Agreement between Pleth Variability Index and oesophageal Doppler to predict fluid responsiveness

Area of Science:

• Anesthesiology
• Critical Care Medicine
• Surgical Fluid Management

Background:

• Esophageal Doppler is established for guiding intraoperative fluid therapy but has limitations.
• Pleth Variability Index (PVI), derived from pulse oximetry, is a potential alternative for assessing fluid responsiveness.
• This study investigated the concordance between PVI and Doppler in predicting fluid responsiveness.

Purpose of the Study:

• To compare the ability of PVI and Doppler to predict fluid responsiveness during major abdominal surgery.
• To assess the concordance between PVI and Doppler in guiding intraoperative fluid administration.
• To evaluate the clinical utility of PVI as an alternative to Doppler for fluid management.

Main Methods:

• Seventy-five patients undergoing major abdominal surgery were randomized to fluid optimization using PVI or Doppler algorithms.
• Both PVI and Doppler were monitored, with one method blinded.
• The primary endpoint was the concordance between methods in predicting a stroke volume increase ≥10% after fluid bolus.

Main Results:

• PVI indicated fluid needs in only one-third of situations where Doppler did (Cohen's kappa = 0.03).
• Both PVI and Doppler algorithms successfully predicted a ≥10% stroke volume increase in approximately half of the indicated situations.
• Mean total fluid bolus volume was similar between PVI (878 ml) and Doppler (826 ml) groups.

Conclusions:

• There was poor agreement between PVI and Doppler for stroke volume optimization.
• Neither PVI nor Doppler demonstrated a strong ability to predict fluid responsiveness.
• The findings do not support the widespread application of the fluid responsiveness concept in this context.