Preconditions of hemostasis in trauma: a review. The influence of acidosis, hypocalcemia, anemia, and hypothermia on functional hemostasis in trauma. ACTA ACUST UNITED AC. 2008;65:951-960. [PMID: 18849817 DOI: 10.1097/ta.0b013e318187e15b]

Hypocalcaemia upon arrival (HUA) in trauma patients who did and did not receive prehospital blood products: a systematic review and meta-analysis

PURPOSE

Hypocalcaemia upon arrival (HUA) to hospital is associated with morbidity and mortality in the trauma patient. It has been hypothesised that there is an increased incidence of HUA in patients receiving prehospital transfusion as a result of citrated blood products. This research aimed to determine if there was a difference in arrival ionised calcium (iCa) levels in trauma patients who did and did not receive prehospital transfusion.

METHODS

We conducted a systematic review and meta-analysis of patients with an Injury Severity Score (ISS) > / = 15 and an iCa measured on hospital arrival. We then derived mean iCa levels and attempted to compare between-group variables across multiple study cohorts.

RESULTS

Nine studies reported iCa on arrival to ED, with a mean of 1.08 mmol/L (95% CI 1.02-1.13; I2 = 99%; 2087 patients). Subgroup analysis of patients who did not receive prehospital transfusion had a mean iCa of 1.07 mmol/L (95% CI 1.01-1.14; I2 = 99%, 1661 patients). Transfused patients in the 3 comparative studies had a slightly lower iCa on arrival compared to those who did not receive transfusion (mean difference - 0.03 mmol/L, 95% CI - 0.04 to - 0.03, I2 = 0%, p = 0.001, 561 patients).

CONCLUSION

HUA is common amongst trauma patients irrespective of transfusion. Transfused patients had a slightly lower initial iCa than those without transfusion, though the clinical impact of this remains to be clarified. These findings question the paradigm of citrate-induced hypocalcaemia alone in trauma. There is a need for consensus for the definition of hypocalcaemia to provide a basis for future research into the role of calcium supplementation in trauma.

Long-Term Safety Analysis of a Fibrinogen Concentrate (RiaSTAP®/Haemocomplettan® P)

Fibrinogen concentrate treatment is recommended for acute bleeding episodes in adult and pediatric patients with congenital and acquired fibrinogen deficiency. Previous studies have reported a low risk of thromboembolic events (TEEs) with fibrinogen concentrate use; however, the post-treatment TEE risk remains a concern. A retrospective evaluation of RiaSTAP®/Haemocomplettan® P (CSL Behring, Marburg, Germany) post-marketing data was performed (January 1986-June 2022), complemented by a literature review of published studies. Approximately 7.45 million grams of fibrinogen concentrate was administered during the review period. Adverse drug reactions (ADRs) were reported in 337 patients, and 81 (24.0%) of these patients experienced possible TEEs, including 14/81 (17.3%) who experienced fatal outcomes. Risk factors and the administration of other coagulation products existed in most cases, providing alternative explanations. The literature review identified 52 high-ranking studies with fibrinogen concentrate across various clinical areas, including 26 randomized controlled trials. Overall, a higher number of comparative studies showed lower rates of ADRs and/or TEEs in the fibrinogen group versus the comparison group(s) compared with those that reported higher rates or no differences between groups. Post-marketing data and clinical studies demonstrate a low rate of ADRs, including TEEs, with fibrinogen concentrate treatment. These findings suggest a favorable safety profile of fibrinogen concentrate, placing it among the first-line treatments effective for managing intraoperative hemostatic bleeding.

[Postpartum Hemorrhage]

Postpartum hemorrhage (PPH) affects about 4% of all deliveries in high-income countries and continues to rise, a trend attributable to the increase in caesarean section rates and maternal morbidity. Preventive measures such as the precautionary administration of uterotonics effectively reduce the risk of severe bleeding irrespective of birth mode. As a time-critical condition and a significant contributor to adverse maternal outcomes, PPH needs to be diagnosed early by measuring, not estimating, blood losses. Institutional treatment algorithms should be available to guide stage-based interdisciplinary management without delay. The main therapy goals are to identify the etiology and stop the bleeding by using uterotonics and mechanical and surgical interventions, to restore hemodynamic stability by volume and transfusion therapy and to optimize hemostasis by laboratory- and viscoelastic assay-guided factor replacement. This review highlights current recommendations for prevention, diagnosis and treatment of PPH.

Effect of ionized calcium level on short-term prognosis in severe multiple trauma patients: a clinical study

Background

Hypocalcemia has been reported as an independent predictor of trauma mortality. We investigated the relationship between temporal variations in blood ionized calcium concentration (iCa) and prognosis in severe trauma patients who underwent massive transfusion protocol (MTP).

Methods

This single-center, retrospective, observational study investigated 117 severe trauma patients treated with MTP in the Department of Emergency Medicine and Critical Care, Saitama Medical Center, Saitama Medical University, between March 2013 and March 2019. Multivariate logistic regression analysis was performed, assigning pH-corrected initial and minimum blood ionized calcium concentration within 24 hours of admission (iCa_min), age, initial systolic blood pressure and Glasgow Coma Scale (GCS) score, and incidence of Ca supplementation as independent variables and 28-day mortality as dependent variable.

Results

The logistic regression analysis identified iCa_min (adjusted OR 0.03, 95% CI 0.002 to 0.4), age (adjusted OR 1.05, 95% CI 1.02 to 1.09), and GCS score (adjusted OR 0.84, 95% CI 0.74 to 0.94) as significant independent predictors of 28-day mortality. The receiver operating characteristic analysis identified optimal cut-off value of iCa_min for predicting 28-day mortality as 0.95 mmoL/L (area under the curve 0.74).

Conclusion

In the management of patients with traumatic hemorrhagic shock, aggressive correction of the iCa to maintain 0.95 mmol/L or higher within 24 hours of admission may improve short-term outcomes.

Level of evidence

Therapeutic/care management, level III.

Hypocalcemia in Trauma is Determined by the Number of Units Transfused, Not Whole Blood Versus Component Therapy

INTRODUCTION

Blood component resuscitation is associated with hypocalcemia (HC) (iCal <0.9 mmol/L) that contributes to coagulopathy and death in trauma patients. It is unknown whether or not whole blood (WB) resuscitation helps mitigate the risk of HC in trauma patients. We hypothesized that calcium homeostasis is maintained and mortality improved in patients who only receive WB.

MATERIALS AND METHODS

This is a retrospective review of all adult trauma patients who received WB from July 2018 to December 2020. Variables included transfusions, ionized calcium levels, and calcium replacement. Patients were characterized as follows based on blood products received: WB or WB with other blood components. Groups were compared with respect to HC, correction of HC, 24 h, and inpatient mortality.

RESULTS

Two hundred twenty-three patients received WB and met the inclusion criteria. 107 (48%) received WB only. HC occurred in 13% of patients who received more than one WB unit compared to 29% of WB and other blood component patients (P = 0.02). WB patients received less calcium replacement (median 250 mg versus 2000 mg, P < 0.01). HC and total units transfused within 4 h were associated with mortality in the adjusted model. HC significantly increased after 5 units of blood products were transfused, regardless of product type. WB was not protective against HC.

CONCLUSIONS

HC and failure to correct HC are significant risk factors for mortality in trauma. Resuscitations with WB only and WB in combination with other blood components are associated with HC especially when more than 5 units of any blood product are transfused. Calcium supplementation should be prioritized in any large volume transfusion, regardless of blood product type.

Impact of restrictive versus liberal transfusion and clinical outcomes in critically ill children: A retrospective observational study

Background and Aims

Critically ill children with anemia often requires blood transfusion, which can cause several complications. It is important to decide when to start the red blood cell (RBC) transfusion; however, the guidelines is still lacking. The aim of this study was to compare restrictive and liberal transfusion strategy.

Methods

This is an observational retrospective study of critically‐ill children who receive RBC transfusion. Subjects categorized into two groups by initial hemoglobin (Hb), that is, restrictive (Hb ≤ 7 g/dl) and liberal (Hb ≤ 9.5 g/dl) strategy. In each group, subjects categorized based on: (1) Hb increment: high (increased ≥2.5 g/dl) and low (increase <2.5 g/dl) and (2) final Hb level: low (<7.0 mg/dl), moderate (7.0–10.0 mg/dl), and high (>10.0 mg/dl). Patient with hematologic or congenital disorder, severe malnutrition, chronic infection‐related anemia, and transfusion in Hb level ≥9.5 g/dl were exclude. Each patients were evaluated for the clinical outcome, which is: intensive care length of stay (IC‐LOS), length of mechanical ventilation (LoMV), and mortality rate.

Results

Clinical outcome and mortality rates of both transfusion strategies are similar. The mortality rates were lower in higher Hb increment and final Hb level (p = 0.04 and p = 0.01, respectively). Multivariate analysis in all groups revealed mortality rate had moderate correlation with Hb increment (odds ratio [OR] = 0.694, 95% confidence interval [CI] 0.549–0.878; p = 0.002) and moderate correlation (OR = 0.642, 95% CI 0.519–0.795; p = 0.000) with final Hb level. The similar results was found after categorization based on transfusion strategy.

Conclusion

We conclude the restrictive and liberal transfusion strategy have a similar effect to IC‐LOS, LoMV, and mortality rate. High Hb increment (≥2.5 g/dl) and moderate‐high final Hb (≥7.0 g/dl) after transfusion reduce the mortality rate.

Hemostatic efficacy of composite polysaccharide powder (starch-chitosan) for emergency bleeding control: An animal model study

BACKGROUND

Blood clot formation or hemostasis is vital to minimize blood loss and mitigate the risk of death from severe bleeding. This study investigates the characteristics of a novel hemostatic composite containing chemically modified chitosan and starch for emergency bleeding control. The performance of this novel hemostatic powder was compared with commercially available starch-based (Arista AH) and chitosan-based (Celox) hemostats.

METHODS

Hemostatic composite was prepared according to the patent registered by the authors (Patent No. 100865, Iranian Intellectual Property Organization) in Bani Zist Baspar Healda, Inc. (Shiraz, Iran). The properties of the product were surveyed by Fourier-transform infrared spectroscopy and compared with Arista-AH and Celox as commercial counterparts. The cytocompatibility, hemolysis, platelet and red blood cells (RBCs) adhesion, biocompatibility, and biodegradability attributes were evaluated in in vivo and in vitro studies. Hemostatic efficacy was evaluated in 24 healthy 6-month-old male New Zealand white rabbits in lethal and sublethal injuries of femoral artery and veins, respectively.

RESULTS

Modification and composition led to a fundamental development in physicochemical characteristics including swelling properties, water absorption, and platelet and RBC adhesion due to improved electrostatic and hydrophilic attributes. The significant superiority in clotting efficiency was confirmed after the application of the composite in 2 models of venous and arterial injury in comparison with common commercial hemostats.

CONCLUSION

Simultaneous use of water-absorbing compounds and introducing positively charged functional groups to hemostatic material led to a considerable control of femoral bleeding in emergency conditions. The introduced composite was biodegradable and biocompatible and prompts RBC aggregation and platelet adhesion.

Hypocalcemia as a predictor of mortality and transfusion. A scoping review of hypocalcemia in trauma and hemostatic resuscitation

Background

Calcium plays an essential role in physiologic processes, including trauma's “Lethal Diamond.” Thus, inadequate serum calcium in trauma patients exacerbates the effects of hemorrhagic shock secondary to traumatic injury and subsequently poorer outcomes compared to those with adequate calcium levels. Evidence to date supports the consideration of calcium derangements when assessing the risk of mortality and the need for blood product transfusion in trauma patients. This review aims to further elucidate the predictive strength of this association for future treatment guidelines and clinical trials.

Methods

Publications were collected on the relationship between i‐Ca and the outcomes of traumatic injuries from PubMed, Web of Science, and CINAHL. Manuscripts were reviewed to select for English language studies. Hypocalcemia was defined as i‐Ca <1.2 mmol/L.

Results

Using PRISMA guidelines, we reviewed 300 studies, 7 of which met our inclusion criteria. Five papers showed an association between hypocalcemia and mortality.

Conclusions

In adult trauma patients, there has been an association seen between hypocalcemia, mortality, and the need for increased blood product transfusions. It is possible we are now seeing an association between low calcium levels prior to blood product administration and an increased risk for mortality and need for transfusion. Hypocalcemia may serve as a biomarker to show these needs. Therefore, hypocalcemia could potentially be used as an independent predictor for multiple transfusions such that ionized calcium measurements could be used predictively, allowing faster administration of blood products.

Trauma-induced hypocalcemia

BACKGROUND

Trauma-induced hypocalcemia is an underappreciated complication of severe injury but is well known to result in the derangement of an array of physiological regulatory mechanisms. Existing literature provides a compelling link between hypocalcemia and worse trauma-induced coagulopathy and increased mortality after injury.

STUDY DESIGN AND METHODS

This narrative review evaluates available data related to the risk factors, mechanisms, and treatment of hypocalcemia after severe injury. The authors did not perform a systemic review or meta-analysis.

RESULTS AND DISCUSSION

The interplay of acidosis, hypothermia, and coagulopathy with hypocalcemia potentiates the bloody vicious cycle of hemorrhagic shock which has been the paradigm of trauma resuscitation for over half a century. However, current screening and treatment of postinjury hypocalcemia are relegated to a secondary consideration in trauma resuscitation. We conclude calcium supplementation should be a primary tier intervention for life-threatening injury.

Plasmatic coagulation profile after major traumatic injury: a prospective observational study

PURPOSE

Uncontrolled hemorrhage is still the major cause of preventable death after trauma and is aggravated by trauma-induced coagulopathy (TIC). The underlying pathophysiology of TIC is still elusive, but several key effectors such as the thrombin-generation capacity, the protein C (PC) pathway, and the fibrinolytic activity could be identified. The aim of this prospective observational study was to investigate plasma coagulation markers attributed to reflect the course of TIC and to identify the mechanisms being responsible for the coagulopathy after major trauma.

METHODS

Seventy-three consecutive patients after major trauma and admission to a level-1-trauma unit were included to the study. During early trauma management, extended coagulation testing including the measurement of circulating thrombin markers and activated PC (APC) was performed and correlated with standard shock parameters and the patients' clinical course and outcome.

RESULTS

In contrast to standard coagulation parameters, thrombin markers and APC were found to be increased in correlation with injury severity. Even in patients with lower impact mechanisms, early endogenous accumulation of thrombin markers and APC (ISS < 16: 0.5 ng/ml; ISS ≥ 16-26: 1.5 ng/ml; ISS > 26: 4.1 ng/ml) were observed. Furthermore, APC showed ISS- and injury-dependent patterns while ROC curve analysis revealed that especially APC plasma levels were predictive for coagulopathy and general patient outcome.

CONCLUSION

Increased levels of APC and thrombin markers in patients after major trauma were positively correlated with injury severity. APC showed an ISS- and injury-dependent kinetic and might serve as candidate biomarker to identify patients at risk for developing TIC.

Indications and diagnosis-specific features of maternal and neonatal peripartum intensive care unit admissions: A retrospective study

BACKGROUND

Although peripartum intensive care unit admission indications are well-reported, clinical and laboratory details rarely are. We described admission indications and categorised laboratory values and vital signs according to admission diagnosis.

METHODS

Retrospective Institutional Review Board approved study. We identified intensive care unit admission diagnosis, laboratory values and vital signs from patient charts. Groups were compared according to admission diagnoses. Data were analysed using descriptive statistics.

RESULTS

We included 91 general intensive care unit admissions among 56,865 deliveries (2011-2015) with complete data. The most common admission diagnosis was postpartum haemorrhage followed by hypertensive diseases of pregnancy and respiratory complications. Women with postpartum haemorrhage had lower mean (standard deviation) platelet counts (120.2 (45.8) vs. 181.2 (109.9), p = .003) and temperatures (35.7 (1.1) vs. 36.5 (1.2), p = .002). Women with hypertensive diseases of pregnancy had higher mean (standard deviation) blood pressures (systolic 150.4 (29.1) vs. 127.4 (21.0), p = .013, diastolic 100.3 (18.7) vs. 76.1 (16.1), p = .001), creatinine (1.1 (0.6) vs. 0.8 (0.3), p = .003), urea (14.6 (7.7) vs. 10.5 (4.7), p = .005) and liver enzymes, including aspartate transaminase (258.4 (297.0) vs. 41.4 (42.9), p = .000), alanine transaminase (184.4 (199.2) vs. 35.1 (75.9), p = .000), and alkaline phosphatase (166.6 (112.6) vs. 96.0 (60.0), p = .006). Women with respiratory complications had lower mean (standard deviation) oxygen saturations (93.7 (6.1) vs. 98.0 (2.6), p = .000), and higher mean (standard deviation) temperatures (37.1 (0.8) vs. 36.0 (1.2), p = .001).

CONCLUSIONS

We report differences in laboratory values and vital signs, according to intensive care unit admission diagnosis. Recognising these differences might help individualise patient assessment and care.

Emergency Blood Transfusion for Trauma and Perioperative Resuscitation: Standard of Care

Uncontrolled and massive bleeding with derangement of coagulation is a major challenge in the management of both surgical and seriously injured patients. The underlying mechanism of trauma-induced or -associated coagulopathy is tissue injury in the presence of shock and acidosis provoking endothelial damage, activation of inflammation, and coagulation disbalancing. Furthermore, the combination of ongoing blood loss and consumption of blood components that are essential for effective coagulation worsens uncontrolled hemorrhage. Additionally, therapeutic actions, such as resuscitation with replacement fluids or allogeneic blood products, can further aggravate coagulopathy. Of the coagulation factors essential to the clotting process, fibrinogen is the first to be consumed to critical levels during acute bleeding and current evidence suggests that normalizing fibrinogen levels in bleeding patients improves clot formation and clot strength, thereby controlling hemorrhage. Three different therapeutic approaches are discussed controversially. Whole blood transfusion is used especially in the military scenario and is also becoming more and more popular in the civilian world, although it is accompanied by a strong lack of evidence and severe safety issues. Transfusion of allogeneic blood concentrates in fixed ratios without any targets has been investigated extensively with disappointing results. Individualized and target-controlled coagulation management based on point-of-care diagnostics with respect to the huge heterogeneity of massive bleeding situations is an alternative and advanced approach to managing coagulopathy associated with massive bleeding in the trauma as well as the perioperative setting.

Damage control in the intensive care unit: what should the intensive care physician know and do?

Damage control surgery has transformed the management of severely injured trauma patients. It was initially described as a three-step process that included bleeding control, abdominal cavity contamination, and resuscitation in the intensive care unit (ICU) before definitive repair of the injuries. When the patient is admitted into the ICU, the physician should identify all the physiological alterations to establish resuscitation management goals. These strategies allow an early correction of trauma-induced coagulopathy and hypoperfusion increasing the likelihood of survival. The objective of this article is to describe the physiological alterations in a severely injured trauma patient who undergo damage control surgery and to establish an adequate management approach. The physician should always be aware and correct the hypothermia, acidosis, coagulopathy and hypocalcemia presented in the severely injured trauma patients.

Massive transfusions and severe hypocalcemia: An opportunity for monitoring and supplementation guidelines

BACKGROUND

Massive transfusion protocols (MTPs) are associated with severe hypocalcemia, contributing to coagulopathy and mortality in severely injured patients. Severity of hypocalcemia following massive transfusion activation and appropriate treatment strategies remain undefined.

STUDY DESIGN AND METHODS

This was a retrospective study of all MTP activations in adult trauma patients at a Level 1 trauma center between August 2016 and September 2017. Units of blood products transfused, ionized calcium levels, and amount of calcium supplementation administered were recorded. Primary outcomes were ionized calcium levels and the incidence of severe ionized hypocalcemia (iCa ≤1.0 mmol/L) in relation to the volume of blood products transfused.

RESULTS

Seventy-one patients had an MTP activated during the study period. The median amount of packed red blood cells (PRBCs) transfused was 10 units (range 1-52). A total of 42 (59.1%) patients had periods of severe hypocalcemia. Patients receiving 13 or more units of PRBC had a greater prevalence of hypocalcemia with 83.3% having at least one measured ionized calcium ≤1.0 mmoL/L (p = .001). The number of ionized calcium levels checked and the amount of supplemental calcium given in patients who experienced hypocalcemia varied considerably.

DISCUSSION

Severe hypocalcemia commonly occurs during MTP activations and correlates with the number of packed red blood cells transfused. Monitoring of ionized calcium and amount of calcium supplementation administered is widely variable. Standardized protocols for recognition and management of severe hypocalcemia during massive transfusions may improve outcomes.

Volume of packed red blood cells and fresh frozen plasma is associated with intraoperative hypocalcaemia during large volume intraoperative transfusion

BACKGROUND

Severe hypocalcaemia is associated with increased transfusion in the trauma population. Furthermore, trauma patients developing severe hypocalcaemia have higher mortality and coagulopathy. Electrolyte abnormalities associated with massive transfusion have been less studied in the surgical population. Here, we tested the primary hypothesis that volume of packed red blood cells and fresh frozen plasma transfused intraoperatively is associated with lower nadir ionised calcium in the surgical population receiving massive resuscitation.

METHODS

We performed a retrospective observational study at an academic quaternary care centre to characterise hypocalcaemia following large volume (4 or more units packed red blood cells) intraoperative transfusion. We used multivariable linear regression to assess if volume of transfusion with packed red blood cells and fresh frozen plasma were independently associated with a lower ionised calcium. We then used multivariable logistic regressions to assess the association between ionised calcium and transfusion with: (i) mortality, (ii) acute kidney injury, and (iii) postoperative coagulopathy.

RESULTS

Hypocalcaemia following large volume resuscitation in the operating room is a very frequent occurrence (70% of cases). After controlling for demographic variables and intraoperative variables, the volume transfused intraoperative was independently associated with hypocalcaemia on multivariable linear regression. Hypocalcaemia, intraoperative transfusion of packed red blood cells, and intraoperative transfusion of fresh frozen plasma were not shown to be associated with clinical outcomes.

CONCLUSIONS

Hypocalcaemia was associated with increased transfusion volume in this single-centre study. Unlike the trauma population, hypocalcaemia was not associated with increased mortality during surgical care. Our findings suggest that despite improved practice patterns of calcium supplementation, intraoperative hypocalcaemia occurs with relatively high frequency following large volume intraoperative transfusion.

Trauma-induced coagulopathy

Uncontrolled haemorrhage is a major preventable cause of death in patients with traumatic injury. Trauma-induced coagulopathy (TIC) describes abnormal coagulation processes that are attributable to trauma. In the early hours of TIC development, hypocoagulability is typically present, resulting in bleeding, whereas later TIC is characterized by a hypercoagulable state associated with venous thromboembolism and multiple organ failure. Several pathophysiological mechanisms underlie TIC; tissue injury and shock synergistically provoke endothelial, immune system, platelet and clotting activation, which are accentuated by the 'lethal triad' (coagulopathy, hypothermia and acidosis). Traumatic brain injury also has a distinct role in TIC. Haemostatic abnormalities include fibrinogen depletion, inadequate thrombin generation, impaired platelet function and dysregulated fibrinolysis. Laboratory diagnosis is based on coagulation abnormalities detected by conventional or viscoelastic haemostatic assays; however, it does not always match the clinical condition. Management priorities are stopping blood loss and reversing shock by restoring circulating blood volume, to prevent or reduce the risk of worsening TIC. Various blood products can be used in resuscitation; however, there is no international agreement on the optimal composition of transfusion components. Tranexamic acid is used in pre-hospital settings selectively in the USA and more widely in Europe and other locations. Survivors of TIC experience high rates of morbidity, which affects short-term and long-term quality of life and functional outcome.

Improved Hemodynamic Recovery and 72-Hour Survival Following Low-Volume Resuscitation with a PEGylated Carboxyhemoglobin in a Rat Model of Severe Hemorrhagic Shock

INTRODUCTION

Hemorrhage is a leading cause of death from potentially survivable civilian and military trauma. As projected conflicts move from settings of tactical and logistical supremacy to hyper-dynamic tactical zones against peer and near-peer adversaries, protracted medical evacuation times are expected. Treatment at the point-of-injury is critical. Although crystalloids like Lactated Ringer's (LR) are ubiquitous, whole blood (WB) is the preferred resuscitation fluid following hemorrhage; however, logistical constraints limit the availability of WB in prehospital settings. Hemoglobin-based oxygen carriers (HBOCs) offer both hemodynamic support and oxygen-carrying capacity while avoiding logistical constraints of WB. We hypothesized that low-volume resuscitation of severe hemorrhagic shock with an HBOC (PEGylated carboxyhemoglobin, [PC]) would improve hemodynamic recovery and 72-hour survival; comparable to WB and superior to LR.

MATERIALS AND METHODS

A total of 21 anesthetized male Sprague-Dawley rats underwent severe hemorrhagic shock followed by randomly assigned low-volume resuscitation with LR, WB, or PC, and then recovered from anesthesia for up to 72-hour observation. Mean arterial pressure (MAP) was recorded continuously under anesthesia, and arterial blood gases were measured at baseline (BL), 60 minutes post-hemorrhage (HS1h), and 24 hours post-resuscitation (PR24h). Survival was presented on a Kaplan-Meier plot and significance determined with a log-rank test. Cardiovascular and blood gas data were assessed with one-way analysis of variance and post hoc analysis where appropriate.

RESULTS

All measured cardiovascular and blood chemistry parameters were equivalent between groups at BL and HS1h. BL MAP values were 90 ± 3, 86 ± 1, and 89 ± 2 mmHg for LR, PC, and WB, respectively. Immediately following resuscitation, MAP values were 57 ± 4, 74 ± 5, and 62 ± 3 mmHg, with PC equivalent to WB and higher than LR (P < 0.05). WB and LR were both lower than BL (P < 0.0001), whereas PC was not (P = 0.13). The PC group's survival to 72 hours was 57%, which was not different from WB (43%) and higher than LR (14%; P < 0.05).

CONCLUSIONS

A single bolus infusion of PC produced superior survival and MAP response compared to LR, which is the standard fluid resuscitant carried by combat medics. PC was not different from WB in terms of survival and MAP, which is encouraging because its reduced logistical constraints make it viable for field deployment. These promising findings warrant further development and investigation of PC as a low-volume, early treatment for hemorrhagic shock in scenarios where blood products may not be available.

Prevention of hypothermia in trauma victims - the HYPOTRAUM 2 study

INTRODUCTION

Hypothermia is common in trauma patients. It contributes to increasing mortality rate. Hypothermia is multifactorial, favoured by exposure to cold, severity of the patient's state and interventions such as infusion of fluids at room temperature.

AIM

To demonstrate that specific management of hypothermia (or of the risk of hypothermia) increases the number of trauma patients arriving at the hospital with a temperature >35°C.

DESIGN

This is a prospective, multicentre, open-label, pragmatic, cluster randomized clinical trial of an expected 1,200 trauma patients included by 12 out-of-hospital mobile intensive care units (MICU). Trauma patients are included in a prehospital setting if they present at least one of the following criteria known to be associated with an increased incidence of hypothermia: ambient temperature <18°C, Glasgow coma scale <15, systolic arterial blood pressure <100 mm Hg or body temperature <35°C. Patients are randomized, by cluster, to receive a conventional management or 'interventional' nursing management associating: continuous epitympanic temperature monitoring, early installation in the heated ambulance (temperature target >30°C controlled by infrared thermometer), protection by a survival blanket, and use of heated solutes (temperature objective >35°C controlled by infrared thermometer). The primary end point is the prevalence of hypothermia on arrival at the hospital. The hypothesis tested is a reduction from 20% to 13% in the prevalence of hypothermia. Secondary end points are to evaluate the interaction between the effectiveness of the measures taken and: (1) the severity of the patients assessed by the Revised Trauma Score; (2) the meteorological conditions when they are managed; (3) the time of care; and (4) therapeutic interventions.

DISCUSSION

This trial will assess the effectiveness of an invasive, out-of-hospital, temperature management on the onset of hypothermia in moderate to severe trauma patients.

IMPACT

Specific management of hypothermia is expected to decrease hypothermia in trauma patients.

Associations of anemia with stroke, bleeding, and mortality in atrial fibrillation: A systematic review and meta-analysis

BACKGROUND

Anemia frequently coexists with atrial fibrillation (AF) and has been variably associated with worse outcomes. We performed a systematic review and meta-analysis to comprehensively assess the effect of anemia on mortality, stroke/systemic thromboembolism, and bleeding events in patients with AF.

METHODS

MEDLINE and Embase were searched from inception until May 2020. Studies examining associations of anemia with the above outcomes in AF patients were included, and maximally adjusted hazard ratios (HRs) meta-analysed. PROSPERO registration number CRD42020171113.

RESULTS

Twenty-eight studies involving 365 484 patients (41% female, mean age 74.7 years) were included. The average study follow-up ranged from 0.2 to 4.0 years, and the prevalence of anemia was 16%. Anemia was associated with a 78% increase in all-cause mortality (HR, 1.78; 95% confidence interval [CI], 1.44-2.20), 60% increase in cardiovascular mortality (HR, 1.60; 95% CI, 1.17-2.19), 134% increase in noncardiovascular mortality (HR, 2.34; 95% CI, 1.58-3.47) 15% increase in stroke/systemic thromboembolism (HR, 1.15; 95% CI, 1.01-1.31), 78% increase in major bleeding (HR, 1.78; 95% CI, 1.54-2.05), and 77% increase in gastrointestinal bleeding (HR, 1.77; 95% CI, 1.23-2.55). Sensitivity analyses including studies that reported odds ratios did not result in any material change.

CONCLUSION

Anemia is a frequently observed comorbidity in patients with AF, and is associated with an increased risk of all-cause, cardiovascular and noncardiovascular mortality, stroke/systemic thromboembolism, and major and gastrointestinal bleeding. Future studies are required to explore the causes of anemia in AF, and whether investigation and treatment may be clinically beneficial in affected individuals.

Hemostatic strategies for uncontrolled bleeding: A comprehensive update

Uncontrolled bleeding remains the leading cause of morbidity and mortality across the entire macrocosm. It refers to excessive loss of blood that occurs inside of body, due to unsuccessful platelet plug formation at the injury site. It is not only limited to the battlefield, but remains the second leading cause of death amongst the civilians, as a result of traumatic injury. Startlingly, there are no effective treatments currently available, to cater the issue of internal bleeding, even though early intervention is of utmost significance in minimizing the mortality rates associated with it. The fatal issue of uncontrolled bleeding is ineffectively being dealt with the use of pressure dressings, tourniquet, and surgical procedures. This is not a practical approach in combat arenas or in emergency situations, where the traumatic injury inflicted is deep inside the body, and cannot be addressed externally, by the application of topical dressings. This review focuses on the traditional hemostatic agents that are used to augment the process of hemostasis, such as mineral zeolites, chitosan based products, biologically active agents, anti-fibrinolytics, absorbable agents, and albumin and glutaraldehyde, as well as the micro- and nano-based hemostatic agents such as synthocytes, thromboerythrocytes, thrombosomes, and the synthetic platelets.

The diamond of death: Hypocalcemia in trauma and resuscitation

INTRODUCTION

Early recognition and management of hemorrhage, damage control resuscitation, and blood product administration have optimized management of severe trauma. Recent data suggest hypocalcemia exacerbates the ensuing effects of coagulopathy in trauma.

OBJECTIVE

This narrative review of available literature describes the physiology and role of calcium in trauma resuscitation. Authors did not perform a systematic review or meta-analysis.

DISCUSSION

Calcium is a divalent cation found in various physiologic forms, specifically the bound, inactive state and the unbound, physiologically active state. While calcium plays several important physiologic roles in multiple organ systems, the negative hemodynamic effects of hypocalcemia are crucial to address in trauma patients. The negative ramifications of hypocalcemia are intrinsically linked to components of the lethal triad of acidosis, coagulopathy, and hypothermia. Hypocalcemia has direct and indirect effects on each portion of the lethal triad, supporting calcium's potential position as a fourth component in this proposed lethal diamond. Trauma patients often present hypocalcemic in the setting of severe hemorrhage secondary to trauma, which can be worsened by necessary transfusion and resuscitation. The critical consequences of hypocalcemia in the trauma patient have been repeatedly demonstrated with the associated morbidity and mortality. It remains poorly defined when to administer calcium, though current data suggest that earlier administration may be advantageous.

CONCLUSIONS

Calcium is a key component of trauma resuscitation and the coagulation cascade. Recent data portray the intricate physiologic reverberations of hypocalcemia in the traumatically injured patient; however, future research is needed to further guide the management of these patients.

A deep learning backcasting approach to the electrolyte, metabolite, and acid-base parameters that predict risk in ICU patients

Background

A powerful risk model allows clinicians, at the bedside, to ensure the early identification of and decision-making for patients showing signs of developing physiological instability during treatment. The aim of this study was to enhance the identification of patients at risk for deterioration through an accurate model using electrolyte, metabolite, and acid-base parameters near the end of patients’ intensive care unit (ICU) stays.

Methods

This retrospective study included 5157 adult patients during the last 72 hours of their ICU stays. The patients from the MIMIC-III database who had serum lactate, pH, bicarbonate, potassium, calcium, glucose, chloride, and sodium values available, along with the times at which those data were recorded, were selected. Survivor data from the last 24 hours before discharge and four sets of nonsurvivor data from 48–72, 24–48, 8–24, and 0–8 hours before death were analyzed. Deep learning (DL), random forest (RF) and generalized linear model (GLM) analyses were applied for model construction and compared in terms of performance according to the area under the receiver operating characteristic curve (AUC). A DL backcasting approach was used to assess predictors of death vs. discharge up to 72 hours in advance.

Results

The DL, RF and GLM models achieved the highest performance for nonsurvivors 0–8 hours before death versus survivors compared with nonsurvivors 8–24, 24–48 and 48–72 hours before death versus survivors. The DL assessment outperformed the RF and GLM assessments and achieved discrimination, with an AUC of 0.982, specificity of 0.947, and sensitivity of 0.935. The DL backcasting approach achieved discrimination with an AUC of 0.898 compared with the DL native model of nonsurvivors from 8–24 hours before death versus survivors with an AUC of 0.894. The DL backcasting approach achieved discrimination with an AUC of 0.871 compared with the DL native model of nonsurvivors from 48–72 hours before death versus survivors with an AUC of 0.846.

Conclusions

The DL backcasting approach could be used to simultaneously monitor changes in the electrolyte, metabolite, and acid-base parameters of patients who develop physiological instability during ICU treatment and predict the risk of death over a period of hours to days.

Venous Waveform Analysis Correlates With Echocardiography in Detecting Hypovolemia in a Rat Hemorrhage Model

BACKGROUND

Assessing intravascular hypovolemia due to hemorrhage remains a clinical challenge. Central venous pressure (CVP) remains a commonly used monitor in surgical and intensive care settings for evaluating blood loss, despite well-described pitfalls of static pressure measurements. The authors investigated an alternative to CVP, intravenous waveform analysis (IVA) as a method for detecting blood loss and examined its correlation with echocardiography.

METHODS

Seven anesthetized, spontaneously breathing male Sprague Dawley rats with right internal jugular central venous and femoral arterial catheters underwent hemorrhage. Mean arterial pressure (MAP), heart rate, CVP, and IVA were assessed and recorded. Hemorrhage was performed until each rat had 25% estimated blood volume removed. IVA was obtained using fast Fourier transform and the amplitude of the fundamental frequency (f1) was measured. Transthoracic echocardiography was performed utilizing a parasternal short axis image of the left ventricle during hemorrhage. MAP, CVP, and IVA were compared with blood removed and correlated with left ventricular end diastolic area (LVEDA).

RESULTS

All 7 rats underwent successful hemorrhage. MAP and f1 peak amplitude obtained by IVA showed significant changes with hemorrhage. MAP and f1 peak amplitude also significantly correlated with LVEDA during hemorrhage (R = 0.82 and 0.77, respectively). CVP did not significantly change with hemorrhage, and there was no significant correlation between CVP and LVEDA.

CONCLUSIONS

In this study, f1 peak amplitude obtained by IVA was superior to CVP for detecting acute, massive hemorrhage. In addition, f1 peak amplitude correlated well with LVEDA on echocardiography. Translated clinically, IVA might provide a viable alternative to CVP for detecting hemorrhage.

The impact of hypothermia on outcomes in massively transfused patients

BACKGROUND

Hypothermia is associated with poor outcomes after injury. The relationship between hypothermia during contemporary large volume resuscitation and blood product consumption is unknown. We evaluated this association, and the predictive value of hypothermia on mortality.

METHODS

Patients predicted to receive massive transfusion at 12 level 1 trauma centers were randomized in the Pragmatic Randomized Optimal Platelet and Plasma Ratios (PROPPR) trial and were grouped into those who were hypothermic (<36°C) or normothermic (36-38.5°C) within the first 6 hours of emergency department arrival. The impact of hypothermia or normothermia on the volume of blood product required during the first 24 hours was determined via negative binomial regression, adjusting for treatment arm, injury severity score, mechanism, demographics, pre-emergency department fluid volume, blood administered before becoming hypothermic, pulse and systolic blood pressure on arrival, and the time exposed to hypothermic or normothermic temperatures.

RESULTS

Of 680 patients, 590 had a temperature measured during the first 6 hours in hospital, and 399 experienced hypothermia. The mean number of red blood cell (RBC) units given to all patients in the first 24 hours of admission was 8.8 (95% confidence interval [CI], 7.9-9.6). In multivariable analysis, every 1°C decrease in temperature below 36.0°C was associated with a 10% increase (incidence rate ratio, 0.90; 95% CI, 0.89-0.92; p < 0.00) in consumption of RBCs during the first 24 hours of admission. There was no association between RBC administration and a temperature above 36°C. Hypothermia on arrival was an independent predictor of mortality, with an adjusted odds ratio of 2.7 (95% CI, 1.7-4.5; p < 0.00) for 24-hour mortality and 1.8 (95% CI, 1.3-2.4; p < 0.00) for 30-day mortality.

CONCLUSION

Hypothermia is associated with increase in blood product consumption and mortality. These findings support the maintenance of normothermia in trauma patients and suggest that further investigation on the impact of cooling or rewarming during massive transfusion is warranted.

LEVEL OF EVIDENCE

Prognostic, level III.

The Role of Serum Calcium Level in Intracerebral Hemorrhage Hematoma Expansion: Is There Any?

Spontaneous intracerebral hemorrhage (ICH) is a devastating form of stroke, with a high rate of mortality and morbidity. Even with the best current medical or surgical interventions, outcomes remain poor. The location and initial hematoma volume are strong predictors of mortality. Hematoma expansion (HE) is a further marker of poor prognosis that may be at least partly preventable. Several risk factors for HE have been identified, including baseline ICH volume, anticoagulation, and computed tomography angiography spot signs. Recent studies have shown the correlation of serum calcium (Ca⁺⁺) levels on admission with HE. Low serum Ca⁺⁺ level has been associated with larger hematoma volume at the time of presentation, HE, and worse outcome. Although the causal and mechanistic links between low serum Ca⁺⁺ level and HE are not well understood, several mechanisms have been proposed including coagulopathy, platelet dysfunction, and higher blood pressure (BP) in the context of low serum Ca⁺⁺ level. However, low serum Ca⁺⁺ level might be only a biomarker of the adaptive response due to acute inflammatory response following acute ICH. The purpose of the current review is to discuss the evidence regarding the possible role of low serum Ca⁺⁺ level on HE in acute ICH.

Controlled Multifactorial Coagulopathy: Effects of Dilution, Hypothermia, and Acidosis on Thrombin Generation In Vitro

BACKGROUND

Coagulopathy and hemostatic abnormalities remain a challenge in patients following trauma and major surgery. Coagulopathy in this setting has a multifactorial nature due to tissue injury, hemodilution, hypothermia, and acidosis, the severity of which may vary. In this study, we combined computational kinetic modeling and in vitro experimentation to investigate the effects of multifactorial coagulopathy on thrombin, the central enzyme in the coagulation system.

METHODS

We measured thrombin generation in platelet-poor plasma from 10 healthy volunteers using the calibrated automated thrombogram assay (CAT). We considered 3 temperature levels (31°C, 34°C, and 37°C), 3 pH levels (6.9, 7.1, and 7.4), and 3 degrees of dilution with normal saline (no dilution, 3-fold dilution, and 5-fold dilution). We measured thrombin-generation time courses for all possible combinations of these conditions. For each combination, we analyzed 2 scenarios: without and with (15 nM) supplementation of thrombomodulin, a key natural regulator of thrombin generation. For each measured thrombin time course, we recorded 5 quantitative parameters and analyzed them using multivariable regression. Moreover, for multiple combinations of coagulopathic conditions, we performed routine coagulation tests: prothrombin time (PT) and activated partial thromboplastin time (aPTT). We compared the experimental results with simulations using a newly developed version of our computational kinetic model of blood coagulation.

RESULTS

Regression analysis allowed us to identify trends in our data (P < 10). In both model simulations and experiments, dilution progressively reduced the peak of thrombin generation. However, we did not experimentally detect the model-predicted delay in the onset of thrombin generation. In accord with the model predictions, hypothermia delayed the onset of thrombin generation; it also increased the thrombin peak time (up to 1.30-fold). Moreover, as predicted by the kinetic model, the experiments showed that hypothermia increased the area under the thrombin curve (up to 1.97-fold); it also increased the height of the thrombin peak (up to 1.48-fold). Progressive acidosis reduced the velocity index by up to 24%; acidosis-induced changes in other thrombin generation parameters were much smaller or none. Acidosis increased PT by 14% but did not influence aPTT. In contrast, dilution markedly prolonged both PT and aPTT. In our experiments, thrombomodulin affected thrombin-generation parameters mainly in undiluted plasma.

CONCLUSIONS

Dilution with normal saline reduced the amount of generated thrombin, whereas hypothermia increased it and delayed the time of thrombin accumulation. In contrast, acidosis in vitro had little effect on thrombin generation.

Forgot calcium? Admission ionized-calcium in two civilian randomized controlled trials of prehospital plasma for traumatic hemorrhagic shock

BACKGROUND

Randomized clinical trials (RCTs) support the use of prehospital plasma in traumatic hemorrhagic shock, especially in long transports. The citrate added to plasma binds with calcium, yet most prehospital trauma protocols have no guidelines for calcium replacement. We reviewed the experience of two recent prehospital plasma RCTs regarding admission ionized-calcium (i-Ca) blood levels and its impact on survival. We hypothesized that prehospital plasma is associated with hypocalcemia, which in turn is associated with lower survival.

METHODS

We studied patients enrolled in two institutions participating in prehospital plasma RCTs (control, standard of care; experimental, plasma), with i-Ca collected before calcium supplementation. Adults with traumatic hemorrhagic shock (systolic blood pressure ≤70 mm Hg or 71-90 mm Hg + heart rate ≥108 bpm) were eligible. We use generalized linear mixed models with random intercepts and Cox proportional hazards models with robust standard errors to account for clustered data by institution. Hypocalcemia was defined as i-Ca of 1.0 mmol/L or less.

RESULTS

Of 160 subjects (76% men), 48% received prehospital plasma (median age, 40 years [interquartile range, 28-53 years]) and 71% suffered blunt trauma (median Injury Severity Score [ISS], 22 [interquartile range, 17-34]). Prehospital plasma and control patients were similar regarding age, sex, ISS, blunt mechanism, and brain injury. Prehospital plasma recipients had significantly higher rates of hypocalcemia compared with controls (53% vs. 36%; adjusted relative risk, 1.48; 95% confidence interval [CI], 1.03-2.12; p = 0.03). Severe hypocalcemia was significantly associated with decreased survival (adjusted hazard ratio, 1.07; 95% CI, 1.02-1.13; p = 0.01) and massive transfusion (adjusted relative risk, 2.70; 95% CI, 1.13-6.46; p = 0.03), after adjustment for confounders (randomization group, age, ISS, and shock index).

CONCLUSION

Prehospital plasma in civilian trauma is associated with hypocalcemia, which in turn predicts lower survival and massive transfusion. These data underscore the need for explicit calcium supplementation guidelines in prehospital hemotherapy.

LEVEL OF EVIDENCE

Therapeutic, level II.

[Hypovolemic and hemorrhagic shock]

The term "shock" refers to a life-threatening circulatory failure caused by an imbalance between the supply and demand of cellular oxygen. Hypovolemic shock is characterized by a reduction of intravascular volume and a subsequent reduction in preload. The body compensates the loss of volume by increasing the stroke volume, heart frequency, oxygen extraction rate, and later by an increased concentration of 2,3-diphosphoglycerate with a rightward shift of the oxygen dissociation curve. Hypovolemic hemorrhagic shock impairs the macrocirculation and microcirculation and therefore affects many organ systems (e.g. kidneys, endocrine system and endothelium). For further identification of a state of shock caused by bleeding, vital functions, coagulation tests and hematopoietic procedures are implemented. Every hospital should be in possession of a specific protocol for massive transfusions. The differentiated systemic treatment of bleeding consists of maintenance of an adequate homeostasis and the administration of blood products and coagulation factors.

Pre-hospital Hemorrhagic Control Effectiveness of Axiostat® Dressing Versus Conventional Method in Acute Hemorrhage Due to Trauma

Accidents and trauma are one of the leading causes of death and disability throughout the world. In developing countries like India where emergency trauma care is still emerging, it accounts for almost 10% of deaths every year. Lack of adequate pre-hospital care and uncontrolled bleeding from the wound site are stated to be the prominent reasons for such deaths. The aim of this study was to evaluate the efficacy of a novel chitosan-based haemostatic dressing, Axiostat® (Axio Biosolutions Private Ltd., Gujarat, India), as a hemorrhage control device in the ambulance setting.

A total of 104 patients with bleeding scalp wounds were randomly allocated into two treatment groups while transporting them to the hospital. Patients in Group I were treated with Axiostat® chitosan haemostatic dressing (n = 47), while a conventional cotton gauze dressing was used in Group II (n = 57). A standard procedure was followed to apply the dressing on bleeding wounds and time to achieve haemostasis, the amount of blood loss, the number of patients with haemostasis, the occurrence of rebleeding, and other side effects were noted.

The mean age of the patients was 40 years and the majority of patients were male - 73 (70%). Most of the wounds were lacerations with venous bleeding. Haemostasis time was 4.68 ± 1.04 minutes and 18.56 ± 5.04 minutes in the Axiostat® and cotton gauze groups, respectively. The use of Axiostat® significantly reduced the time to haemostasis (p < 0.0001). A significant reduction in blood loss was observed with the application of Axiostat®. Successful haemostasis was achieved in 94% of patients in the Axiostat® group and 74% patients in cotton gauze group, respectively (p < 0.05). Moreover, no side effects, such as tissue loss or rebleeding at time of removal, were seen with the use of Axiostat®, while three patients in the cotton gauze group showed some side effects.

Results show that Axiostat® enables rapid haemostasis and can prevent significant blood loss during emergency trauma and accidents. Additionally, it also allows for easier removal from the wound site without leaving any residue, which helps in rendering the wound clean. In conclusion, the study successfully demonstrates the potential of Axiostat® as a first-line intervention in controlling acute haemorrhage in emergency care.

Comparison of Two Different Fibrinogen Concentrates in an in vitro Model of Dilutional Coagulopathy

Introduction

Fibrinogen concentrates are widely used to restore clot stability in situations of bleeding. Fibrinogen preparations are produced using different production methods, resulting in different compounds. Thus, different preparations might have a distinct impact on blood coagulation. We tested the effect of fibrinogen concentrates Haemocomplettan® (CSL Behring, Marburg, Germany) and fibryga® (Octapharma GmbH, Langenfeld, Germany) on the impairments induced by 60% dilutional coagulopathy in vitro.

Materials and Methods

The influence of the fibrinogen concentrates fibryga® and Haemocomplettan® on colloid (gelatine, hydroxyethyl starch [HES], albumin)-induced or crystalloid (Ringer's acetate)-induced dilutional coagulopathy was analysed using rotational thromboelastometry (ROTEM®) and standard laboratory tests. The following experimental conditions were analysed in vitro: whole blood, 60% dilution (40% blood and 60% diluent) ± 50 or 100 mg/kg^-1 fibryga® or Haemocomplettan®, respectively.

Results

Dilution with either diluent resulted in prolonged clotting time (CT) in an extrinsic activated test (CT_EXTEM) and decreased maximum clot firmness (MCF_FIBTEM) as expressed, e.g., by gelatine: (59.5 s [62/54.8] vs. 95 s [102.8/86.8]; p < 0.001 and 14 mm [16/10.5] vs. 3 mm [4-3]; p < 0.001). Substitution after 60% dilution with HES resulted in no difference between the preparations, except for shorter thrombin time with fibryga® (14 s [15/14] vs. 18 s [18.8/17]; p = 0.0093; low dose). CT_EXTEM was higher with Haemocomplettan® in a gelatine-induced dilution (51 s [54.5/47.5] vs. 63 s [71/60.3]; p = 0.0202; low dose) whereas thrombin time was lower with fibryga® (19.5 s [20.8/19] vs. 27 s [29/25.3]; p = 0.0017). In dilution with albumin, differences in CT_EXTEM (69 s [76.5/66] vs. 56 s [57/53.3]; p = 0.0114; low dose) and thrombin time (18 s [18/17] vs. 24.5 s [25.8/24]; p = 0.0202; low dose) were seen. In dilution with crystalloid solution, again differences in CT_EXTEM (53.5 s [57.8/53] vs. 45 s [47/43]; p = 0.035; low dose) and thrombin time (17 s [17/16] vs. 23.5 s [24/23]; p = 0.0014; low dose) were seen. Fibrinogen levels were more increased by high-dose substitution of both preparations.

Conclusion

Based on this data it can be stated that both fibryga® and Haemocomplettan® had the same performance in our in vitro model except for CT_EXTEM and thrombin time.

The European guideline on management of major bleeding and coagulopathy following trauma: fifth edition

BACKGROUND

Severe traumatic injury continues to present challenges to healthcare systems around the world, and post-traumatic bleeding remains a leading cause of potentially preventable death among injured patients. Now in its fifth edition, this document aims to provide guidance on the management of major bleeding and coagulopathy following traumatic injury and encourages adaptation of the guiding principles described here to individual institutional circumstances and resources.

METHODS

The pan-European, multidisciplinary Task Force for Advanced Bleeding Care in Trauma was founded in 2004, and the current author group included representatives of six relevant European professional societies. The group applied a structured, evidence-based consensus approach to address scientific queries that served as the basis for each recommendation and supporting rationale. Expert opinion and current clinical practice were also considered, particularly in areas in which randomised clinical trials have not or cannot be performed. Existing recommendations were re-examined and revised based on scientific evidence that has emerged since the previous edition and observed shifts in clinical practice. New recommendations were formulated to reflect current clinical concerns and areas in which new research data have been generated.

RESULTS

Advances in our understanding of the pathophysiology of post-traumatic coagulopathy have supported improved management strategies, including evidence that early, individualised goal-directed treatment improves the outcome of severely injured patients. The overall organisation of the current guideline has been designed to reflect the clinical decision-making process along the patient pathway in an approximate temporal sequence. Recommendations are grouped behind the rationale for key decision points, which are patient- or problem-oriented rather than related to specific treatment modalities. While these recommendations provide guidance for the diagnosis and treatment of major bleeding and coagulopathy, emerging evidence supports the author group's belief that the greatest outcome improvement can be achieved through education and the establishment of and adherence to local clinical management algorithms.

CONCLUSIONS

A multidisciplinary approach and adherence to evidence-based guidance are key to improving patient outcomes. If incorporated into local practice, these clinical practice guidelines have the potential to ensure a uniform standard of care across Europe and beyond and better outcomes for the severely bleeding trauma patient.

[Viscoelasticity-based treatment of bleeding injuries]

Uncontrolled bleeding is the leading preventable cause of death in patients with multiple injuries. Currently, trauma-induced coagulopathy is seen as an independent disease entity influencing survival. Severely bleeding trauma patients are often treated with classical blood products in predefined ratios (damage control resuscitation). Viscoelasticity-based and target-oriented approaches could possibly be given priority. Viscoelasticity-based diagnostics and therapy enable the qualitative investigation of whole blood and provide therapeutically usable information on initiation, dynamics and sustainability of thrombus formation. Due to the ease of handling and timely results this lends itself as a point-of-care procedure. This article presents the clinical issues with using viscoelastic procedures and current expert recommendations taking the literature into consideration.

THAM Administration to Pediatric Trauma Patients in a Combat Zone

OBJECTIVES

Pediatric casualties made up a significant proportion of patients during the recent military conflicts in Iraq and Afghanistan. Damage control resuscitation strategies used by military physicians included rapid reversal of metabolic acidosis to mitigate its pathophysiologic consequences, primarily through hemorrhage control and volume restoration. Alkalizing agents, including tris(hydroxymethyl)aminomethane (THAM), are potential therapeutic adjuncts to treat significant acidosis. There is, however, limited published data on THAM administration in the pediatric trauma population. We compared demographics and outcomes among pediatric trauma patients in Afghanistan and Iraq receiving THAM versus those not receiving THAM.

METHODS

We queried the Department of Defense Trauma Registry for all of the pediatric patients admitted to US and Coalition fixed-facility hospitals in Afghanistan and Iraq from January 2007 to January 2016. We retrieved data on age, sex, location, mechanism of injury, Injury Severity Scores, ventilator days, days in the intensive care unit, days of total hospitalization, and survival to hospital discharge. We excluded subjects if they were dead on arrival to the emergency department.

RESULTS

From January 2007 to January 2016, there were 3386 pediatric subjects that met our inclusion criteria. Of these, 15 received THAM. The youngest subject receiving THAM was a 2-month-old burn victim. Subjects receiving THAM were more likely to be injured by submersion or burn (P < 0.001), had higher composite Injury Severity Scores (17 vs 10; P < 0.001) and Abbreviated Injury Scores for the thorax and abdomen (P = 0.004 and P = 0.019, respectively), and longer ventilator days/intensive care unit stays/hospital lengths of stay (P < 0.001/P < 0.001/P = 0.013). In addition, subjects receiving THAM had a lower survival rate than subjects not receiving THAM (73.3% vs 91.7%; P = 0.011).

CONCLUSIONS

THAM was administered rarely to pediatric trauma casualties during the conflicts in Afghanistan and Iraq. Subjects receiving THAM were more critically injured than the baseline population.

Slow as Compared to Rapid Rewarming After Mild Hypothermia Improves Survival in Experimental Shock

BACKGROUND

Accidental hypothermia following trauma is an independent risk factor for mortality. However, in most experimental studies, hypothermia clearly improves outcome. We hypothesized that slow rewarming is beneficial over rapid rewarming following mild hypothermia in a rodent model of hemorrhagic shock.

MATERIALS AND METHODS

We subjected 32 male Wistar rats to severe hemorrhagic shock (25-30 mmHg for 30 min). Rats were assigned to four experimental groups (normothermia, hypothermia, rapid rewarming [RW], and slow RW). During induction of severe shock, all but the normothermia group were cooled to 34°C. After 60 min of shock, rats were resuscitated with Ringer's solution. The two RW groups were rewarmed at differing rates (6°C/h versus 2°C/h).

RESULTS

Slow RW animals exhibit a significantly prolonged survival compared with the rapid RW animals (P < 0.05). Nevertheless, hypothermic animals show a significant survival benefit as compared to all other experimental groups. Whereas seven animals of the hypothermia group survived to the end of the experiment, none of the other animals did (P < 0.001). No significant differences were found regarding acid base status, metabolism, parameters of organ injury, and coagulation.

CONCLUSIONS

The results indicate that even slow RW with 2°C/h may be still too fast in the setting of experimental hemorrhage. Too rapid rewarming may result in a loss of the protective effects of hypothermia. As rewarming is ultimately inevitable in patients with trauma, potential effects of rewarming on patient outcome should be further investigated in clinical studies.

Management of bleeding in major burn surgery

Major burn surgery is often associated with excessive bleeding and massive transfusion, and the development of a coagulopathy during major burn surgery is associated with increased morbidity and mortality. The aim of this study was to review the literature on intraoperative haemostatic resuscitation of burn patients during necrectomy to reveal strategies applied for haemostatic monitoring and resuscitation. We searched PubMed, EMBASE, and CENTRAL for studies published in the period 2006-2017 concerning bleeding issues related to burn surgery i.e. coagulopathy, transfusion requirements and clinical outcomes. In a broad search, a total of 1375 papers were identified. 124 of these fulfilled the inclusion criteria, and six of these were included for review. The literature confirmed that transfusion requirements increases with burn injury severity and that haemostatic monitoring by TEG^® (thrombelastography) or ROTEM^® (rotational thromboelastometry) significantly decreased intraoperative transfusions and was useful in predicting and goal-directing haemostatic therapy during excision surgery. Resuscitation of bleeding during major burn surgery in many instances was neither standardized nor haemostatic. We suggest that resuscitation should aim for normal haemostasis during the bleeding phase through close haemostatic monitoring and resuscitation. Randomised controlled trials are highly warranted to confirm the benefit of this concept.

Prehospital Blood Product Transfusion in Mountain Rescue Operations

Severely injured patients with hemorrhage present major challenges for emergency medical services, especially during mountain rescue missions in which harsh environmental conditions and long out-of-hospital times are frequent. Because uncontrolled hemorrhage is the leading cause of death within the first 48 hours after severe trauma, initiating damage control resuscitation (DCR) as early as possible after severe trauma and exporting the concept of DCR to the out-of-hospital arena is pivotal for patient survival. Appropriate bleeding control, management of coagulopathy, and transfusion of blood products are core aspects of DCR. This review summarizes the available evidence on out-of-hospital blood product transfusion and the management of coagulopathy with a special focus on mountain rescue missions. An overview of upcoming trials and possible future trends in the management of coagulopathy during rescue operations is provided.

Hemostatic responses to exercise, dehydration, and simulated bleeding in heat-stressed humans

Heat stress followed by an accompanying hemorrhagic challenge may influence hemostasis. We tested the hypothesis that hemostatic responses would be increased by passive heat stress, as well as exercise-induced heat stress, each with accompanying central hypovolemia to simulate a hemorrhagic insult. In aim 1, subjects were exposed to passive heating or normothermic time control, each followed by progressive lower-body negative pressure (LBNP) to presyncope. In aim 2 subjects exercised in hyperthermic environmental conditions, with and without accompanying dehydration, each also followed by progressive LBNP to presyncope. At baseline, pre-LBNP, and post-LBNP (<1, 30, and 60 min), hemostatic activity of venous blood was evaluated by plasma markers of hemostasis and thrombelastography. For aim 1, both hyperthermic and normothermic LBNP (H-LBNP and N-LBNP, respectively) resulted in higher levels of factor V, factor VIII, and von Willebrand factor antigen compared with the time control trial (all P < 0.05), but these responses were temperature independent. Hyperthermia increased fibrinolysis [clot lysis 30 min after the maximal amplitude reflecting clot strength (LY₃₀)] to 5.1% post-LBNP compared with 1.5% (time control) and 2.7% in N-LBNP ( P = 0.05 for main effect). Hyperthermia also potentiated increased platelet counts post-LBNP as follows: 274 K/µl for H-LBNP, 246 K/µl for N-LBNP, and 196 K/µl for time control ( P < 0.05 for the interaction). For aim 2, hydration status associated with exercise in the heat did not affect the hemostatic activity, but fibrinolysis (LY₃₀) was increased to 6-10% when subjects were dehydrated compared with an increase to 2-4% when hydrated ( P = 0.05 for treatment). Central hypovolemia via LBNP is a primary driver of hemostasis compared with hyperthermia and dehydration effects. However, hyperthermia does induce significant thrombocytosis and by itself causes an increase in clot lysis. Dehydration associated with exercise-induced heat stress increases clot lysis but does not affect exercise-activated or subsequent hypovolemia-activated hemostasis in hyperthermic humans. Clinical implications of these findings are that quickly restoring a hemorrhaging hypovolemic trauma patient with cold noncoagulant fluids (crystalloids) can have serious deleterious effects on the body's innate ability to form essential clots, and several factors can increase clot lysis, which should therefore be closely monitored.

How do external factors contribute to the hypocoagulative state in trauma-induced coagulopathy? - In vitro analysis of the lethal triad in trauma

Background

External factors following trauma and iatrogenic intervention influence blood coagulation and particularly clot formation. In particular, three external factors (in detail dilution via uncritical volume replacement, acidosis and hypothermia), in combination, referred to as the “lethal triad”, substantially aggravate the hypocoagulative state after trauma. Contribution of these external factors to the resulting hypocoagulative state in trauma and especially their influence on primary haemostasis has still not been investigated systematically.

This study aims to assess this contribution to the aggravating hypocoagulative state in trauma-induced coagulopathy (TIC) using an in vitro simulation assay. Emphasis is given to platelet contribution to clot formation and to the investigation of how platelet activation alters under the respective conditions.

Methods

To simulate the conditions of lethal triad in vitro, whole blood samples taken from five healthy volunteers were introduced to the respective conditions. Besides standard coagulation testing, thrombelastometric analysis and differentiated platelet mapping were performed.

Results

All three simulated conditions induced significant impairments of clot formation (clot formation time, CFT; α -angle) and propagation (maximum clot firmness, MCF; Diameter A5-A25), with the highest impact under hypothermia and dilution. Consistently, lethal triad resulted in an additive effect of all conditions. None of the simulated conditions induced a statistically relevant change in coagulation initiation assessed by EXTEM and FIBTEM thrombelastometry.

Platelet contribution to clot formation decreased gradually under the respective conditions, reaching statistical significance for simulated dilution, and attaining its greatest extent under the conditions of lethal triad (Δtrias/baseline 0.59; p = 0.01). Consistent, reduced CD62 expression levels were observed under experimental acidosis (Δacidosis/baseline 0.32; p = 0.006), dilution (Δdilution/baseline 0.34; p = 0.01) and lethal triad (Δlethal triad/baseline 0.24; p = 0.01).

Conclusion

The respective external factors of lethal triad play a pivotal role in the development of coagulopathy, essentially influencing the kinetics of clot formation, and to a varying extent clot diameter, as measured by thrombelastometry. Moreover, impairment of platelet function under the conditions of lethal triad plays a key role in the pathophysiology of TIC, resulting in reduced responsiveness to stimulation with ADP that might also be present after trauma. Our data indicate that impairment of primary haemostasis contribute to the hypocoagulative state in TIC after trauma aggravated by external factors of lethal triad.

[Management of hemorrhage in patients treated with direct oral anticoagulants]

The introduction of nonvitamin K antagonistic, direct oral anticoagulants (DOAC) made thromboembolic prophylaxis easier for patients. For many physicians, however, there is still uncertainty about monitoring, preoperative discontinuation, and restarting of DOAC therapy. Guidelines for the management of bleeding are provided, but require specific therapeutic skills in the management of diagnostics and therapy of acute hemorrhage. Small clinical studies and case reports indicate that unspecific therapy with prothrombin complex concentrates (PCC) and activated PCC (aPCC) concentrate may reverse DOAC-induced anticoagulation. However, PCC or aPCC at higher doses potentially provoke thromboembolic complications. However, idarucizumab, a specific, fast-acting, antidote for dabigatran, provides immediate and sustained reversal with no intrinsic or prohemostatic activity. This review article provides an overview of the pharmacology and potential risk of DOAC and the management in the perioperative period with a focus of current concepts in the treatment of DOAC-associated bleeding.

Role of Thromboelastography and Rotational Thromboelastometry in the Management of Cardiovascular Diseases

The monitoring of coagulation by viscoelastometric methods—thromboelastography and rotational thromboelastometry—may detect the contributions of cellular and plasma components of hemostasis. These methods might overcome some of the serious limitations of conventional laboratory tests. Viscoelastic testing can be repeatedly performed during and after surgery and thus provides a dynamic picture of the coagulation process during these periods. Several experiences with the use of these methods in cardiovascular surgery have been reported, but there is perspective for more frequent use of these assays in the assessment of platelet response to antiplatelet therapy and in the assessment of coagulation in patients on long-term dabigatran therapy. This article reviews the current role and future perspectives of thromboelastography and thromboelastometry in the management of cardiovascular diseases.

Pharmacotherapy Pearls for Emergency Neurological Life Support

The appropriate use of medications during Emergency Neurological Life Support (ENLS) is essential to optimize patient care. Important considerations when choosing the appropriate agent include the patient's organ function and medication allergies, potential adverse drug effects, drug interactions and critical illness and aging pathophysiologic changes. Critical medications used during ENLS include hyperosmolar therapy, anticonvulsants, antithrombotics, anticoagulant reversal and hemostatic agents, anti-shivering agents, neuromuscular blockers, antihypertensive agents, sedatives, vasopressors and inotropes, and antimicrobials. This article focuses on the important pharmacokinetic and pharmacodynamics characteristics, advantages and disadvantages and clinical pearls of these therapies, providing practitioners with essential drug information to optimize pharmacotherapy in acutely ill neurocritical care patients.

Effects of sodium citrate, citric acid and lactic acid on human blood coagulation

INTRODUCTION

Citric acid infusion in extracorporeal blood may allow concurrent regional anticoagulation and enhancement of extracorporeal CO₂ removal. Effects of citric acid on human blood thromboelastography and aggregometry have never been tested before.

METHODS

In this in vitro study, citric acid, sodium citrate and lactic acid were added to venous blood from seven healthy donors, obtaining concentrations of 9 mEq/L, 12 mEq/L and 15 mEq/L. We measured gas analyses, ionized calcium (iCa⁺⁺) concentration, activated clotting time (ACT), thromboelastography and multiplate aggregometry. Repeated measure analysis of variance was used to compare the acidifying and anticoagulant properties of the three compounds.

RESULTS

Sodium citrate did not affect the blood gas analysis. Increasing doses of citric and lactic acid progressively reduced pH and HCO₃^- and increased pCO₂ (p<0.001). Sodium citrate and citric acid similarly reduced iCa⁺⁺, from 0.39 (0.36-0.39) and 0.35 (0.33-0.36) mmol/L, respectively, at 9 mEq/L to 0.20 (0.20-0.21) and 0.21 (0.20-0.23) mmol/L at 15 mEq/L (p<0.001). Lactic acid did not affect iCa⁺⁺ (p=0.07). Sodium citrate and citric acid similarly incremented the ACT, from 234 (208-296) and 202 (178-238) sec, respectively, at 9 mEq/L, to >600 sec at 15 mEq/L (p<0.001). Lactic acid did not affect the ACT values (p=0.486). Sodium citrate and citric acid similarly incremented R-time and reduced α-angle and maximum amplitude (MA) (p<0.001), leading to flat-line thromboelastograms at 15 mEq/L. Platelet aggregometry was not altered by any of the three compounds.

CONCLUSIONS

Citric acid infusions determine acidification and anticoagulation of blood similar to lactic acid and sodium citrate, respectively.

When do trauma patients lose temperature? - a prospective observational study

BACKGROUND

The prevalence of hypothermia in trauma patients is high and rapid recognition is important to prevent further heat loss. Hypothermia is associated with poor patient outcomes and is an independent predictor of increased mortality. The aim of this study was to analyze the changes in core body temperature of trauma patients during different treatment phases in the pre-hospital and early in-hospital settings.

METHODS

A prospective observational cohort study in severely injured patients. Continuous core temperature monitoring using an epitympanic sensor in the auditory canal was initiated at the scene of injury and continued for 3 h. The degree of patient insulation was photo-documented throughout, and graded on a binary scale. The outcome variable was temperature change in each treatment phase.

RESULTS

Twenty-two patients were included with a median injury severity score (ISS) of 21 (IQR 14-29). Most patients (N = 16, 73%) were already hypothermic (< 36°C) on scene at their first measurement. Twenty patients (91%) became colder at the scene of injury; on average, the decline was -1.7°C/h. Full clothing reduced this value to -1.1°C/h. Temperature remained essentially stable during ambulance and emergency department phases.

CONCLUSION

Trauma patients are at risk for hypothermia already at the scene of injury. Lay persons and professionals should focus on early prevention of heat loss. An active, individually tailored approach to counter hypothermia in trauma should begin immediately at the scene of injury and continue during transportation to hospital. Active rewarming during evacuation should be considered.

Parathyroid hormone as a marker for hypoperfusion in trauma: A prospective observational study

BACKGROUND

Hyperparathyroidism is common in critical illness. Intact parathyroid hormone has a half-life of 3 minutes to 5 minutes due to rapid clearance by the liver, kidneys, and bone. In hemorrhagic shock, decreased clearance may occur, thus making parathyroid hormone a potential early marker for hypoperfusion. We hypothesized that early hyperparathyroidism predicts mortality and transfusion in trauma patients.

METHODS

A prospective observational study was performed at a Level I trauma center in consecutive adult patients receiving the highest level of trauma team activation. Parathyroid hormone and lactic acid were added to the standard laboratory panel drawn in the trauma bay on arrival, before the administration of any blood products. The primary outcomes assessed were transfusion in 24 hours and mortality.

RESULTS

Forty-six patients were included. Median age was 47 years, 82.6% were men, 15.2% suffered penetrating trauma, and 21.7% died. Patients who were transfused in the first 24 hours (n = 17) had higher parathyroid hormone (182.0 pg/mL vs. 73.5 pg/mL, p < 0.001) and lactic acid (4.6 pg/mL vs. 2.3 pg/mL, p = 0.001). Patients who did not survive to discharge (n = 10) also had higher parathyroid hormone (180.3 pg/mL vs. 79.3 pg/mL, p < 0.001) and lactic acid (5.5 mmol/L vs. 2.5 mmol/L, p = 0.001). For predicting transfusion in the first 24 hours, parathyroid hormone has an area under the receiver operating characteristic curve of 0.876 compared with 0.793 for lactic acid and 0.734 for systolic blood pressure. Parathyroid hormone has an area under the receiver operating characteristic curve of 0.875 for predicting mortality compared with 0.835 for lactic acid and 0.732 for systolic blood pressure.

CONCLUSION

Hyperparathyroidism on hospital arrival in trauma patients predicts mortality and transfusion in the first 24 hours. Further research should investigate the value of parathyroid hormone as an endpoint for resuscitation.

LEVEL OF EVIDENCE

Prognostic, level II.

Ionised calcium levels in major trauma patients who received blood en route to a military medical treatment facility

BACKGROUND

Hypocalcaemia is a common metabolic derangement in critically ill patients. Blood transfusion can also contribute to depleted calcium levels. The aims of this study were to identify the incidence of hypocalcaemia in military trauma patients receiving blood products en route to a deployed hospital facility and to determine if intravenous calcium, given during the prehospital phase, has an effect on admission calcium levels.

METHODS

This was a retrospective review of patients transported by the UK Medical Emergency Response Team in Afghanistan between January 2010 and December 2014 who were treated with blood products in the prehospital setting. Total units of blood products administered, basic demographics, Injury Severity Score and trauma type were collected. Ionised serum calcium levels on admission to hospital were compared between those who received blood products without prehospital intravenous calcium supplemental therapy (non-treatment) and patients who were treated with 10 mL of intravenous calcium chloride (10%) concurrently with blood products (treatment).

RESULTS

The study included 297 patients; 237 did not receive calcium and 60 did. The incidence of hypocalcaemia in the non-treatment group was 70.0% (n=166) compared with 28.3% (n=17) in the treatment group. Serum calcium levels were significantly different between the groups (1.03 mmol/L vs 1.25 mmol/L, difference 0.22 mmol/L, 95% CI 0.15 to 0.27). In the non-treatment group, 26.6% (n=63) had calcium levels within the normal range compared with 41.7% (n=25) in those who received calcium. There was a dose response of calcium level to blood products with a significant decrease in calcium levels as the volume of blood products increased.

CONCLUSION

Trauma patients who received blood products were at high risk of hypocalcaemia. Aggressive management of these patients with intravenous calcium during transfusion may be required.