Delta neutrophil index versus lactate clearance: Early markers for outcome prediction in septic shock patients

Abstract

BackgroundThis study was carried out to evaluate, compare the clinical utility of delta neutrophil index (DNI) values and lactate-6h-clearance as early indicators for outcome prediction in septic shock patients and to find out and correlate the specificity and sensitivity of each to the patient's mortality. MethodsThe study was carried out in Alexandria Main University Hospital on 53 adult patients with severe sepsis/septic shock after taking an informed written consent and approval of the ethics committee. All patients received all standard therapy and resuscitation measures. Arterial blood samples were obtained for measurement of DNI using an ADVIA 2120 automated cell analyzer. Initial arterial serum lactate level and arterial lactate after 6h from admission were measured for lactate-6h-clearance calculation. Primary outcome measures were hospital mortality (non-survivors) and discharge or transfer to a general medical ward (survivors). Data were analyzed by SPSS® software using (“t” test and chi-square χ2) P<0.05 was considered significant. ResultsA total of 53 severe sepsis/septic shock patients were enrolled in the study, patients were (36) survivors and (17) non-survivors. This study demonstrated the reliability of DNI and lactate-6h-clearance as predictors of negative outcome. Variables identified by the backward logistic regression model as significantly correlated with negative outcome were lactate-6h-clearance <15%; (sensitivity, 92.5%; specificity, 85.0%; positive predictive value, 90.0%; and negative predictive value, 88.0%) and DNI value >5.2; (sensitivity, 95.0%; specificity, 90.0%; positive predictive value, 92.0%; and negative predictive value, 95.0%). ConclusionMonitoring of lactate-6h-clearance can be used to identify patients with severe sepsis/septic shock at high risk of mortality. DNI may serve as a more useful diagnostic and prognostic marker for early diagnosis of disease severity in patients with severe sepsis/septic shock, it is suggested that, increased DNI value should alert clinicians to apply more aggressive therapy.