Initial hyperlactatemia in the ED is associated with poor outcome in patients with ischemic stroke

Background: Hyperlactatemia may be associated with poor outcome in patients with ischemic stroke because it reflects a state of tissue perfusion. This study aims to know whether initial hyperlactatemia in the emergency department (ED) is associated with poor outcome in patients with ischemic stroke. Methods: A retrospective observational study was performed in an urban tertiary hospital ED. Patients with an admission diagnosis of ischemic stroke were consecutively enrolled between April 1, 2010, and March 31, 2011. Lactate and glucose levels were obtained at the time of presentation to the ED, whereas the National Institutes of Health Stroke Scale score was assessed at the time of admission. Poor outcome was defined as a modified Rankin scale score greater than or equal to 2 at 3 months. The survival status at 3 months was also obtained. Hyperlactatemia was defined by lactate levels greater than 2 mmol/L. Results: A total of 292 patients were enrolled. At 3 months after stroke, 183 (62.7%) were considered to have poor outcomes, whereas 16 (5.5%) had died. Seventy (24.0%) had initial hyperlactatemia. Multivariable logistic regression analysis showed that hyperlactatemia was independently associated with a higher risk of poor outcome at 3 months (adjusted odd ratio, 2.15; 95% confidence interval, 1.06-4.37; P =.035) and a trend to death at 3 months (adjusted odd ratio, 4.31; 95% confidence interval, 0.91-20.56; P =.066). Conclusions: Among patients with ischemic stroke, initial hyperlactatemia represents an independent risk factor for poor outcome after controlling for stroke severity, risk factors, initial glucose level, and interval from onset of stroke symptoms to ED arrival.