Repeated short-term warming of red blood cell concentrates has minimal effect on their quality.

BACKGROUND AND OBJECTIVES: Blood components must be stored under controlled temperature conditions, for reasons of component quality and safety. However, there are occasions when components may be exposed to conditions outwith the defined limits. This study aimed to generate prospective data on the effect of red cell exposure to extremes of temperature. MATERIALS AND METHODS: Study 1: red cell concentrates (RCC) in saline, adenine, glucose and mannitol (SAGM), made after ambient overnight hold of whole blood, were exposed to either +22°C or -2°C for up to three periods of 3 h on days 3, 8 and 15 of storage, followed by a 5 h exposure on day 29. Study 2: RCC in SAGM were exposed to 25°C for 24 or 48 h from day 2. In vitro markers of cell quality were measured during storage to 43 days, and compared with control units that had been stored at 2-6°C. RESULTS: Multiple short-term exposures to +22°C or -2°C did not cause any significant changes to pH, haemolysis, supernatant potassium, cellular ATP, 2,3-DPG, or deformability, when compared to control units. Exposure of RCC to 25°C for 24 or 48 h caused a significant fall in pH, ATP, and deformability. CONCLUSION: Red cells may be damaged by prolonged exposure to warm temperatures, but repeated short-term exposure to 22°C or -2°C does not appear to affect the in vitro quality of RCC. It is important to note that no bacterial growth studies were performed during this study.