Assessment of pleth variability index in volume changes during ultrafiltration process

Area of Science:

• Critical Care Medicine
• Nephrology
• Physiology

Background:

• The utility of Pleth variability index (PVI) for assessing fluid status in spontaneously breathing patients remains unclear.
• Hemodialysis (HD) offers a model to study fluid changes and their impact on PVI in patients with end-stage renal failure.
• Understanding PVI's role in spontaneous ventilation is crucial for managing volume status in diverse clinical settings.

Purpose of the Study:

• To investigate the correlation between PVI and fluid volume changes during hemodialysis in spontaneously breathing patients.
• To evaluate the potential of PVI as a non-invasive tool for monitoring volume status in this population.

Main Methods:

• Prospective, observational study involving 60 adult patients undergoing routine hemodialysis.
• PVI measurements were taken before and after each HD session.
• Changes in PVI were analyzed in relation to the volume of fluid removed (ultrafiltration).

Main Results:

• Mean PVI significantly increased from 20.7% ± 5% before HD to 27.7% ± 6% after HD (P < 0.001).
• Changes in PVI were statistically significant based on the amount of fluid removed (P = 0.015).
• A strong positive correlation was observed between the change in PVI (ΔPVI) and the ultrafiltrated volume (r = 0.744, P < 0.001).

Conclusions:

• Fluid removal during hemodialysis leads to an increase in PVI, directly related to the volume of fluid lost.
• PVI monitoring may offer valuable insights into volume status changes in spontaneously breathing patients.
• This suggests PVI could be a useful bedside tool for clinicians managing fluid balance in critically ill patients.