Association between 30-day mortality and serially measured hematologic markers in patients with septic shock in South Korea.

BACKGROUND: Hematologic markers derived from complete blood counts have emerged as potential cost-effective prognostic indicators. Sepsis-induced left ventricular diastolic dysfunction (LVDD) is associated with increased mortality rates. We evaluated the predictive value of serially measured hematologic markers for 30-day mortality and their relationship with LVDD in patients with septic shock. METHODS: This retrospective cohort study analyzed adult patients diagnosed with septic shock in the emergency department of a university hospital between March 2014 and May 2018. Serial neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio, and lymphocyte-to-monocyte ratio (LMR) values were recorded from admission to day 5. The relationship between hematologic markers and LVDD was evaluated in patients who underwent transthoracic echocardiography (TTE). RESULTS: In total, 431 patients were included, with a 30-day mortality rate of 12.5%. The NLR on day 5 and NLR day 5/day 1 ratio had the highest predictive performance (area under the receiver operating characteristic curve [AUROC], 0.743 and 0.746, respectively). Similarly, the LMR on day 5 and the LMR day 5/day 1 ratio showed strong prognostic value (AUROC, 0.707 and 0.753, respectively). In the subgroup analysis of 204 patients who underwent TTE, a higher NLR at admission was significantly associated with LVDD (odds ratio, 1.016; 95% CI, 1.000-1.031; P=0.043). CONCLUSIONS: Serial measurements of the NLR and LMR showed better predictive value for 30-day mortality in patients with septic shock than measurements from a single time point. These findings support the use of hematologic markers as adjunctive tools for risk stratification of patients with septic shock.