Value of Central Venous to Arterial CO2 Difference after Early Goal-directed Therapy in Septic Shock Patients

David Theophilo Araujo; Vinicius Brenner Felice; Andre Felipe Meregalli; Gilberto Friedman

doi:10.5005/jp-journals-10071-23262

Value of Central Venous to Arterial CO₂ Difference after Early Goal-directed Therapy in Septic Shock Patients

Indian J Crit Care Med. 2019 Oct;23(10):449-453. doi: 10.5005/jp-journals-10071-23262.

Authors

David Theophilo Araujo¹, Vinicius Brenner Felice¹, Andre Felipe Meregalli¹, Gilberto Friedman¹

Affiliation

¹ Central ICU, Santa Casa Hospital, Porto Alegre, Rio Grande do Su, Brazil; Programa de Pós-graduação em Ciências Pneumológicas, School of Medicine, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Su, Brazil.

Abstract

Background and aims: Venous to arterial difference of carbon dioxide (Pv-aCO₂) tracks tissue blood flow. We aimed to evaluate if Pv-aCO₂ measured from a superior central vein sample is a prognostic index (ICU length of stay, SOFA score, 28th mortality rate) just after early goal-directed therapy (EGDT)comparing its ICU admission values between patients with normal and abnormal (>6 mm Hg) Pv-aCO₂. As secondary objectives, we evaluated the relationship of Pv-aCO₂ with other variables of perfusion during the 24 hours that followed EGDT.

Materials and methods: Prospective observational study conducted in an academic ICU adult septic shock patients after a 6-hour complete EGTD. Hemodynamic measurements, arterial/central venous blood gases, and arterial lactate were obtained on ICU admission and after 6, 18 and 24 hours.

Results: Sixty patients were included. Admission Pv-aCO₂ values showed no prognostic value. Admission Pv-aCO₂ (ROC curve 0.527 [CI 95% 0.394 to 0.658]) values showed low specificity and sensitivity as predictors of mortality. There was a difference observed in the mean Pv-aCO₂ between nonsurvivors (NS) and survivors (S) after 6 hours. Central venous oxygen saturation (ScvO₂) and Pv-aCO₂ showed significant correlation (R2 = -0.41, P < 0.0001). Patients with normal ScvO₂ (>70%) and abnormal Pv-aCO₂ (>6 mm Hg) showed higher SOFA scores. Normal Pv-aCO₂ group cleared their lactate levels in comparison to the abnormal Pv-aCO₂ group.

Conclusion: In septic shock, admission Pv-aCO₂ after EGDT is not related to worse outcomes. An abnormal Pv-aCO₂ along with a normal ScvO₂ is related to organ dysfunction.

How to cite this article: Araujo DT, Felice VB, Meregalli AF, Friedman G. Value of Central Venous to Arterial CO₂ Difference after Early Goal-directed Therapy in Septic Shock Patients. Indian J Crit Care Med 2019;23(10):449-453.

Keywords: Central venous saturation; Lactate; Mortality; Septic shock; Venous to arterial difference of CO2.