Changes in central venous-to-arterial carbon dioxide tension induced by fluid bolus in critically ill patients

PLoS One. 2021 Sep 10;16(9):e0257314. doi: 10.1371/journal.pone.0257314. eCollection 2021.

Abstract

Background: In this prospective observational study, we evaluated the effects of fluid bolus (FB) on venous-to-arterial carbon dioxide tension (PvaCO2) in 42 adult critically ill patients with pre-infusion PvaCO2 > 6 mmHg.

Results: FB caused a decrease in PvaCO2, from 8.7 [7.6-10.9] mmHg to 6.9 [5.8-8.6] mmHg (p < 0.01). PvaCO2 decreased independently of pre-infusion cardiac index and PvaCO2 changes during FB were not correlated with changes in central venous oxygen saturation (ScvO2) whatever pre-infusion CI. Pre-infusion levels of PvaCO2 were inversely correlated with decreases in PvaCO2 during FB and a pre-infusion PvaCO2 value < 7.7 mmHg could exclude a decrease in PvaCO2 during FB (AUC: 0.79, 95%CI 0.64-0.93; Sensitivity, 91%; Specificity, 55%; p < 0.01).

Conclusions: Fluid bolus decreased abnormal PvaCO2 levels independently of pre-infusion CI. Low baseline PvaCO2 values suggest that a positive response to FB is unlikely.

Publication types

  • Observational Study

MeSH terms

  • Aged
  • Aged, 80 and over
  • Area Under Curve
  • Arteries*
  • Blood Gas Analysis
  • Carbon Dioxide / blood*
  • Cardiac Output
  • Critical Illness*
  • Fluid Therapy
  • Humans
  • Middle Aged
  • Oxygen
  • Prospective Studies
  • Pulmonary Gas Exchange
  • Sensitivity and Specificity
  • Treatment Outcome
  • Veins*

Substances

  • Carbon Dioxide
  • Oxygen

Grants and funding

The authors received no specific funding for this work.