Patients with aneurysmal subarachnoid hemorrhage often present with early lactic acidemia, which is associated with both the clinical and radiographic grade of hemorrhage, according to a study published in Frontiers of Neurology.
Investigators retrospectively reviewed data of 105 consecutive patients with suspected aneurysmal subarachnoid hemorrhage who had serum lactate levels measured within 24 hours of hospital admission (n=105). The primary study objective was to determine the incidence rate of lactic acidemia when patients were admitted.
Additionally, investigators sought to determine specific factors that were positively and negatively associated with levels of lactate. The study also sought to determine whether patient outcomes, including delayed cerebral ischemia, mortality, discharge disposition, and vasospasm, were partially dependent on admission lactic acidemia.
Approximately 53% (n=56) of patients in the study cohort had elevated serum lactic acid levels (>2.2 mmol/L) on hospital admission. Lactic acid levels were positively associated with Hunt & Hess grade (P <.05), glucose (P <.05), troponin I (P <.05), white blood cells (P <.05), and external ventricular drain days (P =.05). The investigators also observed a negative association between lactic acid levels and ventilator-free days (r = -0.35).
Serum lactate at admission did not correlate with vasospasm or development of delayed cerebral ischemia. Patients who died during hospitalization typically had elevated lactic acid levels. Following adjustment for predictors of poor outcome, admission lactic acid was not significantly associated with inpatient mortality (odds ratio 0.97; 95% CI, 0.79-1.20; P =.80) and odds of being discharged home (odds ratio 1.00; 95% CI, 0.80-1.26; P =.97).
The retrospective nature as well as the small sample size represent the study’s primary limitations.
According to the investigators, levels of admission lactic acid “may help clinicians identify potentially reversible pathophysiologic processes, including hypovolemia.”
Poblete RA, Cen SY, Zheng L, Emanuel BA. Serum lactic acid following aneurysmal subarachnoid hemorrhage is a marker of disease severity but is not associated with hospital outcomes. Front Neurol. 2018;9:593.