Changes in RBC deformability and oxygen-delivering ability in cold blood cardioplegia

Purpose: The advantages of blood cardioplegia, which is used for myocardial protection during open heart surgeries, include superior oxygen-carrying capacities, better osmotic properties, and the presence of more antioxidants than a crystalloid counterpart. Although, hyperkalemic organ-preserving solutions for transplantation surgeries are known to decrease RBC deformability essential for tissue perfusion, only few studies have addressed the changes in RBC deformability after exposure to cardioplegic additives. The purpose of this study was to measure deformability and oxygen-delivery capacities in various blood cardioplegic solutions. Methods: Blood from eight healthy volunteers was used. Each sample (100 ml) was divided into 5 groups of 16 ml, and cardioplegia solutions were added (group NS; blood + normal saline, group K; blood + KCl, group D; blood + KCl + diltiazem, group A: blood + KCl + adenosine, group E: blood + KCl + neutrophil elastase inhibitor [Sivelestat]). All samples were incubated at a temperature of 8°C for 10 minutes. Deformability, NO level, 2,3-DPG, and ATP were measured. Results: There was no statistically significant difference (p = 0.92) in deformability between the groups. The NO levels were not significantly different (p = 0.86). The 2,3-DPG (p = 0.27) and ATP levels (p = 0.40) were not significantly different. Conclusions: The deformability and oxygen carrying functions of RBCs did not show a significant difference according to various components of cold blood cardioplegia during 10 minutes of incubation.