Background/Case Studies: The Human Cellular Therapy Laboratory (HCTL) is a part of a medium sized BMT program in Southeastern USA. The HCTL processes human cells, tissues, and cellular and tissue-based products (HCT/Ps) for transplant and novel cell therapies. These products are cryopreserved to maintain their potency until time of use. Maintaining extremely low temperatures within liquid nitrogen tanks (LN2Ts) is critical for this process. Accrediting bodies require systems and alarms to be in place to respond in the event of critical storage failure because HCT/Ps are irretrievable. Herein, we report a catastrophic tank failure in 2023 requiring urgent relocation of stored HCT/Ps while maintaining full processing operations and cold chain.
Study
Design/Methods: The HCTL noted a recurring alarm state of an LN2T above -160°C. Healthcare Technology Management (HTM) investigated the alarm and noted two integrity failures on the implicated LN2T: a cracked lid and jacket leak (Figure 1). The HCTL medical director was notified and determined that the LN2T must be taken out of service due to irreparable failure. Facilities and HCTL medical technologists (MT) staff were recruited to manage refilling the LN2T given increased LN2 demand and removal of the cracked lid. Patient blankets and Styrofoam were retrofitted to seal LN2T when not open for HCT/P removal. Adjacent LN2Ts were used for immediate HCT/Ps relocation. When adjacent tanks were filled, five LN2 dry shippers were charged and used to transport HCT/Ps to long term storage. Senior MT staff maintained normal cell processing functions within the lab while all remaining staff worked to empty the failing LN2T.
Results/Findings: Over the course of 72 hours, 779 HCT/Ps and 7680 ampules were relocated to on-site and off-site storage. The use of LN2 dry shippers allowed for 40 products and 12 ampule boxes to be transported to offsite storage per trip. The estimated number of roundtrips was 14 with 28 miles traveled total. No products were compromised, and no infusions or collections were cancelled.
Conclusions: It is essential for all HCTLs to have a standardized alarm notification system integrated with their LN2Ts, serving as the primary safeguard by providing alerts regarding potential critical LN2T failures. Furthermore, LN2T systems should undergo frequent inspections and continuous monitoring of their physical condition and product inventory. This proactive approach facilitates early detection of potential tank failures, enabling prompt alerts for HCTL staff. Retrieving HCT/Ps from a failing LN2T presents challenges and risks to both product integrity and personnel safety; therefore, thorough contingency plans are critical to prevent and effectively respond to LN2T failures.
