter for urinary obstruction. Urology was consulted and recommended outpatient follow‐up with a Foley catheter in place when the patient was able to match output from his postobstructive diuresis. The patient was hemodynamically stable, doing well and desired to go home. On review of daily labs, however, his thrombocytopenia was worsening and was down to 34,000/μL by hospital day 4. Patient did not have any fevers during this hospitalization and did not have mental status changes. Workup for his anemia and thrombocytopenia revealed a elevated LDH of 468 U/L, low haptoglobin 4 mg/dL, and ADAMTS13 level < 3% (reference range, 66%–158%). A review of his peripheral smear confirmed the presence of schistocytes. A diagnosis of thrombotic thrombocytopenic purpura (TTP) was confirmed. Hematology was consulted and recommended emergent plasmapheresis. Patient continued plasmapheresis for several more days and was eventually discharged with continued hematology outpatient follow‐up.


Many hospitalists have encountered patients with TTP. TTP requires a high degree of suspicion and the threshold to initiate plasmapheresis should be very low, as it is a medical emergency. Some hospitalists, however, still associate the classic pentad of fever, acute renal failure, neurological symptoms, thrombocytopenia and microangiopathic hemolytic anemia (MHA) almost as a prerequisite for diagnosis. It is important to note that thrombocytopenia with associated MHA is enough evidence to initiate empiric therapy with plasmapheresis in the right clinical setting while workup is being done. TTP is caused by numerous triggers including malignancy associated factors. The etiology behind our patient's case is unclear as he does not have any confirmed malignancy or significant drug exposures.


This case highlights the importance of having a high degree of clinical suspicion for the diagnosis of TTP. In addition, this case shows the importance of keeping your differential open and recognizing there may be more than one pathological process behind a patient's presentation.

To cite this abstract:

Khan F. Acute Renal Failure, Urinary Obstruction, and Elevated Psa: Slam Dunk Diagnosis?. Abstract published at Hospital Medicine 2013, May 16-19, National Harbor, Md. Abstract 360. Accessed February 16, 2019.

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