(1261) Correlating Point-of-Care Lactic Acid With Serum Lactic Acid in the Emergency Department

Introduction: Lactate is measured in hospital setting to identify patients with suspected sepsis who are “at risk” in addition to their clinical presentation. Serum lactate levels have been shown to correlate with serious adverse events, including mortality, and is useful in clinical decision making. Prompt recognition, treatment and deciding disposition is of utmost importance in managing patients with suspected sepsis. Studies have shown that Point of Care (POC) lactate is a reliable and feasible way to measure serum lactate at bedside. The use of POC lactate instead of serum lactate will help reduce cost, promote prompt interventions and decrease waiting time in the Emergency Department (ED).

Objective: To study the accuracy of POC lactate as compared to serum lactate sent to central laboratory.

Methods: Prospective cohort study of adult (age 18 years or older) patients who presented to the ED with suspected sepsis or severe sepsis. Setting: Urban tertiary care center ED. Blood drawn from a single venipuncture divided for both Serum Lactate and POC lactate. The serum sample was sent on ice to in-house laboratory. The POC was correlated with the lab test. The association between POC and lab lactate were analyzed using multiple linear regression. Additionally, Bland and Altman plots were used to assess the agreement between the two.

Results: There were 69 patients who had both POC and lab measurements of lactate were included in the study. The mean time between the lab draw and POC draw was 3.06 minutes (95% Confidence Interval(CI):1-4, SD:3.49mins). Time to result for lab draw was 52.03 mins (95% CI-39-63, SD-16.43). Spearman correlation for POC and laboratory lactate showed an R value of 0.969 ( 95% CI- 0.949 to 0.981) with a p value of < 0.0001.

Conclusions: The POC lactate value correlated extremely well with laboratory results of serum lactate and can be used reliably for clinical decision making. Furthermore, using POC values could potentially save significant time spent waiting for laboratory test to be resulted and thus implement treatments quicker. Further evaluation is necessary to see its impact on patient outcomes.