Exsanguinating haemorrhage is the major cause of death in current military conflict operations.1,2 Recent data from Afghanistan and Iraq have shown that up to 15% of combat casualties require massive transfusion for traumatic injuries, with a mortality rate of 20% – 50%.3,4 This is a significantly higher proportion than in most civilian trauma centres, reflecting the severity and polytrauma of blast-associated injuries.
Current battlefield resuscitation practice focuses on early diagnosis and management of haemorrhagic shock, with the aim of rapidly reversing the lethal triad of acidosis, hypothermia, and coagulopathy, using aggressive resuscitation with a 1 : 1 : 1 ratio of red cells to plasma to platelets, and recombinant factor VIIa if required.5,6 Surgical intervention is focused on controlling haemorrhage and contamination (damage control), with definitive care delayed until normal coagulation and metabolic function have been restored.
Supply of fresh liquid blood to combat areas is logistically challenging. Some military forces use pre-screened walking donor panels. However, this practice carries a risk of disease transmission, relies on the availability of appropriate donors, and restricts their duties for a period after donation, with implications for combat readiness (eg, infantry soldiers are probably not fit for combat for at least 24 hours). Blood salvage is not used in the combat environment.7
Historically, the Australian Defence Force (ADF) has relied on fresh blood supplies from the Australian Red Cross Blood Service. But in recent ADF operations in the Middle East, where obtaining supplies of fresh blood is not feasible because of time and distance factors, Australia has been reliant on a Dutch national supply system. The Netherlands armed forces use a sophisticated system for supply of liquid and frozen blood products (red cells, plasma and platelets).8
Here, we review the ADF’s experience with frozen blood products in Afghanistan.
Frozen red cells have been used on deployed military operations since the Vietnam war.9 Using frozen blood during military operations is appealing, as it avoids many logistic resupply issues and extends the shelf-life compared with liquid blood. Deep-frozen red cells can be stored at – 80°C for at least 10 years,10 deep-frozen plasma (DFP) for 7 years and deep-frozen platelets for 2 years.11
The Netherlands developed a state-of-the-art frozen blood component system during North Atlantic Treaty Organization operations in Bosnia in the 1990s.7 In 2002, universal frozen blood products were introduced, including a frozen platelet system. This is the system now in place at the Uruzgan Medical Centre (UMC) at Tarin Kowt in Afghanistan, where the ADF embedded a surgical and intensive care team into the Netherlands-led forward health facility in 2008.
All blood products are sourced from the Netherlands Sanquin Blood Supply Foundation and derived from an unpaid volunteer donor pool.8 Blood is screened and tested in accordance with national and international guidelines. To minimise the risk of transmission of Creutzfeldt–Jakob disease, blood donations are not accepted from people who have a history of transfusion or have lived in the United Kingdom for more than 6 months between 1990 and 1996.12,13
Red cells are frozen in 40% glycerol (w/v) and transported from the Netherlands in temperature-monitored containers (TempTale [Sensitech, Beverly, Mass, USA]) maintained at less than – 65°C, and then transferred to a – 80°C freezer at UMC (Box 1).
Cells are processed in a fully closed, semi-automated ACP 215 processor (Haemonetics, Braintree, Mass, USA). They are deglycerolised with 12% sodium chloride, washed with 0.9% sodium chloride and 0.2% glucose, and resuspended in a citrate-containing nutritional solution (AS3 Nutricel [Gambro BCT, Lakewood, Colo, USA]) (Box 2).
Three units of red cells can be produced every 90 minutes (this includes 30 minutes’ thawing time). Regular processing allows liquid blood stores to be replenished to maintain an immediately available supply. The shelf-life of red cells after thawing and processing is 14 days at 2 – 6°C. Cell vitality studies show a mean freeze–thaw–wash recovery value of 90%, a mean 24-hour post-transfusion survival rate of 85%, normal or slightly impaired oxygen transport function, and minimal haemolysis.10
Group AB Rh D-positive plasma is provided as DFP using single-donor apheresis. Plasma is citrated and leukocyte-depleted. DFP is transported at a temperature of less than – 65°C and stored at – 80°C. Thawing takes about 30 minutes. The performance of DFP is almost identical to that of fresh frozen plasma.9
Leukocyte-depleted, volume-reduced frozen platelets are obtained by apheresis from a single donor, cryoprotected in a solution of 4% – 6% dimethyl sulfoxide and stored at – 80°.14 Each unit contains about 300 × 109 platelets (equivalent to 5–6 donor units of fresh buffy-coat platelets). The freezing process induces both morphological and functional changes.15,16 Compared with liquid-stored platelets, frozen platelets demonstrate a higher capacity to bind factor V and higher thromboxane A2 production after stimulation with adenosine diphosphate.16
Since ADF medical officers joined UMC in 2008, three teams have provided 2-month rotations as part of the International Security Assistance Force in Afghanistan. A prospective database was maintained during the ADF rotations. Of 158 patients undergoing surgery by Australian surgical teams, 17 received blood products intraoperatively (132 red cell units, 75 DFP units, 22 platelet units). One patient received recombinant factor VIIa.
The following case studies illustrate some issues related to the use of frozen blood products.
On 2 February 2009 at 08:20, a suicide bomber self-detonated at the Afghan National Police training barracks in Tarin Kowt, resulting in 22 deaths.
These cases demonstrate the use of integrated liquid and frozen blood components for patients with battlefield trauma. Non-crossmatched units were used immediately, with formal crossmatching, typing, antibody screening and agglutination tests performed as soon as practicable. The cases illustrate that, in an austere environment or during mass casualty events, decisions must frequently be made on clinical grounds, often without recourse to investigations.17
Abstract
Historically, the Australian Defence Force (ADF) has sourced all its blood supplies from the Australian Red Cross Blood Service. Recent ADF operations in the Middle East have highlighted a need to rely on other nations’ blood supply systems.
In 2008, the ADF embedded a surgical and intensive care team into the Netherlands-led forward health facility at the Uruzgan Medical Centre at Tarin Kowt in Afghanistan. To date, three teams have provided 2-month rotations as part of the North Atlantic Treaty Organization International Security Assistance Force in Afghanistan.
The Netherlands armed forces use a sophisticated system for supply of liquid and frozen blood products (frozen red cells, plasma and platelets).
We review Australian experience with the Dutch system of supplying blood products for major trauma resuscitation in Afghanistan.