Bridging Laboratory and Nursing: A Collaborative Approach to Glucose Monitoring in the ICU

Capillary glucose testing is commonly used in Intensive Care Units (ICUs) but often yields inaccurate results in critically ill patients due to poor perfusion. Despite FDA recommendations against its use in this population, it remains widespread. This study, a collaboration between NRL and Cleveland Clinic Abu Dhabi (CCAD), aimed to address these limitations through a structured, nurse-led protocol.

A four-phase study was conducted: Phase 1: The Siemens RP500 blood gas analyzer was validated against the central lab method (Roche Cobas 6000) to avoid additional venous sampling. Glucose was measured on whole blood already drawn for blood gases. Phase 2: Capillary and whole blood glucose results were compared using the Accu-Chek Inform II and RP500. Phase 3: A structured protocol was implemented in 2019, requiring whole blood confirmation for capillary results ≤4.0 or ≥15.0 mmol/L. Phase 4: Long-term monitoring (2019–2024) assessed compliance, clinical impact, and nursing-led refinements. A 10% allowable difference between paired results was adopted to support bedside decision-making.

The RP500 met performance targets (TAE ≤12.5%) and was accepted as a reference method. Initial analysis showed that 2% of capillary readings fell into high-risk CEG Zones D/E; these were eliminated by whole blood confirmation. Protocol compliance improved from 55% in 2019 to >90% by 2024, with no reported adverse events.

The protocol improved glucose testing accuracy and patient safety. It offers a scalable model supported by whole-blood validation, nursing engagement, and practical workflows.