Prognostic value of lactate in out-of-hospital cardiac arrest: a prospective cohort study

Abstract

Background: The prognostic role of lactate in out-of-hospital cardiac arrest (OHCA) remains unclear. Aims: To explore serum lactate as a predictor of return of spontaneous circulation in patients experiencing OHCA after arrival at hospital. Methods: This 13-month prospective observational cohort study involved patients aged ≥18 years. Serum lactate levels were measured during cardiopulmonary resuscitation before ROSC. Patients were divided into two groups by lactate level: Group 1, low (≤9.9 mmol/l) and Group 2, high (≥10 mmol/l). Findings: 105 patients were included, 50 in group 1 and 55 group 2. Median lactate were 7.4 mmol/l and 14.2 mmol/l respectively. More patients in group 1 were found with ventricular fibrillation (40% versus 14.5%; P≤0.01), obtained ROSC more quickly (37 minutes 38 seconds versus 39 minutes 13 seconds; P=0.79) and achieved short-term survival (survived >24 hours) (40% versus 23.5%; P=0.32), versus group 2; prediction of survival did not reach statistical significance. Conclusion: Lower lactate levels in OHCA appear to be associated with better short-term outcomes but the cut-off points regarding survival remain unclear.