Can admission laboratory results aid in early prognostication after aneurysmal subarachnoid hemorrhage? - A prospective cohort study.

OBJECTIVES: Although routine admission laboratory tests are universally obtained and may reflect systemic responses to acute brain injury, their incremental prognostic value beyond established clinical and radiological predictors remains incompletely evaluated. We examined whether admission laboratory parameters improve prediction of clinically relevant outcomes after aSAH. METHODS: We analyzed a prospectively collected registry of consecutive adults with angiographically confirmed aSAH treated at a single tertiary care center between 2014 and 2022. Admission laboratory values obtained within 24 h were extracted from routine blood testing. Four outcomes were assessed: delayed cerebral ischemia (DCI), DCI-related infarction, in-hospital mortality, and unfavorable functional outcome at 12 months (modified Rankin Scale 4-6). Predictive modelling was conducted in two stages. First, 28 laboratory parameters were individually added to a base logistic regression model including Hunt & Hess grade, modified Fisher scale, age, sex, intracerebral hemorrhage, and aneurysm circulation territory. Model improvement was assessed using likelihood ratio tests with false discovery rate correction and change in area under the receiver operating characteristic curve (ΔAUC). Second, biologically defined hepatic/tissue injury (AST, ALT, LDH) and renal function (urea, creatinine) clusters were evaluated in combined models. RESULTS: Of 357 patients, 298 (83.5%) had admission laboratory data available and formed the analytical cohort. The base model showed good discrimination across outcomes (AUC 0.71-0.83). AST was the only individual parameter associated with outcome after correction for multiple testing, modestly improving prediction of DCI (ΔAUC +0.024). Cluster modelling showed that hepatic/tissue injury markers improved prediction of DCI (ΔAUC +0.028, p = 0.013), whereas renal function markers improved prediction of in-hospital mortality (ΔAUC +0.018, p = 0.010). No laboratory parameter or cluster improved prediction of DCI-related infarction or 12-month functional outcome. CONCLUSION: Routine admission laboratory parameters provide modest, outcome-specific prognostic information after aSAH. Hepatic and tissue injury markers were associated with DCI risk, while renal function markers improved prediction of in-hospital mortality. Overall, admission laboratory tests add limited predictive value beyond established clinical and radiological severity markers. TRIAL REGISTRATION: German registry of clinical trials - Deutsches Register Klinischer Studien - DRKS00030505 (https://drks.de/search/en/trial/DRKS00030505).