Understanding the Lactate Test for Sepsis: Key Insights for Caregivers

Lactate Test for Sepsis: Is It Accurate for Early Diagnosis?

Sepsis is a life-threatening emergency that demands immediate diagnosis and intervention. However, early identification remains challenging, and delays significantly increase mortality. The lactate test for sepsis is widely used to assess tissue hypoperfusion, but it has critical limitations. This blog article examines the role of the lactate test in sepsis diagnosis, its drawbacks, and how IntelliSep offers a faster, more accurate alternative based on immune system activity.

What Is a Lactate Test for Sepsis?

A lactate test measures lactate in a blood sample, a byproduct of anaerobic metabolism—when cells lack sufficient oxygen. Elevated levels may signal tissue hypoperfusion, a hallmark of sepsis.¹^,²

The Surviving Sepsis Campaign recommends measuring serum lactate within three hours of presentation and repeating the test if levels are elevated.¹^,⁹ This is part of the broader early management strategy for sepsis patients.

What’s the Difference Between a Lactate Test and a Lactic Acid Test?

The terms lactate test and lactic acid test are used interchangeably. In blood, lactic acid exists mostly as lactate—the form that laboratory tests measure.³^,⁴ These tests are used to evaluate conditions like shock, hypoxia, and metabolic disorders, including sepsis.

What Do Lactate Test Results Mean?

Typical lactate levels range from 0.5 to 2.2 mmol/L.³ Elevated lactate, especially over 2 mmol/L, can suggest impaired oxygen delivery to tissues—but it’s not specific to sepsis.²^,⁹

Lactic acid levels can rise due to intense physical activity, liver dysfunction, certain medications, or other non-septic causes.³^,⁴ This complicates the test’s reliability. When lactate values exceed 4 mmol/L, the risk of death in sepsis patients significantly increases.¹⁰

Limitations of the Lactate Test for Sepsis Detection

Despite its clinical use, lactate testing presents multiple limitations:
• Low specificity: Not all sepsis patients present with elevated lactate.¹
• Nonspecific triggers: Elevated lactate may stem from non-septic causes like strenuous exercise or liver disease.¹
• Need for repetition: Guidelines suggest repeated testing if lactate levels remain high.¹^,⁵^,⁹
• Fluctuation over time: Lactate levels can vary; processing delays or differing clearance rates may impact results.¹^,⁵^,⁹
• Diagnostic ambiguity: The influence of external factors and test variability complicate interpretation.¹^,⁷
Because of these limitations, clinicians—especially in emergency departments—need a more reliable diagnostic tool than lactic acid tests or serum lactate alone.

A Faster, More Accurate Sepsis Test: IntelliSep

IntelliSep® analyzes the mechanical properties of white blood cells to detect immune dysregulation—the defining feature of sepsis.⁸¹⁸ This innovative blood test delivers results in about 8 minutes.⁶^,⁷
Rather than focusing on metabolic byproducts like blood lactate, IntelliSep assesses the immune system’s behavior, offering more precise data for identifying sepsis patients.
Key clinical benefits include:

• Three-tier risk banding to guide triage
• 97.5% negative predictive value, helping providers confidently rule out sepsis⁸^,¹¹
• Improved clarity compared to nonspecific lactic acid markers

Case Study:

At a large regional medical center and teaching hospital in the South, IntelliSep was integrated into the ED’s sepsis protocol with powerful outcomes:

• 30% reduction in risk-adjusted sepsis mortality¹²
• Reduced blood draws, saving 30–40 nursing hours per month¹²
• Reduced hospital length of stay by over a day¹³
• $1,429 per patient tested in estimated cost savings¹³

Following this success, IntelliSep has been adopted in multiple U.S. emergency departments across 5 states, earning accolades for innovation and cost-effectiveness.¹⁴⁻¹⁶

Looking Ahead: Evolving Sepsis Diagnosis

While the lactate test for sepsis remains a valuable part of sepsis management, its limitations—especially the need to interpret elevated lactate within context—underscore the need for complementary solutions.
IntelliSep offers a faster, more precise alternative by identifying sepsis-related immune dysfunction rather than relying on elevated lactate levels caused by multiple potential triggers.
Conclusion

For emergency departments and clinicians seeking to enhance early sepsis diagnosis, IntelliSep delivers results grounded in immune science—making it a powerful complement to traditional lactate testing.
Interested in improving your emergency department’s sepsis response? Contact the Cytovale team to learn more.

References:
1 Rhee C, Murphy MV, Li L, Platt R, Klompas M; for the Centers for Disease Control and Prevention Prevention Epicenters Program. Lactate testing in suspected sepsis: trends and predictors of failure to measure levels. Crit Care Med. 2015;43(8):1669-1676. doi:10.1097/CCM.0000000000001087

2 Lee SM, An WS. New clinical criteria for septic shock: serum lactate level as new emerging vital sign. J Thorac Dis. 2016;8(7):1388-1390. doi:10.21037/jtd.2016.05.55

3 UCSF Health. Lactic Acid Test. https://www.ucsfhealth.org/medical-tests/lactic-acid-test. Accessed March 19, 2025.

4 MedlinePlus. Lactate Test. https://medlineplus.gov/lab-tests/lactate-test/. Accessed March 19, 2025.

5 Gicheru B, Shah J, Wachira B, Omuse G, Maina D. The diagnostic accuracy of an initial point-of-care lactate at the emergency department as a predictor of in-hospital mortality among adult patients with sepsis and septic shock. Front Med. 2023;10:1173286. doi:10.3389/fmed.2023.1173286

6 Cytovale. Sepsis is a Medical Emergency that is Common, Costly, and Difficult to Diagnose. Cytovale. https://cytovale.com/our-solution/intellisep-sepsis-test/. Accessed March 19, 2025.

7 Respiratory Therapy. $100M Funding to Boost Rollout of FDA-Cleared Sepsis Test. Respiratory Therapy. October 10, 2024. https://respiratory-therapy.com/disorders-diseases/critical-care/sepsis/100m-funding-boost-rollout-fda-cleared-sepsis-test/. Accessed March 19, 2025.

8 Dark Daily. 10-Minute Blood Test Uses Digital Images and AI to Determine Sepsis Risk for Emergency Room Patients. September 16, 2024. https://www.darkdaily.com/2024/09/16/10-minute-blood-test-uses-digital-images-and-ai-to-determine-sepsis-risk-for-emergency-room-patients/. Accessed March 19, 2025.

9 Radiometer Medical. Lactate as an aid in sepsis diagnosis and management.
https://www.radiometer.com/en/diagnostics/sepsisdetection/lactate. Accessed March 19, 2025.

10 Espinosa K, Brown SR. Serum Lactate Testing to Predict Mortality in Patients with Sepsis. Am Fam Physician. 2021;103(5):309-310.

11 Philpott J. Cytovale’s sepsis diagnostic test demonstrates 97.5% NPV in latest study. Clinical Trials Arena. May 3, 2024. https://www.clinicaltrialsarena.com/news/cytovales-sepsis-diagnostic-test-demonstrates-97-5-npv-in-latest-study/. Accessed March 19, 2025.

12 CDI Strategies. News: AI-powered diagnostic test reduces sepsis deaths by 20% at Louisiana hospital. July 11, 2024;18(28). https://acdis.org/articles/news-ai-powered-diagnostic-test-reduces-sepsis-deaths-20-louisiana-hospital. Accessed March 19, 2025.

13 Clinical Lab Products. Cytovale’s Sepsis Diagnostic Triages First 5,000 Patients. June 24, 2024. https://clpmag.com/disease-states/sepsis/cytovales-sepsis-diagnostic-triages-first-5000-patients/. Accessed March 19, 2025.

14 Cytovale. Cytovale Recognized as One of Modern Healthcare’s 2024 Best in Business. PR Newswire. December 09, 2024. https://www.prnewswire.com/news-releases/cytovale-recognized-as-one-of-modern-healthcares-2024-best-in-business-302325914.html. Accessed March 19, 2025.

15 Cytovale. Accelerated Demand for Cytovale’s FDA-Cleared Sepsis Detection Solution, IntelliSep® to Drive Growth in 2025. PR Newswire. January 09, 2025. https://www.prnewswire.com/news-releases/accelerated-demand-for-cytovales-fda-cleared-sepsis-detection-solution-intellisep-to-drive-growth-in-2025-302346589.html. Accessed March 19, 2025.

16 Modern Healthcare. Cytovale Best Business 2024 Laboratory Medicine.
https://www.modernhealthcare.com/awards/cytovale-best-business-2024-laboratory-medicine. Accessed March 19, 2025.

17 Leisman DE, Angel C, Schneider SM, D’Amore JA, D’Angelo JK, Doerfler ME. Sepsis Presenting in Hospitals versus Emergency Departments: Demographic, Resuscitation, and Outcome Patterns in a Multicenter Retrospective Cohort. J Hosp Med. 2019;14(6):340-348. doi:10.12788/jhm.3188

18 Singer M, Deutschman CS, Seymour CW, et al. The Third International Consensus Definitions for Sepsis and Septic Shock (Sepsis-3). JAMA. 2016;315(8):801-810. doi:10.1001/jama.2016.0287