Abstract 24: Association Between Serum Lactate During Cardiopulmonary Resuscitation and Survival in Adult Out-Of-Hospital Cardiac Arrest: A Multicenter Cohort Study (The Critical Study in Osaka, Japan)

Abstract

Background: Serum lactate reflects hypoxic insult in many conditions, but its role as prognostic markers after cardiac arrest is still controversial. This study aimed to investigate the association between serum lactate levels during cardiopulmonary resuscitation (CPR) and survival in patients with out-of-hospital cardiac arrest (OHCA). Methods: This study analyzed the data of the Osaka Comprehensive Registry of Intensive Care for OHCA Survival, a prospective multicenter observational study of 14 participating institutions in Osaka Prefecture, Japan. We enrolled consecutive patients aged ≥18 years who were transported to the hospital with ongoing CPR from 2013 to 2016. Based on the serum lactate levels, OHCA patients were divided into 4 quartiles: Q1 (lactate ≤10.6 mEq/L), Q2 (10.6< lactate ≤14.1 mEq/L), Q3 (14.1< lactate ≤18.0 mEq/L) and Q4 (lactate >18.0 mEq/L). The relationships between serum lactate level before return of spontaneous circulation (ROSC) and 1-month survival were assessed. Results: A total of 3,674 OHCA patients were included in the analysis. Overall 1-month survival was 2.3% (88/3,674). The Q1 group had the highest 1-month survival (4.6% [42/921]), followed by Q2 (2.7% [25/920]), Q3 (1.1% [11/966]) and Q4 (0.6% [5/867]), respectively (p for trend < 0.001). In the multivariable logistic regression analysis, the proportion of 1-month survival in the Q4 group was significantly lower, compared with that in the Q1 group (adjusted odds ratio 0.23; 95% confidence interval 0.09 to 0.60). The adjusted proportion of 1-month survival decreased in a stepwise manner across increasing quartiles (p for trend <0.001). In a subgroup analysis by initial rhythm, there was a significant interaction (p=0.003) between the rhythms: 1-month survival of OHCA patients presented with a non-shockable rhythm decreased when the lactate levels increased (p for trend < 0.001), but in patients with a shockable rhythm the similar trend was not observed (p for trend = 0.574). Conclusions: The high serum lactate level before ROSC significantly associated with the worse 1-month survival after OHCA. Serum lactate may be one of the effective prognostic indications for OHCA during CPR, especially with non-shockable initial rhythm.