Abstract

Loggerhead sea (Caretta caretta; Cc) and green turtles (Chelonia mydas; Cm) frequently require blood transfusions to treat anemia from various conditions,¹ but standardized blood banking and transfusion protocols have not been established. The objective of this study was to obtain baseline measurements for osmotic fragility and selected intra-red blood cell (RBC) analytes. Osmotic fragility testing was performed using whole blood samples from 7 Cc and 8 Cm. Fifty % RBC hemolysis was observed at a NaCl concentration between 0.35–0.40% in both species and results were not statistically significant (p=0.3978). RBCs from 13 Cc and 10 Cm were analyzed for intracellular aspartate aminotransferase (AST), glutamate dehydrogenase (GLDH), uric acid, potassium, sodium, chloride, magnesium, phosphorus, and calcium. Both Cc and Cm RBC contained high potassium (mean: 19.5 mmol/L, range: 17.6–25.7 mmol/L, p=0.73) and low sodium (mean: 3.2 mmol/L, range: 0–37.0 mmol/L). RBC also had measureable concentrations of phosphorus (mean: 7.7 mg/dL, range 1.1–11.7 mg/dL), calcium (mean: 0.30 mg/dL, range 0–1.2 mg/dL), AST (mean: 11.2 U/L, range 0–25 U/L), GLDH (mean: 1.2 U/L, range 0–1.3 U/L) and uric acid (mean: 1.7 mg/dL, range 0–2.7 mg/dl). RBC did not contain significant concentrations of chloride or magnesium. The first step in developing a blood bank RBC storage protocol involves determining intra-RBC constituents so that appropriate RBC storage media can be selected. Experiments evaluating RBCs stored in various media over the course of four weeks^2,3 include serial measurements of percent RBC hemolysis, RBC osmotic fragility and evaluate for RBC leakage of selected intracellular constituents such as potassium⁴. Similar to humans, pigs, some dog species, and many horses, Cc and Cm are both species with high intracellular potassium concentrations.⁵ Changes in RBC osmotic fragility during storage reflect susceptibility to hemolysis. Results of this study will help guide future studies evaluating optimal RBC storage solutions.

* Presenting author

Acknowledgements

The authors wish to thank Dr. Dori Borjesson, Naomi Walker, and the staff of the UC Davis School of Veterinary Medicine Blood Bank and Hematology Lab, Samantha Clark and Ashley Isaac at the Loggerhead Marinelife Center, and Caitlin Greene, RVT, and the Rehabilitation Technicians and staff at The Turtle Hospital.

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