Plethysmography Variability Index and Stroke Volume Variation Changes in Relation to Central Venous Pressure Changes During Living Related Donor Right Hepatotomy: A Diagnostic Test Accuracy

Objectives: During donor hepatectomy, we investigated (1) the Electrical Cardiometry associations and agreements between noninvasive plethysmography variability index and noninvasive stroke volume variation, (2) their association with central venous pressure, and (3) their ability to monitor intraoperative changes and discriminate donors with increased blood loss. Materials and Methods: A diagnostic test accuracy was applied among donors (American Society of Anesthesiologists classification I). Data were recorded at 10 minutes after anesthesia induction, hourly during dissection, after resection, and at end of surgery. Crystalloids were restricted during resection to reduce central venous pressure but were otherwise infused to maintain mean invasive arterial blood pressure >60 mm Hg and urine output >0.5 mL/kg/h. Results: All 34 donors were related. Sons or daughters represented 58.8% (median age 26.0 years [interquartile range, 21.0-34.0]). Median values (with interquartile ranges) were anesthesia time, 7.5 hours (7.0-8.0); blood loss, 400 mL (400.0-500.0); infused acetated Ringer solution, 4000.0 mL (3500.0-4500.0); colloids, 250.0 mL (0-500.0); and urine output, 1.4 mL/kg/h (1.30-1.7). No blood products were transfused. Central venous pressure showed negligible negative correlations for both plethysmography variability index and stroke volume variation. Plethysmography variability index showed negligible correlation and poor agreement with stroke volume variation (P < .001, with intraclass correlation = 0.213 and a relatively wide bias; 95% CI, 0.03-0.37). All 3 methods reflected a state of normovolemia despite fluid restriction during resection and were unable to discriminate donors with increased blood loss (>400 mL). Conclusions: Plethysmography variability index and stroke volume variation showed negligible correlation and poor agreement with central venous pressure. Transfusion-free dissection was possible despite normovolemia, with median values of 8 mm Hg central venous pressure, 10% stroke volume variation, and 12% plethysmography variability index. Plethysmography variability index and stroke volume variation were unable to discriminate donors with increased blood loss.