Intrathecal lactate predicting hydrocephalus after aneurysmal subarachnoid hemorrhage.

BACKGROUND: Evidence shows possible benefits from continuous drainage by lumbar drain after aneurysmal subarachnoid hemorrhage (SAH). Under the hypothesis that compartmentalization occurs between the ventricle and subarachnoid space after massive SAH, this study aimed to evaluate the biochemical differences between ventricular and intrathecal cerebrospinal fluid (CSF) and assess the role of CSF lactate in shunt-dependent hydrocephalus (SDHC) after aneurysmal SAH. MATERIALS AND METHODS: Patients with modified Fisher grade III/IV aneurysmal SAH who underwent early obliteration were evaluated. Intrathecal and intraventricular CSF were obtained on day 7 post-SAH to measure their biochemical composition in terms of total protein, glucose, ferritin, and lactate. The associations of SDHC with the clinical parameters and CSF data were analyzed. RESULTS: There were 28 patients (mean age, 55.4 y; males, 46.6%), including 18 (64.3%) with SDHC. Intrathecal CSF had significantly higher levels of total protein, ferritin, hemoglobin, and lactate but lower glucose level than intraventricular CSF (all P < 0.0001). By multivariate analysis of clinical and CSF parameters, elevated intrathecal CSF lactate (P = 0.036) and the presence of intraventricular hemorrhage (P = 0.05) were independent factors associated with SDHC. Moreover, intrathecal lactate >5.5 µM effectively predicted the occurrence of SDHC (odds ratio: 32, 95% confidence interval: 3.8-270.8; P = 0.0015). CONCLUSIONS: By compartmentalization of the subarachnoid space after SAH, intrathecal lactate level is a useful predictive parameter for long-term SDHC in patients with aneurysmal SAH patients.