Association between Multidrug-Resistant Bacterial Infections, Inflammatory Hematological Indices, and Physiological Outcomes: A Predictive Analysis of Neutrophil-to-Lymphocyte Ratio, Platelet Indices, and Physiological Parameters in Bacterial Sepsis

Abstract

Background: Bacterial sepsis is still one of the most common causes of morbidity and mortality in intensive care units (ICUs) and the increasing emergence of multidrug-resistant (MDR) microorganisms only adds to the problem of prognosis and management. Identification of high risk patients early in the process is important for timely intervention. This study aimed to evaluate the predictive value of the Neutrophil to Lymphocyte Ratio (NLR), the Mean Platelet Volume (MPV), the Platelet Distribution Width (PDW) and the physiological parameters (heart rate, mean arterial pressure, respiratory rate) in the assessment of disease severity and outcome among patients with bacterial sepsis to further investigate the relationship between these variables and the presence of MDR infection.

Methods: The methods employed included a prospective cohort study at Abbottabad District Headquarters (DHQ) Hospital from January 2024 to December 2025. There were 150 adult patients diagnosed with bacterial sepsis who were enrolled. Demographic data and physiological parameters and hematological indices (NLR, MPV and PDW) were noted. To culture the blood for the presence of bacterial pathogens and their susceptibility to antimicrobial agents, blood cultures were ordered. In-hospital mortality and the development of septic shock were the main outcomes.

Resuls: The median age of the cohort was 58 years (IQR: 45-71), and there was a male predominance (58%). Acinetobacter baumannii and Klebsiella pneumoniae were the most prevalent MDR organisms, which were found in 41.3% (n=62) of patients. The NLR, MPV and PDW of patients with MDR infections were significantly higher than those with non-MDR infections (p=0.001, p=0.003 and p=0.01 respectively). A significant correlation was found between physiological parameters like increased heart rate, decreased mean arterial pressure and increased NLR and MPV. On multivariate analysis, an NLR > 12.5 (OR: 3.8, 95% CI: 2.1-6.9) and an MPV > 11.2 fL (OR: 2.9, 95% CI: 1.6-5.2) were identified as independent predictors of 28-day mortality. When added to physiological parameters (qSOFA score), NLR and MPV together showed the best predictive performance for mortality (AUC: 0.86) vs either of them alone.

Conclusion: The inflammatory hematological indices were significantly correlated with MDR infections and poor physiological status in sepsis, especially NLR and MPV. When used with clinical physiological markers, these simple, affordable markers can be used as a powerful tool for risk stratification and early identification of those patients at the highest risk for mortality, particularly in resource limited areas such as DHQ Abbottabad.