Evaluation of Serum Lactate, Central Venous Saturation, and Venous-Arterial Carbon Dioxide Difference in the Prediction of Mortality in Postcardiac Arrest Syndrome.

Abstract

Tissue hypoperfusion and hypoxia markers predict mortality in critically ill patients. This study evaluates the ability of serum lactate, central venous oxygen saturation (Scvo 2), and venous-arterial carbon dioxide difference (GapCo 2) to predict mortality in patients with postcardiac arrest (post-CA) syndrome. A prospective observational study of patients with post-CA in a tertiary teaching hospital. Serial assessments of lactate, lactate clearance (Clac), GapCo 2, and Scvo 2 in the first 72 hours post-CA were analyzed. Adults (≥18 years) patients resuscitated from CA were included. The primary end point was 28-day mortality and secondary end points were 24- and 72-hour mortality. A total of 54 patients were recruited, 33 (61,1%) of 54 were men, with a 28-day mortality of 75.9%. Cardiac arrest occurred in-hospital in 84.6% of survivors and 97.5% of nonsurvivors. Lactate and Clac were significantly associated with mortality at 28 days, yielding an area under the receiver-operating characteristic curve of 0.797 (lactate 6 hours) and 0.717 (Clac 6 hours) with a positive predictive value of 96% for lactate 6 hours (> 2.5 mmol/L) and 89.5% for Clac 6 hours (<50%). Survival analysis confirmed the difference between the groups from the 24th hour post-CA. Considering mortality at 24 hours, lactate, Clac, and Scvo 2 (immediately post-CA, 6 and 18 hours) were different between the groups. In mortality at 72 hours, lactate, Clac, Scvo 2 (48 hours), and GapCo 2 (36 and 48 hours) were associated with mortality. In post-CA syndrome, serum lactate and Clac were consistently able to predict mortality.