Evaluation of Correlation Between Pleth Variability Index and Blood Lactate Level in Living Liver Donors

Objectives: This study primary objective to compare simultaneous Pleth Variability Index (PVI) and blood lactate measurements taken during different surgical phases to determine whether PVI is a reliable parameter for fluid monitoring in this patient group. Our secondary objective is to monitor changes in PVI in fluid-restricted liver donors.
Methods: The study was conducted in ASA I–II living liver donors aged 18–55 undergoing right hepatectomy; patients with cardiovascular disease or drug allergies were excluded. PVI and PI were recorded noninvasively using the Masimo SET® device. Measurements were taken at surgical start (T1), 1 hour (T2), end of surgery (T3), postoperative 3 hours (T4) and 24 hours (T5): AST, ALT, BUN, creatinine and blood lactate; and at T1–T4: SpO2, heart rate, arterial pressures, CVP, urine output, blood loss, administered fluid volumes, PVI and PI. Anesthesia and surgery durations, graft weight, and transfused blood/products were recorded.
Results: Our study involved 51 living donors (31 males and 20 females) with a mean age of 28.78 ± 9.64 years. In the intra-group evaluation of PVI, no significant differences were observed across all time periods, but significant correlations in lactate levels were found at multiple time points (p<0.05). A notable correlation between PVI and lactate levels was identified during the T3 period. Additionally, significant changes in sodium and creatinine were observed in T3 and T4 (p<0.05), along with an increase in bleeding and a decrease in urine output during the first hour of surgery (T2) (p<0.05).
Conclusion: We found a correlation between lactate levels at the end of surgery and PVI values in liver transplant donors. Despite adequate hepatic blood flow, hepatocyte damage during surgery may impact lactate metabolism. Therefore, further studies are needed to explore the relationship between PVI and lactate levels in various surgical procedures.

Keywords: Liver translantation, living liver donor, pleth variability index, lactate