Risk Management Analysis of Air Ambulance Blood Product Administration in Combat Operations
Between June-October 2012, 61 flight-medic-directed transfusions took place aboard U.S. Army Medical Evacuation (medevac) helicopters in Afghanistan. This represents the initial experience for pre-hospital blood product transfusion by U.S. Army flight medics.
We performed a retrospective review of clinical records, operating guidelines, after-action reviews, decision and information briefs, bimonthly medical conferences, and medevac-related medical records.
A successful program was administered at 10 locations across Afghanistan. Adherence to protocol transfusion indications was 97%. There were 61 casualties who were transfused without any known instance of adverse reaction or local blood product wastage. Shock index (heart rate/systolic blood pressure) improved significantly en route, with a median shock index of 1.6 (IQR 1.2-2.0) pre-transfusion and 1.1 (IQR 1.0-1.5) post-transfusion (P < 0.0001). Blood resupply, training, and clinical procedures were standardized across each of the 10 areas of medevacoperations.
Potential risks of medical complications, reverse propaganda, adherence to protocol, and diversion and/or wastage of limited resources were important considerations in the development of the pilot program. Aviation-specific risk mitigation strategies were important to ensure mission success in terms of wastage prevention, standardized operations at multiple locations, and prevention of adverse clinical outcomes. Consideration of aviation risk mitigation strategies may help enable other helicopter emergency medical systems to develop remote pre-hospital transfusion capability. This pilot program provides preliminary evidence that blood product administration by medevac is safe.
Les nouvelles modalités de transfusion mettent en avant le bénéfice de l'apport précoce de plasma. Les contraintes logistiques liées à l'emploi de plasma frais sont réelles. L'emploi de plasma lyophilisé permet de raccourcir ce délai et peut représenter dans certaines conditions d'isolement la seule source disponibles de fractions coagulantes. Le plasma lyophylisé est un vieux monsieur, mais dont la place est fondamentale. Largement utilisé notamment par l'armée française pendant la guerre d'indocchine, le SSA a maintenu sa production jusqu'à ce que l'épidémie de VIH ne survienne. Depuis les années 1980, le SSA a travaillé sans relâche pour sécuriser un produit qui retrouve la place qui lui est due dans la stratégie transfusionnelle du blessé de guerre (1) Il s'agit donc d'une redécouverte avec un emploi effectif en opération dès 1996 (2), plutôt que de révolution. Le document proposé à la lecture fait le point sur cette historique et les développements à venir. La lecture de ce document ne doit pas faire oublier la réflexion de plus en plus présente sur l'emploi en situation d'isolement de l'intérêt de la transfusion de sang total, seule source de plaquettes, associé au recours à des fractions coagulantes comme le fibrinogène et les complexes prothrombiques. Une telle association représente probablement l'avenir de la réanimation hémostatique préhospitalière (3, 4).
Historical dried plasma development Event Selected References
1930s Plasma lyophilization developed in the 1930s.
1940—Large scale production of pooled, lyophilized plasma by both the US and British established for war time use (to meet logistical constraints of whole blood and frozen/liquid plasma).ans les années
1941—Spray dried plasma produced for the Swedish Defense Department. 21 WWII Production 20-22 British produced >500,000 U lyophilized plasma during WWII. US produced >6,000,000 U lyophilized plasma during WWII. US/British distributed world-wide. Sweden produced approximately 17,000 U spray dried plasma for Sweden and Finland.
1945—Hepatitis 23 Hepatitis as a result of plasma transfusion recognized by the end of WWII. Believed that benefits outweighed the risk.
1945-1952—Hepatitis 24 Attempts at pathogen reduction and reducing pool size not successful. Several deaths in clinical studies of ultraviolet irradiated pooled plasma.
—Department of the Army (Circular 73) directed that, because of the risk of serum hepatitis, the higher cost, and the need to use it for the production of specific globulins, plasma would not be used “to support blood volume” unless dextran was not available.
—Serum albumin replaced plasma as primary resuscitative product for US Forces in Korea.
1968—National Research Council Committee on Plasma and Plasma Substitutes recommended that “the use of whole, pooled human plasma be discouraged and even discontinued unless a clear cut case can be made for its unique requirements.”
The French Military Blood Institute produced dried plasma from 1949 to 1984, and provided over 40,000 units to French military forces during the Indochina War. In 1985, production was discontinued due to risk of HIV infection.
Damage-control resuscitation and emergency laparotomy: Findings from the PROPPR study
The Pragmatic Randomized Optimal Platelet and Plasma Ratios (PROPPR) trial has demonstrated that damage-controlresuscitation, a massive transfusion strategy targeting a balanced delivery of plasma-platelet-red blood cell in a ratio of 1:1:1, results in improved survival at 3 hours and a reduction in deaths caused by exsanguination in the first 24 hours compared with a 1:1:2 ratio. In light of these findings, we hypothesized that patients receiving 1:1:1 ratio would have improved survival after emergency laparotomy.
Severely injured patients predicted to receive a massive transfusion admitted to 12 Level I North American trauma centers were randomized to 1:1:1 versus 1:1:2 as described in the PROPPR trial. From these patients, the subset that underwent an emergency laparotomy, defined previously in the literature as laparotomy within 90 minutes of arrival, were identified. We compared rates and timing of emergency laparotomyas well as postsurgical survival at 24 hours and 30 days.
Of the 680 enrolled patients, 613 underwent a surgical procedure, 397 underwent a laparotomy, and 346 underwent an emergency laparotomy. The percentages of patients undergoing emergency laparotomy were 51.5% (174 of 338) and 50.3% (172 of 342) for 1:1:1 and 1:1:2, respectively (p = 0.20). Median time to laparotomy was 28 minutes in both treatment groups. Among patients undergoing an emergency laparotomy, the proportions of patients surviving to 24 hours and 30 days were similar between treatment arms; 24-hour survival was 86.8% (151 of 174) for 1:1:1 and 83.1% (143 of 172) for 1:1:2 (p = 0.29), and 30-day survival was 79.3% (138 of 174) for 1:1:1 and 75.0% (129 of 172) for 1:1:2 (p = 0.30).
We found no evidence that resuscitation strategy affects whether a patient requires an emergency laparotomy, time to laparotomy, or subsequent survival.