A survey of low titer O whole blood use within the trauma quality improvement program registry.

INTRODUCTION: The use of low titer O whole blood (LTOWB) has expanded although it remains unclear how many civilian trauma centers are using LTOWB. METHODS: We analyzed data on civilian LTOWB recipients in the American College of Surgeons Trauma Quality Improvement Program (TQIP) database 2020-2021. Unique facility keys were used to determine the number of centers that used LTOWB in that period. RESULTS: A total of 16,603 patients received LTOWB in the TQIP database between 2020 and 2021; 6600 in 2020, and 10,003 in 2021. The total number of facilities that reported LTOWB use went from 287/779 (37%) in 2020 to 302/795 (38%) in 2021. Between 2020 and 2021, among all level 1-3 designated trauma facilities that report to TQIP LTOWB use increased at level-1 centers (118 to 129), and level-2 centers (81 to 86), but decreased in level-3 facilities (9 to 4). Among pediatric and dual pediatric-adult designated hospitals there was a decrease in the number of pediatric level-1 centers (29 to 28) capable of administering LTOWB. Among centers with either single or dual level-1 trauma center designation with adult centers, the number that administered LTOWB to injured pediatric patients also decreased from 17 to 10, respectively. CONCLUSIONS: There was an increase in the number of facilities transfusing LTOWB between 2020 and 2021. The use of LTOWB is underutilized in children at centers that have it available. These findings inform the expansion of LTOWB use in trauma.

Compensatory reserve and pulse character: Enhanced potential to predict urgency for transfusion and other life-saving interventions after traumatic injury.

BACKGROUND: Field triage of trauma patients requires timely assessment of physiologic status to determine resuscitative needs. Vital signs and rudimentary assessments such as pulse character (PC) are used by first responders to guide decision making. The compensatory reserve measurement (CRM) has demonstrated utility as an easily interpretable method for assessing patient status. We hypothesized that the ability to identify injured patients requiring transfusion and other life-saving interventions (LSI) using a measurement of pulse character could be enhanced by the addition of the CRM. METHODS: We performed a prospective observational study on 300 trauma patients admitted to a level I trauma center. CRM was recorded continuously after device placement on arrival. Patient demographics, field and trauma resuscitation unit vital signs, therapeutic interventions, and outcomes were collected. A field SBP <100 mmHg was utilized as a surrogate for abnormal PC as previously validated. A patient with a CRM threshold value of <60% was considered clinically compromised with a risk of onset of decompensated shock. Data were analyzed to assess the capacity of CRM and pulse character separately or in combination to predict LSI defined as need for transfusion, intubation, tube thoracostomy, or operative/ angiographic hemorrhage control. RESULTS: An improvement in the predictive capability for LSI, transfusion, or a composite outcome was demonstrated by the combination of CRM and PC compared to either measure alone. CONCLUSIONS: Combining PC assessment with CRM has the potential to enhance the recognition of injured patients requiring life-saving intervention thus improving sensitivity of decision support for prehospital providers.

The regional whole blood program in San Antonio, TX: A 3-year update on prehospital and in-hospital transfusion practices for traumatic and non-traumatic hemorrhage.

Low titer type O Rh-D + whole blood (LTO + WB) has become a first-line resuscitation medium for hemorrhagic shock in many centers around the World. Showing early effectiveness on the battlefield, LTO + WB is used in both the pre-hospital and in-hospital settings for traumatic and non-traumatic hemorrhage resuscitation. Starting in 2018, the San Antonio Whole Blood Collaborative has worked to provide LTO + WB across Southwest Texas, initially in the form of remote damage control resuscitation followed by in-hospital trauma resuscitation. This program has since expanded to include pediatric trauma resuscitation, obstetric hemorrhage, females of childbearing potential, and non-traumatic hemorrhage. The objective of this manuscript is to provide a three-year update on the successes and expansion of this system and outline resuscitation challenges in special populations.

Trauma-induced lung injury is associated with infiltration of activated TLR expressing myeloid cells.

INTRODUCTION: Traumatic injury with hemorrhage (TH) induces an inflammatory response in the lung resulting in lung injury involving activation of immune cells including myeloid cells (i.e., monocytes, granulocytes and macrophages), in part through TLRs. TLRs, via the recognition of damage associated molecular patterns (DAMPs), are a key link between tissue injury and inflammation. Nonetheless, the role of TLRs in myeloid cell activation and TH-induced lung injury remains ill defined. METHODS: C57BL/6 male mice were subjected to TH or sham treatment (n = 4-6 /group). Lung tissues were collected two hrs. after injury. Single cells were isolated from the lungs by enzymatic digestion and myeloid cell TLR expression and activation (i.e., cytokine production) were assessed using flow cytometry techniques. RESULTS: The injury was associated with a profound change in the lung myeloid cell population. TH markedly increased lung CD11b+ monocyte numbers and Gr1+ granulocyte numbers as compared to sham mice. The number of cells expressing TLR2, TLR4, and TLR9 were increased 4-7 fold in the TH mice. Activation for elevated cytokine (TNFα, IL-10) production was observed in the lung monocyte population of the TH mice. CONCLUSIONS: Trauma-induced lung injury is associated with infiltration of the lungs with TLR expressing myeloid cells that are activated for elevated cytokine responses. This elevation in TLR expression may contribute to DAMP-mediated pulmonary complications of an inflammatory nature and warrants further investigation.

Compensatory reserve detects subclinical shock with more expeditious prediction for need of life-saving interventions compared to systolic blood pressure and blood lactate.

INTRODUCTION: We conducted a prospective observational study on 205 trauma patients at a level I trauma facility to test the hypothesis that a compensatory reserve measurement (CRM) would identify higher risk for progression to shock and/or need a life-saving interventions (LSIs) earlier than systolic blood pressure (SBP) and blood lactate (LAC). METHODS: A composite outcome metric included blood transfusion, procedural LSI, and mortality. Discrete measures assessed as abnormal (ab) were SBP <90 mmHg, CRM <60%, and LAC >2.0. A graded categorization of shock was defined as: no shock (normal [n] SBP [n-SBP], n-CRM, n-LAC); sub-clinical shock (ab-CRM, n-SBP, n-LAC); occult shock (n-SBP, ab-CRM, ab-LAC); or overt shock (ab-SBP, ab-CRM, ab-LAC). RESULTS: Three patients displayed overt shock, 53 displayed sub-clinical shock, and 149 displayed no shock. After incorporating lactate into the analysis, 86 patients demonstrated no shock, 25 were classified as sub-clinical shock, 91 were classified as occult shock, and 3 were characterized as overt shock. Each shock subcategory revealed a graded increase requiring LSI and transfusion. Initial CRM was associated with progression to shock (odds ratio = 0.97; p < .001) at an earlier time than SBP or LAC. CONCLUSIONS: Initial CRM uncovers a clinically relevant subset of patients who are not detected by SBP and LAC. Our results suggest CRM could be used to more expeditiously identify injured patients likely to deteriorate to shock, with requirements for blood transfusion or procedural LSI.

More sophisticated than a drink cooler or an old sphygmomanometer but still not adequate for prehospital blood: A market review of commercially available equipment for prehospital blood transport and administration.

BACKGROUND: Hemorrhage is the leading cause of death in trauma patients with most fatalities occurring before reaching a higher level of care-this applies to both the civilian setting and the military combat setting. Hemostatic resuscitation with increased emphasis on blood transfusion while limiting use of crystalloids has become routine in trauma care. However, the prehospital setting-especially in combat-presents unique challenges with regard to storage, transport, and administration. We sought to evaluate available technology on the market for storage and administration technology that is relevant to the prehospital setting. STUDY DESIGN AND METHODS: We conducted a market review of available technology through subject-matter expert inquiry, reviews of published literature, reviews of Federal Drug Administration databases, internal military publications, and searches of Google. RESULTS: We reviewed and described a total of 103 blood transporters, 22 infusers, and 6 warmers. CONCLUSIONS: The risk of on-scene fatality in trauma patients and recent developments in trauma care demonstrate the need for prehospital transfusion. These transfusions have been logistically prohibited in many operations. We have reviewed the current commercially available equipment and recommended pursuit of equipment that improves accessibility to field transfusion. Current technology has limited applicability for the prehospital setting and is further limited for the military setting.

Prehospital whole blood reduces early mortality in patients with hemorrhagic shock.

BACKGROUND: Low titer O+ whole blood (LTOWB) is being increasingly used for resuscitation of hemorrhagic shock in military and civilian settings. The objective of this study was to identify the impact of prehospital LTOWB on survival for patients in shock receiving prehospital LTOWB transfusion. STUDY DESIGN AND METHODS: A single institutional trauma registry was queried for patients undergoing prehospital transfusion between 2015 and 2019. Patients were stratified based on prehospital LTOWB transfusion (PHT) or no prehospital transfusion (NT). Outcomes measured included emergency department (ED), 6-h and hospital mortality, change in shock index (SI), and incidence of massive transfusion. Statistical analyses were performed. RESULTS: A total of 538 patients met inclusion criteria. Patients undergoing PHT had worse shock physiology (median SI 1.25 vs. 0.95, p < .001) with greater reversal of shock upon arrival (-0.28 vs. -0.002, p < .001). In a propensity-matched group of 214 patients with prehospital shock, 58 patients underwent PHT and 156 did not. Demographics were similar between the groups. Mean improvement in SI between scene and ED was greatest for patients in the PHT group with a lower trauma bay mortality (0% vs. 7%, p = .04). No survival benefit for patients in prehospital cardiac arrest receiving LTOWB was found (p > .05). DISCUSSION: This study demonstrated that trauma patients who received prehospital LTOWB transfusion had a greater improvement in SI and a reduction in early mortality. Patient with prehospital cardiac arrest did not have an improvement in survival. These findings support LTOWB use in the prehospital setting. Further multi-institutional prospective studies are needed.

From battlefront to homefront: creation of a civilian walking blood bank.

Hemorrhagic shock remains the leading cause of preventable death on the battlefield, despite major advances in trauma care. Early initiation of balanced resuscitation has been shown to decrease mortality in the hemorrhaging patient. To address transfusion limitations in austere environments or in the event of multiple casualties, walking blood banks have been used in the combat setting with great success. Leveraging the success of the region-wide whole blood program in San Antonio, Texas, we report a novel plan that represents a model response to mass casualty incidents.

Burn injury is associated with an infiltration of the wound site with myeloid-derived suppressor cells.

Myeloid-derived suppressor cells (MDSCs) have been identified in the burn wound, however their characterization is incomplete. To study this, mice were subjected to a major burn and skin cells were isolated 3 days thereafter for analysis. Significant infiltration of the burn wound with MDSCs was observed as compared with uninjured skin. The skin of naïve mice did not contain MDSCs. Characterization of the cells showed that 33% of MDSCs in the wound were monocytic (M)-MDSCs, which was significantly less than that found in uninjured skin (52%). In contrast, polymorphonuclear (PMN)-MDSCs were greater in the burn wound as compared with uninjured skin. Burn wound TLR expression by both MDSCs subsets was decreased as compared with uninjured skin. Wound MDSCs produced pro- and anti-inflammatory cytokines and iNOS was present in both MDSC subsets, whereas ARG1 was only present in M-MDSCs. In conclusion, both M- and PMN-MDSCs infiltrate burn wound with after injury, however, they displayed decreased TLR expression, suggesting receptor down-regulation.

Give the trauma patient what they bleed, when and where they need it: establishing a comprehensive regional system of resuscitation based on patient need utilizing cold-stored, low-titer O+ whole blood.

BACKGROUND: Despite countless advancements in trauma care a survivability gap still exists in the prehospital setting. Military studies clearly identify hemorrhage as the leading cause of potentially survivable prehospital death. Shifting resuscitation from the hospital to the point of injury has shown great promise in decreasing mortality among the severely injured. MATERIALS AND METHODS: Our regional trauma network (Southwest Texas Regional Advisory Council) developed and implemented a multiphased approach toward facilitating remote damage control resuscitation. This approach required placing low-titer O+ whole blood (LTO+ WB) at helicopter emergency medical service bases, transitioning hospital-based trauma resuscitation from component therapy to the use of whole blood, modifying select ground-based units to carry and administer whole blood at the scene of an accident, and altering the practices of our blood bank to support our new initiative. In addition, we had to provide information and training to an entire large urban emergency medical system regarding changes in policy. RESULTS: Through a thorough, structured program we were able to successfully implement point-of-injury resuscitation with LTO+ WB. Preliminary evaluation of our first 25 patients has shown a marked decrease in mortality compared to our historic rate using component therapy or crystalloid solutions. Additionally, we have had zero transfusion reactions or seroconversions. CONCLUSION: Transfusion at the scene within minutes of injury has the potential to save lives. As our utilization expands to our outlying network we expect to see a continued decrease in mortality among significantly injured trauma patients.

Spinal cord injury and the human microbiome: beyond the brain-gut axis.

In addition to standard management for the treatment of the acute phase of spinal cord injury (SCI), implementation of novel neuroprotective interventions offers the potential for significant reductions in morbidity and long-term health costs. A better understanding of the systemic changes after SCI could provide insight into mechanisms that lead to secondary injury. An emerging area of research involves the complex interplay of the gut microbiome and the CNS, i.e., a brain-gut axis, or perhaps more appropriately, a CNS-gut axis. This review summarizes the relevant literature relating to the gut microbiome and SCI. Experimental models in stroke and traumatic brain injury demonstrate the bidirectional communication of the CNS to the gut with postinjury dysbiosis, gastrointestinal-associated lymphoid tissue-mediated neuroinflammatory responses, and bacterial-metabolite neurotransmission. Similar findings are being elucidated in SCI as well. Experimental interventions in these areas have shown promise in improving functional outcomes in animal models. This commensal relationship between the human body and its microbiome, particularly the gut microbiome, represents an exciting frontier in experimental medicine.

The Cutaneous Microbiome and Wounds: New Molecular Targets to Promote Wound Healing.

The ecological community of microorganisms in/on humans, termed the microbiome, is vital for sustaining homeostasis. While culture-independent techniques have revealed the role of the gut microbiome in human health and disease, the role of the cutaneous microbiome in wound healing is less defined. Skin commensals are essential in the maintenance of the epithelial barrier function, regulation of the host immune system, and protection from invading pathogenic microorganisms. In this review, we summarize the literature derived from pre-clinical and clinical studies on how changes in the microbiome of various acute and chronic skin wounds impact wound healing tissue regeneration. Furthermore, we review the mechanistic insights garnered from model wound healing systems. Finally, in the face of growing concern about antibiotic-resistance, we will discuss alternative strategies for the treatment of infected wounds to improve wound healing and outcomes. Taken together, it has become apparent that commensals, symbionts, and pathogens on human skin have an intimate role in the inflammatory response that highlights several potential strategies to treat infected, non-healing wounds. Despite these promising results, there are some contradictory and controversial findings from existing studies and more research is needed to define the role of the human skin microbiome in acute and chronic wound healing.

Toll-like receptor responses are suppressed in trauma ICU patients.

BACKGROUND: Inflammation and activation of the innate immune system are often associated with traumatic injury and may involve alterations in toll-like receptor (TLR)-mediated responses. METHODS: A prospective observational study was designed and conducted. Twenty-one severely injured (ISS = 16-41) trauma intensive care unit (ICU) patients and six healthy volunteers that served as controls were enrolled. Anticoagulated whole blood was collected at 2-12 d after ICU admission and incubated in the presence of media alone (baseline), zymosan (TLR2 agonist) or lipopolysaccharide (LPS; TLR4 agonist) for 3 h. Supernatant levels of inflammatory cytokines (IL-1ß, IL-6, IL-10, and TNFα) were determined. RESULTS: TLR2-mediated and TLR4-mediated activation of whole blood cell cultures from both healthy volunteers and subjects-induced elevated cytokine levels over that observed in unstimulated cultures. Baseline values of IL-6 were significantly elevated in subject cultures as compared to healthy volunteers. Healthy volunteer cultures had 2-3-fold greater levels of IL-6 and TNFα than subject cultures when stimulated with zymosan (TLR2 agonist) or LPS (TLR4 agonist). IL-1ß and IL-10 levels did not differ significantly between healthy volunteers and subjects. CONCLUSIONS: The ability of circulating leukocytes from trauma ICU patients to be activated by TLR agonists is markedly suppressed and may play a role in the development of subsequent infectious complications.

Complement as a vital nexus of the pathobiological connectome for acute respiratory distress syndrome: An emerging therapeutic target.

The hallmark of acute respiratory distress syndrome (ARDS) pathobiology is unchecked inflammation-driven diffuse alveolar damage and alveolar-capillary barrier dysfunction. Currently, therapeutic interventions for ARDS remain largely limited to pulmonary-supportive strategies, and there is an unmet demand for pharmacologic therapies targeting the underlying pathology of ARDS in patients suffering from the illness. The complement cascade (ComC) plays an integral role in the regulation of both innate and adaptive immune responses. ComC activation can prime an overzealous cytokine storm and tissue/organ damage. The ARDS and acute lung injury (ALI) have an established relationship with early maladaptive ComC activation. In this review, we have collected evidence from the current studies linking ALI/ARDS with ComC dysregulation, focusing on elucidating the new emerging roles of the extracellular (canonical) and intracellular (non-canonical or complosome), ComC (complementome) in ALI/ARDS pathobiology, and highlighting complementome as a vital nexus of the pathobiological connectome for ALI/ARDS via its crosstalking with other systems of the immunome, DAMPome, PAMPome, coagulome, metabolome, and microbiome. We have also discussed the diagnostic/therapeutic potential and future direction of ALI/ARDS care with the ultimate goal of better defining mechanistic subtypes (endotypes and theratypes) through new methodologies in order to facilitate a more precise and effective complement-targeted therapy for treating these comorbidities. This information leads to support for a therapeutic anti-inflammatory strategy by targeting the ComC, where the arsenal of clinical-stage complement-specific drugs is available, especially for patients with ALI/ARDS due to COVID-19.

Burden of unintentional pediatric firearm injury: An examination of the Nationwide Readmission Database.

BACKGROUND: Significant increases in firearm-related mortality in the US pediatric population drive an urgent need to study these injuries to drive prevention policies. The purpose of this study was (1) to characterize those with and without readmissions, (2) to identify risk factors for 90-day unplanned readmission, and (3) to examine reasons for hospital readmission. METHODS: The 2016-2019 Nationwide Readmission Database of the Healthcare Cost and Utilization Project was used to identify hospital admissions with unintentional firearm injury in patients younger than 18 years. Ninety-day unplanned readmission characteristics were assessed and detailed. Multivariable regression analysis was used to assess factors associated with unplanned 90-day readmission. RESULTS: Over 4 years, 1,264 unintentional firearm injury admissions resulted in 113 subsequent readmissions (8.9%). There were no significant differences in age or payor, but more women (14.7% vs. 23%) and older children (13-17 years [80.5%]) had readmissions. The mortality rate during primary hospitalization was 5.1%. Survivors of initial firearm injury were more frequently readmitted if they had a mental health diagnosis (22.1% vs. 13.8%; p = 0.017). Readmission diagnosis included complications (15%), mental health or drug/alcohol (9.7%), trauma (33.6%), a combination of the prior three (28.3%), and chronic disease (13.3%). More than a third (38.9%) of the trauma readmissions were for new traumatic injury. Female children, those with longer lengths of stay, and those with more severe injuries were more likely to have unplanned 90-day readmissions. Mental health and drug/alcohol abuse diagnoses were not an independent predictor for readmission. CONCLUSION: This study provides insight into the characteristics of and risk factors for unplanned readmission in the pediatric unintentional firearm injury population. In addition to using prevention strategies, the utilization of trauma-informed care must be integrated into all aspects of care for this population to help minimize the long-term psychological impact of surviving firearm injury. LEVEL OF EVIDENCE: Prognostic and Epidemiological; Level IV.

Risk of Harm in Needle Decompression for Tension Pneumothorax.

INTRODUCTION: Tension pneumothorax (TPX) is the third most common cause of preventable death in trauma. Needle decompression at the fifth intercostal space at anterior axillary line (5th ICS AAL) is recommended by Tactical Combat Casualty Care (TCCC) with an 83-mm needle catheter unit (NCU). We sought to determine the risk of cardiac injury at this site. METHODS: Institutional data sets from two trauma centers were queried for 200 patients with CT chest. Inclusion criteria include body mass index of =30 and age 18-40 years. Measurements were taken at 2nd ICS mid clavicular line (MCL), 5th ICS AAL and distance from the skin to pericardium at 5th ICS AAL. Groups were compared using Mann-Whitney U and chi-squared tests. RESULTS: The median age was 27 years with median BMI of 23.8 kg/m2. The cohort was 69.5% male. Mean chest wall thickness at 2nd ICS MCL was 38-mm (interquartile range (IQR) 32-45). At 5th ICS AAL, the median chest wall thickness was 30-mm (IQR 21-40) and the distance from skin to pericardium was 66-mm (IQR 54-79). CONCLUSION: The distance from skin to pericardium for 75% of patients falls within the length of the recommended needle catheter unit (83-mm). The current TCCC recommendation to "hub" the 83mm needle catheter unit has potential risk of cardiac injury.

Clinical Assessment of Low Calcium In traUMa (CALCIUM).

Major trauma frequently occurs in the deployed, combat setting and is especially applicable in the recent conflicts with explosives dominating the combat wounded. In future near-peer conflicts, we will likely face even more profound weapons including mortars and artillery. As such, the number of severely wounded will likely increase. Hypocalcemia frequently occurs after blood transfusions, secondary to the preservatives in the blood products; however, recent data suggests major trauma in and of itself is a risk factor for hypocalcemia. Calcium is a major ion involved in heart contractility; thus, hypocalcemia can lead to poor contractility. Smaller studies have linked hypocalcemia to worse outcomes, but it remains unclear what causes hypocalcemia and if intervening could potentially save lives. The objective of this study is to determine the incidence of hypocalcemia on hospital arrival and the association with survival. We are seeking to address the following scientific questions, (1) Is hypocalcemia present following traumatic injury prior to transfusion during resuscitation? (2) Does hypocalcemia influence the amount of blood products transfused? (3) To what extent is hypocalcemia further exacerbated by transfusion? (4) What is the relationship between hypocalcemia following traumatic injury and mortality? We will conduct a multicenter, prospective, observational study. We will gather ionized calcium levels at 0, 3, 6, 12, 18, and 24 hours as part of scheduled calcium measurements. This will ensure we have accurate data to assess the early and late effects of hypocalcemia throughout the course of resuscitation and hemorrhage control. These data will be captured by a trained study team at every site. Our findings will inform clinical practice guidelines and optimize the care delivered in the combat and civilian trauma setting. We are seeking 391 patients with complete data to meet our a priori inclusion criteria. Our study will have major immediate short-term findings including risk prediction modeling to assess who is at risk for hypocalcemia, data assessing interventions associated with the incidence of hypocalcemia, and outcome data including mortality and its link to early hypocalcemia.

The impact of prehospital whole blood on hemorrhaging trauma patients: A multi-center retrospective study.

BACKGROUND: Whole blood (WB) use has become increasingly common in trauma centers across the United States for both in-hospital and prehospital resuscitation. We hypothesize that prehospital WB (pWB) use in trauma patients with suspected hemorrhage will result in improved hemodynamic status and reduced in-hospital blood product requirements. METHODS: The institutional trauma registries of two academic level I trauma centers were queried for all patients from 2015-2019 who underwent transfusion upon arrival to the trauma bay. Patients who were dead on arrival or had isolated head injuries were excluded. Demographics, injury and shock characteristics, transfusion requirements, including massive transfusion protocol (MTP) (>10 U in 24 hours) and rapid transfusion (CAT3+) and outcomes were compared between pWB and non-pWB patients. Significantly different demographic, injury characteristics and pWB were included in univariate followed by stepwise logistic regression analysis to determine the relationship with shock index (SI). Our primary objective was to determine the relationship between pWB and improved hemodynamics or reduction in blood product utilization. RESULTS: A total of 171 pWB and 1391 non-pWB patients met inclusion criteria. Prehospital WB patients had a lower median Injury Severity Score (17 vs. 21, p < 0.001) but higher prehospital SI showing greater physiologic disarray. Prehospital WB was associated with improvement in SI (-0.04 vs. 0.05, p = 0.002). Mortality and (LOS) were similar. Prehospital WB patients received fewer packed red blood cells, fresh frozen plasma, and platelets units across their LOS but total units and volumes were similar. Prehospital WB patients had fewer MTPs (22.6% vs. 32.4%, p = 0.01) despite a similar requirement of CAT3+ transfusion upon arrival. CONCLUSION: Prehospital WB administration is associated with a greater improvement in SI and a reduction in MTP. This study is limited by its lack of power to detect a mortality difference. Prospective randomized controlled trials will be required to determine the true impact of pWB on trauma patients. LEVEL OF EVIDENCE: Prognostic and Epidemiological; Level IV.

An Analysis of the Incidence of Hypocalcemia in Wartime Trauma Casualties.

OBJECTIVE: Background: Massive transfusion protocols implement the use of blood products to restore homeostasis. Citrated blood products are required for massive transfusions and can induce hypocalcemia, resulting in decreased cardiac contractility. Recent data suggests that major trauma alone is associated with hypocalcemia. This phenomenon remains poorly described. We seek to characterize the incidence and risk factors for early hypocalcemia in the setting of combat trauma. MATERIALS AND METHODS: This is a secondary analysis of previously described data from the Department of Defense Trauma Registry from January 2007 to March 2020. In this sub-analysis, we selected only casualties that had at least one ionized calcium measurement. We defined hypocalcemia as an ionized calcium level of less than 1.2mmol/L. RESULTS: Within our study database, there were 142 adult casualties that met inclusion with at least one calcium value documented. We found 72 (51%) experienced at least one episode of hypocalcemia. Median composite injury severity score (ISS) was significantly lower in the control cohort compared to those with hypocalcemia (9 versus 15, p=0.010). Survival was similar between the two groups (97% versus 90%, p=0.166). On multivariable analysis when evaluating serious injuries by body region, only serious injuries to the extremities were significantly associated with developing hypocalcemia (odds ratio [OR] 1.48, 95% confidence interval [CI] 1.00-2.21). When comparing prehospital interventions, only intravenous (IV) fluid administration was associated with high proportions experiencing hypocalcemia (25% versus 43%, p=0.029). In the multivariable model adjusted for ISS, mechanism of injury, and patient category, IV fluids were associated with the development of hypocalcemia (OR 2.48, 95% CI 1.03-5.94). When comparing vital signs, only respiratory rates were noted to be higher in the hypocalcemia cohort (18.6 versus 20.4, p=0.048). CONCLUSIONS: Approximately half of combat casualties with available ionized calcium (iCa) level were hypocalcemic. Prehospital IV fluid use was associated with the development of hypocalcemia. Our study has implications for forward-staged medical teams with limited laboratory analysis capabilities. Additional research is needed to determine whether calcium replacement improves survival from traumatic injury and to identify the specific indications and timing for calcium replacement. This study will help inform a clinical study intended to aid in the development of clinical practice guidelines for deployed medical personnel.

The Use of Whole Blood Transfusion During Non-Traumatic Resuscitation.

BACKGROUND: Evidence from military populations showed that resuscitation using whole blood (WB), as opposed to component therapies, may provide additional survival benefits to traumatically injured patients. However, there is a paucity of data available for the use of WB in uninjured patients requiring transfusion. We sought to describe the use of WB in non-trauma patients at Brooke Army Medical Center (BAMC). MATERIALS AND METHODS: Between January and December 2019, the BAMC ClinComp electronic medical record system was reviewed for all patients admitted to the hospital who received at least one unit of WB during this time period. Patients were sorted based on their primary admission diagnosis. Patients with a primary trauma-based admission were excluded. RESULTS: One hundred patients were identified who received at least one unit of WB with a primary non-trauma admission diagnosis. Patients, on average, received 1,064 mL (750-2,458 mL) of WB but received higher volumes of component therapy. Obstetric/gynecologic (OBGYN) indications represented the largest percentage of non-trauma patients who received WB (23%), followed by hematologic/oncologic indications (16%). CONCLUSION: In this retrospective study, WB was most commonly used for OBGYN-associated bleeding. As WB becomes more widespread across the USA for use in traumatically injured patients, it is likely that WB will be more commonly used for non-trauma patients. More outcome data are required to safely expand the indications for WB use beyond trauma.