Study: Blood Test Enables Early Sepsis Detection at Louisiana Hospital
Cytovale’s IntelliSep test helped the hospital improve compliance with the controversial SEP-1 measure.
In a study of patients at an emergency department in Baton Rouge, Louisiana, a blood test designed for early detection of sepsis helped improve compliance with a controversial quality measure implemented by the US Centers for Medicare & Medicaid Services (CMS). Researchers reported that a treatment protocol incorporating Cytovale’s IntelliSep test increased the rate of compliance with SEP-1, a set of interventions recommended by CMS when a patient presents severe sepsis or septic shock. The study, which was funded by Cytovale, was presented Sept. 7 at the American College of Emergency Physicians (ACEP) conference in Salt Lake City.
“The clinical criteria for the SEP-1 bundle may not always support identification of sepsis early on in the progression of disease,” said principal investigator Hollis O’Neal, MD, medical director of research at Our Lady of the Lake Regional Medical Center (OLOLRMC) in Baton Rouge, in a press release from Cytovale. “IntelliSep, which looks at a patient’s immune dysregulation, has been a critical tool in helping us quickly identify patients during our initial ED triage who otherwise didn’t ‘look septic.’”
The Mayo Clinic describes sepsis as “a serious condition in which the body responds improperly to an infection. The infection-fighting processes turn on the body, causing the organs to work poorly.” In some cases, it can lead to septic shock, “a dramatic drop in blood pressure that can damage the lungs, kidneys, liver and other organs.”
A 2021 task force report from the Infectious Diseases Society of America (IDSA) stated that sepsis “is a major cause of hospital death in the United States and is associated with over 850,000 annual emergency department visits.” The report also noted “the inherent difficulty in establishing the early diagnosis of sepsis.”
The IntelliSep Test
Cytovale, based in South San Francisco, Calif., was founded in 2013 by researchers from MIT and UCLA. IntelliSep is the company’s primary product.
As explained by the company, sepsis causes changes to the biomechanics of white blood cells, including size, deformability, and how they behave in fluid.
In the IntelliSep test, a blood sample is loaded into a device that uses hydrodynamic forces, high-resolution imaging, and computer vision to analyze the cells’ biomechanical properties. The system then presents a numeric value that indicates if the patient has a low, medium, or high probability of sepsis.
The test takes about eight minutes to run. Cytovale cautions that “all results should be interpreted in the context of the other clinical observations and laboratory test results for the patient.”
The US Food and Drug Administration issued a 510(k) clearance for the test in January 2023.
Study Shows Improved Compliance
The OLOLRMC study, which involved 598 patients, measured the impact of the test on compliance the SEP-1 guidelines, which specify how sepsis cases should be managed. For example, clinicians are advised to measure a patient’s lactate level, collect a blood culture, and administer antibiotics within three hours after presentation of severe sepsis.
In July 2024, when the hospital began incorporating the test, SEP-1 compliance was 61.2%, the authors reported. By September, the rate had increased to 72.5%, and it increased to 78.9% by December. They reported that the test enabled clinicians to begin treating the highest-risk patients earlier, increasing the number who received recommended interventions within the three-hour window mandated by SEP-1.
“Unlike traditional approaches that may boost SEP-1 performance by broadly applying sepsis protocols—often at the cost of overtreatment—we integrated IntelliSep into our sepsis protocol to gain objective insight into sepsis risk, ensuring we deliver the SEP-1 bundle to the right patients from the start,” said study co-author Christopher Thomas, MD, of Our Lady Health System, in a press release from Cytovale. “This approach yielded significant results, enabling OLOL to achieve meaningful compliance gains in a short time.” (Photo credit: LSU Health Sciences Center)
Questioning SEP-1
The SEP-1 guidelines are controversial. CMS contends that they reduce hospital mortality. However, in 2023, a coalition of professional societies—including the IDSA, Society of Hospital Medicine, and American College of Emergency Physicians—urged the agency to retire SEP-1.
“The SEP-1 measure does not take into account that many serious conditions present in a similar fashion to sepsis,” they argued. “Pushing clinicians to treat all these patients as if they have sepsis leads to overuse of broad-spectrum antibiotics, which can be harmful to patients who are not infected, those who are infected with viruses rather than bacteria and those who could safely be treated with narrower-spectrum antibiotics.”
They also cited studies showing that SEP-1 has not improved patient outcomes. That position was bolstered earlier this year as a systematic literature review in Annals of Internal Medicine“found no moderate- or high-level evidence to support that compliance with or implementation of SEP-1 was associated with sepsis mortality,” according to the authors.
As noted in the Substack publication PulmCCM, CMS introduced SEP-1 in 2015 as a pay-for-reporting measure, meaning that hospitals were required to report compliance rates, but were not penalized for non-compliance. However, in 2023, CMS proposed making it a pay-for-performance measure as part of the Hospital Value-Based Purchasing Program. As a result, beginning in 2026, payments to hospitals will be adjusted based on their SEP-1 compliance rates.
—Stephen Beale
