Student research inspired by grandmotherís close call
In May 2007, on the morning of my college graduation, I sat with my grandmother in her room at Vanderbilt University Hospital. I was dressed in my cap and gown and stopped in to see her before heading to Alumni Lawn for the ceremony. Hearing her voice and seeing her smile was the best graduation present I could have asked for.
My grandmother’s illness had surprised us all. At 82 years old, she had been the picture of health—active in her community and church, an avid gardener and world traveler, and the matriarch of our large family. A month before my graduation, this suddenly changed.
My grandmother had been hospitalized with abdominal pain, bloody diarrhea and vomiting. Initial studies suggested infectious colitis, but her stool culture came back negative, leading her doctors to consider other non-infectious diagnoses. Over the next few days, my grandmother’s white blood cell count rose, her hemoglobin and platelet count dropped, and she developed renal failure and altered mental status.
My father, a surgeon, began to suspect hemolytic-uremic syndrome (HUS), a life-threatening condition usually caused by E. coli infection. Could the stool culture have been wrong?
Upon transfer to a regional hospital she was quickly diagnosed with ischemic colitis. My family was told that if her colon were not removed immediately, she could be dead within the hour. My grandmother underwent emergent total colectomy, but six days later remained comatose and dialysis-dependent. My father remained suspicious of HUS, especially after discovering that my grandmother had eaten undercooked meatloaf three days prior to her illness.
He reviewed the literature and learned that HUS is almost always caused by food borne infection with Shiga toxin-producing E. coli (STEC). The most common STEC serotype, O157:H7, is routinely tested for in most clinical laboratories. However, recent studies suggest that 20 percent to 50 percent of STEC infections may be caused by different serotypes. Testing for these requires a different type of assay unavailable at many labs, including the one at my grandmother’s hospital. Her negative stool culture probably hadn’t been wrong; it was just the wrong test.
My grandmother’s nephrologist began a trial of plasmapheresis, a process that filters toxins from the blood and which may be beneficial in HUS. My grandmother’s renal function began to improve, and four days later she woke up from her coma. She was transferred to Vanderbilt for the remainder of her care, where I was able to visit her the morning of commencement. Amazingly, my grandmother made a complete recovery.
In July 2007 I returned to Vanderbilt as a first-year medical student. During the first and second years, all students complete a research project as part of the Emphasis Program. When it came time for me to choose my research topic, my grandmother’s experience immediately came to mind. If she had been tested initially for all STEC serotypes, might the course of her illness have been different? Why wasn’t this test available in her hospital’s laboratory? With these questions in mind, I set out to survey all clinical laboratories in Tennessee regarding their STEC detection protocols.
My results were alarming, but not altogether surprising. The Centers for Disease Control (CDC) recommends that labs include the tests for all STEC serotypes in all of their routine stool cultures. However, I found that only 11 percent of Tennessee labs were fully adherent to the CDC’s recommendations.
Last fall, my grandmother’s case report and the results of my survey were published in the journal Emerging Infectious Diseases.
I hope that by sharing my grandmother’s story with the medical community, other patients will benefit from her close call. For my part, it was incredibly rewarding to take a topic of personal interest and follow it through from study design to publication. I met fantastic mentors and discovered an interest in quality-improvement research that I hope to pursue further during residency.
In May, I graduated from Vanderbilt University School of Medicine, and my grandmother was there, this time in the audience.
Lane Crawford, M.D., will be doing her Internal Medicine internship at Vanderbilt, followed by an Anesthesiology residency at Massachusetts General Hospital.