The role of Glucose/Potassium Ratio and Neutrophil/Lymphocyte Ratio in the prognosis of patients with aneurysmal subarachnoid hemorrhage.

Antecedents and objective: Aneurysmal subarachnoid hemorrhage (aSAH) is associated with high morbidity and mortality. Traditional factors strongly associated with poor outcome are neurological condition and the amount of bleeding. Inflammation is considered a relevant mechanism of brain injury after aSAH. This study aims to investigate the potential role of new laboratory indexes related to inflammation for predicting the prognosis of aSAH patients, complementing established prognostic models.

Materials and methods: We conducted a retrospective observational study including adults admitted for aSAH at a single neurosurgery center from 2002 to 2023. Demographic data, clinical parameters, and blood test results at admission were collected. The main outcome variable was Glasgow Outcome Scale (GOS) six month post-bleeding. A second outcome variable was in-hospital mortality. Univariable analyses were performed to identify new laboratory predictors of poor prognosis. The independent association with outcome was evaluated after adjustment of traditional risk factors by logistic regression analysis. The additional value of new laboratory predictors was determined by comparison of the area under the receiver operating curve (AUROC).

Results: Among 542 patients with aSAH, 417 met inclusion criteria (age >18 years old and complete laboratory test available upon admission with aSAH confirmed by CT angiography (CTA) or digital subtraction angiography (DSA)). Elevated glucose/potassium ratio (GKR) in the first blood test at admission was significantly associated with unfavorable outcome and in-hospital mortality according to univariate analysis. The GKR was significantly associated with a worse final prognosis (OR 1.033, 95% CI 1.008-1.040) adjusted for age, WFNS and Fisher scales, history of diabetes mellitus and kidney disease, and prior use of diuretics, oral antidiabetic medications and insulin. Additionally, the inclusion of the GKR improved the predictive accuracy of a prognostic model compared to a model including only clinical and radiological data. The neutrophil-lymphocyte ratio (NLR) was not significantly different between subgroups of patients regarding their outcome.

Conclusion: GKR measured in the first 24 h after aSAH may improve the discrimination of patients with higher risk of experiencing poor outcome at six month after the bleeding.