Page 49 - JSOM Winter 2022

results in multiple biochemical, structural, and metabolic Another way to reduce this risk is to always collect WB from
changes, referred to as to the storage lesion. Whole blood is group O donors, whose titers of anti-A and anti-B antibodies
also exposed to such lesions when cold stored. In particular, are low, to avoid the risk of hemolytic reactions mediated by
the relative rate of hemolysis observed in whole blood is equiv- these antibodies. This kind of donor can be considered a uni-
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alent to the one in packed red blood cells. A link between the versal donor. Such blood is called low-titer O whole blood.
length of storage of transfused red blood cells and important This approach reduces the risk of mistakes in selecting the do-
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clinical outcomes has never been pointed out. Nevertheless, nor in the field. It requires a selection of the electable poten-
one might consider a potential beneficial effect of fresh whole tial donors prior to the deployment. Initially developed among
blood in the context of the hemorrhagic shock, notably for the Norwegian SOF and the 75th Ranger Regiment, this approach
repayment of the oxygen debt. is nowadays allowed in many Western armed forces. 2,22–24
Many militaries, including the US Armed Forces, collect blood
In many studies, it seems that WB could be more effective for only from low-titer O donors, thus preventing the risk of ABO
a bleeding patient, especially for war-injured personnel. 13,14 mismatch. Although other countries, notably France, allow
Moreover, during such a procedure, the blood transfused to this approach, they give priority to group-specific donors be-
the injured will be warm. This will also help fight hypother- cause the antierythrocyte titer can vary in a lifetime for the
mia, which is one of the components of the lethal triad. It is for same donor. 16,25 These two approaches both seem consistent;
this reason that the Tactical Combat Casualty Care (TCCC) the most important thing is to define upstream procedures
guidelines, as in the French Armed Forces transfusion policy, adapted to the way that forward medical support works for
whole blood is the most recommended resuscitation fluid for each country.
casualties in hemorrhagic shock. 15,16
The risk of TTD transmission must also be considered. Mo-
lecular biology or serology cannot be performed on the bat-
Are “Buddy Transfusions” Safe for the Donor?
tlefield. Rapid tests for only the most common and serious
The first question to ask is whether the donor has the capability TTDs are available under these conditions. A strict protocol
to carry on with the mission and even resume fighting after for prescreening potential donors and meeting local regula-
a blood donation. Two studies led by the Norwegian Naval tory and legal requirements must be in place to control this
Special Operations Commandos explored this issue. The first risk before implementing a “buddy transfusion” program in a
study showed, under experimental conditions, that well-trained unit. The medical selection of volunteer donors is fundamen-
Soldiers, after a blood donation of 450mL, did not show a de- tal. Preferably, it is done upstream. Volunteer donors can thus
crease in endurance capacity or shooting skills. Another study, undergo a medical interview and medical examination during
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which was randomized and double-blinded, was conducted which they are informed about TTDs. Each reason to defer
after a prolonged escape field exercise as a way to simulate blood donation is queried, including recent risk behaviors.
the severe fatigue of deployed conditions (6 days, with a mean Laboratory testing can also be performed before deployment.
weight loss of 3 kg for each participant). Although relative and The duration of validity of the tests differs from country to
absolute maximal oxygen uptake (VO max) decreased after country, ranging from a single blood donation for Norway to
2
a 450mL blood donation, there was no significant difference 12 months for France and the United States. If this cannot
in physical performance between Soldiers who had donated be anticipated before deployment, donors must be selected in
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blood compared to those who did not. These results were the operation theater solely on the basis of medical interview
from Special Operations Forces Soldiers, who were well trained data. Medical teams must be trained to perform such a selec-
and probably very motivated and cannot be generalized to the tion. Some authors have developed questionnaires operable by
general population or even to all Soldiers. Nevertheless, it still a nonphysician if no medical personnel are on site. The most
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shows the feasibility of a blood donation in the field. It is rec- rigorous selection of donors, in addition to the use of rapid
ommended that the donor drink a volume of at least 500mL diagnostic tests on the battlefield, allows control of the risk
during the blood donation to limit the risk of syncope. 18,19 enough to be lower than the expected benefit of a WB transfu-
sion to a bleeding combat casualty in a remote setting.
Are ”Buddy Transfusions” Safe for the Recipient?
Are “Buddy Transfusions” Medically Adequate
Two major risks for the recipient must be controlled for when for a Bleeding Patient?
considering a warm fresh whole-blood procedure: the risk of
ABO mismatches and the risk of transfusion-transmitted dis- A recent study conducted among French SOF commando can-
eases (TTDs). The former is clearly the more significant. The didates during their selection brings partial answers about the
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latter often worries Soldiers and it is important to explain that hemostatic capacities of such blood. Considering the selec-
it is controlled. tion course as an experimental model by placing participants
into the same physiological conditions as those faced by de-
Mismatch of ABO blood group is preventable with compliance ployed fighters, the authors compared coagulation markers at
to standard clinical transfusion practice. However, with stress the beginning and after six weeks of course. These data suggest
and fatigue due to combat, human errors may occur. When the that there is no obvious modification of hemostatic properties
procedure is implemented in a unit, potential blood donors are and that their blood could be well adapted for a war-injured
prescreened before deployment; thus, blood types of each Op- patient for a “buddy transfusion” procedure. Such modifica-
erator are listed beforehand. This procedure allows for control tions are incontestably beneficial for the hemorrhaging patient
of this ABO mismatch risk. Some countries, including France, (increased fibrinogen level and shortened prothrombin time
add a systematic blood group check of both donor and patient and activated partial thromboplastin time at 6 weeks). A de-
before donation on the field, using rapid ABO testing (devices creased thrombin generation is also pointed out, which may
with predried reagents). 20 reflect lower levels of circulating procoagulant proteins, as

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