Monocyte Distribution Width
Monocyte Distribution Width (MDW), proprietary to Beckman Coulter analyzers, is the only regulatory-cleared hematological biomarker that helps to establish severity of infection and risk of sepsis in adult patients in the emergency department. MDW is a measure of increased morphological variability of monocytes in response to bacterial, viral or fungal infections.
MDW is reported automatically as part of a routine CBC with Differential test on the DxH 900 and DxH 690T hematology analyzers using the Early Sepsis Indicator (ESId) application*, which enables automatic reporting with no workflow changes or need to order an additional test.
Diagnostic Uncertainty
Clinicians are faced with time pressures to make early risk stratification decisions for patient disposition and treatment initiation. Clinicians must triage patients and quickly determine where they need to go. In many cases, the patients may be discharged home or, perhaps, missed to taken ICU, but rather to the general ward – and both scenarios are associated with increased mortality - higher mortality in patients discharged to the general ward (42.7%) or home (61.6%) vs. ICU (29.5%).2-3 Initial disposition home of emergency department patients with potential sepsis results in twice the mortality and 4x healthcare costs per patient.1
Diagnostic uncertainty is a major challenge for patients presenting to the emergency department with a low number of signs and symptoms. Over 30% of septic shock patients that present with vague symptoms may be missed by the EMR alerts, encounter longer time to antibiotics, and experience worse outcomes.4
Mitigate Diagnostic Uncertainty
MDW is available early in-patient assessment to help determine patient acuity and risk of sepsis.

What Makes MDW Unique?
- Monocyte Activation is a common physiological signal in severe infection and sepsis
- MDW is backed by rigorously designed patient trials and several rounds of in-depth review to meet the standards required for FDA-clearance and CE mark
- MDW has been studied for the past decade with more than 15 peer-review publications and over 11,000 patients6-15, confirming the robustness and reproducibility of MDW performance in different patient populations
- MDW helps reduce diagnostic uncertainty. It is available early to enhance the initial risk assessment and potentially shift your clinical decision point helping clinicians escalate or de-escalate care
Add Value to Your Emergency Department’s Triage Protocol with MDW
FDA-Cleared
MDW, proprietary to Beckman Coulter analyzers, is the only FDA-cleared hematological biomarker that helps to establish severity of infection and risk of sepsis in adult patients in the ED.
Available Early
MDW helps reduce diagnostic uncertainty. It is available early to help clinicians escalate or de-escalate care in patients with suspected infectious etiology.
CBC Diff
MDW is available early in patient assessments as part of CBC with Differential tests—no need to order additional tests.
MDW Patient Case Studies
T-47 Minutes to Antibiotics Administration
MDW biomarker identified a risk of severe infection and reclassified the patient into higher acuity category in conjunction with current standard of care.

Abnormal MDW 27.3 Changed Patient’s Trajectory
The inclusion of monocyte distribution width (MDW) biomarker in the clinical thought process helped physicians to uncover an underlying infection which could have otherwise been missed leading to inappropriate therapeutic interventions. We can prevent sepsis by preventing evolution of infection to sepsis.

Blog What is Monocyte Distribution Width?
A large unmet clinical need for the early detection of sepsis exists. MDW is a novel, FDA-cleared biomarker intended to meet this need.
Read blogPeer-Reviewed Clinical Study MDW Improves SIRS and qSOFA Early Sepsis Detection in the Emergency Department
New analysis from a pivotal study shows that patients with abnormal MDW values at presentation have increased odds of sepsis.
Read studyWebinar The Science Behind Early Sepsis Indicator: Why Do Monocytes Matter?
Learn how monocytes contribute to the development of sepsis and discover the scientific evidence behind MDW.
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- S. Fernando et al., Emergency Department Disposition Decisions and Associated Mortality and Costs in ICU Patients with Suspected Infection, Crit Care 2018; 22,172. https://doi.org/10.1186/s13054-018-2096-8
- E. Rivers et al., Early and Innovative Interventions for Severe Sepsis and Septic Shock: Taking Advantage of a Window of Opportunity, CMAJ 2005; 173(9):1054-65. https://doi.org/10.1503/cmaj.050632
- A. Vijayan et al., Procalcitonin: A Promising Diagnostic Marker for Sepsis and Antibiotic Therapy, Journal of Intensive Care 2017; 5:51. https://doi.org/10.1186/s40560-017-0246-8
- M. Filbin et al., Presenting Symptoms Independently Predict Mortality in Septic Shock: Importance of a Previously Unmeasured Confounder, Critical Care Medicine 2018; 46(10), 1592-1599. https://doi.org/10.1097/ccm.0000000000003260
- UniCel DxH 900 Coulter Cellular Analysis System Early Sepsis Indicator (ESId) Application Addendum PN C42014AC April 2020
- E. Piva et al., Monocyte Distribution Width (MDW) Parameter as a Sepsis Indicator in Intensive Care Units, Clin Chem Lab Med 2021. https://doi.org/10.1515/cclm-2021-0192
- P. Hausfater et al., Monocyte Distribution Width (MDW) Performance as an Early Sepsis Indicator in the Emergency Department: Comparison with CRP and Procalcitonin in a Multicenter International European Prospective Study, Crit Care 2021; 25, 227. https://doi.org/10.1186/s13054-021-03622-5
- A. Woo et al., Monocyte Distribution Width Compared with C-Reactive Protein and Procalcitonin for Early Sepsis Detection in the Emergency Department, PLoS ONE 2021; 16(4): e0250101. https://doi.org/10.1371/journal.pone.0250101
- H. Lin et al., Clinical Impact of Monocyte Distribution Width and Neutrophil-to-Lymphocyte Ratio for Distinguishing COVID-19 and Influenza from Other Upper Respiratory Tract Infections: A Pilot Study, PLoS ONE 2020 15(11): e0241262. https://doi.org/10.1371/journal.pone.0241262
- L. Agnello et al., Monocyte Distribution Width (MDW) as a Screening Tool for Sepsis in the Emergency Department, Clin Chem Lab Med 2020; 58(11):1951-1957. https://doi:10.1515/cclm-2020-0417
- G. Riva et al., Monocyte Distribution Width (MDW) as Novel Inflammatory Marker with Prognostic Significance in COVID‑19 Patients, Scientific Report 2021; 11:12716. https://doi.org/10.1038/s41598-021-92236-6
- Marcos-Morales, A et al., Elevated monocyte distribution width in trauma: An early cellular biomarker of organ dysfunction, Injury 2021; S0020-1383(21):00933-00935. https://doi.org/10.1016/j.injury.2021.11.026
- E. Crouser et al., Monocyte Distribution Width: A Novel Indicator of Sepsis-2 and Sepsis-3 in High-Risk Emergency Department Patients, Critical Care Med 2019; 47:1018-1025. https://doi.org/10.1097/CCM.0000000000003799
- E. Crouser et al., Improved Early Detection of Sepsis in the ED with a Novel Monocyte Distribution Width Biomarker, CHEST 2017; 152(3):518-526. https://doi.org/10.1016/j.chest.2017.05.039
- A. Ognibene et al., Elevated Monocyte Distribution Width in COVID-19 Patients: The Contribution of the Novel Sepsis Indicator, Clinica Chimica Acta 2020; 509: 22-24. https://doi.org/10.1016/j.cca.2020.06.002