Calcium Chloride Requirement and Postreperfusion Rebound During Massive Transfusion in Liver Transplantation

Abstract

Objectives: The administration of citrated blood products during massive transfusion requires calcium salt administration to prevent citrate toxicity and to maintain ionized calcium values. The literature does not provide adequate guidance for the amount of calcium required during massive transfusions during liver transplantation. This study was conducted to provide guidance on calcium salt replacement during a massive transfusion in liver transplant patients, with a focus on the phase of transplantation during which citrate metabolism was minimal.

Design: An observational retrospective chart review.

Setting: An academic single-institution study of hospitalized patients.

Participants: One hundred thirty-two patients after liver transplantation.

Interventions: The study authors observed documented measurements of ionized calcium and observed the ratio of calcium salts to citrated bank blood products in patients undergoing liver transplantation with complete data sets. They also observed the effect of continuous venovenous hemofiltration on the distribution of ionized calcium values.

Measurements and main results: Prereperfusion, an average of 1.09 g CaCl₂/L of citrated blood was administered to maintain ionized calcium in the normal range. Postreperfusion, less CaCl₂ was administered, and a rebound of ionized calcium occurred. Prereperfusion, continuous venovenous hemofiltration reduced the number of ionized calcium values outside of 2 standard deviations, meaning fewer values were critically low.

Conclusions: With massive transfusions up to 67 liters (approximately 13 blood volumes), 1.09 g CaCl₂/L citrated blood maintained ionized calcium in the normal range in the absence of citrate metabolism. This ratio may have value in empiric treatment when ionized calcium measurements are unavailable, and massive transfusion rates exceed metabolic capacity.

Keywords: calcium chelation; calcium replacement; citrate intoxication; liver transplantation; massive transfusion.