Band Counts Should Be Deleted from Sepsis Guidelines
The 2012 International Guidelines for Management of Severe Sepsis and Septic Shock were published in Critical Care Medicine 2013;41:580-637. Table 1 lists the diagnostic criteria for sepsis. Inflammatory variables include:
- Leukocytosis (WBC count >12, 000 per µL)
- Leukopenia (WBC count < 4000 per µL)
- Normal WBC count with greater than 10% immature forms
- Plasma C-reactive protein more than two SD above the normal value
- Plasma procalcitonin more than two SD above the normal value
The problem with the third bullet point is that most laboratories stopped reporting manual band counts on adult patients more than 10 years ago because it is a time-consuming, non-specific, inaccurate, and imprecise laboratory test. The 95% confidence interval for a 10% band count is 4 to 18%. Most studies of suspected bacterial infection in adults have demonstrated poor performance of the band count as a diagnostic test, with unacceptably low sensitivity and/or specificity.
A review of the literature lends little support for the clinical utility of the band count in patients greater than three months of age. The total white blood cell count and absolute neutrophil count have been repeatedly shown to be much better predictors of bacterial infection, to which the band count adds no additional useful information. For these reasons, most clinical laboratories in the United States have ceased to report band counts.
Most modern hematology instruments can be programmed to report Left Shift when they detect an increased number of bands while performing an automated white blood cell differential count. For example, Sysmex XN9000 can be programmed to report Left Shift when the band count is >10% and/or the IG% (immature granulocytes) is >4%. Immature granulocytes include metamyelocytes, myelocytes and promyelocytes. Sepsis guidelines should be updated to replace band counts with Left Shift.
