Operation Blood Rain Phase 2: Evaluating the Effect of Airdrop on Fresh and Stored Whole Blood.

Background: Transfusion of whole blood (WB) is a lifesaving treatment that prolongs life until definitive surgical intervention can be performed; however, collecting WB is a time-consuming and resource-intensive process. Furthermore, it may be difficult to collect sufficient WB at the point of injury to treat critically wounded patients or multiple hemorrhaging casualties. This study is a follow-up to the proof-of-concept study on the effect of airdrop on WB. In addition, this study confirms the statistical significance for the plausibility of using airdrop to deliver WB to combat medics treating casualties in the pre-hospital setting when Food and Drug Administration (FDA)-approved cold-stored blood products are not available.

Methods: Forty-eight units of WB were collected and loaded into a blood cooler that was dropped from a fixed-wing aircraft under a Standard Airdrop Training Bundle (SATB) parachute or 68-in pilot chute. Twenty-four of these units were dropped from a C-145 aircraft, and 24 were dropped from a C-130 aircraft. A control group of 15 units of WB was storedin a blood cooler that was not dropped. Baseline and post-intervention laboratory tests were measured in both airdroppedand control units, including complete blood count; prothrombin time/partial thromboplastin time (PT/PTT); pH, lactate,potassium, bilirubin, glucose, fibrinogen, and lactate dehydrogenase (LDH) levels; and peripheral blood smears.

Results: The blood cooler, cooling packs, and all 48 WB units did notsustain any major damage from the airdrop. There was noevidence of hemolysis. Except for the one slightly damagedbag that was not sampled, all airdropped blood met parameters for transfusion per the Joint Trauma System Whole BloodTransfusion Clinical Practice Guideline and the Associationfor the Advancement of Blood and Biotherapies (AABB) Circular of Information for the Use of Human Blood and BloodComponents.

Conclusions: Airdrop of fresh or stored WB in ablood cooler with a chute is a viable way of delivering bloodproducts to combat medics treating hemorrhaging patientsin the pre-hospital setting. This study also demonstrated theportability of this technique for multiple aircraft. The techniques evaluated in this study have the potential for utilizationin other austere settings such as wilderness medicine or humanitarian disasters where an acute need for WB delivery by airdrop is the only option.