Background:In critical patients, it has been proposed to measure the parameters derived from partial CO 2 pressures as indicators of adequate peripheral perfusion and tissue oxygenation. Its use in cardiac surgery (CC) with extracorporeal circulation (CPB) is not yet elucidated. Primary objective: To determine the utility of Dp v-a CO 2 and the quotient Dp v-a CO 2 /C a-v O 2 as indicators of cardiac output and anaerobic metabolism. As a secondary objective: to study the prognostic value of both, in adult patients undergoing CC with CPB. Methods: A literature search was carried out on: PubMed, EBSCOhost, LILACS, SciELO, COCHRANE and on the SCIENCE DIRECT website. 12 original articles were selected. Results: 7 studies analyzed the Dp v-a CO 2 and 2 the quotient Dp v-a CO 2 / C a-v O 2 . There was no relationship between these variables with the cardiac output, S v O 2 , S vc O 2 and lactate or this was statistically very weak, so its clinical relevance was questionable. 7 studies analyzed the prognostic value Dp v-a CO 2 and/or Dp v-a CO 2 /C a-v O 2 in terms of postoperative complications and/or morta-