Ionised calcium levels in major trauma patients who received blood in the Emergency Department

Impact of hypocalcemia on mortality in pediatric trauma patients who require transfusion

BACKGROUND

Admission hypocalcemia has been associated with poor outcomes in injured adults. The impact of hypocalcemia on mortality has not been widely studied in pediatric trauma.

METHODS

A pediatric trauma center database was queried retrospectively (2013-2022) for children younger than 18 years who received blood transfusion within 24 hours of injury and had ionized calcium (iCal) level on admission. Children who received massive transfusion (>40 mL/kg) prior to hospital arrival or calcium prior to laboratory testing were excluded. Hypocalcemia was defined by the laboratory lower limit (iCal <1.00). Main outcomes were in-hospital mortality and 24-hour blood product requirements. Logistic regression analysis was performed to adjust for Injury Severity Score (ISS), admission shock index, Glasgow Coma Scale (GCS) score, and weight-adjusted total transfusion volume.

RESULTS

In total, 331 children with median (IQR) age of 7 years (2-3 years) and median (IQR) ISS 25 (14-33) were included, 32 (10%) of whom were hypocalcemic on arrival to the hospital. The hypocalcemic cohort had higher ISS (median (IQR) 30(24-36) vs. 22 (13-30)) and lower admission GCS score (median (IQR) 3 (3-12) vs. 8 (3-15)). Age, sex, race, and mechanism were not significantly different between groups. On univariate analysis, hypocalcemia was associated with increased in-hospital (56% vs. 18%; p < 0.001) and 24-hour (28% vs. 5%; p < 0.001) mortality. Children who were hypocalcemic received a median (IQR) of 22 mL/kg (7-38) more in total weight-adjusted 24-hour blood product transfusion following admission compared to the normocalcemic cohort ( p = 0.005). After adjusting for ISS, shock index, GCS score, and total transfusion volume, hypocalcemia remained independently associated with increased 24-hour (odds ratio, 4.93; 95% confidence interval, 1.77-13.77; p = 0.002) and in-hospital mortality (odds ratio, 3.41; 95% confidence interval, 1.22-9.51; p = 0.019).

CONCLUSION

Hypocalcemia is independently associated with mortality and receipt of greater weight-adjusted volumes of blood product transfusion after injury in children. The benefit of timely calcium administration in pediatric trauma needs further exploration.

LEVEL OF EVIDENCE

Prognostic and Epidemiological; Level III.

Calcium supplementation during trauma resuscitation: a propensity score-matched analysis from the TraumaRegister DGU®

BACKGROUND

In major trauma patients, hypocalcemia is associated with increased mortality. Despite the absence of strong evidence on causality, early calcium supplementation has been recommended. This study investigates whether calcium supplementation during trauma resuscitation provides a survival benefit.

METHODS

We conducted a retrospective analysis using data from the TraumaRegister DGU® (2015-2019), applying propensity score matching to balance demographics, injury severity, and management between major trauma patients with and without calcium supplementation. 6 h mortality, 24 h mortality, and in-hospital mortality were considered as primary outcome parameters.

RESULTS

Within a cohort of 28,323 directly admitted adult major trauma patients at a European trauma center, 1593 (5.6%) received calcium supplementation. Using multivariable logistic regression to generate propensity scores, two comparable groups of 1447 patients could be matched. No significant difference in early mortality (6 h and 24 h) was observed, while in-hospital mortality appeared higher in those with calcium supplementation (28.3% vs. 24.5%, P = 0.020), although this was not significant when adjusted for predicted mortality (P = 0.244).

CONCLUSION

In this matched cohort, no evidence was found for or against a survival benefit from calcium supplementation during trauma resuscitation. Further research should focus on understanding the dynamics and kinetics of ionized calcium levels in major trauma patients and identify if specific conditions or subgroups could benefit from calcium supplementation.

Retrospective analysis of the effects of hypocalcemia in severely injured trauma patients

BACKGROUND

It has been suggested that the Lethal Triad be modified to include hypocalcemia, coined as the Lethal Diamond. Hypocalcemia in trauma has been attributed to multiple mechanisms, but new evidence suggests that traumatic injury may result in the development of hypoCa independent of blood transfusion. We hypothesize that hypocalcemia is associated with increased blood product requirements and mortality.

METHODS

A retrospective study of 1,981 severely injured adult trauma patients from 2016 to 2019. Ionized calcium (iCa) levels were obtained on arrival and subjects were categorized by a threshold iCa level of 1.00 mmol/L and compared. Univariable and multivariable logistic regression analysis was performed.

RESULTS

The hypocalcemia (iCa <1.00 mmol/L) group had increased rate of overall (p = 0.001), 4-hr (p = 0.007), and 24-hr (p = 0.003) mortality. There was no difference in prehospital transfusion volume between groups (p = 0.25). Hypocalcemia was associated with increased blood product requirements at 4 h (p <0.001), 24 h (p <0.001), and overall hospital length of stay (p <0.001). Logistic regression analysis showed increased odds of 4-hour mortality (OR 0.077 [95 % CI 0.011, 0.523], p = 0.009) and 24-hour mortality (OR 0.121 [95 % CI 0.019, 0.758], p = 0.024) for every mmol/L increase in iCa.

CONCLUSIONS

This study shows the association of hypoCa and traumatic injury. Severe hypoCa was associated with increased odds of early and overall mortality and increased blood product requirements. These results support the need for future prospective trials assessing the role of hypocalcemia in trauma.

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.

Severe hypocalcemia at admission is associated with increased transfusion requirements: A retrospective study in a level 1 trauma center

INTRODUCTION

In recent years, hypocalcemia has been added to the "lethal triad" of the trauma patient, thus constituting the "lethal diamond". Nevertheless, its proper role remains debated. The aim of this study is to evaluate the association between severe hypocalcemia at admission and 24 h- transfusion requirements in severe trauma patients in a level 1 trauma center.

STUDY DESIGN AND METHODS

In a monocentric retrospective observational study from January 2015 to May 2021, 137 traumatized adult patients transfused within 24 h after hospital admission was included in the study. The threshold for severe hypo ionized calcemia was ≤ 0.9 mmol/L.

RESULTS

137 patients were included in the study, 23 presented with severe hypo-iCa at admission, 111 moderate hypo-iCa (0.9-1.2 mmol/L) and 3 normal iCa (≥ 1.2 mmol/L). Patients with severe hypo-iCa at admission had higher severity scores (SAPSII 58 IQR [51-70] vs. 45 IQR [32-56]; p = 0.001 and ISS 34 IQR [26-39] vs. 26 IQR [17-34]; p = 0.003). 24 h-transfusion requirements were greater for patients with severe hypo-iCa, regardless of the type of blood products transfused. There was a significant negative correlation between admission iCa and 24 h-transfusion (r = -0.45, p < 0.001). The difference in mortality was not significant between the two groups (24 h mortality: 17 % (4/23) for severe hypo-iCa vs. 8 % (9/114) for non-severe hypo-iCa; p = 0.3).

DISCUSSION

This study highlights the high prevalence of severe hypocalcemia in trauma patients and its association with increased 24 h- transfusion requirements.

Incidence of admission ionised hypocalcaemia in paediatric major trauma: protocol for a systematic review and meta-analysis

INTRODUCTION

Hypocalcaemia forms part of the 'diamond of death' in major trauma, alongside hypothermia, acidosis and coagulopathy. In adults, admission hypocalcaemia prior to transfusion is associated with increased mortality, increased blood transfusion requirements and coagulopathy. Data on paediatric major trauma patients are limited. This systematic review and meta-analysis aims to describe and synthesise the available evidence relevant to paediatric trauma, admission hypocalcaemia and outcome.

METHODS AND ANALYSIS

The Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols guidelines will be used to construct this review. A planned literature search for articles in the English language will be conducted from inception to the date of searches using MEDLINE on the EBSCO platform, CINAHL on the EBSCO platform and Embase on the Ovid platform. The grey literature will also be searched. Both title and abstract screening and full-text screening will be done by two reviewers, with an adjudicating third reviewer. Heterogeneity will be assessed using the I2 test, and the risk of bias will be assessed using the ROBINS-I tool. A meta-analysis will be undertaken using ratio measures (OR) and mean differences for measures of effect. When possible, the estimate of effect will be presented along with a CI and a p value.

ETHICAL REVIEW AND DISSEMINATION

Ethical review is not required, as no original data will be collected. Results will be disseminated through peer-reviewed publications and at academic conferences.

PROSPERO REGISTRATION NUMBER

CRD42023425172.

New frontiers in neonatal red blood cell transfusion research

Red blood cell (RBC) transfusions are common in neonates requiring intensive care. Recent studies have compared restricted versus liberal transfusion guidelines, but limitations exist on evaluations of outcomes in populations that never required a transfusion compared to those receiving any transfusion. Although there are well-established risks associated with RBC transfusions, new data has emerged that suggests additional clinically relevant associations, including adverse neurodevelopmental outcomes, donor sex differences, and inflammation or immunosuppression. Further research is needed to delineate the magnitude of these risks and to further improve the safety of transfusions. The goal of this review is to highlight underappreciated, yet clinically important risks associated with neonatal RBC transfusions and to introduce several areas in which neonates may uniquely benefit from alterations in practice.

EVALUATION OF TRANEXAMIC ACID AND CALCIUM CHLORIDE IN MAJOR TRAUMAS IN A PREHOSPITAL SETTING: A NARRATIVE REVIEW

ABSTRACT

Excessive blood loss in the prehospital setting poses a significant challenge and is one of the leading causes of death in the United States. In response, emergency medical services (EMS) have increasingly adopted the use of tranexamic acid (TXA) and calcium chloride (CaCl 2 ) as therapeutic interventions for hemorrhagic traumas. Tranexamic acid functions by inhibiting plasmin formation and restoring hemostatic balance, while calcium plays a pivotal role in the coagulation cascade, facilitating the conversion of factor X to factor Xa and prothrombin to thrombin. Despite the growing utilization of TXA and CaCl 2 in both prehospital and hospital environments, a lack of literature exists regarding the comparative effectiveness of these agents in reducing hemorrhage and improving patient outcomes. Notably, Morgan County Indiana EMS recently integrated the administration of TXA with CaCl 2 into their treatment protocols, offering a valuable opportunity to gather insight and formulate updated guidelines based on patient-centered outcomes. This narrative review aims to comprehensively evaluate the existing evidence concerning the administration of TXA and CaCl 2 in the prehospital management of hemorrhages, while also incorporating and analyzing data derived from the co-administration of these medications within the practices of Morgan County EMS. This represents the inaugural description of the concurrent use of both TXA and CaCl 2 to manage hemorrhages in the scientific literature.

Trauma-induced disturbances in ionized calcium levels correlate parabolically with coagulopathy, transfusion, and mortality: a multicentre cohort analysis from the TraumaRegister DGU®

BACKGROUND

To which extent trauma- induced disturbances in ionized calcium (iCa2+) levels have a linear relationship with adverse outcomes remains controversial. The goal of this study was to determine the association between the distribution and accompanying characteristics of transfusion-independent iCa2+ levels versus outcome in a large cohort of major trauma patients upon arrival at the emergency department.

METHODS

A retrospective observational analysis of the TraumaRegister DGU® (2015-2019) was performed. Adult major trauma patients with direct admission to a European trauma centre were selected as the study cohort. Mortality at 6 h and 24 h, in-hospital mortality, coagulopathy, and need for transfusion were considered as relevant outcome parameters. The distribution of iCa2+ levels upon arrival at the emergency department was calculated in relation to these outcome parameters. Multivariable logistic regression analysis was performed to determine independent associations.

RESULTS

In the TraumaRegister DGU® 30 183 adult major trauma patients were found eligible for inclusion. iCa2+ disturbances affected 16.4% of patients, with hypocalcemia (< 1.10 mmol/l) being more frequent (13.2%) compared to hypercalcemia (≥ 1.30 mmol/l, 3.2%). Patients with hypo- and hypercalcemia were both more likely (P < .001) to have severe injury, shock, acidosis, coagulopathy, transfusion requirement, and haemorrhage as cause of death. Moreover, both groups had significant lower survival rates. All these findings were most distinct in hypercalcemic patients. When adjusting for potential confounders, mortality at 6 h was independently associated with iCa2+ < 0.90 mmol/L (OR 2.69, 95% CI 1.67-4.34; P < .001), iCa2+ 1.30-1.39 mmol/L (OR 1.56, 95% CI 1.04-2.32, P = 0.030), and iCa2+  ≥ 1.40 mmol/L (OR 2.87, 95% CI 1.57-5.26; P < .001). Moreover, an independent relationship was determined for iCa2+ 1.00-1.09 mmol/L with mortality at 24 h (OR 1.25, 95% CI 1.05-1.48; P = .0011), and with in-hospital mortality (OR 1.29, 95% CI 1.13-1.47; P < .001). Both hypocalcemia < 1.10 mmol/L and hypercalcemia ≥ 1.30 mmol/L had an independent association with coagulopathy and transfusion.

CONCLUSIONS

Transfusion-independent iCa2+ levels in major trauma patients upon arrival at the emergency department have a parabolic relationship with coagulopathy, need for transfusion, and mortality. Further research is needed to confirm whether iCa2+ levels change dynamically and are more a reflection of severity of injury and accompanying physiological derangements, rather than an individual parameter that needs to be corrected as such.

Impact of Transfused Citrate on Pathophysiology in Massive Transfusion

This narrative review article seeks to highlight the effects of citrate on physiology during massive transfusion of the bleeding patient.

DATA SOURCES

A limited library of curated articles was created using search terms including "citrate intoxication," "citrate massive transfusion," "citrate pharmacokinetics," "hypocalcemia of trauma," "citrate phosphate dextrose," and "hypocalcemia in massive transfusion." Review articles, as well as prospective and retrospective studies were selected based on their relevance for inclusion in this review.

STUDY SELECTION

Given the limited number of relevant studies, studies were reviewed and included if they were written in English. This is not a systematic review nor a meta-analysis.

DATA EXTRACTION AND SYNTHESIS

As this is not a meta-analysis, new statistical analyses were not performed. Relevant data were summarized in the body of the text.

CONCLUSIONS

The physiologic effects of citrate independent of hypocalcemia are poorly understood. While a healthy individual can rapidly clear the citrate in a unit of blood (either through the citric acid cycle or direct excretion in urine), the physiology of hemorrhagic shock can lead to decreased clearance and prolonged circulation of citrate. The so-called "Diamond of Death" of bleeding-coagulopathy, acidemia, hypothermia, and hypocalcemia-has a dynamic interaction with citrate that can lead to a death spiral. Hypothermia and acidemia both decrease citrate clearance while circulating citrate decreases thrombin generation and platelet function, leading to ionized hypocalcemia, coagulopathy, and need for further transfusion resulting in a new citrate load. Whole blood transfusion typically requires lower volumes of transfused product than component therapy alone, resulting in a lower citrate burden. Efforts should be made to limit the amount of citrate infused into a patient in hemorrhagic shock while simultaneously addressing the induced hypocalcemia.

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.

Early Hypocalcemia in Pediatric Major Trauma: A Retrospective Cohort Study

OBJECTIVE

Early hypocalcemia (EH) is common in adult major trauma patients and has been associated with coagulopathy, shock, increased transfusion requirements, and mortality. The incidence of EH in pediatric severe trauma has not been investigated. We aimed to explore the incidence of EH among severely injured children.

METHODS

We conducted a retrospective cohort study at a tertiary children's hospital and a level 1 pediatric trauma center. We extracted the medical records of all pediatric major trauma patients, defined as an age less than 18 years and an Injury Severity Score (ISS) greater than 15, admitted after trauma team activation from January 2010 to December 2020.The primary outcome was the presence of EH. Patients were classified into 3 groups: severe hypocalcemia (ionized calcium [iCa] <1 mmol/L), hypocalcemia (1 < iCa < 1.16 mmol/L), and normal calcium (iCa ≥1.16 mmol/L).

RESULTS

During the study period, 5126 children were hospitalized because of trauma. One hundred eleven children met the inclusion criteria. The median age was 11 years (interquartile range [IQR], 4-15), and 78.4% (87) were male. The median ISS was 21 (IQR, 17-27).Hypocalcemia was found in 19.8% (22) and severe hypocalcemia in 2.7% (3) of the patients.Although not statistically significant, hypocalcemic pediatric trauma patients had higher ISS (25.5 [IQR, 17-29] vs 21 [IQR, 17-26], P = 0.39), lower Glasgow Coma Scale (11 [IQR, 3-15] vs 13 [IQR, 7-15], P = 0.24), a more prolonged hospital stay (8 days [IQR, 2-16] vs 6 days [IQR, 3-13], P = 0.36), a more frequent need for blood products (27.3% vs 20.2%, P = 0.74), and higher mortality rates (9.1% vs 1.1%, P = 0.18) compared with normocalcemic patients.

CONCLUSIONS

Our data suggest that in the setting of major trauma, EH is less frequent in children than previously reported in adults. Our preliminary data suggest that pediatric patients with EH may be at risk of increased morbidity and mortality compared with children with normal admission iCa requiring further studies.

Pre-hospital blood products and calcium replacement protocols in UK critical care services: A survey of current practice

Introduction

In the United Kingdom, prehospital blood products are increasingly carried for the early resuscitation of hypovolaemia in patients who are shocked or in cardiac arrest. There is an association between hypocalcaemia and mortality in trauma patients, but no current national guidelines on the timing or dose of calcium replacement exist. The objective of this study was to establish the availability of prehospital blood products, and the current calcium replacement protocols used by UK prehospital services.

Methods

A cross sectional survey of all UK air ambulances and additional prehospital critical care organisations was conducted in April-May 2022 via an on-line questionnaire. The survey asked 11 questions about availability of prehospital blood products, calcium replacement for patients requiring prehospital blood products, and the use of point of care testing.

Results

There was a 100% response rate with 20/22 UK air ambulances carrying blood products and five additional prehospital services identified. There were 15 different combinations of prehospital blood products. 23/25 services had a standard operating procedure for the replacement of calcium. This was recommended before any blood product administration in 5 services (22%), during or after the 1st unit in 5 services (22%), during or after the 2nd unit in 6 services (26%) and during or after the 4th unit in 7 services (30%). Only six services carried point of care testing and no services routinely used this to measure calcium levels in patients requiring prehospital blood products.

Conclusion

In 2022, 91% of UK air ambulances carry prehospital blood products and there is significant variation between services in the combination of blood products provided. There is no consensus on the timing or dose of calcium replacement. Further prospective research should examine the association between traumatic bleeding and ionized calcium levels before and during blood product transfusion in order to produce more robust guidelines for routine calcium replacement.

Dimethyl malonate slows succinate accumulation and preserves cardiac function in a swine model of hemorrhagic shock

BACKGROUND

Succinate (SI) is a citric acid cycle metabolite that accumulates in tissues during hemorrhagic shock (HS) due to electron transport chain uncoupling. Dimethyl malonate (DMM) is a competitive inhibitor of SI dehydrogenase, which has been shown to reduce SI accumulation and protect against reperfusion injury. Whether DMM can be therapeutic after severe HS is unknown. We hypothesized that DMM would prevent SI buildup during resuscitation (RES) in a swine model of HS, leading to better physiological recovery after RES.

METHODS

The carotid arteries of Yorkshire pigs were cannulated with a 5-Fr catheter. After placement of a Swan-Ganz catheter and femoral arterial line, the carotid catheters were opened and the animals were exsanguinated to a mean arterial pressure (MAP) of 45 mm. After 30 minutes in the shock state, the animals were resuscitated to a MAP of 60 mm using lactated ringers. A MAP above 60 mm was maintained throughout RES. One group received 10 mg/kg of DMM (n = 6), while the control received sham injections (n = 6). The primary end-point was SI levels. Secondary end-points included cardiac function and lactate.

RESULTS

Succinate levels increased from baseline to the 20-minute RES point in control, while the DMM cohort remained unchanged. The DMM group required less intravenous fluid to maintain a MAP above 60 (450.0 vs. 229.0 mL; p = 0.01). The DMM group had higher pulmonary capillary wedge pressure at the 20-minute and 40-minute RES points. The DMM group had better recovery of cardiac output and index during RES, while the control had no improvement. While lactate levels were similar, DMM may lead to increased ionized calcium levels.

DISCUSSION

Dimethyl malonate slows SI accumulation during HS and helps preserve cardiac filling pressures and function during RES. In addition, DMM may protect against depletion of ionized calcium. Dimethyl malonate may have therapeutic potential during HS.

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.

Prehospital Plasma Transfusion: What Does the Literature Show?

Background

Early initiation of blood products transfusion after injury has been associated with improved patient outcomes following traumatic injury. The ability to transfuse patients' plasma in the prehospital setting provides a prime opportunity to begin resuscitation with blood products earlier and with a more balanced plasma: RBC ratio than what has traditionally been done. Published studies on the use of prehospital plasma show a complex relationship between its use and improved survival.

Summary

Examination of the literature shows that there may be a mortality benefit from the use of prehospital plasma, but that it may be limited to certain subgroups of trauma patients. The likelihood of realizing these survival benefits appears to be predicted by several factors including the type of injury, length of transport time, presence of traumatic brain injury, and total number of blood products transfused, whether the patient required only a few products or a massive transfusion. When taken as a whole the evidence appears to show that prehospital plasma may have a mortality benefit that is most clearly demonstrated in patients with blunt injuries, moderate transfusion requirements, traumatic brain injury, and/or transport time greater than 20 min, as well as those who demonstrate a certain cytokine expression profile.

Key Messages

The evidence suggests that a targeted use of prehospital plasma will most likely maximize the benefits from the use of this limited resource. It is also possible that prehospital plasma may best be provided through whole blood as survival benefits were greatest in patients who received both prehospital plasma and RBCs.

Hypocalcemia is associated with adverse clinical course in patients with upper gastrointestinal bleeding

Acute non-variceal upper gastrointestinal bleeding (NV-UGIB) is associated with significant morbidity and mortality. Early and efficient risk stratification can facilitate management and improve outcomes. We aimed to determine whether the level of ionized calcium (Ca⁺⁺), an essential co-factor in the coagulation cascade, is associated with the severity of bleeding and the need for advanced interventions among these patients. This was a retrospective single-center cohort study of all patients admitted due to NV-UGIB. The primary outcome was transfusion of ≥ 2 packed red blood cells, arterial embolization, or emergency surgery. Secondary outcomes included (1) transfusion of ≥ 2 packed red blood cells, (2) arterial embolization, or emergency surgery, and (3) all-cause in-hospital mortality. Multivariable logistic regression was performed to determine whether Ca⁺⁺ was an independent predictor of these adverse outcomes. 1345 patients were included. Hypocalcemia was recorded in 604 (44.9%) patients. The rates of primary adverse outcome were significantly higher in the hypocalcemic group, 14.4% vs. 5.1%, p < 0.001. Secondary outcomes-multiple transfusions, need for angiography or surgery, and mortality were also increased (9.9% vs. 2.3%, p < 0.001, 5.3% vs. 2.8%, p = 0.03, and 33.3% vs. 24.7%, p < 0.001, respectively). Hypocalcemia was an independent predictor of primary and all the secondary outcomes, except mortality. Hypocalcemia in high-risk hospitalized patients with NV-UGIB is common and independently associated with adverse outcomes. Ca⁺⁺ monitoring in this population may facilitate the rapid identification of high-risk patients. Trials are needed to assess whether correction of hypocalcemia will lead to improved outcomes.

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.

Does Gender Matter: A Multi-Institutional Analysis of Viscoelastic Profiles for 1565 Trauma Patients With Severe Hemorrhage

BACKGROUND

Viscoelastic tests including thromboelastography (TEG) and rotational thromboelastometry (ROTEM) are being used in patients with severe hemorrhage at trauma centers to guide resuscitation. Several recent studies demonstrated hypercoagulability in female trauma patients that was associated with a survival advantage. The objective of our study was to elucidate the effects of gender differences in TEG/ROTEM values on survival in trauma patients with severe hemorrhage.

METHODS

A retrospective review of consecutive adult patients receiving massive transfusion protocol (MTP) at 7 Level I trauma centers was performed from 2013 to 2018. Data were stratified by gender and then further examined by TEG or ROTEM parameters. Results were analyzed using univariate and multi-variate analyses.

RESULTS

A total of 1565 patients were included with 70.9% male gender (n = 1110/1565). Female trauma patients were older than male patients (43.5 ± .9 vs 41.1 ± .6 years, P = .01). On TEG, females had longer reaction times (6.1 ± .9 min vs 4.8 ± .2 min, P = .03), increased alpha angle (68.6 ± .8 vs 65.7 ± .4, P < .001), and higher maximum amplitude (59.8 ± .8 vs 56.3 ± .4, P < .001). On ROTEM, females had significantly longer clot time (99.2 ± 13.7 vs 75.1 ± 2.6 sec, P = .09) and clot formation time (153.6 ± 10.6 sec vs 106.9 ± 3.8 sec, P < .001). When comparing by gender, no difference for in-hospital mortality was found for patients in the TEG or ROTEM group (P > .05). Multivariate analysis showed no survival difference for female patients (OR 1.11, 95% CI .83-1.50, P = .48).

CONCLUSIONS

Although a difference between male and females was found on TEG/ROTEM for certain clotting parameters, no difference in mortality was observed. Prospective multi-institutional studies are needed.

Hypocalcemia in Military Casualties From Point of Injury to Surgical Teams in Afghanistan

INTRODUCTION

Hypocalcemia is a known sequela of citrated blood product transfusion. Civilian data suggest hypocalcemia on hospital admission is associated with worse outcomes. Initial calcium levels in military casualties have not previously been analyzed. The objective of this retrospective review aimed to assess the initial calcium levels in military trauma casualties at different Forward Surgical Teams (FST) locations in Afghanistan and describe the effects of prehospital blood product administration on arrival calcium levels.

MATERIALS AND METHODS

This is a retrospective cohort analysis of military casualties arriving from point of injury to one of two FSTs in Afghanistan from August 2018 to February 2019 split into four locations. The primary outcome was incidence of hypocalcemia (ionized calcium < 1.20 mmol/L).

RESULTS

There were 101 patients included; 55 (54.5%) experienced hypocalcemia on arrival to the FST with a mean calcium of 1.16 mmol/L (95% confidence interval [CI], 1.14 to 1.18). The predominant mechanism of injury consisted of blast patterns, 46 (45.5%), which conferred an increased risk of hypocalcemia compared to all other patterns of injury (odds ratio = 2.42, P = .042). Thirty-eight (37.6%) patients required blood product transfusion. Thirty-three (86.8%) of the patients requiring blood product transfusion were hypocalcemic on arrival. Mean initial calcium of patients receiving blood product was 1.13 mmol/L (95% CI, 1.08 to 1.18), which was significantly lower than those who did not require transfusion (P = .01). Eight (7.9%) of the patients received blood products before arrival, with 6/8 (75%) presenting with hypocalcemia.

CONCLUSIONS

Hypocalcemia develops rapidly in military casualties and is prevalent on admission even before transfusion of citrated blood products. Blast injuries may confer an increased risk of developing hypocalcemia. This data support earlier use of calcium supplementation during resuscitation.

The Use of Whole Blood Transfusion During Non-Traumatic Resuscitation

BACKGROUND

Evidence from military populations showed that resuscitation using whole blood (WB), as opposed to component therapies, may provide additional survival benefits to traumatically injured patients. However, there is a paucity of data available for the use of WB in uninjured patients requiring transfusion. We sought to describe the use of WB in non-trauma patients at Brooke Army Medical Center (BAMC).

MATERIALS AND METHODS

Between January and December 2019, the BAMC ClinComp electronic medical record system was reviewed for all patients admitted to the hospital who received at least one unit of WB during this time period. Patients were sorted based on their primary admission diagnosis. Patients with a primary trauma-based admission were excluded.

RESULTS

One hundred patients were identified who received at least one unit of WB with a primary non-trauma admission diagnosis. Patients, on average, received 1,064 mL (750-2,458 mL) of WB but received higher volumes of component therapy. Obstetric/gynecologic (OBGYN) indications represented the largest percentage of non-trauma patients who received WB (23%), followed by hematologic/oncologic indications (16%).

CONCLUSION

In this retrospective study, WB was most commonly used for OBGYN-associated bleeding. As WB becomes more widespread across the USA for use in traumatically injured patients, it is likely that WB will be more commonly used for non-trauma patients. More outcome data are required to safely expand the indications for WB use beyond trauma.

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.

Damage control strategy in bleeding trauma patients

Hemorrhagic shock is a main cause of death in severe trauma patients. Bleeding trauma patients have coagulopathy on admission, which may even be aggravated by incorrectly directed resuscitation. The damage control strategy is a very urgent and essential aspect of management considering the acute coagulopathy of trauma and the physiological status of bleeding trauma patients. This strategy has gained popularity over the past several years. Patients in extremis cannot withstand prolonged definitive surgical repair. Therefore, an abbreviated operation, referred to as damage control surgery (DCS), is needed. In addition to DCS, the likelihood of survival should be maximized for patients in extremis by providing appropriate critical care, including permissive hypotension, hemostatic resuscitation, minimization of crystalloid use, early use of tranexamic acid, and avoidance of hypothermia and hypocalcemia. This review presents an overview of the evolving strategy of damage control in bleeding trauma patients.

Civilian prehospital transfusion - experiences from a French region

BACKGROUND AND OBJECTIVES

Haemorrhagic shock is a leading cause of avoidable mortality in prehospital care. For several years, our centre has followed a procedure of transfusing two units of packed red blood cells outside the hospital. Our study's aim was twofold: describe the patient characteristics of those receiving prehospital blood transfusions and analyse risk factors for the 7-day mortality rate.

MATERIALS AND METHODS

We performed a monocentric retrospective observational study. Demographic and physiological data were recovered from medical records. The primary outcome was mortality at seven days for all causes. All patients receiving prehospital blood transfusions between 2013 and 2018 were included.

RESULTS

Out of 116 eligible patients, 56 patients received transfusions. Trauma patients (n = 18) were younger than medical patients (n = 38) (P = 0·012), had lower systolic blood pressure (P = 0·001) and had higher haemoglobin levels (P = 0·016). Mortality was higher in the trauma group than the medical group (P = 0·015). In-hospital trauma patients received more fresh-frozen plasma and platelet concentrate than medical patients (P < 0·05). Predictive factors of 7-day mortality included transfusion for trauma-related reasons, low Glasgow Coma Scale, low peripheral oxygen saturation, prehospital intensive resuscitation, existing coagulation disorders, acidosis and hyperlactataemia (P < 0·05).

CONCLUSION

Current guidelines recommend early transfusion in patients with haemorrhagic shock. Prehospital blood transfusions are safe. Coagulation disorders and acidosis remain a cause of premature death in patients with prehospital transfusions.

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.

Hypocalcemia and Massive Blood Transfusions: A Pilot Study in a Level I Trauma Center

Trauma is a leading cause of death in the United States, and uncontrolled hemorrhage is often the primary cause of mortality. Massive transfusions provide lifesaving treatment for the bleeding trauma patient; yet, this is not a benign intervention. Calcium levels can be significantly decreased with rapidly transfused blood products due to the citrate preservative that is added. Citrate binds to the patient's endogenous calcium when blood products are administered, rendering calcium inactive. As a result, undesirable physiological effects can occur. Although there is a plethora of evidence reporting the negative effects of hypocalcemia during resuscitation, the research for standardization of calcium monitoring and replacement during a massive transfusion event is less robust. Consequently, monitoring and replacement of this vital electrolyte are often overlooked. Trauma department employees at an urban academic hospital were given a pretest to assess their knowledge of calcium monitoring and replacement during a massive transfusion. On the basis of test results and a need for staff education, a short, animated video was designed and distributed for viewing. Following the educational video, a posttest was administered and yielded higher scores when compared with the pretest (p = .001). Lack of knowledge and national standards may be root causes for hypocalcemia. Educational interventions such as innovative, brief videos can be effective for enhancing staff members' knowledge and improving patient care.

Bleeding Management Practices of Australian Cardiac Surgeons, Anesthesiologists and Perfusionists: A Cross-Sectional National Survey Incorporating the Theoretical Domains Framework (TDF) and COM-B Model

Purpose

Excessive bleeding is an acknowledged consequence of cardiac surgery, occurring in up to 10% of adult patients. This clinically important complication leads to poorer patient outcomes. Clinical practice guidelines are available to support best practice however variability in bleeding management practice and related adverse outcomes still exist. This study had two objectives: 1) to gain insight into current bleeding management practice for adult cardiac surgery in Australia and how that compared to guidelines and literature; and 2) to understand perceived difficulties clinicians face implementing improvements in bleeding management.

Methods

A national cross-sectional questionnaire survey was utilized. Perspectives were sought from cardiac surgeons, cardiac anesthesiologists and perfusionists. Thirty-nine closed-ended questions focused on routine bleeding management practices to address pre and intra-operative care. One open-ended question was asked; “What would assist you to improve bleeding management with cardiac surgery patients?” Quantitative data were analysed with SPSS. Qualitative data were categorized into the domains of the Theoretical Domains Framework; the domains were then mapped to the COM-B model.

Results

Survey responses from 159 Anesthesiologists, 39 cardiac surgeons and 86 perfusionists were included (response rate 37%). Four of the recommendations queried in this survey were reported as routinely adhered to < 50% of the time, 9 queried recommendations were adhered to 51–75% of the time and 4 recommendations were routinely followed >76% of the time.

Conclusion

There is a wide variation in peri-operative bleeding management practice among cardiac anaesthesiologists, surgeons and perfusionists in Australian cardiac surgery units. Conceptualizing factors believed necessary to improve practice with the TDF and COM-B model found that bleeding management could be improved with a standardized approach including; point of care diagnostic assays, a bleeding management algorithm, access to concentrated coagulation factors, cardiac surgery specific bleeding management education, multidisciplinary team agreement and support, and an overarching national approach.

Sialochemical analysis in polytraumatized patients in intensive care units

The profiles of polytraumatized patients in intensive care units were characterized. Serum and salivary markers were compared with normality between Classes I and II of APACHE II and between periods of hospitalization; these results were correlated. This was a prospective study on saliva charts and collection (n = 70). Profile: male, 27 years old, blunt traumas and collisions. Serum parameters with normality: decrease in pH, creatinine at admission to Class I, and at 48 and 72 hours in both classes; K+ at 48 h in Class II; Ca+ on admission in both classes and at 72 h in Class I. Increase in urea at 72 h in Class II, glucose at all times and in all classes, and Ca+ at 48 h in both classes. Class II had high Na+ at 48 and 72 h compared to Class I. In Class I, creatinine reduction occurred in 48 h and 72 h compared to admission and an increase of Ca+ at 48 h with admission. In Class II, pH and Na+ increased at 48 h and 72 h compared to admission. K+ decreased from admission to 48 h and increased from 48 h to 72 h. Urea increased from 48 to 72 hours. Creatinine decreased from admission to 48 and 72 hours. Ca+ increased from admission to 48 hours and decreased from 48 to 72 hours. There was an increase in the saliva levels in both classes and times in relation to normality. There was an increase in urea at admission, glucose at 72 h, and Ca+ at 48 h in Class II compared with Class I. Class I urea increased from admission to 48 h and Ca+ decreased from admission to 48 h. Class II urea decreased from 48 h to 72 h. Strong or very strong positive correlation was identified between blood and creatinine saliva at all times and regular and negative Ca+ at 72 h. This study provides evidence that salivary and serum biomarkers can be used together to monitor the evolution of the clinical symptoms of ICU patients.

Probable Hypocalcemia Induced Ventricular Fibrillation and Torsades de Pointes following Blood Product Administration

A 35-year-old male underwent open-heart surgery and required multiple blood product transfusions. Citrate, a preservative in blood products, caused serum ionized calcium chelation leading to hypocalcemia, a prolonged corrected QT (QTc) interval, and separate episodes of ventricular fibrillation and torsades de pointes (TdP). This case highlights an uncommon complication of blood product transfusion-induced hypocalcemia with precipitant arrhythmia.

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.