Understanding Sepsis Misdiagnosis

What Is Sepsis Misdiagnosis?

Failing to correctly identify or mistakenly identifying sepsis in a patient is among the most frequent and consequential diagnostic errors in modern medicine. Diagnosing sepsis correctly is notoriously difficult, and the stakes are exceptionally high.

Several factors contribute to the misdiagnosis of sepsis, including its nonspecific symptoms, time-sensitive nature, and pressure on clinicians to act quickly. Until recently, there were no objective diagnostic tests available to help clinicians determine whether a patient was experiencing the biologic dysfunction that defines sepsis. As a result, sepsis misdiagnosis remains alarmingly common—especially in Emergency Departments, where most patients with sepsis first seek care.

Historically, a key contributor to the difficulty of sepsis diagnosis is its vague presentation. Simply put, there is no consistent pattern of symptoms that definitively confirms or rules out sepsis. Without clear-cut signs, clinicians must rely on indirect markers such as elevated temperature or white blood cell count. But these indicators are unreliable: many patients showing these signs do not have sepsis, while up to one in eight patients who do may not show these signs at all. This uncertainty contributes to both diagnostic errors and delayed treatment.

The True Cost of Sepsis Misdiagnosis

Making matters worse, sepsis is a time-dependent emergency. Every hour of delayed treatment—especially for septic shock—can significantly increase the risk of death or irreversible organ failure. Many states now mandate that hospitals implement early-identification protocols. Additionally, CMS’s SEP-1 performance measure compels hospitals to follow a standardized care bundle for any patients ultimately diagnosed with sepsis.

However, the combination of vague clinical presentations and regulatory urgency often leads to both over- and under-diagnosis. Too often, patients without sepsis are treated for it, and many with true sepsis are missed—resulting in diagnostic errors, ineffective treatment, and worse outcomes.

Why Is Sepsis Misdiagnosed So Often?

The challenge of sepsis diagnosis becomes even more complex because many other critical conditions closely mimic sepsis. Some patients may actually be suffering from other life-threatening emergencies—like myocardial infarction, pulmonary embolism, withdrawal syndromes, or cardiogenic shock—that require very different treatment strategies.
When a patient is misdiagnosed with sepsis, doctors may initiate unnecessary therapies and delay essential treatment for the actual condition. Sepsis interventions like aggressive fluid resuscitation, broad-spectrum antibiotics, and invasive diagnostics like blood cultures and imaging, carry risks of their own, especially when not truly needed. Therefore, diagnostic errors in sepsis can create harm on both ends of the spectrum: overtreatment and missed diagnosis.

How Cytovale’s IntelliSep Can Prevent Sepsis Misdiagnosis

Preventing sepsis misdiagnosis requires a better method of identifying patients at risk—and confirming the presence of sepsis through an objective measure. An ideal solution would distinguish between a dangerous dysregulated immune response (which defines sepsis) and more localized infection or unrelated critical illnesses.

Cytovale’s IntelliSep test is designed to address this. The test analyzes structural changes in innate immune cells that occur when the body initiates the dysregulated response associated with sepsis. It then reports a quantitative score, the IntelliSep Index, ranging from 0.1 to 10.0. The score is stratified into three band categories where Band 1 indicates a low probability of sepsis and Band 3 indicates a high probability of sepsis.

Applied early in the Emergency Department, the test supports timely assessment of patients who present with signs of infection. This approach can facilitate earlier and more accurate sepsis diagnosis, improve allocation of sepsis-specific resources, and aid in the management of those at risk of septic shock or organ failure. It also helps avoid diagnostic errors by flagging patients whose symptoms resemble sepsis but are more likely due to an alternative, time-sensitive condition.

By helping to reduce both false positives and missed cases, IntelliSep provides a novel tool to address the persistent challenge of sepsis misdiagnosis.

Contact the Cytovale team to learn more about IntelliSep and how it can support your clinical decisions.