An Analysis of the Association of Arrival Hemoglobin With Overtransfusion at 24 Hours in a Trauma Population.

BACKGROUND: Hemorrhage control and resuscitative concepts have evolved in recent years, leading to aggressive use of blood products in trauma patients. There is subsequently a potential risk for overtransfusion, adverse effects, and waste associated with unnecessary transfusion. Methods for conserving blood products are of particular importance in future large-scale combat operations where supply chains are likely to be strained. This study examined the association of emergency department (ED) arrival hemoglobin (HGB) with overtransfusion among survivors at 24 hours after major trauma at a military trauma center. MATERIALS AND METHODS: We performed a retrospective cohort study of patients who had a "major trauma" activation and received any red blood cells. Overtransfusion was defined as a HGB level ≥11.0 g/dL at 24 hours (outcome variable). Multivariable logistic regression statistics were used to compare groups and adjust for confounders (injury severity score, arrival modified shock index, injury type, age, and gender). A receiver operating characteristic was constructed with overtransfusion at 24 hours as the outcome (binary) and arrival HGB (continuous) as the independent variable. RESULTS: A total of 382 patients met inclusion criteria. Overtransfusion occurred in 30.4% (n = 116) of patients, with mean ED HGB levels of 13.2 g/dL (12.9 to 13.6) versus 11.6 g/dL (11.3 to 11.8, P < .001). Receiver operating characteristic analysis showed that ED HGB was highly sensitive (0.931) for predicting 24-hour overtransfusion. In our multivariable logistic regression analysis, when adjusting for injury severity score, arrival modified shock index, injury type, age, and gender, we found that the ED HGB value had a per-unit odds ratio of 1.60 (95% CI, 1.38 to 1.86) for 24-hour overtransfusion. Hospital and intensive care unit length of stay, mechanical ventilator days, and mortality did not increase. CONCLUSION: We found that the arrival HGB value was associated with overtransfusion among 24-hour survivors in a civilian trauma setting. Our findings will inform future prospective studies that investigate blood sparing clinical practice guidelines.

Genomic surveillance of SARS-CoV-2 in US military compounds in Afghanistan reveals multiple introductions and outbreaks of Alpha and Delta variants.

BACKGROUND: With the emergence and spread of SARS-CoV-2 variants, genomic epidemiology and surveillance have proven invaluable tools for variant tracking. Here, we analyzed SARS-CoV-2 samples collected from personnel located at the US/NATO bases across Afghanistan. RESULTS: Sequencing and phylogenetic analyses revealed at least 16 independent introductions of SARS-CoV-2 into four of these relatively isolated compounds during April and May 2021, including multiple introductions of Alpha and Delta variants. Four of the introductions resulted in sustained spread of the virus within, and in two cases between, the compounds. Three of these outbreaks, one Delta and two Alpha, occurred simultaneously. CONCLUSIONS: Even in rigorously controlled and segregated environments, SARS-CoV-2 introduction and spread may occur frequently.

AB569, a non-toxic combination of acidified nitrite and EDTA, is effective at killing the notorious Iraq/Afghanistan combat wound pathogens, multi-drug resistant Acinetobacter baumannii and Acinetobacter spp.

Multi-drug resistant (MDR) Acinetobacter baumannii (Ab) and Acinetobacter spp. present monumental global health challenges. These organisms represent model Gram-negative pathogens with known antibiotic resistance and biofilm-forming properties. Herein, a novel, nontoxic biocide, AB569, consisting of acidified nitrite (A-NO2-) and ethylenediaminetetraacetic acid (EDTA), demonstrated bactericidal activity against all Ab and Acinetobacter spp. strains, respectively. Average fractional inhibitory concentrations (FICs) of 0.25 mM EDTA plus 4 mM A-NO2- were observed across several clinical reference and multiple combat wound isolates from the Iraq/Afghanistan wars. Importantly, toxicity testing on human dermal fibroblasts (HDFa) revealed an upper toxicity limit of 3 mM EDTA plus 64 mM A-NO2-, and thus are in the therapeutic range for effective Ab and Acinetobacter spp. treatment. Following treatment of Ab strain ATCC 19606 with AB569, quantitative PCR analysis of selected genes products to be responsive to AB569 revealed up-regulation of iron regulated genes involved in siderophore production, siderophore biosynthesis non-ribosomal peptide synthetase module (SBNRPSM), and siderophore biosynthesis protein monooxygenase (SBPM) when compared to untreated organisms. Taken together, treating Ab infections with AB569 at inhibitory concentrations reveals the potential clinical application of preventing Ab from gaining an early growth advantage during infection followed by extensive bactericidal activity upon subsequent exposures.

Effects of Early Altitude Exposure on the Open Abdomen After Laparotomy in Trauma.

INTRODUCTION: While damage control surgery and resuscitation techniques have revolutionized the care of injured service members who sustain severe traumatic hemorrhage, the physiologic and inflammatory consequences of hemostatic resuscitation and staged abdominal surgery in the face of early aeromedical evacuation (AE) have not been investigated. We hypothesized that post-injury AE with an open abdomen would have significant physiologic and inflammatory consequences compared to AE with a closed abdomen. MATERIALS AND METHODS: Evaluation of resuscitation and staged abdominal closure was performed using a murine model of hemorrhagic shock with laparotomy. Mice underwent controlled hemorrhage to a systolic blood pressure of 25 mmHg and received either no resuscitation, blood product resuscitation, or Hextend resuscitation to a systolic blood pressure of either 50 mmHg (partial resuscitation) or 80 mmHg (complete resuscitation). Laparotomies were either closed prior to AE (closed abdomens) or left open during AE (open abdomens) and subsequently closed. AE was simulated with a 1-hour exposure to a hypobaric hypoxic environment at 8,000 feet altitude. Mice were euthanized at 0, 4, or 24 hours following AE. Serum was collected and analyzed for physiologic variables and inflammatory cytokine levels. Samples of lung and small intestine were collected for tissue cytokine and myeloperoxidase analysis as indicators of intestinal inflammation. Survival curves were also performed. RESULTS: Unresuscitated mice sustained an 85% mortality rate from hemorrhage and laparotomy, limiting the assessment of the effect of simulated AE in these subgroups. Overall survival was similar among all resuscitated groups regardless of the presence of hypobaric hypoxia, type of resuscitation, or abdominal closure status. Simulated AE had no observed effects on acid/base imbalance or the inflammatory response as compared to ground level controls. All mice experienced both metabolic acidosis and an acute inflammatory response after hemorrhage and injury, represented by an initial increase in serum interleukin (IL)-6 levels. Furthermore, mice with open abdomens had an elevated inflammatory response with increased levels of serum IL-10, serum tumor necrosis factor alpha, intestinal IL-6, intestinal IL-10, and pulmonary myeloperoxidase. CONCLUSION: These results demonstrate the complex interaction of AE and temporary or definitive abdominal closure after post-injury laparotomy. Contrary to our hypothesis, we found that AE in those animals with open abdomens is relatively safe with no difference in mortality compared to those with closed abdomens. However, given the physiologic and inflammatory changes observed in animals with open abdomens, further evaluation is necessary prior to definitive recommendations regarding the safety or downstream effects of exposure to AE prior to definitive abdominal closure.

Ketamine versus hydromorphone patient-controlled analgesia for acute pain in trauma patients.

BACKGROUND: It is unknown whether ketamine administered via patient-controlled analgesia (PCA) provides adequate analgesia while reducing opioid consumption in the traumatically injured patient. Differences in opioid consumption, pain scores, and adverse effects between ketamine and hydromorphone PCA were studied. MATERIALS AND METHODS: This is an investigator-initiated, single-center, double-blinded, randomized, pilot trial conducted from 2014 to 2016 at a level 1 trauma center. Nonintubated trauma patients in intensive care, who were receiving PCA, were randomized to ketamine or hydromorphone PCA plus opioid analgesics for breakthrough pain. RESULTS: Twenty subjects were randomized. There was no difference in median daily breakthrough opioid use (10 [0.63-19.38] mg versus 10 [4.38-22.5] mg, P = 0.55). Subjects in the ketamine group had lower median cumulative opioid use on therapy day 1 than the hydromorphone group (4.6 [2.5-15] mg versus 41.8 [31.8-50] mg, P < 0.001), as well as in the first 48 h (10 [3.3-15] mg versus 48.5 [32.1-67.5] mg, P < 0.001) and first 72 h (10 [4.2-15] mg versus 42.5 [31.7-65.2] mg, P < 0.001) of therapy. Daily oxygen supplementation requirements were lower in the ketamine group (0.5 [0-1.5] L/min versus 2 [0.5-3] L/min, P = 0.020). Hallucinations occurred more frequently in the ketamine group (40% versus 0%, P = 0.090). CONCLUSIONS: Ketamine PCA led to lower cumulative opioid consumption and lower oxygen supplementation requirements, though hallucinations occurred more frequently with use of ketamine. Additional studies are needed to investigate the tolerability of ketamine as an alternative to traditional opioid-based PCA.

Proximal penetrating extremity injuries-An opportunity to decrease overtriage?

BACKGROUND: Penetrating injuries to the extremity proximal to the elbow or knee are anatomic criteria for full trauma team activation (FFTA) by the American College of Surgeon's Committee on Trauma standards. This criterion lacks objective evidence-based support. Overtriage of trauma team activation may result in excessive costs and resource burden at trauma centers. We hypothesized that FFTA for penetrating injuries to the proximal extremities by anatomic criteria alone may lead to significant overtriage. METHODS: A 3-year retrospective review (2013-2015) was completed of all patients evaluated at an urban Level I trauma center with isolated penetrating extremity injuries. Data included the number of full and limited trauma team activations as well as criterion met, Injury Severity Score (ISS), injury, limb characteristics, and disposition. Overtriage was defined as FFTA for an ISS of 15 or less, with a goal rate less than 50%. RESULTS: We identified 6,335 total trauma team activations with 795 isolated penetrating extremity injuries. Of these injuries, 413 (51.9%) were injuries proximal to the joint. Within this subgroup, 71.2% of patients were discharged from the emergency department with a median ISS of 1 and no additional intervention. Only 5.3% of patients that did not meet additional FFTA criteria underwent immediate operative intervention. By comparison, 21% of FFTAs and 5.8% of limited trauma team activations underwent immediate operative intervention during the 3-year period. Of the 413 isolated penetrating proximal-extremity injuries, only one had an ISS of 15 or greater, resulting in a 99.7% overtriage rate. CONCLUSION: Penetrating injuries to the extremities are common in urban trauma centers. Full trauma team activation based on anatomic, rather than physiologic, criteria may lead to a significant overtriage rate. Further distinction in the level of trauma team activation may be made based on hard signs of neurovascular injury. LEVEL OF EVIDENCE: Epidemiological study, level III; Care Management, level IV.

Performance of Portable Ventilators Following Storage at Temperature Extremes.

In the current theater of operation, medical devices are often shipped and stored at ambient conditions. The effect of storage at hot and cold temperature extremes on ventilator performance is unknown. We evaluated three portable ventilators currently in use or being evaluated for use by the Department of Defense (731, Impact Instrumentation; T1, Hamilton Medical; and Revel, CareFusion) at temperature extremes in a laboratory setting. The ventilators were stored at temperatures of 60°C and -35°C for 24 hours and were allowed to acclimate to room temperature for 30 minutes before evaluation. The T1 required an extra 15 to 30 minutes of acclimation to room temperature before the ventilator would deliver breaths. All delivered tidal volumes at room temperature and after storage at temperature extremes were less than the ±10% American Society for Testing and Materials standard with the Revel. Delivered tidal volumes at the pediatric settings were less than the ±10% threshold after storage at both temperatures and at room temperature with the 731. Storage at extreme temperature affected the performance of the portable ventilators tested. This study showed that portable ventilators may need an hour or more of acclimation time at room temperature after storage at temperature extremes to operate as intended.

Evaluation of Oxygen Concentrators and Chemical Oxygen Generators at Altitude and Temperature Extremes.

Oxygen cylinders are heavy and present a number of hazards, and liquid oxygen is too heavy and cumbersome to be used in far forward environments. Portable oxygen concentrators (POCs) and chemical oxygen generators (COGs) have been proposed as a solution. We evaluated 3 commercially available POCs and 3 COGs in a laboratory setting. Altitude testing was done at sea level and 8,000, 16,000, and 22,000 ft. Temperature extreme testing was performed after storing devices at 60°C and -35°C for 24 hours. Mean FIO2 decreased after storage at -35°C with Eclipse and iGo POCs and also at the higher volumes after storage at 60°C with the Eclipse. The iGo ceased to operate at 16,000 ft, but the Eclipse and Saros were unaffected by altitude. Oxygen flow, duration of operation, and total oxygen volume varied between COGs and within the same device type. Output decreased after storage at -35°C, but increased at each altitude as compared to sea level. This study showed significant differences in the performance of POCs and COGs after storage at temperature extremes and with the COGs at altitude. Clinicians must understand the performance characteristics of devices in all potential environments.

System Design Verification for Closed Loop Control of Oxygenation With Concentrator Integration.

BACKGROUND: Addition of an oxygen concentrator into a control loop furthers previous work in autonomous control of oxygenation. Software integrates concentrator and ventilator function from a single control point, ensuring maximum efficiency by placing a pulse of oxygen at the beginning of the breath. We sought to verify this system. METHODS: In a test lung, fraction of inspired oxygen (FIO2) levels and additional data were monitored. Tests were run across a range of clinically relevant ventilator settings in volume control mode, for both continuous flow and pulse dose flow oxygenation. RESULTS: Results showed the oxygen concentrator could maintain maximum pulse output (192 mL) up to 16 breaths per minute. Functionality was verified across ranges of tidal volumes and respiratory rates, with and without positive end-expiratory pressure, in continuous flow and pulse dose modes. For a representative test at respiratory rate 16 breaths per minute, tidal volume 550 mL, without positive end-expiratory pressure, pulse dose oxygenation delivered peak FIO2 of 76.83 ± 1.41%, and continuous flow 47.81 ± 0.08%; pulse dose flow provided a higher FIO2 at all tested setting combinations compared to continuous flow (p < 0.001). CONCLUSIONS: These tests verify a system that provides closed loop control of oxygenation while integrating time-coordinated pulse-doses from an oxygen concentrator. This allows the most efficient use of resources in austere environments.

Oxygen requirement to reverse altitude-induced hypoxemia with continuous flow and pulsed dose oxygen.

BACKGROUND: Hypoxemia secondary to reduced barometric pressure is a complication of ascent to altitude. We designed a study to compare the reversal of hypobaric hypoxemia at 14,000 ft with continuous flow oxygen from a cylinder and pulsed dose oxygen from a portable concentrator. METHODS: There were 30 healthy volunteers who were randomized to one of three study groups, placed in an altitude chamber, and ascended to 14,000 ft. There were 10 subjects in each study group. Subjects breathed room air for 10 min to induce hypoxemia. Oxygen was then delivered via a nasal cannula from a cylinder at 1, 2, or 3 lpm of continuous flow for 10 min. The subjects again breathed room air at altitude for 10 min and were then placed on pulsed dose oxygen and titrated to obtain the continuous flow Spo2 equivalent. Spo2, Etco2, RR, HR, Hgb, and tissue oxygenation (Sto2) were continuously recorded. RESULTS: The 1-lpm group's Spo2 range was 89-99%. The 2-lpm group's Spo2 range was 95-98%, and the 3-lpm group's Spo2 range was 95-99%. The 2-lpm and 3-lpm flows were able to correct hypoxemia in every subject. The mean pulsed dose required to achieve an equivalent Spo2 ranged from 36.8 ml ± 18.9 ml in the 1-lpm arm, and 102.4 ml ± 53.8 in the 3-lpm arm. CONCLUSIONS: Portable oxygen concentrators using pulsed dose technology corrected hypoxemia in every subject. Oxygen concentrators may be an alternative to liquid oxygen or cylinders for use during aeromedical evacuation.

Reducing secondary insults in traumatic brain injury.

OBJECTIVES: To determine the alterations in intracranial pressure (ICP) during U. S. Air Force Critical Care Air Transport Team transport of critically injured warriors with ICP monitoring by intraventricular catheter (IVC). METHODS: Patients with an IVC following traumatic brain injury requiring aeromedical evacuation from Bagram to Landstuhl Regional Medical Center were studied A data logger monitored both ICP and arterial blood pressure and was equipped with an integral XYZ accelerometer to monitor movement. RESULTS: Eleven patients were studied with full collection of data from takeoff to landing. The number of instances of ICP>20 mm Hg ranged from 0 to 238 and duration of instances ranged from 0 to 3,281 seconds. The number of instances of ICP±50% of the baseline ICP ranged from 0 to 921 and duration of instances ranged from 0 to 9,054 seconds. Five of the patients did not experience ICP>20 mm Hg throughout their flight, but 10 patients showed instances of ICP±50% of baseline ICP. CONCLUSION: Patient movement results in changes in ICP both from external stimuli (vibration, noise) and from acceleration and deceleration forces. During transport, Critical Care Air Transport Team crews should prioritize monitoring and correcting ICP including additional sedation and/or venting IVC.

Pre-hospital oxygen therapy.

Oxygen use in prehospital care is aimed at treating or preventing hypoxemia. However, excess oxygen delivery has important consequences in select patients, and hyperoxia can adversely impact outcome. The unique environment of prehospital care poses logistical and educational challenges. Oxygen therapy in prehospital care should be provided to patients with hypoxemia and titrated to achieve normoxemia. Changes to the current practice of oxygen delivery in prehospital care are needed.

Simulated aeromedical evacuation does not affect systemic inflammation or organ injury in a murine model of hemorrhagic shock.

Hemorrhagic shock is a primary injury amongst combat casualties. Aeromedical evacuation (AE) of casualties exposes patients to a hypobaric, hypoxic environment. The effect of this environment on the host response to hemorrhagic shock is unknown. In the present study, we sought to determine the effect of simulated AE on systemic inflammation and organ injury using a murine model of hemorrhagic shock. Mice underwent femoral artery cannulation and were hemorrhaged for 60 minutes. Mice were then resuscitated with a 1:1 ratio of plasma:packed red blood cells. At 1 or 24 hours after resuscitation, mice were exposed to a 5-hour simulated AE or remained at ground level (control). Serum was analyzed for cytokine concentrations and organs were assessed for neutrophil accumulation and vascular permeability. Mice in the simulated AE groups demonstrated reduced arterial oxygen saturation compared to ground controls. Serum cytokine concentrations, neutrophil recruitment, and vascular permeability in the lung, ileum, and colon in the simulated AE groups were not different from the ground controls. Our results demonstrate that mice exposed to simulated AE following hemorrhagic shock do not exhibit worsened systemic inflammation or organ injury compared to controls. The data suggest that AE has no adverse effect on isolated hemorrhagic shock.

Lessons from the tip of the spear: medical advancements from Iraq and Afghanistan.

The conflicts in Iraq and Afghanistan have seen the advancement of combat medicine. The nature of the conflicts, with troops located in remote areas and faced with explosive ordinance designed to focus massive injuries on dismounted personnel, have forced military medical personnel to adapt accordingly. There has been a rekindling of interest in the use of tourniquets to stop exsanguination from extremity wounds, as well as in the transfusion of fresh whole blood from walking blood banks. These previously discarded techniques, born on battlefields long ago, have been refined and perfected and have led to an unprecedented survival for our wounded warriors. New developments in the field of applied hemostatic agents, damage control surgical techniques, and the implementation of an efficient evacuation system have also contributed to these results. The field of combat medicine has taken several concepts initially designed in civilian settings, such as temporary abdominal packing and vascular shunting, and adapted them to the military setting to provide state of the art trauma management to our troops in combat. In turn, developments in the resuscitation of the trauma patient, using increased blood and plasma products and less crystalloid, have been pioneered in conflict and transitioned to the civilian sector. Advancements made during the wars in Iraq and Afghanistan, as well as those still being developed, will shape the care of the injured patient, in both civilian and military settings, for the foreseeable future.

New strategies for massive transfusion in the bleeding trauma patient.

Trauma continues to be the leading cause of death among those younger than 40 years. A major cause of death within the first 24 hours is hemorrhage. Many of these patients present with severe coagulopathy and require massive transfusion. Earlier control of coagulopathy has been shown to improve survival. To address coagulopathy sooner, changes in the way we identify and resuscitate the exsanguinating trauma patient have evolved. These changes include early identification of at-risk patients and early, aggressive transfusion of plasma and platelets. This article reviews the key massive transfusion triggers and resuscitation strategy of damage control resuscitation.

Damage control resuscitation decreases systemic inflammation after hemorrhage.

BACKGROUND: Severe hemorrhagic shock and resuscitation initiates a dysfunctional systemic inflammatory response leading to end-organ injury. Clinical evidence supports the transfusion of high ratios of plasma and packed red blood cells (pRBCs) in the treatment of hemorrhagic shock. The effects of resuscitation with different ratios of fresh blood products on inflammation and organ injury have not yet been characterized. MATERIALS AND METHODS: Mice underwent femoral artery cannulation and pressure-controlled hemorrhage for 60 min, then resuscitation with fresh plasma and pRBCs collected from donor mice. Plasma alone, pRBCs alone, and ratios of 2:1, 1:1, and 1:2 plasma:pRBCs were used for resuscitation strategies. Mice were sacrificed to determine biochemical and hematologic parameters, serum cytokine concentrations, tissue myeloperoxidase levels, and vascular permeability. RESULTS: Compared with other resuscitation strategies, mice resuscitated with pRBCs alone exhibited increased hemoglobin levels, while other hematologic and biochemical parameters were not significantly different among groups. Compared with 1:1, mice resuscitated with varying ratios of plasma:pRBCs exhibited increased cytokine concentrations of KC, MIP-1α, and MIP-2, and increased intestinal and lung myeloperoxidase levels. Mice resuscitated with 1:1 had decreased vascular permeability in the intestine and lung as compared with other groups. CONCLUSIONS: Resuscitation with a 1:1 ratio of fresh plasma:pRBCs results in decreased systemic inflammation and attenuated organ injury. These findings support the potential advantage of transfusing blood products in physiologic ratios to improve the treatment of severe hemorrhagic shock.

Use of a single ventilator to support 4 patients: laboratory evaluation of a limited concept.

INTRODUCTION: A mass-casualty respiratory failure event where patients exceed available ventilators has spurred several proposed solutions. One proposal is use of a single ventilator to support 4 patients. METHODS: A ventilator was modified to allow attachment of 4 circuits. Each circuit was connected to one chamber of 2 dual-chambered, test lungs. The ventilator was set at a tidal volume (V(T)) of 2.0 L, respiratory frequency of 10 breaths/min, and PEEP of 5 cm H(2)O. Tests were repeated with pressure targeted breaths at 15 cm H(2)O. Airway pressure, volume, and flow were measured at each chamber. The test lungs were set to simulate 4 patients using combinations of resistance (R) and compliance (C). These included equivalent C and R, constant R and variable C, constant C and variable R, and variable C and variable R. RESULTS: When R and C were equivalent the V(T) distributed to each chamber of the test lung was similar during both volume (range 428-442 mL) and pressure (range 528-544 mL) breaths. Changing C while R was constant resulted in large variations in delivered V(T) (volume range 257-621 mL, pressure range 320-762 mL). Changing R while C was constant resulted in a smaller variation in V(T) (volume range 418-460 mL, pressure range 502-554 mL) compared to only C changes. When R and C were both varied, the range of delivered V(T) in both volume (336-517 mL) and pressure (417-676 mL) breaths was greater, compared to only R changes. CONCLUSIONS: Using a single ventilator to support 4 patients is an attractive concept; however, the V(T) cannot be controlled for each subject and V(T) disparity is proportional to the variability in compliance. Along with other practical limitations, these findings cannot support the use of this concept for mass-casualty respiratory failure.

All massive transfusion criteria are not created equal: defining the predictive value of individual transfusion triggers to better determine who benefits from blood.

BACKGROUND: As familiarity with military massive transfusion (MT) triggers has increased, there is a growing interest in applying these in the civilian population to initiate MT protocols (MTP) earlier. We hypothesize that these triggers do not have equal predictability for MT and understanding the contribution of each would improve our ability to initiate the MTP earlier. METHODS: All patients presenting to a Level I trauma center from October 2007 to September 2008 requiring immediate operation were included in this study. Emergency department records, operative logs, and blood transfusion data from arrival to procedure end were analyzed using multivariate regression techniques. Triggers included systolic blood pressure (SBP) <90 mm Hg, hemoglobin <11 g/dL, temperature <35.5°C, International normalized ratio (INR) >1.5, and base deficit ≥6. RESULTS: One hundred seventy patients required immediate operation with an overall survival of 91%. Transfusion of packed red blood cells was noted in 45% (77 of 170) with the mean number of transfused units highest in those meeting SBP (12.9 Units) or INR (12.3 Units) triggers. The triggers do not contribute equal predictive value for the need for transfusion with INR being the most predictive (odds ratio, 16.7; 95% confidence interval, 2-137) for any transfusion and highly predictive for the need for MT (odds ratio, 11.3; 95% confidence interval, 3-47). In fact, if patients met either INR or SBP triggers alone, they were likely to receive MT (p = 0.018 and 0.003, respectively). CONCLUSION: Triggers have differential predictive values for need for transfusion. Defining the individual utility of each criterion will help to identify those most likely to benefit from an early initiation of the MTP.