Changes in canine ionised calcium under three storage conditions

Area of Science:

• Veterinary Clinical Pathology
• Biochemistry
• Analytical Chemistry

Background:

• Accurate measurement of ionized calcium concentration (iCa) is crucial in veterinary diagnostics.
• Standard blood collection and storage protocols can influence iCa and pH values.
• Assessing the stability of iCa in collected samples is essential for retrospective analysis.

Purpose of the Study:

• To evaluate iCa and pH in aerobically collected blood samples.
• To compare iCa and pH in heparinized whole blood and plasma after 48 hours under various storage conditions.
• To determine the feasibility of retrospective iCa measurement.

Main Methods:

• Blood samples from 17 dogs were analyzed for iCa and pH using a blood gas analyzer.
• Samples were collected aerobically into heparinized syringes and plain syringes (transferred to tubes).
• Analyses were performed within 10 minutes, and remaining samples were stored at room temperature or 4°C for 48 hours.

Main Results:

• No significant difference in iCa or pH between aerobic and anaerobic collection methods within 10 minutes.
• A decrease in iCa concentration was observed at 48 hours across all storage conditions.
• pH changes did not consistently correlate with iCa concentration changes over the storage period.

Conclusions:

• Aerobically collected samples are suitable for immediate and 48-hour iCa measurement under the tested conditions.
• Retrospective analysis of iCa is possible, but a decrease in concentration should be considered.
• Further studies may be needed to optimize storage protocols for long-term iCa stability.