Neutrophil-to-Lymphocyte Ratio as a Prognostic Marker for Hospital-Acquired Infections in Neurosurgical Patients

Renata Jabłońska,1 Robert Ślusarz,1 Magdalena Zając,2 Agnieszka Królikowska,1 Karolina Filipska-Blejder,1 Paweł Sokal3 1Faculty of Health Science, Department of Neurological and Neurosurgical Nursing, Department of Interventional Nursing, Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University in Toruń, Bydgoszcz, Poland; 2Department of Pedagogy, Kazimierz Wielki University, Bydgoszcz, Poland; 3Faculty of Health Science, Department of Neurosurgery, Functional and Stereotactic Neurosurgery, Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University in Toruń, Bydgoszcz, PolandCorrespondence: Renata Jabłońska, Faculty of Health Science, Department of Neurological and Neurosurgical Nursing, Department of Interventional Nursing, Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University in Toruń, 1 Łukasiewicza St., Bydgoszcz, 85-821, Poland, Tel +48 605417833, Email renjab_1@wp.plPurpose: The neutrophil-to-lymphocyte ratio (NLR) is an inflammatory marker associated with adverse outcomes, including hospital-acquired infections (HAIs) and mortality. This study evaluated its prognostic value in neurosurgical patients.Patients and Methods: In this retrospective study of 5474 neurosurgical admissions, 147 HAIs occurred in 93 patients (HAIs group). A control group of 181 patients was matched for age, sex, and mortality status. Clinical (Nutrition Risk Screening 2002 [NRS-2002], Glasgow Coma Scale [GCS]) and demographic variables were compared with NLR. Survival was analyzed using Kaplan–Meier curves. Statistical tests included chi-square, Mann–Whitney, ANOVA, log-rank.Results: Patients with HAIs (58.1% male, mean age 63.7 ± 15.5 years) more often had malnutrition risk (NRS ≥ 3: 65.6% vs 11.0%, p < 0.001) and severe neurological impairment (GCS 3– 8: 31.2% vs 8.8%, p < 0.001) than controls. Median length of hospital stay was longer in HAIs (40 vs 5.4 days, p < 0.001). Mean NLR was higher in HAIs (9.25 ± 6.11) than controls (7.99 ± 5.21, p = 0.0001), peaking at 12.78 in patients with central nervous system tumors. An NLR ≥ 17.7 predicted in-hospital mortality with 57.1% sensitivity and 89.4% specificity. In controls, mortality increased significantly above this threshold (χ2 = 14.83, p = 0.00012), whereas in HAIs the association was not significant. NLR was not linked to hospital stay.Conclusion: NLR is a cost-effective marker predicting in-hospital mortality in neurosurgical patients without HAIs, with ≥ 17.7 identifying high-risk cases. Its prognostic value in HAIs is limited and requires multicenter validation.Keywords: neurosurgery, inflammatory biomarkers, hospital-acquired infection, prognosis, survival analysis