A diagnosis of sepsis can sound like a horror story. When bacteria get into your blood stream, your body mobilizes every defense it has. But even then, without treatment you can die within two days.
The problem with sepsis is that diagnosis itself can take two to fifteen days. With a mortality time frame of two days, that doesn’t leave any room for error. A research group in the Texas Tech University Department of Chemistry & Biochemistry has developed a quick and novel diagnostic test to fix this problem.
Sepsis is one of the leading causes of death in hospitals, where patients usually contract the illness. Immuno-compromised patients end up with a runaway response from their immune system if they contract sepsis on top of another illness or surgery recovery. When the immune system is over stimulated, the initial response is systemic inflammatory response syndrome. This initial reaction is the body getting the immune system ready to fight the bacteria overrunning the body. As the syndrome progresses, the body enters sepsis and finally septic shock, where blood pressure crashes, organs fail and the patient eventually dies.
If caught early, sepsis is easily treatable with a heavy dose of antibiotics. Doctors initially look for increased temperature and rapid heartbeat and breathing. If sepsis is suspected, a patient is usually treated before the confirming diagnostic test, a bacterial culture, is done. Bacterial culture can take anywhere from two to fifteen days to confirm a case of sepsis. Obviously, if doctors were to wait this long, their patient would be long gone.
“It is estimated there are 1 million new cases of sepsis in hospitalized patients per year in the United States,” said Dr. John Griswold, professor and chair emeritus in the Department of Surgery at the Texas Tech University Health Sciences Center. “Sepsis is the leading cause of death in intensive care units in the United States, and patients with the diagnosis of sepsis have a minimum of a 30 percent chance of dying of their disease; if their vital organ systems – brain, heart, lungs, liver, kidneys – are affected, they have a 70 percent chance of dying. The elderly have the highest rate and, in some studies, death is over 85 percent in those over the age of 75.”
Dimitri Pappas, an associate professor of chemistry, and graduate student Ye Zhang have been able to create a novel diagnostic test to identify sepsis in hours instead of days to weeks. The test could essentially halt the serious threat that sepsis brings to hospitals. Using microfluidics, Pappas and Zhang built tiny chips that allow very small volumes of liquid to travel through channels, separating out single cells and proteins.
The chips are designed to identify a certain type of white blood cells using only a single drop of blood. The user can apply a specific dye to the chip that would highlight the white blood cells that activate an immune response to infection. Using this method, a sepsis diagnosis can be confirmed in four hours.
“That rapid detection will let doctors intervene sooner and intervene when necessary, but it also allows them not just to detect it but to follow up treatment,” Pappas said. “If a patient is septic and they’re identified as such, and then you give them this heavy course of antibiotics, you can follow and retest them over time to make sure the body’s response is returning to normal.”
This type of test can be broadly distributed to hospitals everywhere. For now, the chip will be tested at the Health Sciences Center in Lubbock starting this month.
Sources: Texas Tech News
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