Kurt W. Grathwohl

The ratio of fibrinogen to red cells transfused affects survival in casualties receiving massive transfusions at an army combat support hospital.

BACKGROUND To treat the coagulopathy of trauma, some have suggested early and aggressive use of cryoprecipitate as a source of fibrinogen. Our objective was to determine whether increased ratios of fibrinogen to red blood cells (RBCs) decreased mortality in combat casualties requiring massive transfusion. METHODS We performed a retrospective chart review of 252 patients at a U.S. Army combat support hospital who received a massive transfusion (>or=10 units of RBCs in 24 hours). The typical amount of fibrinogen within each blood product was used to calculate the fibrinogen-to-RBC (F:R) ratio transfused for each patient. Two groups of patients who received either a low (<0.2 g fibrinogen/RBC Unit) or high (>or=0.2 g fibrinogen/RBC Unit) F:R ratio were identified. Mortality rates and the cause of death were compared between these groups, and logistic regression was used to determine if the F:R ratio was independently associated with survival. RESULTS Two-hundred and fifty-two patients who received a massive transfusion with a mean (SD) ISS of 21 (+/-10) and an overall mortality of 75 of 252 (30%) were included. The mean (SD) F:R ratios transfused for the low and high groups were 0.1 grams/Unit (+/-0.06), and 0.48 grams/Unit (+/-0.2), respectively (p < 0.001). Mortality was 27 of 52 (52%) and 48 of 200 (24%) in the low and high F:R ratio groups respectively (p < 0.001). Additional variables associated with survival were admission temperature, systolic blood pressure, hemoglobin, International Normalized Ratio (INR), base deficit, platelet concentration and Combined Injury Severity Score (ISS). Upon logistic regression, the F:R ratio was independently associated with mortality (odds ratio 0.37, 95% confidence interval 0.171-0.812, p = 0.013). The incidence of death from hemorrhage was higher in the low F:R group, 23/27 (85%), compared to the high F:R group, 21/48 (44%) (p < 0.001). CONCLUSIONS In patients with combat-related trauma requiring massive transfusion, the transfusion of an increased fibrinogen: RBC ratio was independently associated with improved survival to hospital discharge, primarily by decreasing death from hemorrhage. Prospective studies are needed to evaluate the best source of fibrinogen and the optimal empiric ratio of fibrinogen to RBCs in patients requiring massive transfusion.

Warm Fresh Whole Blood Is Independently Associated With Improved Survival for Patients With Combat-Related Traumatic Injuries

BACKGROUND Increased understanding of the pathophysiology of the acute coagulopathy of trauma has lead many to question the current transfusion approach to hemorrhagic shock. We hypothesized that warm fresh whole blood (WFWB) transfusion would be associated with improved survival in patients with trauma compared with those transfused only stored component therapy (CT). METHODS We retrospectively studied US Military combat casualty patients transfused >or=1 unit of red blood cells (RBCs). The following two groups of patients were compared: (1) WFWB, who were transfused WFWB, RBCs, and plasma but not apheresis platelets and (2) CT, who were transfused RBC, plasma, and apheresis platelets but not WFWB. The primary outcomes were 24-hour and 30-day survival. RESULTS Of 354 patients analyzed there were 100 in the WFWB and 254 in the CT group. Patients in both groups had similar severity of injury determined by admission eye, verbal, and motor Glasgow Coma Score, base deficit, international normalized ratio, hemoglobin, systolic blood pressure, and injury severity score. Both 24-hour and 30-day survival were higher in the WFWB cohort compared with CT patients, 96 of 100 (96%) versus 223 of 254 (88%), (p = 0.018) and 95% to 82%, (p = 0.002), respectively. An increased amount (825 mL) of additives and anticoagulants were administered to the CT compared with the WFWB group, (p < 0.001). Upon multivariate logistic regression the use of WFWB and the volume of WFWB transfused was independently associated with improved 30-day survival. CONCLUSIONS In patients with trauma with hemorrhagic shock, resuscitation strategies that include WFWB may improve 30-day survival, and may be a result of less anticoagulants and additives with WFWB use in this population.

Effect of plasma and red blood cell transfusions on survival in patients with combat related traumatic injuries.

BACKGROUND The amount and age of stored red blood cells (RBCs) are independent predictors of multiorgan failure and death in transfused critically ill patients. The independent effect of plasma transfusion on survival has not been evaluated. Our objective was to determine the independent effects of plasma and RBC transfusion on survival for patients with combat-related traumatic injuries receiving any blood products. METHODS We performed a retrospective review of 708 patients transfused at least one unit of a blood product at one combat support hospital between November 2003 and December 2004. Admission vital signs, laboratory values, amount of blood products transfused in a 24-hour period, and Injury Severity Score (ISS) were analyzed by multivariate logistic regression to determine independent associations with in-hospital mortality. RESULTS Seven hundred and eight of 3,287 (22%) patients admitted for traumatic injuries were transfused a blood product. Median ISS was 14 (range, 9-25). In-hospital mortality was 12%. Survival was associated with admission Glasgow Coma Scale score, SBP, temperature, hematocrit, base deficit, INR, amount of RBCs transfused, and massive transfusion. Each transfused FFP unit was independently associated with increased survival (OR: 1.17; 95% CI: [1.06-1.29]; p = 0.002); each transfused RBC unit was independently associated with decreased survival (OR: 0.86; [0.8-0.92]; p = 0.001). A subset analysis of patients (n = 567) without massive transfusion (1-9 RBC/FWB units) also revealed an independent association between each FFP unit and improved survival (OR: 1.22; 95% CI: [1.0-1.48]; p = 0.05) and between each RBC unit and decreased survival (OR: 0.77; [0.64-0.92]; p = 0.004). CONCLUSION For trauma patients transfused at least one unit of a blood product, FFP and RBC amounts were independently associated with increased survival and decreased survival, respectively. Prospective studies are needed to determine whether the early and increased use of plasma and decreased use of RBCs affect mortality for patients with traumatic injuries requiring transfusion.

An Evaluation of the Impact of Apheresis Platelets Used in the Setting of Massively Transfused Trauma Patients

INTRODUCTION Trauma is a major cause of morbidity and mortality worldwide. Of patients arriving to trauma centers, patients requiring massive transfusion (MT, >or=10 units in 24 hours) are a small patient subset but are at the highest risk of mortality. Transfusion of appropriate ratios of blood products to such patients has recently been an area of interest to both the civilian and military medical community. Plasma is increasingly recognized as a critical component, though less is known about appropriate ratios of platelets. Combat casualties managed at the busiest combat hospital in Iraq provided an opportunity to examine this question. METHODS In-patient records for 8,618 trauma casualties treated at the military hospital in Baghdad more than a 3-year interval between January 2004 and December 2006 were retrospectively reviewed and patients requiring MT (n = 694) were identified. Patients who required MT in the first 24 hours and did not receive fresh whole blood were divided into study groups defined by source of platelets: (1) patient receiving a low ratio of platelets (<1:16 apheresis platelets per stored red cell unit, aPLT:RBC) (n = 214), (2) patients receiving a medium ratio of platelets (1:16 to <1:8 aPLT:RBC) (n = 154), and (3) patients receiving a high ratio of platelets (>or=1:8 aPLT:RBC) (n = 96). The primary endpoint was survival at 24 hours and at 30 days. RESULTS At 24 hours, patients receiving a high ratio of platelets had higher survival (95%) as compared with patients receiving a medium ratio (87%) and patients receiving the lowest ratio of platelets (64%) (log-rank p = 0.04 and p < 0.001, respectively). The survival benefit for the high and medium ratio groups remained at 30 days as compared with those receiving the lowest ratio of platelets (75% and 60% vs. 43%, p < 0.001 for both comparisons). On multivariate regression, plasma:RBC ratios and aPLT:RBC were both independently associated with improved survival at 24 hours and at 30 days. CONCLUSION Transfusion of a ratio of >or=1:8 aPLT:RBC is associated with improved survival at 24 hours and at 30 days in combat casualties requiring a MT within 24 hours of injury. Although prospective study is needed to confirm this finding, MT protocols outside of investigational research should consider incorporation of appropriate ratios of both plasma and platelets.

The effect of recombinant activated factor VII on mortality in combat-related casualties with severe trauma and massive transfusion

BACKGROUND The majority of patients with potentially survivable combat-related injuries die from hemorrhage. Our objective was to determine whether the use of recombinant activated factor VII (rFVIIa) decreased mortality in combat casualties with severe trauma who received massive transfusions and if its use was associated with increased severe thrombotic events. METHODS We retrospectively reviewed a database of combat casualty patients with severe trauma (Injury Severity Score [ISS] >15) and massive transfusion (red blood cell [RBCs] >/=10 units/24 hours) admitted to one combat support hospital in Baghdad, Iraq, between December 2003 and October 2005. Admission vital signs and laboratory data, blood products, ISS, 24-hour and 30-day mortality, and severe thrombotic events were compared between patients who received rFVIIa (rFVIIa) and did not receive rFVIIa (rFVIIa). RESULTS Of 124 patients in this study, 49 patients received rFVIIa and 75 did not. ISS, laboratory values, and admission vitals did not differ between rFVIIa and rFVIIa groups, except for systolic blood pressure (mm Hg) 105 +/- 33 and 92 +/- 28, p = 0.02 and temperature ( degrees F) 96.3 +/- 2.1 and 95.2 +/- 2.4, p = 0.03, respectively. Interactions between all vital signs and laboratory values measured upon admission, to include systolic blood pressure and temperature, were not significant when measured between rFVIIa use and 30-day mortality. Twenty-four-hour mortality was 7 of 49 (14%) in rFVIIa and 26 of 75 (35%) in rFVIIa, (p = 0.01); 30-day mortality was 15 of 49 (31%) and 38 of 75 (51%), (p = 0.03). Death from hemorrhage was 8 of 14 (57%) for rFVIIa patients compared with 29 of 37 (78%) for rFVIIa patients, (p = 0.12). The incidence of severe thrombotic events was similar in both groups. CONCLUSIONS The early use of rFVIIa was associated with decreased 30-day mortality in severely injured combat casualties requiring massive transfusion, but was not associated with increased risk of severe thrombotic events.

Risks associated with fresh whole blood and red blood cell transfusions in a combat support hospital

Objective:Fresh whole blood (FWB) and red blood cells (RBCs) are transfused to injured casualties in combat support hospitals. We evaluated the risks of FWB and RBCs transfused to combat-related casualties. Design:Retrospective chart review. Setting:Deployed U.S. Army combat support hospitals. Subjects:Donors of FWB and recipients of FWB and RBCs. Measurements and Results:The storage age of RBCs at transfusion was measured as an indicator of overall risk associated with the storage lesion of RBCs between January 2004 and December 2004 at one combat support hospital. Between April 2004 and December 2004, FWB was prescreened only at one combat support hospital for human immunodeficiency virus, hepatitis C virus, and hepatitis B surface antigen before transfusion. To estimate the general incidence of infectious agent contamination in FWB units, samples collected between May 2003 and February 2006 were tested retrospectively for human immunodeficiency virus, hepatitis B surface antigen, hepatitis C virus, and human lymphotropic virus. Results were compared between FWB samples prescreened and not prescreened for infectious agents before transfusion. At one combat support hospital in 2004, 87 patients were transfused 545 units of FWB and 685 patients were transfused 5,294 units of RBCs with a mean age at transfusion of 33 days (±6 days). Retrospective testing of 2,831 samples from FWB donor units transfused in Iraq and Afghanistan between May 2003 and February 2006 indicated that three of 2,831 (0.11%) were positive for hepatitis C virus recombinant immunoblot assay, two of 2,831 (0.07%) were positive for human lymphotropic virus enzyme immunoassay, and none of 2,831 were positive for both human immunodeficiency virus 1/2 and hepatitis B surface antigen by Western blot and neutralization methods, respectively. The differences in the incidence of hepatitis C virus contamination of FWB donor units between those prescreened for hepatitis C virus (zero of 406; 0%) and not prescreened (three of 2,425; 0.12%) were not significant (p = .48). Conclusions:The risk of infectious disease transmission with FWB transfusion can be minimized by rapid screening tests before transfusion. Because of the potential adverse outcomes of transfusing RBCs of increased storage age to combat-related trauma patients, the risks and benefits of FWB transfusions must be balanced with those of transfusing old RBCs in patients with life-threatening traumatic injuries.

Comparison of Platelet Transfusion as Fresh Whole Blood Versus Apheresis Platelets for Massively Transfused Combat Trauma patients

BACKGROUND: At major combat hospitals, the military is able to provide blood products to include apheresis platelets (aPLT), but also has extensive experience using fresh whole blood (FWB). In massively transfused trauma patients, we compared outcomes of patients receiving FWB to those receiving aPLT.

Continuous noninvasive tissue oximetry in the early evaluation of the combat casualty: a prospective study

BACKGROUND We hypothesized that near-infrared spectroscopy (NIRS)-derived tissue oxygenation saturation (StO2) could assist in identifying shock in casualties arriving to a combat support hospital and predict the need for life-saving interventions (LSIs) and blood transfusions. METHODS We performed a prospective observational trial at a single US Army combat support hospital in Iraq from August to December 2007. Arriving casualties had NIRS-derived StO2 recorded in the emergency department. Minimum (StO2 min) and initial 2-minute averaged StO2 and tissue hemoglobin index readings were used as end points. Outcomes measured were requirement for LSIs, any blood transfusion, massive transfusion (>10 units in 24 hours), and early mortality. The data were subjected to univariate and multivariate logistic regression modeling. RESULTS Of the 147 combat casualties enrolled in the trial, 72 (49%) required an LSI, 42 (29%) required blood transfusion, and 10 (7%) required massive transfusion. On multivariate logistic regression analysis of the whole study group, systolic blood pressure (SBP), international normalized ratio, tissue hemoglobin index, and hematocrit predicted blood transfusion with an area under the curve of 0.90 (0.84-0.96), with a confidence interval of 95%. When just the group with an SBP >90 was analyzed, independent predictors of patients requiring blood transfusion on logistic regression analysis were StO2 min (odds ratio of 1.35) and hematocrit (odds ratio of 2.66) for an area under the curve of 0.84 (0.76-0.92). CONCLUSIONS NIRS-derived StO2 obtained on arrival predicts the need for blood transfusion in casualties who initially seem to be hemodynamically stable (SBP >90). Further study of this technology for use in the resuscitation of trauma patients is warranted.

Critical care in the austere environment: providing exceptional care in unusual places.

Background:War and other disasters are inexorably linked to illness and injury. As a consequence of this, healthcare providers will be challenged to provide advanced physiological support to preserve human life. Given the mobility and modularity of modern medical systems, the ability to provide critical care outside of the confines of traditional hospitals under such circumstances has become not only a reality and periodic necessity, but an expectation. Austerity amplifies the complexity of providing high-level critical care, because resources are frequently limited, providers are asked to fill unexpected roles determined by necessity, security may be threatened, and the population at risk and their afflictions can be highly diverse. Discussion:Our current deployed military medical experience and a review of published literature pertaining to civilian medical disaster response efforts support these stated challenges. The fundamentals of successful critical care practice in unusual settings include proper planning with an emphasis on attention to detail, the careful management of all resources, using the proper equipment, leveraging aeromedical evacuation assets, and employing the right people with the right skills. Summary:Adherence to sound, evidence-based, routine practice, within bounds of the circumstances, must underscore everything.

Organizational characteristics of the austere intensive care unit: The evolution of military trauma and critical care medicine; applications for civilian medical care systems

Critical care in the U.S. military has significantly evolved in the last decade. More recently, the U.S. military has implemented organizational changes, including the use of multidisciplinary teams in austere environments to improve outcomes in severely injured polytrauma combat patients. Specifically, organizational changes in combat support hospitals located in combat zones during Operation Iraqi Freedom have led to decreased intensive care unit mortality and length of stay as well as resource use. These changes were implemented without increases in logistic support or the addition of highly technologic equipment. The mechanism for improvement in mortality is likely attributable to the adherence of basic critical care medicine fundamentals. This intensivist-directed team model provides sophisticated critical care even in the most austere environments. To optimize critically injured patients’ outcomes, intensive care organizational models similar to the U.S. military, described in this article, can possibly be adapted to those of civilian care during disaster management to meet the challenges of emergency mass critical care.