COMPARISON BETWEEN THE VENOARTERIAL CARBON DIOXIDE DIFFERENCE AND LACTATE AS A MARKER IN SEPTIC SHOCK
Description
Background: The venoarterial carbon dioxide difference, or P(v-a)CO2, is a marker of tissue perfusion as well lactate. International guidelines use lactate as a target in management algorithms of patients with septic shock. Objective: Determine whether there is a difference in the behavior of P(v-a)CO2 and venous lactate in patients with septic shock during their evolution. Methods: A case-control study from a historical cohort was conducted. Results from 62 patients admitted to ICU in a third level hospital were included. They were divided into two groups based on their outcome (survivors or deaths). Lactate samples and P(v-a)CO2 calculation were collected every 24 hours from admission to discharge. The results were analyzed departing from the outcome. A Student’s T was performed on the samples of each day looking for a difference between both groups. A Pearson’s r was performed looking for a relationship between P(v-a)CO2 and lactate. Results: A significant elevation of lactate was found in deaths 2 days prior to the outcome (p.= 0.007). No significant difference in P(v-a)CO2 was found between the groups. No relationship between P(v-a)CO2 and lactate was found (r= 0.01). Conclusions: Lactate elevation before death may be an indicator of poor prognosis. Prior to outcome, P(v-a)CO2 does not act in the same way. Keywords: septic shock, venous-to-arterial carbon dioxide difference (P(v-a)CO2), lactate