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Abstract

Introduction: Background: An increase in WBC accompanied by a specific increase in neutrophils especially immature neutrophils, referred to as a left shift, are associated with a bacterial infection. It has become such common knowledge that many textbooks simply state that in a bacterial infection one should expect an increase in WBC and a left shift. Objectives: To Compare Proven culture positive bacterial And viral infections With The The Left And Right Shifts To Determine if the 'shift' Is significant in sepsis patients. Methods: Study Was Completed At Level 1 Trauma Center And Urban, Teaching ED With 97,000 Annual Visits. A Retrospective Cohort Study Of All ED Patients Presenting Over 2 Years From 2009-2011 Who Had A Full WBC Count And Differential Performed On ED Admit With Necessary Supporting Medical Record Info Obtained Through The Azyxxi EMR ( Smith M And Microsoft, Redmond, WA). Viral Disease Was Confirmed With A Positive Viral Swab Or PCR And Bacterial Infection Was Confirmed With A Positive Blood Culture Or PCR. Sepsis Was Confirmed by admitting definition and positive blood culture. All included patients were analyzed for initial differential by manual count on CBC obtained on presentation to the ED. Results: A total of 205 bacterial infections and 107 viral infections met the strict criteria and were included during study period. There was a difference for Age and gender between the bacterial and viral groups: mean age: bacterial 62.2 years ( 95% CI: 51.4- 73.7) VS.. Viral: 44.5 yr (95% CI: 36.6-50.9) bacterial were 51% female and viral were 65% female. An elevated level of 8,000 neutrophils was 79% accurate for a Left Shift. Finding Left Shift in Septic Patients LEFT SHIFT =( neutrophil >75% and WBC > 10,000 Specificity for: 86% Sensitivity: 44%for bacterial sepsis. Right Shift = ( lymphocytes > 45% and WBC > 10,000) Not significant for viral infection, p = 0.67 Sens/Spec 27%/49%. Conclusions: In the presence of elevated WBC count, a Left Shift is a Fair predictive finding. In Sepsis patients, both WBC and Neutrophil are more consistent with WBC >10,000 and neutrophils > 75% to predict bacterial sepsis but the lymphocyte predominance or 'right shift' is not a significant finding and should be dropped from the ICU lexicon. Higher WBC values did not linearly correlate with more severe sepsis when compared to admitting SOFA scores.