Assessment of macro- and micro-oxygenation parameters during fractional fluid infusion: A pilot study

J Crit Care. 2017 Aug;40:91-98. doi: 10.1016/j.jcrc.2017.03.021. Epub 2017 Mar 27.


Purpose: The main goal of this study was to assess whether maximal fluid infusion improves both oxygen delivery (DO2) and micro-circulatory parameters during hemodilution. The secondary objective was to assess the ability of baseline micro-circulatory parameters to predict oxygen consumption (VO2) response following fluid infusion.

Materials and methods: In a postoperative cardiac ICU, patients received repeated fluid infusion until stroke volume (SV) was maximized. Before and after each fluid expansion, macro- (DO2, VO2) and micro-circulatory oxygenation parameters were recorded [central venous oxygen saturation (ScVO2), blood lactate, difference in veno-arterial carbon dioxide tension (P(v-a)CO2), somatic and cerebral oxygen saturation (rSO2)]. Patients were classified as VO2-Responders or VO2-Non-Responders according to an increase in VO2 above or below 15%, respectively.

Results: After maximal fluid infusion, all patients showed improved macro- and micro-circulatory oxygenation parameters, but VO2-Responders had lower values (especially for ScVO2 and cerebral rSO2). Only baseline ScVO2 and cerebral rSO2 were useful to predict the VO2 response to maximal fluid infusion (ROCAUC 0.80 (95% CI: 0.54-0.95, P=0.012) and 0.83 (95% CI: 0.57-0.96, P=0.001).

Conclusions: Maximal fluid infusion improves macro- and micro-circulatory oxygenation parameters. For VO2-Responders, only ScVO2 and cerebral rSO2 could serve as markers of tissue hypoxia.

Keywords: Cardiac output; Fluid loading; Oxygen consumption; Oxygen delivery.

Publication types

  • Observational Study

MeSH terms

  • Aged
  • Area Under Curve
  • Cardiovascular Surgical Procedures*
  • Critical Illness / therapy*
  • Female
  • Fluid Therapy*
  • Hemodynamics
  • Humans
  • Hypovolemia / therapy*
  • Male
  • Oxygen / blood*
  • Pilot Projects
  • Postoperative Period
  • Prospective Studies


  • Oxygen