The ATLS(®) classification of hypovolaemic shock: a well established teaching tool on the edge?

When do benefits turn to risks? Impact of a 900 mL whole blood donation on Special Forces performance

BACKGROUND

Special Forces (SF) teams operate in remote environments with limited medical support. As a result, they may need to rely on buddy transfusions to treat bleeding teammates. Considering that 450 mL has no direct impact on their combat performances, it might be tempting to take more blood from a compatible donor to save a hemorrhaging teammate. This study investigates the effect of a 900 mL blood donation on SF operator performance and recovery time following this donation.

STUDY DESIGN AND METHODS

Participants underwent a multifactorial assessment including measures of physiological parameters, vigilance, and physical performance. Results from the day of blood donation were compared with baseline values obtained 1 week earlier (i.e., immediate effect), as well as repeated testing at 7, 14, and approximately 30 days after blood donation (i.e., recovery period).

RESULTS

Hemoglobin levels and heart rate were affected by giving blood. The participants also experienced a significant decrease in physical performance of more than 50% immediately after blood donation. Recovery was slow over the following weeks, remaining significantly different from baseline until full recovery around day 30. However, participants were still able to respond to a simple stimulus and adjust their response, if necessary, even immediately after donating blood.

DISCUSSION

A 900 mL blood donation greatly affects the physical fitness of SF operators. A donation may be worthwhile if it is the only life-saving procedure available and does not endanger the donor's life. The donor would then become a patient and unable to complete the mission.

Comparison of Vital Sign Cutoffs to Identify Children With Major Trauma

Importance

Vital signs are essential components in the triage of injured children. The Advanced Trauma Life Support (ATLS) and Pediatric Advanced Life Support (PALS) physiologic criteria are frequently used for trauma assessments.

Objective

To evaluate the performance of ATLS and PALS criteria vs empirically derived criteria for identifying major trauma in children.

Design, Setting, and Participants

This retrospective cohort study used 2021 American College of Surgeons Trauma Quality Improvement Program (TQIP) data contributed by US trauma centers. Included encounters involved pediatric patients (aged <18 years) with severe injury, excluding those who experienced out-of-hospital cardiac arrest, were receiving mechanical ventilation, or were transferred from another facility. Data were analyzed between April 9 and December 21, 2023.

Exposure

Initial hospital vital signs, including heart rate, respiratory rate, and systolic blood pressure (SBP).

Main Outcome and Measures

Major trauma, determined by the Standard Triage Assessment Tool, a composite measure of injury severity and interventions performed. Multivariable models developed from PALS and ATLS vital sign criteria were compared with models developed from the empirically derived criteria using the area under the receiver operating characteristic curve. Validation of the findings was performed using the 2019 TQIP dataset.

Results

A total of 70 748 patients (median [IQR] age, 11 [5-15] years; 63.4% male) were included, of whom 3223 (4.6%) had major trauma. The PALS criteria classified 31.0% of heart rates, 25.7% of respiratory rates, and 57.4% of SBPs as abnormal. The ATLS criteria classified 25.3% of heart rates, 4.3% of respiratory rates, and 1.1% of SBPs as abnormal. Among children with all 3 vital signs documented (64 326 [90.9%]), PALS had a sensitivity of 88.4% (95% CI, 87.1%-89.3%) and specificity of 25.1% (95% CI, 24.7%-25.4%) for identifying major trauma, and ATLS had a sensitivity of 54.5% (95% CI, 52.7%-56.2%) and specificity of 72.9% (95% CI, 72.6%-73.3%). The empirically derived cutoff vital sign z scores had a sensitivity of 80.0% (95% CI, 78.5%-81.3%) and specificity of 48.7% (95% CI, 48.3%-49.1%) and area under the receiver operating characteristic curve of 70.9% (95% CI, 69.9%-71.8%), which was similar to PALS criteria (69.6%; 95% CI, 68.6%-70.6%) and greater than ATLS criteria (65.4%; 95% CI, 64.4%-66.3%). Validation using the 2019 TQIP database showed similar performance to the derivation sample.

Conclusions and Relevance

These findings suggest that empirically derived vital sign criteria strike a balance between the sensitivity of PALS criteria and the specificity of ATLS criteria in identifying major trauma in children. These criteria may help to identify children at greatest risk of trauma-related morbidity and mortality.

The Effectiveness of Prehospital Subcutaneous Continuous Lactate Monitoring in Adult Trauma: A Systematic Review

INTRODUCTION

Existing diagnostics for polytrauma patients continue to rely on non-invasive monitoring techniques with limited sensitivity and specificity for critically unwell patients. Lactate is a known diagnostic and prognostic marker used in infection and trauma and has been associated with mortality, need for surgery, and organ dysfunction. Point-of-care (POC) testing allows for the periodic assessment of lactate levels; however, there is an associated expense and equipment burden associated with repeated sampling, with limited feasibility in prehospital care. Subcutaneous lactate monitoring has the potential to provide a dynamic assessment of physiological lactate levels and utilize these trends to guide management and response to given treatments.

STUDY OBJECTIVE

The aim of this study was to appraise the current literature on dynamic subcutaneous continuous lactate monitoring (SCLM) in adult trauma patients and its use in lactate-guided therapy in the prehospital environment.

METHODS

The systematic review was conducted in accordance with the PRISMA guidelines and registered with PROSPERO. Searched databases included PubMed, EMBASE via Ovid SP, Cochrane Library, and Web of Science. Databases were searched from inception to March 29, 2022. Relevant manuscripts were further scrutinized for reference citations to interrogate the fullness of the adjacent literature.

RESULTS

Searches returned 600 studies, including 551 unique manuscripts. Following title and abstract screening, 14 manuscripts met the threshold for full-text sourcing. Subsequent to the scrutiny of all 14 manuscripts, none fully met the specified eligibility criteria. Following careful examination, no article was found to cover the exact area of scientific inquiry due to disparity in technological or environmental characteristics.

CONCLUSION

Little is known about the utility of dynamic subcutaneous lactate monitoring, and this review highlights a clear gap in current literature. Novel subcutaneous lactate monitors are in development, and the literature describing the prototype experimentation has been summarized. These studies demonstrate device accuracy, which shows a close correlation with venous lactate while providing dynamic readings without significant lag times. Their availability and cost remain barriers to implementation at present. This represents a clear target for future feasibility studies to be conducted into the clinical use of dynamic subcutaneous lactate monitoring in trauma and resuscitation.

The AccuFlow sensor: a novel digital health tool to assess intrapartum blood loss at cesarean delivery

OBJECTIVES

During obstetric hemorrhage, peripheral vasoconstriction maintains heart rate and blood pressure until compensatory mechanisms are overwhelmed and patients deteriorate rapidly. Real-time perfusion measurements could quantify vasoconstriction, improving early recognition of hemorrhage and facilitating early intervention to reduce morbidity and mortality. The AccuFlow device makes rapid, non-invasive, quantitative measurements of perfusion, but has not been studied for hemorrhage detection or used in surgical settings. This study evaluated feasibility, tolerability, and preliminary efficacy of the AccuFlow for assessment of blood loss at cesarean delivery (CD).

METHODS

In this pilot study, sensors were applied to the wrist, forearm, bicep, and chest wall of 25 patients undergoing scheduled CD. Postoperatively, sensors were removed and patients rated the AccuFlow and the standard anesthesia monitoring equipment on a validated comfort rating scale for wearable computers (CRS). Blood loss was estimated by the surgical team (EBL) and calculated from change in hematocrit, weight, and height (CBL). CRS scores were compared via Wilcoxon signed ranks tests. Coefficients of correlation between sensor readings and CBL, and between EBL and CBL, were compared using Fisher's R-to-z transformation.

RESULTS

There were no safety events; no participants requested device removal. CRS ratings of the AccuFlow and the standard monitoring equipment were similar (7.2 vs. 8.8, p=0.25). Change in wrist perfusion from delivery to dressing placement was more strongly correlated with CBL than was EBL (R=-0.48 vs. R=0.087, p=0.03).

CONCLUSIONS

The AccuFlow sensor is well-tolerated and shows promise in detecting intrapartum hemorrhage, though larger studies are needed.

Haemodynamic effects of methoxyflurane versus fentanyl and placebo in hypovolaemia: a randomised, double-blind crossover study in healthy volunteers

Background

Methoxyflurane is approved for relief of moderate to severe pain in conscious adult trauma patients: it may be self-administrated and is well suited for use in austere environments. Trauma patients may sustain injuries causing occult haemorrhage compromising haemodynamic stability, and it is therefore important to elucidate whether methoxyflurane may adversely affect the haemodynamic response to hypovolaemia.

Methods

In this randomised, double-blinded, placebo-controlled, three-period crossover study, inhaled methoxyflurane 3 ml, i.v. fentanyl 25 μg, and placebo were administered to 15 healthy volunteers exposed to experimental hypovolaemia in the lower body negative pressure model. The primary endpoint was the effect of treatment on changes in cardiac output, while secondary endpoints were changes in stroke volume and mean arterial pressure and time to haemodynamic decompensation during lower body negative pressure.

Results

There were no statistically significant effects of treatment on the changes in cardiac output, stroke volume, or mean arterial pressure during lower body negative pressure. The time to decompensation was longer for methoxyflurane compared with fentanyl (hazard ratio 1.9; 95% confidence interval 0.4-3.4; P=0.010), whereas there was no significant difference to placebo (hazard ratio -1.3; 95% confidence interval -2.8 to 0.23; P=0.117).

Conclusions

The present study does not indicate that methoxyflurane has significant adverse haemodynamic effects in conscious adults experiencing hypovolaemia.

Clinical trial registration

ClinicalTrials.gov (NCT04641949) and EudraCT (2019-004144-29) https://www.clinicaltrialsregister.eu/ctr-search/trial/2019-004144-29/NO.

Evaluation During Postpartum Hemorrhage

Postpartum hemorrhage is an obstetric emergency that is the leading and the most preventable cause of maternal death that occurs on the day of birth. The treatment of postpartum hemorrhage in a timely fashion is crucial to prevent morbidity and mortality. The accurate assessment of blood loss during delivery and the postpartum period remains a major challenge. Hence, it is imperative to have a standardized evaluation strategy for accurate assessment of blood loss, adequate classification of hemorrhage, and timely initiated interventions. The multidisciplinary evaluation strategy should be in place regardless of the delivery route.

Interventions of Postpartum Hemorrhage

Postpartum hemorrhage is a common and potentially life-threatening obstetric complication, with successful management relying heavily on early identification of hemorrhage and prompt intervention. This article will review the management of postpartum hemorrhage, including initial steps, exam-specific interventions, medical therapy, minimally invasive, and surgical interventions.

Value of contrast-enhanced arterial phase imaging in addition to portovenous phase in CT evaluation of blunt abdominopelvic trauma

OBJECTIVES

Compare the diagnostic performance of the arterial phase plus portovenous phases (AP + PVP) of abdominopelvic CT (CT) with PVP alone in the detection and characterization of traumatic vascular injury and the effects on radiologists' confidence.

METHODS

CT of 103 consecutive inpatients (median 36 years, 83 males) with blunt abdominopelvic injuries were retrospectively included if performed within 24 h after trauma and before definitive management. Images were re-reviewed by two blinded radiologists with disagreements resolved by the third radiologist.

RESULTS

Sixty vascular injuries (liver 23, spleen 15, kidneys 9, pancreas 2, adrenals 3, mesentery, and pelvis 4 each) were found with 4 injuries (liver 2, spleen, and kidneys 1 each) not detected at initial CT. Nineteen (liver 6, spleen 10, kidneys 2, adrenal 1) were visualized only on AP. The sensitivity and accuracy of AP + PVP were 89.58-91.67% and 94.44-95.15%, compared to 61.67-62.50% and 77.67-80.00% of PVP alone. The agreements on the types of injury with final diagnoses were higher for AP + PVP than for PVP alone (78.69% vs. 44.26%). The mean diagnostic radiologist confidence ((1 = 25%, 2 = 50%, 3 = 75%, 4 > 90%) increased significantly in the detection (from 3.38 to 3.71) and characterization (from 2.46 to 3.67) of vascular injuries with AP + PVP compared to PVP alone. For 19 lesions detected only on AP, 11 (spleen 8, liver 2, adrenal 1) received nonoperative management; others had transarterial embolization or surgery.

CONCLUSIONS

The addition of AP improves the detection and characterization of vascular injuries in CT evaluation of blunt abdominopelvic trauma.

KEY POINTS

• AP+PVP was more sensitive and precise than PVP alone in the detection of traumatic vascular abdominopelvic injuries. • AP+PVP improved the characterization of traumatic abdominopelvic vascular injuries. • When all abdominopelvic vascular injuries were considered, AP increased radiologists' diagnostic confidence in the detection and characterization of vascular injuries.

Agitation in the Trauma Bay Is an Early Indicator of Hemorrhagic Shock

INTRODUCTION

Agitation on arrival in trauma patients is known as a sign of impending demise. The aim of this study is to determine outcomes for trauma patients who present in an agitated state. We hypothesized that agitation in the trauma bay is an early indicator for hemorrhage in trauma patients.

METHODS

We performed a single-institution prospective observational study from September 2018 to December 2020 that included any trauma patient who arrived agitated, defined as a Richmond Agitation-Sedation Scale of +1 to +4. Variables collected included demographics, mechanism of injury, admission physiology, blood alcohol level, toxicity screen, and injury severity. The primary outcomes were need for massive transfusion (≥ 10 units) and need for emergent therapeutic intervention for hemorrhage control (laparotomy, preperitoneal pelvic packing, sternotomy, thoracotomy, or angioembolization).

RESULTS

Of 4657 trauma admissions, 77 (2%) patients arrived agitated. Agitated patients were younger (40 versus 46, P = 0.03), predominantly male (94% versus 66%, P < 0.0001) sustained more penetrating trauma (31% versus 12%, P < 0.0001), had a lower systolic blood pressure (127 versus 137, P < 0.0001), and a higher Injury Severity Score (17 versus 9, P < 0.0001). On multivariable logistic regression, agitation was independently associated with massive transfusion (odds ratio: 2.63 [1.20-5.77], P = 0.02) and emergent therapeutic intervention for hemorrhage control (odds ratio: 2.60 [1.35-5.03], P = 0.005).

CONCLUSIONS

Agitation in trauma patients may serve as an early indicator of hemorrhagic shock, as agitation is independently associated with a two-fold increase in the need for massive transfusion and emergent therapeutic intervention for hemorrhage control.

Using Vital Signs to Place Acutely Ill Patients Quickly and Easily into Clinically Helpful Pathophysiologic Categories: Derivation and Validation of Eight Pathophysiologic Categories in Two Distinct Patient Populations of Acutely Ill Patients

BACKGROUND

Early warning scores reliably identify patients at risk of imminent death, but do not provide insight into what may be wrong with the patient or what to do about it.

OBJECTIVE

Our aim was to explore whether the Shock Index (SI), pulse pressure (PP), and ROX Index can place acutely ill medical patients in pathophysiologic categories that could indicate the interventions required.

METHODS

A retrospective post-hoc analysis of previously obtained and reported clinical data for 45,784 acutely ill medical patients admitted to a major regional referral Canadian hospital between 2005 and 2010 and validated on 107,546 emergency admissions to four Dutch hospitals between 2017 and 2022.

RESULTS

SI, PP, and ROX values divided patients into eight mutually exclusive physiologic categories. Mortality was highest in patient categories that included ROX Index value < 22, and a ROX Index value < 22 multiplied the risk of any other abnormality. Patients with a ROX Index value < 22, PP < 42 mm Hg, and SI > 0.7 had the highest mortality and accounted for 40% of deaths within 24 h of admission, whereas patients with a PP ≥ 42 mm Hg, SI ≤ 0.7, and ROX Index value ≥ 22 had the lowest risk of death. These results were the same in both the Canadian and Dutch patient cohorts.

CONCLUSIONS

SI, PP, and ROX Index values can place acutely ill medical patients into eight mutually exclusive pathophysiologic categories with different mortality rates. Future studies will assess the interventions needed by these categories and their value in guiding treatment and disposition decisions.

Predictive value of tachycardia for mortality in trauma-related haemorrhagic shock: a systematic review and meta-regression

OBJECTIVES

Heart rate (HR) is one of the physiological variables in the early assessment of trauma-related haemorrhagic shock, according to Advanced Trauma Life Support (ATLS). However, its efficiency as predictor of mortality is contradicted by several studies. Furthermore, the linear association between HR and the severity of shock and blood loss presented by ATLS is doubtful. This systematic review aims to update current knowledge on the role of HR in the initial haemodynamic assessment of patients who had a trauma.

DESIGN

This study is a systematic review and meta-regression that follows the Preferred Reporting Items for Systematic Reviews and Meta-Analyses recommendations.

DATA SOURCES

EMBASE, MEDLINE, CENTRAL and Web of Science databases were systematically searched through on 1 September 2020.

ELIGIBILITY CRITERIA

Papers providing early HR and mortality data on bleeding patients who had a trauma were included. Patient cohorts were considered haemorrhagic if the inclusion criteria of the studies contained transfusion and/or positive focused assessment with sonography for trauma and/or postinjury haemodynamical instability and/or abdominal gunshot injury. Studies on burns, traumatic spinal or brain injuries were excluded. Papers published before January 2010 were not considered.

DATA EXTRACTION AND SYNTHESIS

Data extraction and risk of bias were assessed by two independent investigators. The association between HR and mortality of patients who had a trauma was assessed using meta-regression analysis. As subgroup analysis, meta-regression was performed on patients who received blood products.

RESULTS

From a total of 2017 papers, 19 studies met our eligibility criteria. Our primary meta-regression did not find a significant relation (p=0.847) between HR and mortality in patients who had a trauma with haemorrhage. Our subgroup analysis included 10 studies, and it could not reveal a linear association between HR and mortality rate.

CONCLUSIONS

In accordance with the literature demonstrating the multiphasic response of HR to bleeding, our study presents the lack of linear association between postinjury HR and mortality. Modifying the pattern of HR derangements in the ATLS shock classification may result in a more precise teaching tool for young clinicians.

Effectiveness of massive transfusion protocol activation in pre-hospital setting for major trauma

INTRODUCTION

Hemorrhage in major trauma is life-threatening and the activation of the Massive Transfusion Protocol (MTP) was found to reduce the time to transfusion and mortality. The purpose was (i) to verify whether MTP activation identifies patients that require massive transfusions once admitted to the Emergency Department (ED), (ii) to establish whether pre-hospital MTP activation reduces the time to transfusion on arrival at the ED, (iii) to identify the variable that best predicts MTP activation.

MATERIALS AND METHODS

This is a retrospective, single-center study. The MTP was implemented at the end of 2012; it was activated for major trauma in pre-hospital setting on the basis on established criteria. Pre-hospital MTP activation aimed to make blood products available prior to the patients' arrival at the ED. The blood products are transfused when the patient arrives at the hospital.

RESULTS

The MTP was activated in pre-hospital setting in 219 patients. On arrival at the hospital, the Trauma Team Leader confirmed MTP activation in 146 (66.7%) patients. Patients with MTP criteria received a higher amount of blood products than the patients without MTP criteria, median 7 (IQR 2-13) units versus 2 (0-6) units, respectively (P < 0.001). At the same time, patients with a Shock Index ≥ 0.9 received more transfusions (5.5 [2-13] units) compared with patients characterized by a lower SI (2 [0-7.25] units, P = 0.009). 146 patients were transfused in the first hour of ED admission. Poisson's multiple regression shows that the SI is the variable that better predicted MTP activation compared to age, gender and the number of injured sites.

CONCLUSIONS

Pre-hospital MTP activation is useful to identify patients that require an urgent blood transfusion on arrival at the ED. Further analysis should be considered to evaluate the implementation of the Shock Index as a criterion to activate MTP.

Resuscitation Patterns and Massive Transfusion for the Critical Bleeding Dog-A Multicentric Retrospective Study of 69 Cases (2007-2013)

Objective: To describe resuscitation patterns of critically bleeding dogs, including those receiving massive transfusion (MT). Design: Retrospective study from three universities (2007-2013). Animals: Critically bleeding dogs, defined as dogs who received ≥ 25 ml/kg of blood products for treatment of hemorrhagic shock caused by blood loss. Measurements and Main Results: Sixty-nine dogs were included. Sources of critical bleeding were trauma (26.1%), intra/perioperative surgical period (26.1%), miscellaneous (24.6%), and spontaneous hemoabdomen (23.1%). Median (range) age was 7 years (0.5-18). Median body weight was 20 kg (2.6-57). Median pre-transfusion hematocrit, total protein, systolic blood pressure, and lactate were 25% (10-63), 4.1 g/dl (2-7.1), 80 mm Hg (20-181), and 6.4 mmol/L (1.1-18.2), respectively. Median blood product volume administered was 44 ml/kg (25-137.4). Median plasma to red blood cell ratio was 0.8 (0-4), and median non-blood product resuscitation fluid to blood product ratio was 0.5 (0-3.6). MT was given to 47.8% of dogs. Survival rate was 40.6%. The estimated odds of survival were higher by a factor of 1.8 (95% CI: 1.174, 3.094) for a dog with 1 g/dl higher total protein above reference interval and were lower by a factor of 0.6 (95% CI: 0.340, 0.915) per 100% prolongation of partial thromboplastin time above the reference interval. No predictors of MT were identified. Conclusions: Critical bleeding in dogs was associated with a wide range of resuscitation patterns and carries a guarded to poor prognosis.

Hemorrhage control-Proper application of direct pressure, pressure dressings, and tourniquets for controlling acute life-threatening hemorrhage

BACKGROUND

Timely application of hemorrhage control interventions is lifesaving. Any amount of blood loss may be detrimental and, therefore, trauma-induced hemorrhage must be addressed immediately and aggressively. Early and prompt hemorrhage control is one of the main priorities of treating hemorrhagic shock. Trauma-induced hemorrhage remains a leading cause of preventable death. A vast majority of bleeding wounds encountered are not initially life-threatening but become life-threatening with delay in appropriate hemorrhage control.

DESCRIPTION

Appropriate immediate hemorrhage control interventions for the exsanguinating small animal include direct pressure, wound packing, hemostatic dressings, pressure bandage, and, possibly, tourniquet application. Although tourniquet application is a lifesaving intervention in people experiencing extremity hemorrhage, it has not been shown to be a necessary intervention for small animals.

SUMMARY

The aim of this companion article is to briefly describe the basic methods for achieving immediate hemorrhage control in small animals in a prehospital or life-threatening situation.

KEY POINTS

Common sources of trauma-induced massive hemorrhage include injury to a major artery or other large vessel (eg, external jugular), a highly vascular organ(s) (liver and spleen), or from a combination thereof. Blood loss from a major arterial source (ie, femoral or carotid artery) may rapidly lead to exsanguination and death in as little as 3-5 min. Placing a circumferential compressive bandage that is too tight or restrictive around the neck, thorax, or abdomen may occlude the patient's airway, restrict chest expansion, or prevent adequate respiration. Noncircumferential bandages often do not generate sufficient enough pressure to abate arterial hemorrhage, particularly when systolic arterial blood pressure is restored postfluid resuscitation. Definitive hemostasis for massive internal hemorrhage is best achieved through early surgical intervention. Direct pressure remains the most effective "medical" intervention for initial hemorrhage control. When feasible, elevate and splint (immobilize) any bleeding extremity or body part as an adjunctive aid for hemorrhage control when used in conjunction with other methods of control, especially direct pressure.

Pathophysiology of hemorrhagic shock

BACKGROUND

Hemorrhagic shock is a common condition that may lead to hemodynamic instability, decreased oxygen delivery, cellular hypoxia, organ damage, and ultimately death.

CLINICAL IMPORTANCE

This review addresses the pathophysiology of hemorrhagic shock. Hemorrhagic shock can be rapidly fatal and is the leading cause of death in human trauma patients. Understanding the pathophysiology of hemorrhagic shock is imperative in understanding the current hemostatic and resuscitative strategies and is foundational to the development of new therapeutic options.

KEY POINTS

Shock is a state of inadequate cellular energy production and can be triggered by many causes Both traumatic and non-traumatic causes of hemorrhage can lead to the development of hemorrhagic shock Prompt recognition and attenuation of hemorrhage is paramount in preventing the onset or potentiation of hemorrhagic shock Acute hemorrhage produces distinct physiological responses depending on the magnitude and rate of hemorrhage. Hemorrhagic shock may be directly related to the initial injury but may also be exacerbated and complicated by a post-traumatic coagulopathy, termed acute traumatic coagulopathy.

Should tranexamic acid be used for 3 days after total knee replacement? A randomized study in 250 patients

The aim is to study whether a 3 day course of Tranexamic acid (TXA) is more effective in reducing blood loss following a TKR than a 1 day course. 250 patients were prospectively randomised into Group A (n=138; Perioperative and additional oral TXA for two days) and Group B (n=112; only perioperative TXA). Total Blood loss was calculated by the Haemoglobin (Hb) loss method at 4 days and compared in both groups using Mann Whitney test. The mean peri- operative blood loss in group A was 631.69 ± 264.99 ml as compared to 685.55 ± 239.033 ml in group B (p=0.0434). Use of TXA for 3 days following a TKR can be more effective in reducing blood loss.

Monitoring drainage flow rate facilitates prompt intervention with re-laparoscopy for postoperative bleeding after laparoscopic gynecologic surgery: A case-control study

INTRODUCTION

We aimed to identify the characteristics of cases involving postoperative bleeding after laparoscopic gynecologic surgery, and to clarify the optimal cutoff value of postoperative drainage and vital sign trends for predicting the need for re-laparoscopy.

METHODS

Of 6366 patients with gynecologic benign pathologies who underwent laparoscopic surgery at our institution between 2009 and 2018, 13 (0.2%) required re-laparoscopy for postoperative bleeding. After reviewing the perioperative course in the re-laparoscopy group, we examined the postoperative total drainage volume (mL), drainage flow rate (mL/h), and vital sign trends in the re-laparoscopy group (n = 13) and among patients with substantial drainage volume ≥300 mL at 12 hours postoperatively but who did not need re-laparoscopy (observation group, n = 107).

RESULTS

In the re-laparoscopy group, initial laparoscopic surgery included uterine surgery (myomectomy, n = 7; hysterectomy, n = 1), adnexal surgery (n = 3), and uterine plus adnexal surgery (n = 2). Postoperative bleeding sites included the uterine wound (n = 6), adnexal wound (n = 5), umbilical trocar site (n = 1), and mesentery (n = 1). The re-laparoscopy and observation groups did not differ regarding initial surgical characteristics or postoperative vital sign trends. For distinguishing between the re-laparoscopy and observation groups, the drainage flow rate was superior to total drainage volume. Continuous excessive drainage (flow rate >50 mL/h) at 3 hours postoperatively was associated with a remarkably increased risk for re-laparoscopy (odds ratio, 40.07; 95% confidence interval, 5.44 to 1776.41, P < 0.001).

CONCLUSION

In cases with continuous excessive drainage later than 3 hours postoperatively (flow rate >50 mL/h) should be considered for exploratory re-laparoscopy to enable prompt diagnosis and intervention.

Comparison of the Previous and Current Trauma-Related Shock Classifications: A Retrospective Cohort Study from a Level I Trauma Center

PURPOSE

The aim was to examine the predictive value of the hypovolemic shock classification currently accepted by the Advanced Trauma Life Support (ATLS) program over the previous one, which used only vital signs (VS) for patient allocation. The primary outcome was 30-day mortality; as secondary outcome, heart rate (HR), systolic blood pressure (SBP), Glasgow Coma Scale (GCS) and base deficit (BD) data were compared and investigated in terms of mortality prediction.

METHODS

Retrospective analysis at a level I trauma center between 2014 and 2019. Adult patients treated by trauma teams were allocated into severity classes (I-IV) based on the criteria of the current and previous ATLS classifications, respectively. The prognostic values for the classifications were determined with Fisher's exact test and χ2 test for independence, and compared with the 2-proportion Z test. The individual variables were analyzed with receiver-operating characteristic (ROC) analyses.

RESULTS

A total of 156 patients met the inclusion criteria. Mortality was effectively predicted by both classifications, and there was no statistically significant difference between the predictive performances. According to ROC analyses, GCS, BD and SBP had significant prognostic values while HR change was ineffective in this regard.

CONCLUSIONS

The currently used ATLS shock classification does not appear to be superior to the VS-based previous classification. GCS, BD and SBP are useful parameters to predict the prognosis. Changes in HR do not reflect the clinical course accurately; thus, further studies will be needed to determine the value of this parameter in trauma-associated hypovolemic-hemorrhagic shock conditions.

Reverse shock index multiplied by Glasgow coma scale as a predictor of massive transfusion in trauma

BACKGROUND AND PURPOSE

Previous studies have identified that the reverse shock index multiplied by the Glasgow Coma Scale score (rSIG) is a good predictor of mortality in trauma patients. However, it is unknown if rSIG has utility as a predictor for massive transfusion (MT) in trauma patients. The present study evaluated the ability of rSIG to predict MT in trauma patients.

METHODS

This was a retrospective, observational study performed at a level 1 trauma center. Consecutive patients who presented to the trauma center emergency department between January 2016 and December 2018 were included. The predictive ability of rSIG for MT was assessed as our primary outcome measure. Our secondary outcome measures were the predictive ability of rSIG for coagulopathy, in-hospital mortality, and 24-h mortality. We compared the prognostic performance of rSIG with the shock index, age shock index, and quick Sequential Organ Failure Assessment.

RESULTS

In total, 1627 patients were included and 117 (7.2%) patients received MT. rSIG showed the highest area under the receiver operating characteristic (AUROC) curve (0.842; 95% confidence interval [CI], 0.806--0.878) for predicting MT. rSIG also showed the highest AUROC for predicting coagulopathy (0.769; 95% CI, 0.728-0.809), in-hospital mortality (AUROC 0.812; 95% CI, 0.772-0.852), and 24-h mortality (AUROC 0.826; 95% CI, 0.789-0.864). The sensitivity of rSIG for MT was 0.79, and the specificity of rSIG for MT was 0.77. All tools had a high negative predictive value and low positive predictive value.

CONCLUSION

rSIG is a useful, rapid, and accurate predictor for MT, coagulopathy, in-hospital mortality, and 24- h mortality in trauma patients.

Macrocirculatory Parameters and Oxygen Debt Indices in Pigs During Propofol Or Alfaxalone Anesthesia When Subjected to Experimental Stepwise Hemorrhage

Background: Pigs are anesthetized when used for emergency procedures live tissue training (LTT) of civilian and military medical personnel or for experimental purposes, but there is a paucity in the literature regarding anesthesia of pigs for this purpose. Objective(s): The main goals of the study were to compare oxygen debt, macrocirculatory parameters, and time to cardiac arrest between pigs in hemorrhagic shock and anesthetized with propofol-ketamine-dexmedetomidine or alfaxalone-ketamine-dexmedetomidine. Design: A prospective, non-blinded randomized study design was used. Sixteen pigs were randomized in blocks of four to be anesthetized with either propofol-ketamine-dexmedetomidine (n = 8) or alfaxalone-ketamine-dexmedetomidine (n = 8) as a continuous infusion. Interventions: Premedication with ketamine 15 mg kg^-1 and midazolam 1 mg kg^-1 was given i.m. Anesthesia was maintained with propofol 8 mg kg^-1 h^-1 or alfaxalone 5 mg kg^-1 h^-1 combined with ketamine 5 mg kg^-1 h^-1 and dexmedetomidine 4 μg kg^-1 h^-1 i.v. A stepwise, volume-controlled model for hemorrhage was created by exsanguination. Main Outcome Measures: Indices of oxygen debt (lactate, base excess, and oxygen extraction), macrocirculatory (PR, SAP, DAP, MAP, and CI, SVI, and TPR) variables, and time to death was compared between groups. Results: Pigs in the alfaxalone group had significantly higher SAP than pigs given propofol. No difference in other macrocirculatory variables or indices of oxygen debt could be found. A blood loss of 50% of the total blood volume or more was possible in most pigs with both anesthetic regimes. Conclusions: Pigs anesthetized with propofol or alfaxalone combined with ketamine and dexmedetomidine tolerated substantial blood loss.

Should We Use Intra-articular Tranexamic Acid Before or After Capsular Closure During Total Knee Replacement? A Study of 100 Knees

BACKGROUND

Intraarticular (IA) administration of tranexamic acid (TXA) is a proven way of reducing blood loss in total knee replacement (TKR). However, different methods of administration have been described in literature such as placement of an intra-articular swab soaked in TXA before capsular closure or injecting TXA intraarticularly after capsular closure. We decided to compare these two methods.

MATERIALS AND METHODS

One hundred consecutive patients planned for unilateral TKR between December 2018 and March 2019 were selected for the study and divided into 2 groups of 50 patients each. All patients received IV and oral TXA identically-15 mg/kg TXA IV preoperatively, 10 mg/kg IV TXA at 3 and 6 h postoperatively, and 1 g oral TXA for the next 2 days. Group A was given IA TXA via swab soaked with 1 g TXA in 100 ml normal saline (NS) before closure of arthtrotomy, while Group B was given 1 g of IA TXA via injection in the knee after capsular closure. Preoperative haemoglobin (Hb) and postoperative day 4 Hb values were measured. Blood loss was calculated and compared in both groups using Mann Whitney test.

RESULT

The mean blood loss was 652.23 ± 64.36 ml in Group A and 542.68 ± 266.23 ml in Group B. The difference in blood loss between both groups was found to be clinically significant with a p-value of 0.03236 (significant, p < 0.05).

CONCLUSION

Injecting TXA intraarticularly after capsular closure is more effective than using an intra-articular swab containing TXA.

LEVEL OF EVIDENCE

Level III Retrospective Comparative study.

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.

Trauma-Induced Coagulopathy: Overview of an Emerging Medical Problem from Pathophysiology to Outcomes

Coagulopathy induced by major trauma is common, affecting approximately one-third of patients after trauma. It develops independently of iatrogenic, hypothermic, and dilutive causes (such as iatrogenic cause in case of fluid administration), which instead have a pejorative aspect on coagulopathy. Notwithstanding the continuous research conducted over the past decade on Trauma-Induced Coagulopathy (TIC), it remains a life-threatening condition with a significant impact on trauma mortality. We reviewed the current evidence regarding TIC diagnosis and pathophysiological mechanisms and summarized the different iterations of optimal TIC management strategies among which product resuscitation, potential drug administrations, and hemostatis-focused approaches. We have identified areas of ongoing investigation and controversy in TIC management.

Fluid Resuscitation for Refractory Hypotension

Hypotension is a common occurrence, especially in anesthetized patients and in critical patients suffering from hypovolemia due to shock and sepsis. Hypotension can also occur in normovolemic animals, anesthetized or conscious, under conditions of vasodilation or decreased cardiac function. The main consequence of hypotension is decreased organ perfusion and tissue injury/dysfunction. In the human literature there is no consensus on what is the threshold value for hypotension, and ranges from < 80 to < 100 mmHg for systolic blood pressure and from < 50 to < 70 mmHg for mean arterial blood pressure have been referenced for intraoperative hypotension. In veterinary medicine, similar values are referenced, despite marked differences in normal arterial blood pressure between species and with respect to humans. Therapeutic intervention involves fluid therapy to normalize volemia and use of sympathomimetics to enhance cardiac function and regulate peripheral vascular resistance. Despite these therapeutic measures, there is a subset of patients that are seemingly refractory and exhibit persistent hypotension. This review covers the physiological aspects that govern arterial blood pressure control and blood flow to tissues/organs, the pathophysiological mechanisms involved in hypotension and refractory hypotension, and therapeutic considerations and expectations that include proper interpretation of cardiovascular parameters, fluid recommendations and therapy rates, use of sympathomimetics and vasopressors, and newer approaches derived from the human literature.

Uso de los gases arteriales en trauma

El trauma continúa siendo una de las primeras causas de muertes prevenibles en nuestro país. A pesar de la disminución del trauma militar, la incidencia que abarca todas las formas de trauma continúa siendo alta y congestiona los servicios de urgencias, por eso es fundamental el adecuado enfoque inicial para disminuir la mortalidad. Tradicionalmente, se han utilizado marcadores, como los signos vitales, para la identificación del choque hemorrágico, pero estudios observacionales de gran escala han demostrado cómo estos muchas veces no logran identificar a los pacientes con choque hemorrágico, haciendo necesario usar marcadores más objetivos, como los gases arteriales, con la medición del lactato y el déficit de base, que según literatura tienen mejor predicción de mortalidad, identificación temprana del choque y activación temprana de protocolos transfusionales.

Evaluation and management of haemorrhagic shock in polytrauma: Clinical practice guidelines

Haemorrhagic shock is the most common preventable cause of early mortality in polytrauma patients. Road traffic injuries are the most common cause for polytrauma and most commonly include orthopaedic injuries. Hence, orthopaedic trainees and junior orthopaedic surgeons need to be well aware of evaluation and management of haemorrhagic shock in the multiple injured patient. The present narrative review discusses evaluation and current principles in management of haemorrhagic shock in a polytrauma patient. A classification system for haemorrhagic shock based on ATLS guidelines has been described along with novel use of colour coding to facilitate better and effective use of the classification. A treatment algorithm has also been presented for quick reference. The emphasis is to avoid overloading with crystalloid fluids, replacing with blood and blood products (Balanced resuscitation), permissive hypotension, prevent and acutely treat lethal conditions such as hypothermia, acidosis and coagulopathy. The management of haemorrhagic shock in polytrauma patient is quite challenging and require a detailed knowledge of its management. An arbitrary and haphazard management of these patients may lead to severe complications. We have mentioned the broad principles of management of hypovolemic shock in a polytrauma patient.

The Need for a Physiological Classification of Hemorrhagic Shock

Classifications mean to conceptualize in a cluster and rapidly summarize the assessment and management of a clinical scenario. In the specific case of a hemorrhagic shock (HS), a classification should serve the purpose of allowing a rapid clinical assessment of the shock level and the earliest or right timing of source control, possibly also on whether to apply damage control surgery (DCS) strategy or not. ATLS^® classification of HS is not sensitive and specific enough to help decision-making in reference to the timing of management, based only on the amount of blood loss that may be or may not rightly estimated, for example, blood loss on the floor in penetrating injuries before theatre. Moreover, it focuses also on other parameters, which are taken singularly, instead of the individual generalized physiological response to hemorrhage, which is the core by definition of the derangement we call "shock." It is unhelpful, difficult, and impractical to apply as well. A new classification, which may well be called as the "physiological HS classification" or "therapeutic HS classification," was proposed since 2010, following the new developments on microcirculation and an already going-on sensible praxis among some trauma surgeons. It bases on some physiological considerations such as the significance of fluid-blood resistant hypotension, body natural hemostatic mechanisms, the right definition of shock, and the relevance that hemorrhage-triggered ischemia-reperfusion toxemia and systemic inflammatory response have in critical illness scenarios as secondary insults from ischemia, which is what we mean to prevented with DCS. The key factor remains the persistence of hypotension, following fluid challenge.

Cognitive and physical performance are well preserved following standard blood donation: A noninferiority, randomized clinical trial

BACKGROUND

A walking blood bank (WBB) refers to the use of fellow combatants for battlefield blood donation. This requires pretesting combatants for infectious diseases and blood type. A fundamental prerequisite for this technique is that the donating soldier will suffer minimal physiological and mental impact. The purpose of the current study is to assess the effect of blood shedding on battlefield performance.

METHODS

This is a double-blind randomized control trial. Forty Israel Defense Forces combatants volunteered for the study. Participants underwent baseline evaluation, including repeated measurement of vital signs, cognitive evaluation, physical evaluation, and a strenuous shooting test. Three weeks after the baseline evaluation, subjects were randomized to either blood donation or the control group. For blinding purposes, all subjects underwent venous catheterization for the duration of a blood donation. Repeated vital signs and function evaluation were then performed.

RESULTS

Thirty-six patients were available for randomization. Baseline measurements were similar for both groups. Mean strenuous shooting score was 80.5 ± 9.5 for the control group and 82 ± 6.6 for the test group (p = 0.58). No clinically or statistically significant differences were found in tests designed to evaluate cognitive performance or physical functions. Vital signs taken multiple times were also similar between the test and control groups.

CONCLUSIONS

Executive, cognitive, and physical functions were well preserved after blood donation. This study supports the hypothesis that a WBB does not decrease donor combat performance. The categorical prohibition of physical exercise following blood donation might need to be reconsidered in both military and civilian populations.

Early experience with transfusing low titer group O whole blood in the pre-hospital setting in Israel

BACKGROUND

The Israeli Defense Force Medical Corps (IDF-MC) recently implemented the use of low titer group O whole blood (LTOWB) in the airborne combat search and rescue unit (CSAR) for both military and civilian patients during transport to definitive care. LTOWB is preferentially used by the CSAR instead of red blood cell units and freeze-dried plasma (FDP) for patients with signs of hemorrhagic shock. Ten percent of group O donors were eligible to donate LTOWB as they had anti-A and -B IgM titers of <50.

METHODS

All patients treated by CSAR providers with LTOWB between July 2018 and June 2019 were included.

RESULTS

Between July 2018 and June 2019, eight patients have received 10 units of LTOWB. All patients suffered blunt injuries, 6 out of 8 (75%) of whom were due to motor vehicle accidents. Four patients (4 out of 8, 50%) received a single LTOWB unit, two patients (2 out of 8, 25%) received two units. Two pediatric patients received fewer than one unit of LTOWB. Median (range) heart rate was 130 (30-150) bpm, median systolic blood pressure was 107 (80-124) mmHg, and median Glasgow coma scale was 8 (on a scale of 3-15). For four (4 out of 8, 50%) patients, LTOWB was the only blood product used for volume resuscitation. All six adult patients were treated with 1 g of tranexamic acid at the point of injury.

CONCLUSIONS

The CSAR has successfully implemented a LTOWB program for the pre-hospital treatment of bleeding patients, and as its experience grows this product will be made available to other units and in civilian hospitals.

Relative blood loss in forensic medicine-do we need a change in doctrine?

In forensic medicine, blood loss is encountered frequently, either as a cause of death or as a contributing factor. Here, risk to life and lethality assessment is based on the concept of relative blood loss (absolute loss out of total volume). In emergency medicine, the Advanced Trauma Life Support (ATLSⓇ) classification also refers to relative blood loss. We tested the validity of relative blood loss benchmarks with reference to lethality. Depending on the quality of the total blood volume (TBV) estimation formula, relative blood loss rates should be reflected in the case cohort as significantly higher absolute blood loss in heavier individuals since all TBV estimation formulas positively correlate body weight with TBV.

METHOD

80 autopsy cases with sudden, quantifiable, exclusively internal blood loss were retrospectively analyzed and a total of 8 different formulas for TBV estimation were applied.

RESULTS

No statistical correlation between body weight and absolute blood loss was found for any of the tested TBV estimation algorithms. All cases showed a wide spread of both absolute and relative blood loss.

DISCUSSION

The principle of relative blood loss is of very limited use in casework. It opens the forensic expert opinion to unnecessary criticism and possible negative legal implications.

CONCLUSION

We challenge the use of relative blood loss benchmarks in textbooks and practical casework and advocate for its elimination from the ATLSⓇ 's grading system. If necessary, we recommend the use of BMI-adjusted algorithms for TBV estimation.

Breast Reduction with Deskinning of a Superomedial Pedicle: A Retrospective Cohort Study

BACKGROUND

In most breast reduction techniques, the pedicle of the nipple-areola complex (NAC) is de-epithelialized to preserve the subdermal plexus, thereby decreasing the risk of NAC necrosis. However, deskinning the pedicle is faster and makes it more pliable, which potentially improves the aesthetic outcome. There is no scientific evidence regarding the beneficial effects of de-epithelialization. In this study, we present data from patients undergoing breast reduction with deskinning of a superomedial pedicle.

METHODS

In the period June 2013 to March 2019, a single surgeon performed all breast reductions using a superomedial glandular pedicle. The patients were included retrospectively and data were collected by reviewing the medical records. The NAC necrosis rate was compared with data from the literature through a systematic review.

RESULTS

The cohort consisted of 142 consecutive patients. The median resection weight was 287 g (interquartile range (IQR), 197-399) per breast. No complete NAC necroses occurred during the follow-up period, but two patients (1.4%) developed partial NAC necrosis. In the literature, the rate of NAC necrosis (complete or partial) was 1.5% of patients undergoing breast reduction with de-epithelialization.

CONCLUSION

The rate of NAC necrosis after breast reduction with deskinning of the pedicle was comparable with breast reductions with de-epithelialization that has been reported in the literature. Our findings support that the pedicle in breast reduction surgery can be deskinned safely in patients with low resection weights.

Pediatric resuscitation: Weight-based packed red blood cell volume is a reliable predictor of mortality

BACKGROUND

The definition of massive transfusion (MT) in civilian pediatric trauma patients is not established. In combat-injured pediatric patients, the definition of MT is based on the volume of total blood products transfused. The aim of this study is to define MT in civilian pediatric trauma patients based on a packed red blood cell (PRBC) volume threshold and compare its predictive power to a total blood products volume threshold.

METHODS

An analysis of the pediatric American College of Surgeons Trauma Quality Improvement Program database was performed (2014-2016) including pediatric trauma patients (4-18 years) who received blood products within 24 hours. Receiver operator characteristic curves for predicting mortality determined the optimal PRBC MT threshold. Area under receiver operating characteristic curve (AUROC) curve analysis was performed to compare the predictive power of a PRBC threshold to a total blood product threshold.

RESULTS

A total of 1,495 patients were included. Sensitivity and specificity for 24-hour and in-hospital mortality were optimal at a PRBC threshold of 20 mL/kg. As compared with total blood products threshold, 20 mL/kg PRBCs volume achieved higher discriminatory power for predicting 24-hour (AUROC, 0.803 vs. 0.672; p < 0.001) and in-hospital mortality (AUROC, 0.815 vs. 0.686, p < 0.001). Patients who received an MT had higher Injury Severity Score (p < 0.001) and were more likely to receive mechanical ventilation (p < 0.001) and intensive care unit admission (p < 0.001). Overall 24-hour mortality (23.1% vs. 7.6%, p < 0.001) and in-hospital mortality (44.9% vs. 15.8%, p < 0.001) were higher in the MT group. On regression analysis, MT significantly predicted in-hospital mortality (odds ratio, 3.8 [2.9-4.9, 95% CI]) and 24-hour mortality (odds ratio, 3.3 [2.4-4.7, 95% CI]).

CONCLUSION

The use of a PRBCs MT definition in civilian pediatric patients is a better predictor of mortality compared with total blood products threshold. These results provide a framework for MT protocol development.

LEVEL OF EVIDENCE

Prognostic study, level III.

[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.

The Complication Rates of Oral Anticoagulation Therapy in Deep Venous Thrombosis

The objective of the current study is to evaluate the complication rates (embolic and hemorrhagic events) in deep venous thrombosis (DVT) patients on different types of oral anticoagulation therapy (OAC): direct oral anticoagulant therapy and vitamin K antagonist therapy.

Methods: A number of 62 DVT patients were included and divided in two groups, depending on the type of oral anticoagulation therapy administered. The first group was composed of patients treated with direct oral anticoagulant treatment (Dabigatran, Rivaroxaban) and the second group was composed of patients treated with vitamin K antagonist (Acenocumarol). General data, including BMI and comorbidities were noted. Embolic and hemorrhagic events were noticed.

Results: in the first group of patients (DOAC therapy), a number of 34 patients were included (14 of them with BMI higher than 25 kg/m2 and 14 with concomitant atrial fibrillation), while the second group comprised of 28 patients treated with VKA (21 of them with a high BMI and only 3 of them with atrial fibrillation). After a mean period of 36 months of anticoagulant therapy, complications were present in 17 patients, hematuria (8 episodes) and pulmonary embolism (4 cases) were the most frequent, with no difference regarding the treatment applied.

Conclusion: No statistically significant difference was encountered regarding embolic and hemorrhagic event rates in our deep vein thrombosis patients.

Damage Control Resuscitation in polytrauma patient

Haemorrhagic shock is one of the main causes of mortality in severe polytrauma patients. To increase the survival rates, a combined strategy of treatment known as Damage Control has been developed. The aims of this article are to analyse the actual concept of Damage Control Resuscitation and its three treatment levels, describe the best transfusion strategy, and approach the acute coagulopathy of the traumatic patient as an entity. The potential changes of this therapeutic strategy over the coming years are also described.

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.

Electronic supplementary material

The online version of this article (10.1186/s13054-019-2347-3) contains supplementary material, which is available to authorized users.

A quantitative exploration of gastrointestinal bleeding in intensive care unit patients

Background

Quantitative assessments of the severity of bleeding in patients with bleeds within the gastrointestinal tract (GIB) are generally limited to blood tests like the hematocrit. The varied and irregular nature of the data collected during such observations makes it difficult in retrospective data analysis to characterize the complete course of bleeding. We intend to quantify the rate of blood loss over the course of an ICU stay, facilitating more precise analysis of retrospective data, and to use this quantification to examine questions about the effects of GIB.

Methods and findings

A population of 2,445 intensive care admissions across 2,266 patients with a diagnosis of GIB was studied. Using statistical techniques for smoothing data and accepted medical approaches for calculating blood loss, we are able to convert collections of individual laboratory readings that are difficult to understand into a simple, interpretable overview of the patient’s bleeding status over time. To demonstrate this method, we compare patients’ standard vital signs while bleeding heavily to times when they are not bleeding, finding a 3.0 ± 0.5% increase in heart rate, a 1.3 ± 0.4% decrease in systolic blood pressure and a 0.9 ± 0.5% decrease in diastolic blood pressure. After considering the effect of bleeding on standard vital signs, we demonstrate that patients with upper GIB have significantly elevated blood urea nitrogen levels while bleeding heavily, with a mean increase of 11.7 ± 7.2%, while patients with lower GIB do not, with a mean increase of 4.2 ± 6.6%.

Conclusions

This study introduces a novel method of processing retrospective laboratory data to characterize the course of bleeds within the gastrointestinal tract. This method is used to examine the direct effects of bleeding on a patient and can be deployed in future studies of bleeding using retrospective data.

A data-driven artificial intelligence model for remote triage in the prehospital environment

In a mass casualty incident, the factors that determine the survival rate of injured patients are diverse, but one of the key factors is the time for triage. Additionally, the main factor that determines the time of triage is the number of medical personnel. However, when relying on a small number of medical personnel, the ability to increase survivability is limited. Therefore, developing a classification model for survival prediction that can quickly and precisely triage via wearable devices without medical personnel is important. In this study, we designed a consciousness index to substitute the factor by manpower and improved the classification accuracy by applying a machine learning algorithm. First, logistic regression analysis using vital signs and a consciousness index capable of remote monitoring through wearable devices confirmed the high efficiency of the consciousness index. We then developed a classification model with high accuracy which corresponds to existing injury severity scoring systems through the machine learning algorithms. We extracted 460,865 cases which met our criteria for developing the survival prediction from the national sample project in the national trauma databank which contains 408,316 cases of blunt injury and 52,549 cases of penetrating injury. Among the dataset, 17,918 (3.9%) cases died while the other survived. The AUCs with 95% confidence intervals (CIs) for the different models with the proposed simplified consciousness score as follows: RTS (as baseline), 0.78 (95% CI = 0.775 to 0.785); logistic regression, 0.87 (95% CI = 0.862 to 0.870); random forest, 0.87 (95% CI = 0.862 to 0.872); deep neural network, 0.89 (95% CI = 0.882 to 0.890). As a result, we confirmed the possibility of remote triage using a wearable device. It is expected that the time required for triage can be effectively reduced by using the developed classification model of survival prediction.

Tachycardic and non-tachycardic responses in trauma patients with haemorrhagic injuries

BACKGROUND

Analyses of large databases have demonstrated that the association between heart rate (HR) and blood loss is weaker than what is taught by Advanced Trauma Life Support training. However, those studies had limited ability to generate a more descriptive paradigm, because they only examined a single HR value per patient.

METHODS

In a comparative, retrospective analysis, we studied the temporal characteristics of HR through time in adult trauma patients with haemorrhage, based on documented injuries and transfusion of ≥3 units of red blood cells (RBCs). We analysed archived vital-sign data of up to 60 min during either pre-hospital or emergency department care.

RESULTS

We identified 133 trauma patients who met the inclusion criteria for major haemorrhage and 1640 control patients without haemorrhage. There were 55 haemorrhage patients with a normal median HR and 78 with tachycardia. Median ΔHR was -0.8 and +0.7 bpm per 10 min, respectively. Median time to documented hypotension was 8 and 5 min, respectively. RBCs were not significantly different; median volumes were 6 (IQR: 4-13) and 10 units (IQR: 5-16), respectively. Time-to-hypotension and mortality were not significantly different. Tachycardic patients were significantly younger (P < 0.05). Only 10 patients with normal HR developed transient/temporary tachycardia, and only 11 tachycardic patients developed a transient/temporary normal HR.

CONCLUSIONS

The current analysis suggests that some trauma patients with haemorrhage are continuously tachycardic while others have a normal HR. For both cohorts, hypotension typically develops within 30 min, without any consistent temporal increases or trends in HR.

Endovascular aneurysm sealing with the Nellix endograft in hemodynamically-unstable ruptured abdominal aortic aneurysm with challenging anatomy

BACKGROUND

To assess immediate and midterm outcomes of hemodynamically-unstable patients with ruptured abdominal aortic aneurysm (rAAA) treated with the Nellix endovascular sealing system (EVAS).

METHODS

From June 2014 to June 2017, 21 hemodynamically-unstable rAAA patients with challenging anatomies were treated with EVAS. The mean AAA diameter and neck length measured 73±15 mm and 14±10 mm, respectively. All the patients presented an advance trauma life support (ATLS) hemorrhage class ≥1 confirming a compromised hemodynamic status. Primary endpoints include technical success, treatment success, primary safety and 30-day survival. Secondary endpoints include re-intervention rate and time free-from-reintervention.

RESULTS

Technical success was achieved in 95% (N.=20/21); one patient was converted intraoperatively to open surgery due to ongoing hemorrhage. Seven re-interventions were performed within 30-days and one during the follow-up; treatment success rate of 67% and re-intervention rate of 33%. Early endoleaks were diagnosed in 5 patients (24%). Primary safety was 52%. After a mean follow-up of 11±10 months, survival rates were 81%, 62% and 57% at 1, 6 and 12 months, respectively. Time free-from-reintervention was 15±11 months.

CONCLUSIONS

Emergency-EVAS (eEVAS) appeared feasible and useful, especially in hemodynamically-unstable patients with challenging anatomies. There are some limitations in this cohort study and larger, prospective and comparative studies are required to confirm eEVAS as part of an emergency treatment protocol for rAAA.

A clinically relevant and bias-controlled murine model to study acute traumatic coagulopathy

Acute traumatic coagulopathy (ATC) is an acute and endogenous mechanism triggered by the association of trauma and hemorrhage. Several animal models have been developed, but some major biases have not yet been identified. Our aim was to develop a robust and clinically relevant murine model to study this condition. Anesthetized adult Sprague Dawley rats were randomized into 4 groups: C, control; T, trauma; H, hemorrhage; TH, trauma and hemorrhage (n = 7 each). Trauma consisted of laparotomy associated with four-limb and splenic fractures. Clinical variables, ionograms, arterial and hemostasis blood tests were compared at 0 and 90 min. ATC and un-compensated shock were observed in group TH. In this group, the rise in prothrombin time and activated partial thromboplastin was 29 and 40%, respectively. Shock markers, compensation mechanisms and coagulation pathways were all consistent with human pathophysiology. The absence of confounding factors, such as trauma-related bleeding or dilution due to trans-capillary refill was verified. This ethic, cost effective and bias-controlled model reproduced the specific and endogenous mechanism of ATC and will allow to identify potential targets for therapeutics in case of trauma-related hemorrhage.

Comparing the accuracy of four prognostic scoring systems in patients operated on for ruptured abdominal aortic aneurysms

OBJECTIVE

Ruptured abdominal aortic aneurysms (rAAAs) are associated with high mortality and morbidity. Several prognostic scoring systems are available for prediction of outcome, but scarcity of external validation and evaluation of predictive value has hampered widespread implementation. The aim of this study was to examine the discriminatory value of four scores in a consecutive Norwegian cohort.

METHODS

This was a retrospective study of a consecutive series of patients operated on for primary rAAA at Stavanger University Hospital from January 2000 to December 2014. The Hardman Index, Vancouver Score (VS), updated Glasgow Aneurysm Score, and Edinburgh Ruptured Aneurysm Score (ERAS) were calculated. Predictive ability in discriminating survivors and nonsurvivors was compared using receiver operating characteristics analyses and presented as area under the curve.

RESULTS

Altogether, 177 patients underwent surgery for rAAA. Mortality at 30 days was 46.3%. In receiver operating characteristics analysis, the Hardman Index had an area under the curve of 0.674 (95% confidence interval [CI], 0.588-0.753); the VS, 0.684 (95% CI, 0.610-0.752); the Glasgow Aneurysm Score, 0.680 (95% CI, 0.605-0.749); and the ERAS, 0.586 (95% CI, 0.509-0.660). VS had a significantly better fit than ERAS (P = .022).

CONCLUSIONS

The accuracy of the available scores is limited. The findings question the clinical value of such scores for decision-making.

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

BACKGROUND

Severe trauma continues to represent a global public health issue and mortality and morbidity in trauma patients remains substantial. A number of initiatives have aimed to provide guidance on the management of trauma patients. This document focuses on the management of major bleeding and coagulopathy following trauma and encourages adaptation of the guiding principles to each local situation and implementation within each institution.

METHODS

The pan-European, multidisciplinary Task Force for Advanced Bleeding Care in Trauma was founded in 2004 and included representatives of six relevant European professional societies. The group used 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 reconsidered and revised based on new scientific evidence 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. This guideline represents the fourth edition of a document first published in 2007 and updated in 2010 and 2013.

RESULTS

The guideline now recommends that patients be transferred directly to an appropriate trauma treatment centre and encourages use of a restricted volume replacement strategy during initial resuscitation. Best-practice use of blood products during further resuscitation continues to evolve and should be guided by a goal-directed strategy. The identification and management of patients pre-treated with anticoagulant agents continues to pose a real challenge, despite accumulating experience and awareness. The present guideline should be viewed as an educational aid to improve and standardise the care of the bleeding trauma patients across Europe and beyond. This document may also serve as a basis for local implementation. Furthermore, local quality and safety management systems need to be established to specifically assess key measures of bleeding control and outcome.

CONCLUSIONS

A multidisciplinary approach and adherence to evidence-based guidance are key to improving patient outcomes. The implementation of locally adapted treatment algorithms should strive to achieve measureable improvements in patient outcome.

Developmentally regulated effects of severe hemorrhage on cardiovascular homeostasis and the arterial baroreflex control of heart rate

The purpose of this study was to investigate in developing animals, the cardiovascular responses to severe hemorrhage at which compensatory mechanisms fail and when blood pressure remains decreased after blood loss. Two groups of conscious lambs (Group I: one to two weeks, N = 7; group II: six to seven weeks, N = 7) were studied. Mean arterial pressure, systolic and diastolic pressures, and heart rate were measured for 20 min before (Control, C) and for 60 min after a fixed hemorrhage of 30% of blood volume. The arterial baroreflex control of heart rate was assessed before (C), and at 30 and 60 min intervals after hemorrhage. Mean arterial pressure decreased for up to 60 min after hemorrhage in both groups of lambs. In group I, heart rate decreased from 200 ± 29 (C) to 164 ± 24 beat min(-1) at 30 min then increased to 232 ± 45 beat min(-1) at 60 min, whereas heart rate remained unaltered in group II. With respect to the arterial baroreflex control of heart rate, by 30 min after hemorrhage in group I, there was a decrease in the heart rate range over which the baroreflex operates (P1) from 192 ± 13 (C) to 102 ± 9 beats min(-1); by 60 min after hemorrhage, there was a decrease in minimum heart rate (P4) from 72 ± 10 (C) to 32 ± 25 beats min(-1). In group II, P1 decreased to a lesser extent than group I from 134 ± 21 (C) to 82 ± 10 beats min(-1) at 30 min; minimum heart rate (P4) decreased from 40 ± 15 (C) to 24 ± 9 and 20 ± 13 beats min(-1) at 30 and 60 min, respectively. These results provide the first assessment of the arterial baroreflex control of heart rate following blood loss and new evidence that the cardiovascular responses to severe hemorrhage are developmentally regulated.