Pcv-aCO2/Ca-cvO2 Combined With Arterial Lactate Clearance Rate as Early Resuscitation Goals in Septic Shock

Abstract

Background: We aimed to investigate the prognostic significance of central venous-arterial carbon dioxide tension to arterial-central venous oxygen content ratio (Pcv-aCO₂/Ca-cvO₂) combined with arterial lactate clearance rate (LCR) as early resuscitation goals in septic shock.

Materials and methods: We enrolled 145 septic shock patients admitted to our department from March 2013 to May 2017 in this study. They all received an initial resuscitation therapy according to the Surviving Sepsis Campaign guideline, and were classified into 4 groups according to Pcv-aCO₂/Ca-cvO₂ and LCR at 6 hours after resuscitation (T6): Group A: Pcv-aCO₂/Ca-cvO₂ > 1.8, LCR < 30%; Group B: Pcv-aCO₂/Ca-cvO₂ > 1.8, LCR ≥ 30%; Group C: Pcv-aCO₂/Ca-cvO₂ ≤ 1.8, LCR < 30% and Group D: Pcv-aCO₂/Ca-cvO₂ ≤ 1.8, LCR ≥ 30%. General demographics, hemodynamic parameters, metabolic parameters, Acute Physiology and Chronic Health Evaluation II scores, Sequential Organ Failure Assessment scores, length of intensive care unit stay and 28-day mortality were compared among groups.

Results: Group D had the lowest Acute Physiology and Chronic Health Evaluation II and Sequential Organ Failure Assessment score at day 3, the shortest intensive care unit stay and the lowest 28-day mortality. Kaplan-Meier survival curves up to day 28 showed group D had the longest median survival time. Pcv-aCO₂/Ca-cvO₂ and LCR at T6 were independent predictors of 28-day mortality. The area under ROC curve for Pcv-aCO₂/Ca-cvO₂ combined with LCR was significantly greater than either Pcv-aCO₂/Ca-cvO₂ or LCR alone (both P < 0.05).

Conclusions: Combination of Pcv-aCO₂/Ca-cvO₂ ratio and LCR is better than either alone to predict the adverse outcomes in septic shock, and may provide useful information for assessing the adequacy of resuscitation in early-stage septic shock.

Keywords: Arterial-central venous oxygen content difference; Central venous-arterial carbon dioxide difference; Lactic clearance rate; Septic shock.