Cerebrospinal fluid red blood cells and total protein are associated with clinical outcome in spontaneous subarachnoid hemorrhage

Background and Purpose: Prognostication in patients with spontaneous subarachnoid hemorrhage (SAH) can be challenging. The aim of this study was to assess whether cerebrospinal fluid (CSF) red blood cell (RBC) count and total protein (TP) concentration are associated with SAH prognosis. Methods: Patients with SAH treated at the neurological intensive care unit (ICU) in Innsbruck were included in this real-world, observational study. Longitudinal CSF samples were collected as part of routine diagnostics. RBC count and CSF TP at the time of admission (RBCfirst, TPfirst), in Week 1 (RBCDays1-7, TPDays1-7), Week 2 (RBCDays8-14, TPDays8-14), and Week 3 or thereafter (RBCDay>14, TPDay>14), the highest detected value (RBChighest, TPhighest), as well as the RBC count adjusted for disease duration (RBCadjusted) were assessed. Primary outcomes were good functional outcome after 3 months, defined as modified Rankin scale score <= 2 and ICU survival. Results: A total of 183 SAH patients with a female predominance (69%), a median (interquartile range [IQR]) age of 60 (50-70) years and median (IQR) Hunt and Hess score of 4 (3-5) were included. Multivariable analyses revealed that lower values of RBCfirst, RBCadjusted, RBChighest, TPfirst and TPhighest were associated with good functional outcome and hospital survival. Lower TP concentrations in Weeks 1, 2 and 3 were associated with good functional outcome, and in Weeks 1 and 2 with ICU survival. Early RBC measurements (Week 1) were associated with good functional outcome and ICU survival. Conclusions: Low CSF RBC counts and TP concentrations were associated with good functional outcome and ICU survival in a real-world cohort of SAH patients requiring external ventricular drainage.