Use of a Portable Point-of-Care (Vetscan Vs2) Biochemical Analyzer for Measuring Plasma Biochemical Levels in Free-Living Loggerhead Sea Turtles (Caretta caretta)

Abstract

The agreement of plasma biochemical values between a portable point-of-care analyzer and a veterinary diagnostic laboratory in wild caught loggerhead sea turtles (Caretta caretta) was tested. Banked plasma samples from presumptively healthy turtles collected for an on-going project that involves health assessments of sea turtles from the southeast coast of Florida were used for this study. Plasma biochemical analytes evaluated included albumin, aspartate aminotransferase, calcium, creatinine kinase, glucose, potassium, sodium, phosphorus, total protein, bile acids, and uric acid. Paired plasma samples were run in duplicates and compared between a point-of-care analyzer and a veterinary diagnostic laboratory (VDL). Overall, the precision was greater as measured within the point-of-care analyzer than within the VDL analyzer; however, agreement between the two testing methods was poor. Correlation (r(i)) between the two analyzers was high for many of the analytes; however, the small P-value and high relative error led to the conclusion that the two analyzers were not equivalent. In addition, a comparison was made between the biochemical values obtained at the time of collection and after storage in an ultralow freezer for up to 2.5 yr. Plasma samples analyzed at the VDL, performed on different models of the same machine, were significantly lower after storage than those acquired near the time of collection. This difference was most likely because of sample degradation that occurred during storage. Whereas, statistically significant differences were observed within and between the analyzers, many of these differences may not be clinically significant. Even though this study has a few limitations, including a technical malfunction and the use of two different diagnostic laboratories, biochemical values for the given population are reported when using both a portable system and a diagnostic laboratory. Based on the findings of this study, the authors believe that point-of-care analyzers can provide valuable adjunctive diagnostics, especially in field situations.