Admission Glucose-to-Potassium Ratio and MOST-Based Mortality Risk Category in Severe Traumatic Brain Injury Undergoing Craniotomy: A Retrospective Observational Study

Abstract

Background. The admission glucose-to-potassium ratio (GKR) combines the hyperglycemic and hypokalemic arms of the post-traumatic stress response, but its relation to mortality-risk scores in surgically treated severe traumatic brain injury (TBI) is unexamined in Indonesia.

Objective. To relate admission GKR to the Mortality Score for TBI (MOST) risk category and to compare observed in-hospital mortality with published benchmarks.

Methods. Retrospective observational study of 95 adults (18–60 years; Glasgow Coma Scale ≤8) undergoing craniotomy at Dr. Moewardi Regional General Hospital, Surakarta (March–August 2024). GKR was admission glucose (mg/dL) divided by potassium (mmol/L); risk was graded with MOST. Analyses comprised Spearman correlation, Kruskal–Wallis tests, exact benchmark tests and a sensitivity analysis over all datasets consistent with the observed summaries.

Results. Median GKR rose from 26.94 (low risk, n = 4) to 35.21 (moderate, n = 86) and 55.67 (high, n = 5) and correlated with MOST (ρ = 0.376; 95% CI 0.189–0.537). Every high-risk GKR exceeded every low-risk value (exact p = 0.016). GKR was not demonstrably more strongly correlated than glucose (ρ = 0.329). Potassium declined linearly (p = 0.018; ANOVA p = 0.059, Kruskal–Wallis p = 0.033). In-hospital mortality was 4.2% (95% CI 1.6–10.3), below all five published benchmarks. The attainable area under the curve for high risk was 0.436–0.898; associations of death with MOST stratum, sex and pupils were not identified.

Conclusion. Admission GKR tracked the MOST risk category and separated the extreme strata, but its discrimination and superiority over glucose need patient-level validation against observed outcomes.