DISCUSSION
Our results are the first reported use of thermal control technology to reduce blood wastage in conjunction with EVLP utilizing OCS Lung. Compared to our previous passive refrigeration standard using the Performance cooler, the thermal control technology with the ProMed cooler offered superior conditioning and transportation capabilities. In addition, the ProMed cooler offers an 18-fold longer validated time to maintain the required 1 to 6 °C blood storage temperature than our previous cooler. In keeping with this extended period of stable storage temperature, wastage dropped from 37.5% of pRBC units to 0% when the ProMed cooler was implemented for OCS lung. While limited, these findings suggest significant early improvement in blood wastage for lung recovery.
Previous publications have demonstrated the superiority of thermal control technology over passive refrigeration for medication and emergency blood transportation. Clancy et al. found that the industry-accepted passive refrigeration was ineffective for temperature-sensitive medication transport and resulted in significant temperature excursions for trip durations lasting greater than 3 hours.15 Utilizing thermal control technology, Krook et al. reported only 1.2% of unit wastage during a four-year review of prehospital blood transfusion within a Canadian helicopter emergency medical service.11 Blood is a valuable resource that is often in short supply.16,17 The coronavirus disease 2019 (COVID-19) pandemic has adversely affected blood donation due to social distancing and resulted in the cancellation of blood drives, creating an increasing strain on the national blood supply.18-20 Hospitals should routinely monitor blood product wastage as a quality indicator, investigate factors contributing to the wastage, and establish systems to reduce wastage.21
Blood wastage accounted for 14.2% of the total units issued for lung recovery by our institution’s blood bank. All these wasted units were transported with the Performance cooler. Based on organ transplantation’s essential and emergent nature, these pRBC units were stored longer than their cooler’s validated storage duration, resulting in temperature excursions. Our multidisciplinary team of perfusionists and blood bank personnel have become more familiar over time with the storage and stewardship processes, demonstrating the success of quality improvement practices. To date, all unused pRBC units from canceled recoveries using the ProMed coolers have been successfully returned to our blood bank within the validated storage timeframe and reallocated for future use. In addition to avoiding wastage of a valuable resource, the ability of thermal control technology to maintain a stable temperature long-term resulted in a five-year cost savings of approximately $18,000.
Ultimately, thermal control technology with continuous temperature monitoring improves quality measurement and patient safety. Using the iLog temperature logger during the recovery phase allows for real-time, data-driven clinical decision support. Additionally, every data set is retrospectively reviewed for quality improvement and assurance. Returned units are quarantined until the temperature data logger can be reviewed to ensure proper temperature compliance throughout transportation. At the same time, process improvements for administered units, such as inadequate conditioning time, can be identified and addressed.
The implementation of thermal control technology had no impact on operational efficiency. There is no additional storage or freezer equipment requirement as the TIC gel panels are stored in existing refrigerators or freezers at our institution’s blood bank. However, the conditioning process required for TIC gel panels prior to issuance required a minimal workflow change for the blood bank technologists.
The ProMed cooler is constructed to protect medical materials such as blood and commercial bio-pharma products, with relatively easy conditioning of the modular TIC system panels. However, periodic inspection of the VIP lid and base surfaces is imperative as this innovative technology is highly effective only if they hold an internal vacuum. Therefore, the manufacturer recommends the replacement of the VIP every five years.
These key features, along with other findings of Martin et al., were the basis of our institution’s selection of the ProMed cooler for use with both OCS Lung recovery and the Aeromedical Network.22
In the future, a multi-center approach to thermal control technology should be further explored and investigated in conjunction with other ex vivo organ perfusion platforms, such as the OCS Heart and Liver, which recently received approval from the United States Food and Drug Administration.