Investigation of the quality of stored red blood cells after simulated air drop in the maritime environment.

BACKGROUND: Maritime medical capability may be compromised by blood resupply. Air-dropped red blood cells (RBCs) is a possible mitigation factor. This study set out to evaluate RBC storage variables after a simulated parachute air drop into the sea, as limited data exist. STUDY DESIGN AND METHODS: The air load construction for the air drop of blood was subject to static drop assessment to simulate a worst-case parachute drop scenario. One control and two test Golden Hour shipping containers were each packaged with 10 RBC units. The control box was not dropped; Test Boxes 1 and 2 were further reinforced with waterproof boxes and underwent a simulated air drop on Day 7 or Day 8 postdonation, respectively. One day after the drop and once a week thereafter until Day 43 of storage, RBCs from each box were sampled and tested for full blood counts, hemolysis, adenosine triphosphate, 2,3-diphosphoglycerate, pH, extracellular potassium, glucose, lactate, deformability, and RBC microvesicles. RESULTS: The packaging configuration completed the air drop with no water ingress or physical damage. All units met UK specifications for volume, hemoglobin, and hemolysis. There were no significant differences for any of the variables studied between RBCs in the control box compared to RBCs in Test Boxes 1 and 2 combined over storage. CONCLUSION: The test proved that the packaging solution and the impact of a maritime air drop as performed in this study, on Day 7 or Day 8 postdonation, did not affect the in vitro quality of RBCs in SAGM over storage for 35 days.

The 30 minute rule for red blood cells: in vitro quality assessment after repeated exposure to 30°C.

BACKGROUND: Red blood cells (RBC) may be out of temperature control only for 30 minutes before they must be discarded, but evidence for this rule is weak. We investigated the effect on RBC quality of multiple exposures to 30°C. STUDY DESIGN AND METHODS: RBC units made after 24 hours of whole blood ambient hold were pooled and split into adult and pediatric units and exposed to permitted deviations (5-hr core temperature 10°C, 12-hr surface temperature 10°C). Test units were exposed to 30°C once, twice, or three times on each of Days 15, 17, and 21, for 30 or 60 minutes. Negative controls were not exposed to 30°C; positive control was exposed to 30°C for 24 hours. RESULTS: Adult units exposed once for 30 or 60 minutes (×3 occasions) showed no more hemolysis than negative control. Units exposed to 30°C for two or three periods of 60 minutes showed more hemolysis from Day 28. Hemolysis in pediatric units exposed for 30 minutes (×3) was not increased but units exposed to one or two periods of 60 minutes (×3) showed higher hemolysis. No differences were seen in supernatant potassium. ATP remained at an acceptable level on Day 28 in all but positive controls. CONCLUSIONS: There was no evidence of significant damage to RBC after exposure to 30°C for three periods of 30 minutes. Multiple exposures of 60 minutes caused limited damage but this was within current regulatory limits if there were three or fewer exposures, suggesting that a 60-minute rule may be feasible.