Point-of-care ionised calcium testing: lab validation and clinical feasibility study

Area of Science:

• Biochemistry
• Medical Devices
• Point-of-Care Testing

Background:

• Thyroid and parathyroid surgery patients require frequent blood calcium monitoring.
• Current calcium level assessments are predominantly performed in hospital laboratories.
• There is a need for accessible, point-of-care (POC) devices for blood calcium measurement.

Purpose of the Study:

• To evaluate a non-medical LAQUA device as a portable POC tool for measuring blood calcium.
• To assess the device's accuracy and precision in patient blood samples after thyroid and parathyroid surgery.

Main Methods:

• Phase 1: Surveyed available technologies for rapid, accurate calcium measurement in small blood volumes.
• Phase 2: Laboratory testing of the LAQUA device with standardized solutions.
• Phase 3: Prospective study involving 30 patients, comparing LAQUA measurements (venous and capillary) with 'gold standard' laboratory platforms (Roche Cobas-Calcium-Gen.2 and ABL90).

Main Results:

• LAQUA was identified as a promising POC device based on size, ease of use, and cost.
• The device demonstrated good accuracy and precision in laboratory settings.
• In patients, LAQUA showed a strong positive correlation with 'gold standard' venous ionized calcium measurements (R=0.75). Correlations were weaker for capillary blood samples.

Conclusions:

• The LAQUA device accurately measures ionized calcium in small venous blood samples.
• Further development is required to improve its performance with capillary blood.
• The device shows potential as a future POC tool for post-surgical calcium monitoring.