Urinary Tract Pathology Case Studies


CASE 7: Acute tubular necrosis with ethylene glycol poisoning


Clinical History:

This 46-year-old homeless man was found in a stuporous condition one morning by the owner of an auto parts store. Apparently the man had broken into the store. A half empty container of antifreeze was found next to him (go to any store that sells automobile antifreeze to view the container warning label). The owner called paramedics, who transported him to a local hospital, where he was admitted. It was soon noted that he had no urine output. His serum BUN and creatinine, which were 25 mg/dL and 1.5 mg/dL respectively on admission, continued to rise. He died a week later.
  1. What is the diagnosis?

    2. This is acute tubular necrosis due to ethylene glycol poisoning. Alcoholics will sometimes drink anything that smells like alcohol. Ethylene glycol is a nephrotoxin.

  2. What histopathologic findings are present in the kidney?

    3. The tubules are dilated and the tubular epithelium shows vacuolization. In addtion, there are many scattered calcium oxalate crystals.

    Note: most cases of acute tubular necrosis are due to ischemia from hypotension (usually from heart failure).

  3. What are potential ethical concerns in treating a patient who had premeditated this event and willfully consumed the antifreeze?

    The ethical issue is that we are almost by definition treating someone who does not want to be treated. What if the patient asks us to stop? Or has an advance directive making that request?

    The short answer is that the very act of attempting suicide changes the usual presumption of capacity. Intervening to prevent a successful suicide is thus generally valid.

    But what if the damage is great, and now there is no chance of really saving the life of the person and restoring the patient to prior function, but only keeping the patient alive in a significantly diminished state? And what if the patient's family agrees with the patient, or advanced directives? There are no absolute rules here: the initial intervention may have been justified, but that does not require that we continue maximal efforts. There will be cases where a suicide attempt is not initially successful, but did enough organ damage that it is reasonable to stop treatment and let the patient die.