Utility of temperature‐sensitive indicators for temperature monitoring of red‐blood‐cell units

Background and Objectives The 30‐min rule has been used to maintain a core temperature (CT) of red‐blood‐cell (RBC) units below 10°C during transportation. We evaluated the utility of temperature‐sensitive indicators (TIs) to monitor the surface temperature (ST) of RBC units and to explore whether TIs can help with compliance with the 30‐min rule by extrapolating or correlating temperature change with time. Materials and Methods Two US FDA‐approved TIs, Safe‐T‐Vue 10 (STV10; Temptime Corporation, Morris Plains, NJ, USA) and Timestrip Blood Temp 10 (BT10; Timestrip UK Ltd, Cambridge, UK), were attached to 50 RBC units. After issue, their colour change indicating 10°C was monitored, and temperature excursions were measured by standard reading. In additional 18 RBC units, both ST and CT were monitored simultaneously. Results In 50 RBC units, 94% of STV10 and 100% of BT10 showed colour change indicating 10°C within 30 min; 4% of STV10 and 18% of BT10 showed it during transportation. The time for colour change indicating 10°C differed significantly between STV10 and BT10 (19·0 vs. 5·6 min, P