Serial blood lactate measurements and its prognostic significance in intensive care unit management of aneurysmal subarachnoid hemorrhage patients.

PURPOSE: This study assesses the behavior of serial blood lactate measurements during intensive care unit (ICU) stay to identify prognostic factors of unfavorable neurological outcomes (UO) in patients with aneurysmal subarachnoid hemorrhage (SAH).

METHODS: We retrospectively reviewed all patients who were consecutively hospitalized with SAH between 2009 and 2016. Arterial blood lactate levels were routinely obtained on admission and every 6h in the ICU. Univariate/multivariate analyses were performed to identify independent predictors of UO (modified Rankin scale of 3-6 upon hospital discharge).

RESULTS: There were 145 patients with 46% of UO. Initially, increased lactate levels reached maximum levels during the first 24h and then decreased to within the normal range. Then, the levels slightly increased again to within the normal range for the next 24h, especially in UO. On multiple regression analysis, lactate levels measured at 24h, and 48h after admission were strong predictors of UO. Lactate level measured at 48h after admission demonstrated the greatest accuracy and the highest specificity (area under the curve, 0.716; sensitivity, 40%; specificity, 92.1%).

CONCLUSIONS: The lactate level at 48h after admission was the most accurate predictor of UO with a high specificity in SAH patients.