Abstract
The purpose of this study was to further investigation into practical applications of blood gas analysis (BGA) in a clinical setting. The special protocol and equipment typically required for BGA has limitations when it comes to marine mammal medicine. Blood collection from marine mammals is often performed outside in ambient conditions, not in a sterile laboratory, and there are many factors in clinical settings that may preclude running a cartridge immediately on site or in the field. BGA was documented on routine and clinical blood draws from the Miami Seaquarium’s resident bottlenose dolphins (Tursiops truncatus), Pacific white-sided dolphins (Lagenorhynchus obliquidens), and killer whale (Orcinus orca). An i-STAT handheld analyzer and two different test cartridges were used to analyze whole blood within 10 minutes of collection and lithium-heparinized blood one hour later.
The initial objective was to determine which acid-base status indicators could provide diagnostic information one hour after collection. All cartridge analytes were recorded, but only four were statistically analyzed. The pH did not change significantly over time. Though differences in HCO3, TCO2, and iCa values were documented, they could still provide diagnostic information. The second objective was to investigate cartridge comparability by comparing pH and HCO3 values from both cartridges. There were no statistically significant differences between cartridge pH values. Differences in HCO3 values were reported, as they might still be useful in mixed cartridge scenarios. The third objective was to examine the comparability of cartridge and serum chemistry TCO2 values. Both cartridges yielded comparable TCO2 values to each other. Though 90% of the serum chemistry values had a statistically lower difference, they still might have practical value. The final objective was to explore the clinical advantages of the i-STAT by investigating a correlation between cartridge iCa and serum chemistry total calcium. The iCa and serum total calcium values were positively correlated, which enabled iCa to expedite the diagnostic process and guide treatment plans.
Preliminary evaluation has revealed several practical facets to BGA, thereby expanding its diagnostic capabilities. These results support one hour as a realistic and flexible time frame between collection and analysis of blood samples for pH.