Transfusion: -80°C Frozen Blood Products Are Safe and Effective in Military Casualty Care

Abstract

Introduction: The Netherlands Armed Forces use -80°C frozen red blood cells (RBCs), plasma and platelets combined with regular liquid stored RBCs, for the treatment of (military) casualties in Medical Treatment Facilities abroad. Our objective was to assess and compare the use of -80°C frozen blood products in combination with the different transfusion protocols and their effect on the outcome of trauma casualties.

Materials and methods: Hemovigilance and combat casualties data from Afghanistan 2006-2010 for 272 (military) trauma casualties with or without massive transfusions (MT: ≥6 RBC/24hr, N = 82 and non-MT: 1-5 RBC/24hr, N = 190) were analyzed retrospectively. In November 2007, a massive transfusion protocol (MTP; 4:3:1 RBC:Plasma:Platelets) for ATLS® class III/IV hemorrhage was introduced in military theatre. Blood product use, injury severity and mortality were assessed pre- and post-introduction of the MTP. Data were compared to civilian and military trauma studies to assess effectiveness of the frozen blood products and MTP.

Results: No ABO incompatible blood products were transfused and only 1 mild transfusion reaction was observed with 3,060 transfused products. In hospital mortality decreased post-MTP for MT patients from 44% to 14% (P = 0.005) and for non-MT patients from 12.7% to 5.9% (P = 0.139). Average 24-hour RBC, plasma and platelet ratios were comparable and accompanying 24-hour mortality rates were low compared to studies that used similar numbers of liquid stored (and on site donated) blood products.

Conclusion: This report describes for the first time that the combination of -80°C frozen platelets, plasma and red cells is safe and at least as effective as standard blood products in the treatment of (military) trauma casualties. Frozen blood can save the lives of casualties of armed conflict without the need for in-theatre blood collection. These results may also contribute to solutions for logistic problems in civilian blood supply in remote areas.

Fig 1. Transfused casualties and product use per month at MBTK.

MTBK indicates Multinational Base Tarin Kowt, RBC; red blood cells, MTP: Massive Transfusion Protocol, nr: number, MT: massive transfusion, EC: Erythrocyte Concentrate. Upper panel: black bars: nr of MT patients, green bars: nr non-MT patients. Middle panel: orange: sum of thawed deglycerolized RBC units, purple: sum of EC units. Lower panel: yellow: sum of frozen plasma units, blue: sum of (plasma of) frozen platelets units.

Fig 2. Transfusion, injury and outcome of MT and non-MT patients, pre- and post-MTP.

MT indicates massive transfusion, MTP: Massive Transfusion Protocol, RBC: red blood cells; Plasma: frozen plasma; PLT: frozen platelets. clear bars: pre-MTP, padded bars: post-MTP, *: significantly different compared to pre-MTP.

Fig 3. Transfusion and in-hospital survival per category of 24hr transfused blood products.

MT indicates massive transfusion, RBC: red blood cells; plasma: frozen plasma; platelets: frozen platelets, LOS: length of stay. clear bars: pre-MTP, padded bars: post-MTP, x/xx: deceased/total number of patients.

Fig 4. Introduction of TDFP, effect on blood product use and accompanying survival.

TDFP indicates thawed deep frozen plasma, MT: massive transfusion, MTP: Massive Transfusion Protocol, RBC: red blood cell, DTC: deep frozen thrombocyte concentrate, pts: patients. Upper panel: red = RBC; yellow = frozen plasma; blue = frozen platelets. Middle panel: yellow: (plasma + plasma of DTC):RBC ≥1:1.5, blue: DTC:RBC ≥1:5. Lower panel left: yellow: (plasma + plasma of DTC)/RBC, blue: DTC/RBC, circles: MT pts, squares: non-MT pts. Lower panel right: black diamonds: MT pts, white diamonds: non-MT pts. Time frames during the period studied: pre-MTP; pre-TDFP: 08/2006–10/2007, N = 25 MT / 55 non-MT post-MTP; pre-TDFP: 11/2007–03/2009, N = 24 MT / 59 non-MT post-MTP; post-TDFP: 04/2009–10/2010, N = 33 MT / 76 non-MT.