The impact of phenylephrine, ephedrine, and increased preload on third-generation Vigileo-FloTrac and esophageal doppler cardiac output measurements

Anesth Analg. 2011 Oct;113(4):751-7. doi: 10.1213/ANE.0b013e31822649fb. Epub 2011 Aug 4.

Abstract

Background: Cardiac output (CO) monitoring based on pulse contour analysis (Vigileo-FloTrac) has the potential to be used for goal-directed fluid therapy in the perioperative setting. However, factors such as vasopressor usage may impact Vigileo-FloTrac's reliability in tracking CO changes. We tested third-generation Vigileo-FloTrac system's ability to accurately measure the changes in CO induced by vasopressor administration and increased preload in comparison with esophageal Doppler measurements.

Methods: In 33 anesthetized patients, CO was monitored simultaneously by the third-generation Vigileo-FloTrac and esophageal Doppler. Hemodynamic challenges included phenylephrine (to increase vasomotor tone), ephedrine (to increase myocardial contractility and heart rate), and whole-body tilting (to increase preload). Measurements were performed before and after each intervention.

Results: Overall, 176 pairs of CO measurements were obtained. The difference between paired pulse contour and Doppler measurements of CO was 0.14 ± 2.13 L/min (mean ± SD), and the percentage error (2 SD of the difference divided by the mean CO of the reference method) was 66%. The trending ability of pulse contour versus Doppler was 23% (concordance, the percentage of the total number of data points that are in 1 of the 2 quadrants of agreement) after phenylephrine treatment, 69% (concordance) after ephedrine treatment, and 96% (concordance) after whole-body tilting.

Conclusions: The pulse contour method of measuring CO, as implemented in the third-generation Vigileo-FloTrac device, accurately tracks changes in CO when preload changes. However, the pulse contour method does not accurately track changes in CO induced with phenylephrine and ephedrine.

Publication types

  • Comparative Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • California
  • Cardiac Output / drug effects*
  • Cardiotonic Agents / therapeutic use*
  • Echocardiography, Doppler*
  • Echocardiography, Transesophageal*
  • Ephedrine / therapeutic use*
  • Equipment Design
  • Female
  • Fluid Therapy
  • Head-Down Tilt
  • Humans
  • Linear Models
  • Male
  • Middle Aged
  • Monitoring, Intraoperative* / instrumentation
  • Monitoring, Intraoperative* / methods
  • Myocardial Contraction / drug effects
  • Patient Positioning
  • Phenylephrine / therapeutic use*
  • Predictive Value of Tests
  • Reproducibility of Results
  • Signal Processing, Computer-Assisted
  • Time Factors
  • Transducers, Pressure*
  • Vasoconstriction / drug effects
  • Vasoconstrictor Agents / therapeutic use*

Substances

  • Cardiotonic Agents
  • Vasoconstrictor Agents
  • Phenylephrine
  • Ephedrine