Changing the 30-min Rule in Canada: The Effect of Room Temperature on Bacterial Growth in Red Blood Cells

Abstract

Background: To maintain product quality and safety, the ‘30-min rule' requires the discard of red blood cells (RBCs) that are exposed to uncontrolled temperatures for more than 30 min. Recent studies suggest this rule may safely be extended to a 60-min rule. Methods: A pool-and-split design study (N = 4) was run in parallel at Canadian Blood Services (SAGM RBCs) and Héma-Québec (AS-3 RBCs). RBCs were spiked with ∼1 colony-forming unit/ml of mesophilic and psychrophilic bacteria. Control units remained in storage at 1-6 °C for 42 days. Test 30 (T30) and T60 units were exposed to room temperature (RT) six times during storage, each time for 30 and 60 min, respectively. Bacterial proliferation was monitored. Results: Mesophilic bacteria do not proliferate in RBCs. The growth of psychrophilic bacteria is not significantly different in RBCs exposed for 30 or 60 min to RT (p < 0.05). Conclusion: The study findings were the final evidence to support extension from a 30-min rule to a 60-min rule in Canada.

The impact of red blood cell manufacturing variables on bacterial growth dynamics: a pilot study

“…Similar to the current study, in Ramirez‐Arcos et al ., S. epidermidis did not survive in RBC in AS‐3 manufactured by whole blood filtration ; however, in contrast to the current study, S. epidermidis was viable in RBC in SAGM produced by RBC filtration. One possible explanation may be differences in the RBC filtration method used in the current study (in which units were produced by the Atreus system at Héma‐Québec) and the previous study (in which units were produced by semi‐automated RBC filtration at Canadian Blood Services ). In the previous study, RBC were stored in full‐sized bags rather than small volume bags, which have different plastic thickness and texture, and may also account for the differences observed in survival of this bacterium .…”

“…In the Héma‐Québec study , S. marcescens did not grow in room temperature‐exposed RBC in AS‐3; however, bacterial growth was observed in room temperature‐exposed RBC in SAGM on day 42. In the Canadian Blood Services study , preferential survival of S. epidermidis and K. pneumoniae in SAGM compared to AS‐3 RBC was observed. We noted that in addition to AS, factors including the manufacturing process could affect bacterial growth and warrant further investigation.…”

“…This is the first study to specifically address the impact of RBC AS, manufacturing method and donor factors on the survival or proliferation of bacteria in inoculated RBC. Our hypothesis that these factors may impact bacterial survival or proliferation was based on data from recent studies from our organizations that looked at the risk of bacterial growth in RBC exposed to regular excursions outside cold storage [17,18]. In the H ema-Qu ebec study [18], S. marcescens did not grow in room temperatureexposed RBC in AS-3; however, bacterial growth was observed in room temperature-exposed RBC in SAGM on day 42.…”

“…Before inoculation, RBC were split into four paediatric bags, each containing 40 ml [16], using a Fenwal Quadruple Transfer Pack (4R2004; Fresenius-Kabi AG). Bacteria were prepared from frozen stocks of known concentration as described previously [17]. Each paediatric bag was inoculated to reach a target concentration 10 colony-forming units (CFU)/ml of either Klebsiella pneumoniae (WHO PEI-P-B-08), Staphylococcus epidermidis (ATCC 700562), Yersinia enterocolitica (ATCC 49397) or Propionibacterium acnes (CBS 11032), via a sample site coupler or needle-free collection port.…”

Enlargement of the WHO international repository for platelet transfusion‐relevant bacteria reference strains

“…Six of the repository strains were used to compare the growth kinetics and detection by a bacterial culture system in PCs suspended in plasma and platelet additive solution (PAS) (C. McDonald, personal communication, November 2016). Klebsiella pneumoniae PEI‐B‐P‐08 was used in a bacterial tracking study during buffy‐coat production of PCs , a validation of sterility testing of cord blood and a study on the 30‐min rule for red cell concentrates . It is envisaged that other investigators will follow, especially as regulators begin to endorse the use of standardized strains.…”