Predictors of mortality in post-neurosurgical Gram-negative bacterial meningitis: a five-year retrospective study

Abstract

Introduction: The incidence of Gram-negative bacterial meningitis (GNBM) has increased with the growing number of neurosurgical procedures. Concurrently, global antimicrobial resistance, particularly among Gram-negative pathogens causing healthcare-associated infections, has contributed to high morbidity and mortality. This study aimed to identify clinical and laboratory parameters associated with mortality in post-neurosurgical GNBM (PN-GNBM).

Methodology: This retrospective study included adult patients who developed GNBM at least 48 hours after a neurosurgical procedure in the intensive care unit of a tertiary hospital between January 2019 and March 2024. Clinical findings and laboratory results before and at the time of diagnosis were obtained from the hospital information system. The factors associated with all-cause 28-day mortality were evaluated. Statistical analyses were performed using SPSS version 19, with p < 0.05 considered statistically significant.

Results: A total of 21 PN-GNBM patients were included. The 28-day mortality rate was 60%. Evaluation of peripheral blood leukocyte ratios at the time of diagnosis revealed that a low lymphocyte-to-platelet ratio (LPR) significantly predicted mortality on days 7, 14, and 21 (p = 0.046, 0.003, and 0.005, respectively), whereas a high neutrophil-to-lymphocyte ratio (NLR) predicted 14-day mortality (p = 0.035). Acinetobacter baumannii was the most frequently isolated pathogen with 81.81% carbapenem resistance rate.

Conclusions: NLR and LPR are inexpensive and readily accessible biomarkers that may support early mortality prediction and risk stratification in PN-GNBM. These preliminary findings should be validated in larger multicenter studies.