The cellular, metabolic, and systemic consequences of aggressive fluid resuscitation strategies

Fluid Management in Critically Ill Children: Single-Center Retrospective Comparison of Trauma and Postoperative Patients, 2020-2022

OBJECTIVE

Injury and surgery both represent well-defined starting points of a predictable inflammatory response, but the consequent response to IV fluids has not been studied. We aimed to review and compare our single-center fluid management strategies in these two populations.

DESIGN

Retrospective cohort study from January 2020 to July 2022. The primary outcome was total IV fluid volume administered. Net fluid balances and select clinical outcomes were also evaluated.

SETTING

Single tertiary academic center and level 1 pediatric trauma center in New York.

PATIENTS

A dataset of critically ill trauma and surgical patients aged 0-18 years who were admitted to the PICU, 2020-2022. Trauma patients had at least moderate traumatic injuries (Injury Severity Score ≥ 9) and surgical patients had at least a 1-hour operation time.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We identified 25 trauma and 115 surgical patients. During the first 5 days of hospitalization, we did not identify an association between grouping and total IV fluids administered and fluid balance in the prehospital, emergency department, and operating room (p = 0.90 and p = 0.79), even when adjusted for weight (p = 0.96). Time trend graphs of net fluid balance and IV fluid administered illustrated analogous fluid requirement and response with the transition from net positive to net negative fluid balance between 48 and 72 hours. There was an association between total IV fluid and ventilator requirement (p = 0.003).

CONCLUSIONS

Critically ill pediatric trauma and postoperative patients seem to have similar fluid management and balance after injury or surgery. In our opinion, these two critically ill populations could be combined in large prospective studies on optimal fluid therapy in critically ill children.

Induced Moderate Hypothermia in Aortic Rupture With Retroperitoneal Bleeding: A Randomized Porcine Study

OBJECTIVE

Induced hypothermia improves outcome in aortic arch surgery, neonatal neurointensive care, and transplant surgery for example. In contrast, spontaneous hypothermia has been associated with worse outcomes in patients suffering from hemorrhagic shock, mostly explained by its adverse effects on the coagulation system. We investigated if induced hypothermia would impair short-term survival in experimental aortic rupture with retroperitoneal bleeding.

METHODS

Anesthetized pigs were randomized into 2 groups: hypothermia by peritoneal lavage of ice-cold Ringer's acetate and external cooling (n = 10) and normothermia (n = 10). Aortic rupture with retroperitoneal bleeding was induced by endovascular means creating a 6 mm hole in the retroperitoneal portion of abdominal aorta. Survival (primary outcome), hemodynamics, and arterial blood gases including lactate were collected and analyzed up to 180 min after aortic rupture.

RESULTS

The body temperature (mean ± standard deviation) in the hypothermic group was 31.5 ± 1.0 °C and 38.7 ± 0.4 °C in the normothermic group at the time for aortic rupture. Survival up to 180 min after the retroperitoneal bleeding was significantly higher in the hypothermic compared with the normothermic group (P = 0.023).

CONCLUSIONS

Induced hypothermia did not impair survival in this experimental retroperitoneal aortic bleeding model in anesthetized pigs. This finding may indicate a minor role for the coagulation system in this type of bleeding.

Trends in pre-hospital volume resuscitation of blunt trauma patients: a 15-year analysis of the British (TARN) and German (TraumaRegister DGU®) National Registries

INTRODUCTION

Fluid resuscitation has long been a cornerstone of pre-hospital trauma care, yet its optimal approach remains undetermined. Although a liberal approach to fluid resuscitation has been linked with increased complications, the potential survival benefits of a restrictive approach in blunt trauma patients have not been definitively established. Consequently, equipoise persists regarding the optimal fluid resuscitation strategy in this population.

METHODS

We analysed data from the two largest European trauma registries, the UK Trauma Audit and Research Network (TARN) and the German TraumaRegister DGU® (TR-DGU), between 2004 and 2018. All adult blunt trauma patients with an Injury Severity Score > 15 were included. We examined annual trends in pre-hospital fluid resuscitation, admission coagulation function, and mortality rates.

RESULTS

Over the 15-year study period, data from 68,510 patients in the TARN cohort and 82,551 patients in the TR-DGU cohort were analysed. In the TARN cohort, 3.4% patients received pre-hospital crystalloid fluids, with a median volume of 25 ml (20-36 ml) administered. Conversely, in the TR-DGU cohort, 91.1% patients received pre-hospital crystalloid fluids, with a median volume of 756 ml (750-912 ml) administered. Notably, both cohorts demonstrated a consistent year-on-year decrease in the volume of pre-hospital fluid administered, accompanied by improvements in admission coagulation function and reduced mortality rates.

CONCLUSION

Considerable variability exists in pre-hospital fluid resuscitation strategies for blunt trauma patients. Our data suggest a trend towards reduced pre-hospital fluid administration over time. This trend appears to be associated with improved coagulation function and decreased mortality rates. However, we acknowledge that these outcomes are influenced by multiple factors, including other improvements in pre-hospital care over time. Future research should aim to identify which trauma populations may benefit, be harmed, or remain unaffected by different pre-hospital fluid resuscitation strategies.

Patient-Reported Outcomes Following Severe Abdominal Trauma: A Secondary Analysis of the Damage Control Laparotomy Trial

INTRODUCTION

Little is known about patient-reported outcomes (PROs) following abdominal trauma. We hypothesized that patients undergoing definitive laparotomy (DEF) would have better PROs compared to those treated with damage control laparotomy (DCL).

METHODS

The DCL Trial randomized DEF versus DCL in abdominal trauma. PROs were measured using the European Quality of Life-5 Dimensions-5 Levels (EQ-5D) questionnaire at discharge and six months postdischarge (1 = perfect health, 0 = death, and <0 = worse than death) and Posttraumatic Stress Disorder (PTSD) Checklist-Civilian. Unadjusted Bayesian analysis with a neutral prior was used to assess the posterior probability of achieving minimal clinically important difference.

RESULTS

Of 39 randomized patients (21 DEF versus 18 DCL), 8 patients died (7 DEF versus 1 DCL). Of those who survived, 28 completed the EQ-5D at discharge (12 DEF versus 16 DCL) and 25 at 6 mo (12 DEF versus 13 DCL). Most patients were male (79%) with a median age of 30 (interquartile range (IQR) 21-42), suffered blunt injury (56%), and were severely injured (median injury severity score 33, IQR 21 - 42). Median EQ-5D value at discharge was 0.20 (IQR 0.06 - 0.52) DEF versus 0.31 (IQR -0.03 - 0.43) DCL, and at six months 0.51 (IQR 0.30 - 0.74) DEF versus 0.50 (IQR 0.28 - 0.84) DCL. The posterior probability of minimal clinically important difference DEF versus DCL at discharge and six months was 16% and 23%, respectively.

CONCLUSIONS

Functional deficits for trauma patients persist beyond the acute setting regardless of laparotomy status. These deficits warrant longitudinal studies to better inform patients on recovery expectations.

Capillary leak and endothelial permeability in critically ill patients: a current overview

Capillary leak syndrome (CLS) represents a phenotype of increased fluid extravasation, resulting in intravascular hypovolemia, extravascular edema formation and ultimately hypoperfusion. While endothelial permeability is an evolutionary preserved physiological process needed to sustain life, excessive fluid leak-often caused by systemic inflammation-can have detrimental effects on patients' outcomes. This article delves into the current understanding of CLS pathophysiology, diagnosis and potential treatments. Systemic inflammation leading to a compromise of endothelial cell interactions through various signaling cues (e.g., the angiopoietin-Tie2 pathway), and shedding of the glycocalyx collectively contribute to the manifestation of CLS. Capillary permeability subsequently leads to the seepage of protein-rich fluid into the interstitial space. Recent insights into the importance of the sub-glycocalyx space and preserving lymphatic flow are highlighted for an in-depth understanding. While no established diagnostic criteria exist and CLS is frequently diagnosed by clinical characteristics only, we highlight more objective serological and (non)-invasive measurements that hint towards a CLS phenotype. While currently available treatment options are limited, we further review understanding of fluid resuscitation and experimental approaches to target endothelial permeability. Despite the improved understanding of CLS pathophysiology, efforts are needed to develop uniform diagnostic criteria, associate clinical consequences to these criteria, and delineate treatment options.

Pediatric perioperative fluid management

The purpose of perioperative fluid management in children is to maintain adequate volume status, electrolyte level, and endocrine system homeostasis during the perioperative period. Although hypotonic solutions containing glucose have traditionally been used as pediatric maintenance fluids, recent studies have shown that isotonic balanced crystalloid solutions lower the risk of hyponatremia and metabolic acidosis perioperatively. Isotonic balanced solutions have been found to exhibit safer and more physiologically appropriate characteristics for perioperative fluid maintenance and replacement. Additionally, adding 1-2.5% glucose to the maintenance fluid can help prevent children from developing hypoglycemia as well as lipid mobilization, ketosis, and hyperglycemia. The fasting time should be as short as possible without compromising safety; recent guidelines have recommended that the duration of clear fluid fasting be reduced to 1 h. The ongoing loss of fluid and blood as well as the free water retention induced by antidiuretic hormone secretion are unique characteristics of postoperative fluid management that must be considered. Reducing the infusion rate of the isotonic balanced solution may be necessary to avoid dilutional hyponatremia during the postoperative period. In summary, perioperative fluid management in pediatric patients requires careful attention because of the limited reserve capacity in this population. Isotonic balanced solutions appear to be the safest and most beneficial choice for most pediatric patients, considering their physiology and safety concerns.

Pilot randomized controlled trial of restricted versus liberal crystalloid fluid management in pediatric post-operative and trauma patients

BACKGROUND

Intravenous (IV) fluid therapy is essential in the treatment of critically ill pediatric surgery and trauma patients. Recent studies have suggested that aggressive fluids may be detrimental to patients. Prospective studies are needed to compare liberal to restricted fluid management in these patients. The primary objective of this pilot trial is to test study feasibility-recruitment and adherence to the study treatment algorithm.

METHODS

We conducted a two-part pilot randomized controlled trial (RCT) comparing liberal to restricted crystalloid fluid management in 50 pediatric post-operative (1-18 years) and trauma (1-15 years) patients admitted to our pediatric intensive care unit (PICU). Patients were randomized to a high (liberal) volume or low (restricted) volume algorithm using unblinded, blocked randomization. A revised treatment algorithm was used after the 29th patient for the second part of the RCT. The goal of the trial was to determine the feasibility of conducting an RCT at a single site for recruitment and retention. We also collected data on the safety of study interventions and clinical outcomes, including pulmonary, infectious, renal, post-operative, and length of stay outcomes.

RESULTS

Fifty patients were randomized to either liberal (n = 26) or restricted (n = 24) fluid management strategy. After data was obtained on 29 patients, a first study analysis was performed. The volume of fluid administered and triggers for intervention were adapted to optimize the treatment effect and clarity of outcomes. Updated and refined fluid management algorithms were created. These were used for the second part of the RCT on patients 30-50. During this second study period, 54% (21/39, 95% CI 37-70%) of patients approached were enrolled in the study. Of the patients enrolled, 71% (15/21, 95% CI 48-89%) completed the study. This met our a priori recruitment and retention criteria for success. A data safety monitoring committee concluded that no adverse events were related to study interventions. Although the study was not powered to detect differences in outcomes, after the algorithm was revised, we observed a non-significant trend towards improved pulmonary outcomes in patients on the restricted arm, including decreased need for and time on oxygen support and decreased need for mechanical ventilation.

CONCLUSION

We demonstrated the feasibility and safety of conducting a single-site RCT comparing liberal to restricted crystalloid fluid management in critically ill pediatric post-operative and trauma patients. We observed trends in improved pulmonary outcomes in patients undergoing restricted fluid management. A definitive multicenter RCT comparing fluid management strategies in these patients is warranted.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT04201704 . Registered 17 December 2019-retrospectively registered.

Effect of restrictive fluid resuscitation on the coagulation function and hemodynamic parameters in patients with hemorrhagic traumatic shock

OBJECTIVES

To investigate the changes in the coagulation function and hemodynamic parameters in patients with Hemorrhagic Traumatic Shock (HTS) after restrictive fluid resuscitation.

METHODS

A total of 139 patients with HTS admitted to our hospital were enrolled, among which 69 HTS patients were divided into the control group and the remaining 70 HTS patients as the observation group. Patients in the control group underwent regular fluid resuscitation, while those in the observation group underwent restrictive fluid resuscitation.

RESULTS

During treatment, 70 patients in the observation group had a lower bleeding amount, infusion amount, and blood transfusion volume than those in the control group (p < 0.05). After treatment, patients in the observation group had better hemodynamic parameters and blood coagulation than those in the control group (p < 0.05), and the incidence rate in the observation group was only 12.9%, which was significantly lower than 60.87% in the control group, while the cure rate in the observation group was 100%, which was significantly higher than that in the control group (p < 0.05).

CONCLUSIONS

Restrictive fluid resuscitation could remarkably increase the cure rate and reduce the bleeding amount during HTS treatment, thereby benefiting the recovery of the patient's blood coagulation.

The 2023 Sir David Cuthbertson Lecture. A fluid journey: Experiments that influenced clinical practice

This review summarises some of my work on fluid and electrolyte balance over the past 25 years and shows how the studies have influenced clinical practice. Missing pieces in the jigsaw are filled in by summarising the work of others. The main theme is the biochemical, physiological and clinical problems caused by inappropriate use of saline solutions including the hyperchloraemic acidosis caused by 0.9% saline. The importance of accurate and near-zero fluid balance in clinical practice is also emphasised. Perioperative fluid and electrolyte therapy has important effects on clinical outcome in a U-shaped dose response fashion, in which excess or deficit progressively increases complications and worsens outcome. Salt and water overload, with weight gain in excess of 2.5 kg worsens surgical outcome, impairs gastrointestinal function and increases the risk of anastomotic dehiscence. Hyperchloraemic acidosis caused by overenthusiastic infusion of 0.9% saline leads to adverse outcomes and dysfunction of many organ systems, especially the kidney. Salt and water deficit causes similar adverse effects as fluid overload at the cellular level and also leads to worse outcomes. Serum albumin is shown to be affected mainly by dilution and inflammation and is not a good nutritional marker. These findings have been incorporated in the British consensus Guidelines on Intravenous Fluid Therapy for Adult Surgical Patients (GIFTASUP) and National Institute for Health and Care Excellence (NICE) guidelines on intravenous fluid therapy in adults in hospital and are helping change clinical practice and improve outcomes.

Damage control surgery in emergency general surgery: What you need to know

ABSTRACT

Damage-control surgery (DCS) is a strategy adopted to limit initial operative interventions in the unstable surgical patient, delaying definitive repairs and abdominal wall closure until physiologic parameters have improved. Although this concept of "physiology over anatomy" was initially described in the management of severely injured trauma patients, the approaches of DCS have become common in the management of nontraumatic intra-abdominal emergencies.While the utilization of damage-control methods in emergency general surgery (EGS) is controversial, numerous studies have demonstrated improved outcomes, making DCS an essential technique for all acute care surgeons. Following a brief history of DCS and its indications in the EGS patient, the phases of DCS will be discussed including an in-depth review of preoperative resuscitation, techniques for intra-abdominal source control, temporary abdominal closure, intensive care unit (ICU) management of the open abdomen, and strategies to improve abdominal wall closure.

Impact of intraoperative blood products, fluid administration, and persistent hypothermia on bleeding leading to reexploration after cardiac surgery

OBJECTIVE

Risk factors for severe postoperative bleeding after cardiac surgery remain multiple and incompletely elucidated. We evaluated the impact of intraoperative blood product transfusions, intravenous fluid administration, and persistently low core body temperature (CBT) at intensive care unit arrival on risk of perioperative bleeding leading to reexploration.

METHODS

We retrospectively queried our tertiary care center's Society of Thoracic Surgeons Institutional Database for all index, on-pump, adult cardiac surgery patients between July 2016 and September 2022. Intraoperative fluid (crystalloid and colloid) and blood product administrations, as well as perioperative CBT data, were harvested from electronic medical records. Linear and nonlinear mixed models, treating surgeon as a random effect to account for inter-surgeon practice differences, were used to assess the association between above factors and reexploration for bleeding.

RESULTS

Of 4037 patients, 151 (3.7%) underwent reexploration for bleeding. Reexplored patients experienced remarkably greater postoperative morbidity (23% vs 6%, P < .001) and 30-day mortality (14% vs 2%, P < .001). In linear models, progressively increasing IV crystalloid administration (adjusted odds ratio, 1.11, 95% confidence interval, 1.03-1.19) and decreasing CBT on intensive care unit arrival (adjusted odds ratio, 1.20; 95% confidence interval, 1.05-1.37) were associated with greater risk of bleeding leading to reexploration. Nonlinear analysis revealed increasing risk after ∼6 L of crystalloid administration and a U-shaped relationship between CBT and reexploration risk. Intraoperative blood product transfusion of any kind was not associated with reexploration.

CONCLUSIONS

We found evidence of both dilution- and hypothermia-related effects associated with perioperative bleeding leading to reexploration in cardiac surgery. Interventions targeting modification of such risk factors may decrease the rate this complication.

Atraumatic Polycompartment Syndrome Secondary to Cardiogenic Shock: A Case Report

We report the case of a 53-year-old male who developed polycompartment syndrome (PCS) secondary to cardiogenic shock. After suffering a cardiac arrest, a self-perpetuating cycle of intra-abdominal hypertension (IAH) and vital organ damage led to abdominal compartment syndrome (AbCS), which then contributed to the precipitation of extremity compartment syndrome (CS) in bilateral thighs, legs, forearms, and hands. This report is followed by a review of the literature regarding the pathophysiology of this rare sequela of cardiogenic shock. While the progression from cardiogenic shock to AbCS and ultimately to PCS has been hypothesized, no prior case reports demonstrate this. Furthermore, this case suggests more generally that IAH may be a risk factor for extremity CS. Future studies should examine the potential interplay between IAH and extremity CS in patients at risk, such as polytrauma patients with tibial fractures.

Articles on hemorrhagic shock published between 2000 and 2021: A CiteSpace-Based bibliometric analysis

Objective

To conduct a bibliometric analysis of literature on hemorrhagic shock published between 2000 and 2021 with the help of Citespace to explore the current status, hotspots and research trends in this regard, with the results presented in a visualized manner.

Methods

The data over the past 22 years were retrieved from the Web of Science (WOS) Core Collection database and downloaded as the "Full Record and Cited References". Cooperative analysis, cluster analysis, co-citation analysis, and burst analysis were performed based on the data on countries/regions, institutions, journals, authors, and keywords through Citespace.

Results

A total of 2027 articles were retrieved. The number of annual publications fluctuated but was generally on an upward trend. The United States stands out as the most productive country (989 articles), the University of Pittsburgh the most productive publishing institution (109 articles), SHOCK the most cited journal (1486 articles), TAO LI the most productive author (40 articles), DEITCH EA the most cited author (261 times of citation), hemorrhagic shock the most frequent keyword (725 times of occurrence), and "traumatic brain injury" the most covered article in keyword clustering (29 articles). The burst analysis revealed Harvard University as the institution with the highest strength value and the Journal of Trauma and Acute Care Surgery the most important journal. It was also concluded that HASAN B ALAM, AARON M WILLIAMS, and LIMIN ZHANG may continue to publish high-quality articles in the future. In the meanwhile, both "protect" and "transfusion" were considered the hotspots and trends in current research.

Conclusions

The United States has been a major contributor to the publication of the articles over the past 22 years, with the most productive publishing institution, the most cited journal, and the most cited author all coming from the US. Hemorrhagic shock, injury, resuscitation, trauma, models, activation, expression, fluid resuscitation, rats, and nitric oxide are hot topics in relevant research. According to the keyword burst analysis, the areas related to "protect" and "transfusion" may rise as the research directions in the future. However, since the hotspots in the research of hemorrhagic shock are short-lived and fast-changing, the researchers should pay more attention to the development trend in this field.

Elamipretide mitigates ischemia-reperfusion injury in a swine model of hemorrhagic shock

ischemia-reperfusion injury (IRI) after hemorrhage is potentiated by aortic occlusion or resuscitative endovascular balloon occlusion of the aorta (REBOA). Given the central role of mitochondrial injury in shock, we hypothesized that Elamipretide, a peptide that protects mitochondria, would mitigate IRI after hemorrhagic shock and REBOA. Twelve pigs were subjected to hemorrhagic shock and 45 min of REBOA. After 25 min of REBOA, animals received either saline or Elamipretide. Animals were transfused with autologous blood during balloon deflation, and pigs were resuscitated with isotonic crystalloids and norepinephrine for 4.25 h. Elamipretide-treated animals required less crystalloids than the controls (62.5 [50-90] and 25 [5-30] mL/kg, respectively), but similar amounts of norepinephrine (24.7 [8.6-39.3] and 9.7 [2.1-12.5] mcg/kg, respectively). Treatment animals had a significant reduction in serum creatinine (control: 2.7 [2.6-2.8]; Elamipretide: 2.4 [2.4-2.5] mg/dL; p = 0.04), troponin (control: 3.20 [2.14-5.47] ng/mL, Elamipretide: 0.22 [0.1-1.91] ng/mL; p = 0.03), and interleukin-6 concentrations at the end of the study. There were no differences in final plasma lactate concentration. Elamipretide reduced fluid requirements and protected the kidney and heart after profound IRI. Further understanding the subcellular consequences of REBOA and mitochondrial rescue will open new therapeutic avenues for patients suffering from IRI after hemorrhage.

Retrospective analysis of the use of canine-specific albumin in 125 critically ill dogs

OBJECTIVE

To describe the clinical use of canine-specific albumin (CSA) in critically ill dogs, report adverse events, and evaluate measurable clinical effects of CSA administration.

DESIGN

Retrospective case series from 2019 to 2020.

SETTING

Large, urban, private-practice referral and emergency center.

ANIMALS

Consecutive sample of 125 client-owned dogs administered CSA transfusions.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The conditions most commonly associated with the use of CSA were surgical (32/125) and nonsurgical (20/125) gastrointestinal disease. Both serum albumin and total plasma protein concentrations were significantly increased posttransfusion (P < 0.001), and 16% albumin transfusions produced the greatest magnitude increase in serum albumin (P = 0.0015). Concurrent crystalloid administration did not affect change in albumin. While there was no significant improvement in blood pressure seen in those patients that received albumin, a significant improvement in shock index was identified (P = 0.02). Adverse events were uncommon; however, 8 critically ill dogs died during CSA administration.

CONCLUSIONS

CSA appears to be a relatively safe alternative to synthetic colloids and complementary to crystalloids in critically ill patients. More concentrated solutions may be more effective in raising serum albumin concentration. Further investigation into the indications for and efficacy of CSA will continue to improve our knowledge of this blood product.

Resuscitation with whole blood or blood components improves survival and lessens the pathophysiological burden of trauma and haemorrhagic shock in a pre-clinical porcine model

PURPOSE

In military trauma, disaster medicine, and casualties injured in remote locations, times to advanced medical and surgical treatment are often prolonged, potentially reducing survival and increasing morbidity. Since resuscitation with blood/blood components improves survival over short pre-surgical times, this study aimed to evaluate the quality of resuscitation afforded by blood/blood products or crystalloid resuscitation over extended 'pre-hospital' timelines in a porcine model of militarily relevant traumatic haemorrhagic shock.

METHODS

This study underwent local ethical review and was done under the authority of Animals (Scientific Procedures) Act 1986. Forty-five terminally anaesthetised pigs received a soft tissue injury to the right thigh, haemorrhage (30% blood volume and a Grade IV liver injury) and fluid resuscitation initiated 30 min later [Group 1 (no fluid); 2 (0.9% saline); 3 (1:1 packed red blood cells:plasma); 4 (fresh whole blood); or 5 (plasma)]. Fluid (3 ml/kg bolus) was administered during the resuscitation period (maximum duration 450 min) when the systolic blood pressure fell below 80 mmHg. Surviving animals were culled with an overdose of anaesthetic.

RESULTS

Survival time was significantly shorter for Group 1 compared to the other groups (P < 0.05). Despite the same triggers for resuscitation when compared to blood/blood components, saline was associated with a shorter survival time (P = 0.145), greater pathophysiological burden and significantly greater resuscitation fluid volume (P < 0.0001).

CONCLUSION

When times to advanced medical care are prolonged, resuscitation with blood/blood components is recommended over saline due to the superior quality and stability of resuscitation achieved, which are likely to lead to improved patient outcomes.

Pediatric traumatic hemorrhagic shock consensus conference recommendations

ABSTRACT

Hemorrhagic shock in pediatric trauma patients remains a challenging yet preventable cause of death. There is little high-quality evidence available to guide specific aspects of hemorrhage control and specific resuscitation practices in this population. We sought to generate clinical recommendations, expert consensus, and good practice statements to aid providers in care for these difficult patients.The Pediatric Traumatic Hemorrhagic Shock Consensus Conference process included systematic reviews related to six subtopics and one consensus meeting. A panel of 16 consensus multidisciplinary committee members evaluated the literature related to 6 specific topics: (1) blood products and fluid resuscitation for hemostatic resuscitation, (2) utilization of prehospital blood products, (3) use of hemostatic adjuncts, (4) tourniquet use, (5) prehospital airway and blood pressure management, and (6) conventional coagulation tests or thromboelastography-guided resuscitation. A total of 21 recommendations are detailed in this article: 2 clinical recommendations, 14 expert consensus statements, and 5 good practice statements. The statement, the panel's voting outcome, and the rationale for each statement intend to give pediatric trauma providers the latest evidence and guidance to care for pediatric trauma patients experiencing hemorrhagic shock. With a broad multidisciplinary representation, the Pediatric Traumatic Hemorrhagic Shock Consensus Conference systematically evaluated the literature and developed clinical recommendations, expert consensus, and good practice statements concerning topics in traumatically injured pediatric patients with hemorrhagic shock.

Management of Hemorrhagic Shock: Physiology Approach, Timing and Strategies

Hemorrhagic shock (HS) management is based on a timely, rapid, definitive source control of bleeding/s and on blood loss replacement. Stopping the hemorrhage from progressing from any named and visible vessel is the main stem fundamental praxis of efficacy and effectiveness and an essential, obligatory, life-saving step. Blood loss replacement serves the purpose of preventing ischemia/reperfusion toxemia and optimizing tissue oxygenation and microcirculation dynamics. The "physiological classification of HS" dictates the timely management and suits the 'titrated hypotensive resuscitation' tactics and the 'damage control surgery' strategy. In any hypotensive but not yet critical shock, the body's response to a fluid load test determines the cut-off point between compensation and progression between the time for adopting conservative treatment and preparing for surgery or rushing to the theater for rapid bleeding source control. Up to 20% of the total blood volume is given to refill the unstressed venous return volume. In any critical level of shock where, ab initio, the patient manifests signs indicating critical physiology and impending cardiac arrest or cardiovascular accident, the balance between the life-saving reflexes stretched to the maximum and the insufficient distal perfusion (blood, oxygen, and substrates) remains in a liable and delicate equilibrium, susceptible to any minimal change or interfering variable. In a cardiac arrest by exsanguination, the core of the physiological issue remains the rapid restoration of a sufficient venous return, allowing the heart to pump it back into systemic circulation either by open massage via sternotomy or anterolateral thoracotomy or spontaneously after aorta clamping in the chest or in the abdomen at the epigastrium under extracorporeal resuscitation and induced hypothermia. This is the only way to prevent ischemic damage to the brain and the heart. This is accomplishable rapidly and efficiently only by a direct approach, which is a crush laparotomy if the bleeding is coming from an abdominal +/- lower limb site or rapid sternotomy/anterolateral thoracotomy if the bleeding is coming from a chest +/- upper limbs site. Without first stopping the bleeding and refilling the heart, any further exercise is doomed to failure. Direct source control via laparotomy/thoracotomy, with the concomitant or soon following venous refilling, are the two essential, initial life-saving steps.

MKK4 Knockdown Plays a Protective Role in Hemorrhagic Shock-Induced Liver Injury through the JNK Pathway

Hemorrhagic shock (HS) triggers tissue hypoxia and organ failure during severe blood loss, and the liver is sensitive to HS. Mitogen-activated protein kinase kinase 4 (MKK4) activates the c-Jun NH2-terminal kinase (JNK) pathway, and its expression is upregulated in the serum of HS patients and mouse livers at 1 h post-HS. However, the function of MKK4 in HS-induced liver injury is unclear. The role of MKK4 was investigated in vivo using rat models of HS. Before HS, lentivirus harboring shRNA against MKK4 was injected into rats via the tail vein to knock down MKK4 expression. HS was induced by bloodletting via intubation of the femoral artery followed by resuscitation. The results showed that MKK4 knockdown reduced HS-induced apoptosis in the liver by decreasing Bax expression and the cleavage of caspase 3 and promoting Bcl-2 expression. Moreover, the generation of intracellular reactive oxygen species (ROS) and malondialdehyde (MDA) in the liver was promoted, while superoxide dismutase (SOD) activity was inhibited by HS. However, the effect of HS on oxidative stress was abrogated by MKK4 knockdown. Furthermore, MKK4 knockdown restored MMP and complex I and complex III activities and promoted ATP production, suggesting that HS-induced mitochondrial dysfunction in the liver was ameliorated by MKK4 knockdown. The inhibitory effect of MKK4 knockdown on the phosphorylation and activation of the JNK/c-Jun pathway was confirmed. Overall, MKK4 knockdown may suppress oxidative stress and subsequent apoptosis and improve mitochondrial function in the liver upon HS by inhibiting the JNK pathway. The MKK4/JNK axis was shown to be a therapeutic target for HS-induced liver injury in this study.

Prehospital synergy: Tranexamic acid and blood transfusion in patients at risk for hemorrhage

BACKGROUND

Growing evidence supports improved survival with prehospital blood products. Recent trials show a benefit of prehospital tranexamic acid (TXA) administration in select subgroups. Our objective was to determine if receiving prehospital packed red blood cells (pRBC) in addition to TXA improved survival in injured patients at risk of hemorrhage.

METHODS

We performed a secondary analysis of all scene patients from the Study of Tranexamic Acid during Air and ground Medical Prehospital transport trial. Patients were randomized to prehospital TXA or placebo. Some participating EMS services utilized pRBC. Four resuscitation groups resulted: TXA, pRBC, pRBC+TXA, and neither. Our primary outcome was 30-day mortality and secondary outcome was 24-hour mortality. Cox regression tested the association between resuscitation group and mortality while adjusting for confounders.

RESULTS

A total of 763 patients were included. Patients receiving prehospital blood had higher Injury Severity Scores in the pRBC (22 [10, 34]) and pRBC+TXA (22 [17, 36]) groups than the TXA (12 [5, 21]) and neither (10 [4, 20]) groups (p < 0.01). Mortality at 30 days was greatest in the pRBC+TXA and pRBC groups at 18.2% and 28.6% compared with the TXA only and neither groups at 6.6% and 7.4%, respectively. Resuscitation with pRBC+TXA was associated with a 35% reduction in relative hazards of 30-day mortality compared with neither (hazard ratio, 0.65; 95% confidence interval, 0.45-0.94; p = 0.02). No survival benefit was observed in 24-hour mortality for pRBC+TXA, but pRBC alone was associated with a 61% reduction in relative hazards of 24-hour mortality compared with neither (hazard ratio, 0.39; 95% confidence interval, 0.17-0.88; p = 0.02).

CONCLUSION

For injured patients at risk of hemorrhage, prehospital pRBC+TXA is associated with reduced 30-day mortality. Use of pRBC transfusion alone was associated with a reduction in early mortality. Potential synergy appeared only in longer-term mortality and further work to investigate mechanisms of this therapeutic benefit is needed to optimize the prehospital resuscitation of trauma patients.

LEVEL OF EVIDENCE

Therapeutic/Care Management; Level III.

Nine year in-hospital mortality trends in a high-flow level one trauma center in Italy

Trauma is the leading cause of death in young people with a considerable socio-economic impact worldwide. A trimodal distribution of trauma mortality was described in the past, but recently different studies underlined a progressive change in trauma mortality distribution linked to improvement in trauma care. This study aimed to analyze the mortality trends in a Level-One Trauma Center in Italy. Data on 6065 patients consecutively admitted to the Trauma Center between 2011 and 2020 were selected and retrospectively analyzed. Causes of Death (CODs) and time of death were stratified in four main groups and the patient sample was further divided into five age groups. Multivariate regression models were then performed to identify independent predictors of mortality. The most common COD in all age groups was Central Nervous System injuries. Immediate deaths (in ED) affected mostly patients over 75 years of age (34.3%). Deaths caused by massive hemorrhage occurred soon upon arrival in the ED, whereas deaths due to other causes (e.g. sepsis, MOF) after the first week. Patients' characteristics, the need for emergency procedures and high trauma severity scores were independent predictors of deaths. This study represented the first analysis on trauma mortality distribution in Italy over a nine-year period. The trimodal distribution described in the past seems to be no longer present in Italy, due to improvements in trauma systems and critical care. However, the high number of immediate and acute deaths underlies a persisting need for efforts in injury prevention and control .

Cryoprecipitate use during massive transfusion: A propensity score analysis

INTRODUCTION

Cryoprecipitate is frequently administered as an adjunct to balanced transfusion in the setting of traumatic hemorrhage. However, civilian studies have not demonstrated a clear survival advantage, and prior observational studies noted selection bias when analyzing cryoprecipitate use. Additionally, due to the logistics involved in cryoprecipitate administration, it is inconsistently implemented alongside standardized massive transfusion protocols. This study aims to evaluate the effects of early cryoprecipitate administration on inpatient mortality in the setting of massive transfusion for exsanguinating trauma and to use propensity score analysis to minimize selection bias.

METHODS

The registry of an urban level 1 trauma center was queried for adult patients who received at least 6 units of packed red blood cells within 4 h of presentation. Univariate analysis, multiple logistic regression, and propensity score matching were performed.

RESULTS

562 patients were identified. Patients with lower median RTS (6.86 (IQR 4.09-7.84) vs 7.6 (IQR 5.97-7.84), P<0.01), decreased Glasgow coma scale (12 (IQR 4-15) vs 15 (IQR 10-15), P<0.01), and increased lactate (7.5 (IQR 4.3-10.2) vs 4.9 (IQR 3.1-7.2), P<0.01) were more commonly administered cryoprecipitate. Mortality was greater among those who received cryoprecipitate (40.2% vs 23.7%, p<0.01) on univariate analysis. Neither multiple logistic regression (OR 0.917; 95% confidence interval 0.462-1.822; p = 0.805) nor propensity score matching (average treatment effect on the treated 2.3%, p = 0.77) revealed that cryoprecipitate administration was associated with a difference in inpatient mortality.

CONCLUSIONS

Patients receiving cryoprecipitate within 4 h of presentation were more severely injured at presentation and had increased inpatient mortality. Multivariable logistic regression and propensity score analysis failed to show that early administration of cryoprecipitate was associated with survival benefit for exsanguinating trauma patients. The prospect of definitively assessing the utility of cryoprecipitate in exsanguinating hemorrhage warrants prospective investigation.

High-rise syndrome in cats and dogs

OBJECTIVE

To review the current literature pertaining to the pathophysiology, diagnosis, and treatment of injuries sustained from high-rise syndrome in cats and dogs.

ETIOLOGY

High-rise syndrome is defined as a fall from a height of 2 or more stories that results in a constellation of injuries, including thoracic, abdominal, orthopedic, and orofacial trauma. Animals often fall after slipping from windowsills, engaging in mating behavior, or chasing prey. Cats suffer less severe injuries than dogs due to their "righting reflex" and smaller body mass. Affected animals are younger, and the frequency of falls is higher in warmer months.

DIAGNOSIS

Physical examination coupled with radiographs, ultrasound, and computed tomography can diagnose a myriad of injuries that include pneumothorax, pleural or abdominal effusion, orthopedic fractures, and orofacial injuries. Bloodwork may identify anemia, thrombocytopenia, or increases in hepatic, renal, or pancreatic values consistent with trauma to these organs. Serial venous or arterial blood gas can help determine the severity of respiratory compromise and influence resuscitative efforts. Traditional coagulation tests and thromboelastography can assess trauma-induced coagulopathy and guide transfusion therapy.

THERAPY

Animals presenting in shock require hemodynamic stabilization. Initial resuscitation may incorporate crystalloids, colloids, blood products, and analgesics. Thoracic injuries may require oxygen, thoracocentesis, chest tube placement, and mechanical ventilation. Fractures and wounds are decontaminated and splinted/bandaged, with definitive fixation pursued after stabilization. Abdominal injuries are managed medically unless there is severe ongoing bleeding, sepsis, or injury to the urinary tract.

PROGNOSIS

In feline high-rise syndrome, the prognosis is generally excellent following treatment, with survival exceeding 90%. Canine literature is sparse. The largest retrospective study reported a >90% survival to discharge and a greater need for surgical stabilization in this species. There are no prognostic factors identified that are associated with survival for either species.

Elevated monocyte distribution width in trauma: An early cellular biomarker of organ dysfunction

INTRODUCTION

Traumatic injury elicits an inflammatory response such as the one occurring during systemic infection. Monocyte distribution width (MDW) has been found to distinguish sepsis in a pool of patients with suspected infection. We hypothesized that an elevated MDW in trauma patients would be associated with the development of multiple organ dysfunction syndrome (MODS) and an increased mortality.

MATERIALS AND METHODS

Observational study in a dedicated trauma Intensive Care Unit (ICU) in Madrid during 2019-2020. Patients were classified according to their first MDW value on admission, as greater or lesser than 21 U. Clinical data was obtained and univariate and multivariate analysis were realized, as well as a test performance analysis.

RESULTS

354 patients were studied, with a median age of 46 years, 78% male. Half presented with severe trauma ISS > 15, mostly with a blunt mechanism of injury. A MDW ≥ 21 U on admission was found in 17% of cases. These patients were more likely to present with hemodynamic instability and MODS. They had a higher length of stay (3.8 vs 2 days) and higher mortality (21 vs 5%) compared to the low MDW group. These findings remained statistically significant in the multivariate analysis, with an OR 4.6 (IC 95% 1.7-12) for MODS and 3.1 (IC 95% 1.2-8.3) for mortality.

CONCLUSIONS

In trauma patients, a MDW ≥ 21 U on admission was independently associated with a greater risk of MODS, a higher mortality and a higher length of stay. This biomarker could be useful in predicting severity in the initial evaluation of trauma patients.

Fluid Overload Phenotypes in Critical Illness-A Machine Learning Approach

BACKGROUND

The detrimental impact of fluid overload (FO) on intensive care unit (ICU) morbidity and mortality is well known. However, research to identify subgroups of patients particularly prone to fluid overload is scarce. The aim of this cohort study was to derive "FO phenotypes" in the critically ill by using machine learning techniques.

METHODS

Retrospective single center study including adult intensive care patients with a length of stay of ≥3 days and sufficient data to compute FO. Data was analyzed by multivariable logistic regression, fast and frugal trees (FFT), classification decision trees (DT), and a random forest (RF) model.

RESULTS

Out of 1772 included patients, 387 (21.8%) met the FO definition. The random forest model had the highest area under the curve (AUC) (0.84, 95% CI 0.79-0.86), followed by multivariable logistic regression (0.81, 95% CI 0.77-0.86), FFT (0.75, 95% CI 0.69-0.79) and DT (0.73, 95% CI 0.68-0.78) to predict FO. The most important predictors identified in all models were lactate and bicarbonate at admission and postsurgical ICU admission. Sepsis/septic shock was identified as a risk factor in the MV and RF analysis.

CONCLUSION

The FO phenotypes consist of patients admitted after surgery or with sepsis/septic shock with high lactate and low bicarbonate.

Staying on target: Maintaining a balanced resuscitation during damage-control resuscitation improves survival

BACKGROUND

Damage-control resuscitation (DCR) improves survival in severely bleeding patients. However, deviating from balanced transfusion ratios during a resuscitation may limit this benefit. We hypothesized that maintaining a balanced resuscitation during DCR is independently associated with improved survival.

METHODS

This was a secondary analysis of the Prospective Observational Multicenter Major Trauma Transfusion (PROMMTT) study. Patients receiving >3 U of packed red blood cells (PRBCs) during any 1-hour period over the first 6 hours and surviving beyond 30 minutes were included. Linear regression assessed the effect of percent time in a high-ratio range on 24-hour survival. We identified an optimal ratio and percent of time above the target ratio threshold by Youden's index. We compared patients with a 6-hour ratio above the target and above the percent time threshold (on-target) with all others (off-target). Kaplan-Meier analysis assessed the combined effect of blood product ratio and percent time over the target ratio on 24-hour and 30-day survival. Multivariable logistic regression identified factors independently associated with 24-hour and 30-day survival.

RESULTS

Of 1,245 PROMMTT patients, 524 met the inclusion criteria. Optimal targets were plasma/PRBC and platelet/PRBC of 0.75 (3:4) and ≥40% time spent over this threshold. For plasma/PRBC, on-target (n = 213) versus off-target (n = 311) patients were younger (median, 31 years; interquartile range, [22-50] vs. 40 [25-54]; p = 0.002) with similar injury burdens and presenting physiology. Similar patterns were observed for platelet/PRBC on-target (n = 116) and off-target (n = 408) patients. After adjusting for differences, on-target plasma/PRBC patients had significantly improved 24-hour (odds ratio, 2.25; 95% confidence interval, 1.20-4.23) and 30-day (odds ratio, 1.97; 95% confidence interval, 1.14-3.41) survival, while on-target platelet/PRBC patients did not.

CONCLUSION

Maintaining a high ratio of plasma/PRBC during DCR is independently associated with improved survival. Performance improvement efforts and prospective studies should capture time spent in a high-ratio range.

LEVEL OF EVIDENCE

Epidemiologic/prognostic study, level II; Therapeutic, level IV.

Prognostic factors for development of acute respiratory distress syndrome following traumatic injury - a systematic review and meta-analysis

PURPOSE

To summarise the prognostic associations between various clinical risk factors and the development of the acute respiratory distress syndrome (ARDS) following traumatic injury.

METHODS

We conducted this review in accordance with the PRISMA and CHARMS guidelines. We searched six databases from inception through December 2020. We included English language studies describing the clinical risk factors associated with the development of post-traumatic ARDS, as defined by either the American-European Consensus Conference or the Berlin definition. We pooled adjusted odds ratios for prognostic factors using the random effects method. We assessed risk of bias using the QUIPS tool and certainty of findings using GRADE methodology.

RESULTS

We included 39 studies involving 5 350 927 patients. We identified the amount of crystalloid resuscitation as a potentially modifiable prognostic factor associated with the development of post-traumatic ARDS (adjusted odds ratio [aOR] 1.19 for each additional liter of crystalloid administered within first 6 h after injury, 95% CI 1.15 to 1.24, high certainty). Non-modifiable prognostic factors with a moderate or high certainty of association with post-traumatic ARDS included increasing age, non-Hispanic white race, blunt mechanism of injury, presence of head injury, pulmonary contusion, or rib fracture; and increasing chest injury severity.

CONCLUSION

We identified one important modifiable factor, the amount of crystalloid resuscitation within the first 24 h of injury, and several non-modifiable factors associated with development of post-traumatic ARDS. This information should support the judicious use of crystalloid resuscitation in trauma patients and may inform the development of a risk-stratification tools.

Possible Predictive Factor of Acute Respiratory Distress Syndrome Development After Mild Traumatic Brain Injury: A Single Rural Trauma Center Preliminary Study

Introduction Acute respiratory distress syndrome (ARDS) after mild traumatic brain injury (TBI) can be associated with significant morbidity and mortality. This study aimed to evaluate the potential predictive factors of ARDS development following mild TBI in trauma patients. Methods A retrospective chart review was done for adult trauma patients with mild TBI (GCS 13-15) requiring admission at our center from 2012 to 2020. Linear regression analysis and chi-square test were utilized to identify independent predictors of the association with ARDS in adults with mild TBI.  Results A total of 784 mild TBI patients were admitted during the time of interest; 34 patients developed ARDS during their index hospitalization. Patients who had ARDS were more likely to have acute kidney injury (AKI; p < 0.0001), sepsis (p < 0.01), rib fractures (p < 0.05), use of anticoagulants (p < 0.001), deep vein thrombosis (p < 0.001), transfusion during the first 4four hours upon admission (p = 0.01), intravenous fluid (IVF) resuscitation during the first four hours (p <0.05), the first eight hours (p = 0.01), the first 12 hours (p = 0.03), and intubation upon the admission (p < 0.0001). ARDS associated with mild TBI demonstrated a statistically significant increase in mortality during the index hospitalization (p < 0.0001). Conclusion ARDS after mild TBI can be associated with significant morbidity and mortality. Key risk factors identified include AKI, sepsis, anticoagulant use, deep vein thrombosis (DVT), transfusion in the first four hours, IVF resuscitation in the first four, eight, and 12 hours, and intubation upon admission.

The Story of Blood for Shock Resuscitation: How the Pendulum Swings

Whole blood transfusion (WBT) began in 1667 as a treatment for mental illness with predictably poor results. Its therapeutic utility and widespread use were initially limited by deficiencies in transfusion science and antisepsis. James Blundell, a British obstetrician, was recognized for the first allotransfusion in 1825. However, WBT did not become safe and therapeutic until the early 20^th century with the advent of reliable equipment, sterilization and blood typing. The discovery of citrate preservation in World War I allowed a separation of donor from recipient and introduced the practice of blood banking. During World War II, Elliott and Strumia were the first to separate whole blood into blood component therapy (BCT), producing dried plasma as a resuscitative product for "traumatic shock". During the 1970s, infectious disease, blood fractionation and financial opportunities further drove the change from WBT to BCT with little supporting data. Following a period of high-volume crystalloid and BCT resuscitation well into the early 2000's, measures to avoid the resulting iatrogenic resuscitation injury were developed under the concept of damage control resuscitation. Modern transfusion strategies for hemorrhagic shock target balanced BCT to reapproximate whole blood. Contemporary research has expanded the role of WBT to therapy for the acute coagulopathy of trauma and the damaged endothelium. Many US trauma centers are now using WBT as a front-line treatment in tandem with BCT for patients suffering hemorrhagic shock. Looking ahead, it is likely that WBT will once again be the resuscitative fluid of choice for patients in hemorrhagic shock.

Volume Resuscitation in the Acutely Hemorrhaging Patient: Historic Use to Current Applications

Acute hemorrhage in small animals results from traumatic and non-traumatic causes. This review seeks to describe current understanding of the resuscitation of the acutely hemorrhaging small animal (dog and cat) veterinary patient through evaluation of pre-clinical canine models of hemorrhage and resuscitation, clinical research in dogs and cats, and selected extrapolation from human medicine. The physiologic dose and response to whole blood loss in the canine patient is repeatable both in anesthetized and awake animals and is primarily characterized clinically by increased heart rate, decreased systolic blood pressure, and increased shock index and biochemically by increased lactate and lower base excess. Previously, initial resuscitation in these patients included immediate volume support with crystalloid and/or colloid, regardless of total volume, with a target to replace lost vascular volume and bring blood pressure back to normal. Newer research now supports prioritizing hemorrhage control in conjunction with judicious crystalloid administration followed by early consideration for administration of platelets, plasma and red blood during the resuscitation phase. This approach minimizes blood loss, ameliorates coagulopathy, restores oxygen delivery and correct changes in the glycocalyx. There are many hurdles in the application of this approach in clinical veterinary medicine including the speed with which the bleeding source is controlled and the rapid availability of blood component therapy. Recommendations regarding the clinical approach to volume resuscitation in the acutely hemorrhaging veterinary patient are made based on the canine pre-clinical, veterinary clinical and human literature reviewed.

Lactate as a mediator of prehospital plasma mortality reduction in hemorrhagic shock

BACKGROUND

Prehospital plasma transfusion in trauma reduces mortality. However, the underlying mechanism remains unclear. Reduction in shock severity may play a role. Lactate correlates with physiologic shock severity and mortality after injury. Our objective was to determine if prehospital plasma reduces lactate and if this contributes to the mortality benefit of plasma.

METHODS

Patients in the Prehospital Air Medical Plasma trial in the upper quartile of injury severity (Injury Severity Score, >30) were included to capture severe shock. Trial patients were randomized to prehospital plasma or standard care resuscitation (crystalloid ± packed red blood cells). Regression determined the associations between admission lactate, 30-day mortality, and plasma while adjusting for demographics, prehospital crystalloid, time, mechanism, and injury characteristics. Causal mediation analysis determined what proportion of the effect of plasma on mortality is mediated by lactate reduction.

RESULTS

A total of 125 patients were included. The plasma group had a lower adjusted admission lactate than standard of care group (coefficient, -1.64; 95% confidence interval [CI], -2.96 to -0.31; p = 0.02). Plasma was associated with lower odds of 30-day mortality (odds ratio [OR], 0.27; 95% CI, 0.08-0.90; p = 0.03). When adding lactate to this model, the effect of plasma on 30-day mortality was no longer significant (OR, 0.36; 95% CI, 0.07-1.88; p = 0.23), while lactate was associated with mortality (OR, 1.74 per 1 mmol/L increase; 95% CI, 1.10-2.73; p = 0.01). Causal mediation demonstrated 35.1% of the total effect of plasma on 30-day mortality was mediated by the reduction in lactate among plasma patients.

CONCLUSION

Prehospital plasma is associated with reduced 30-day mortality and lactate in severely injured patients. More than one third of the effect of plasma on mortality is mediated by a reduction in lactate. Thus, reducing the severity of hemorrhagic shock appears to be one mechanism of prehospital plasma benefit. Further study should elucidate other mechanisms and if a dose response exists.

LEVEL OF EVIDENCE

Therapeutic, level II.

Restrictive versus liberal fluid resuscitation strategy, influence on blood loss and hemostatic parameters in mild obstetric hemorrhage: An open-label randomized controlled trial. (REFILL study)

Background

Evidence for optimal hemostatic resuscitation in postpartum hemorrhage (PPH) is lacking. Liberal fluid administration may result in acidosis, hypothermia and coagulopathy.

Objective

We hypothesize that in early PPH a restrictive fluid administration results in less progression to moderate PPH.

Study design

In four Dutch hospitals we recruited women of 18 years and over, and more than 24 weeks pregnant. Exclusion criteria were: anticoagulant therapy, known coagulation disorders, pre-eclampsia, antenatal diagnosis of abnormally adhesive placenta, and a contraindication for liberal fluid therapy. We blindly randomized participants at 500 mL and ongoing blood loss in the third stage of labor between restrictive fluid administration (clear fluids 0.75–1.0 times the volume of blood lost) and liberal fluid administration (clear fluids 1.5–2.0 times the volume of blood lost). The primary outcome was progression to more than 1000 mL blood loss. Analyses were according to the intention-to-treat principle.

Results

From August 2014 till September 2019, 5190 women were informed of whom 1622 agreed to participate. A total of 252 women were randomized of which 130 were assigned to the restrictive group and 122 to the liberal group. In the restrictive management group 51 of the 130 patients (39.2%) progressed to more than 1000 mL blood loss versus 61 of the 119 patients (51.3%) in the liberal management group (difference, -12.0% [95%-CI -24.3% to 0.3%], p = 0.057). There was no difference in the need for blood transfusion, coagulation parameters, or in adverse events between the groups.

Conclusions

Although a restrictive fluid resuscitation in women with mild PPH could not been proven to be superior, it does not increase the need for blood transfusion, alter coagulation parameters, or cause a rise in adverse events. It can be considered as an alternative treatment option to liberal fluid resuscitation.

Trial registration

NTR3789.

Battlefield Medicine: Anesthesia and Critical Care in the Combat Zone

The US Military Joint Trauma System has been developed to mitigate the harsh conditions under which medical providers care for combat casualties and provide continuity of care from the battlefield to US medical centers. We review the components of this system with emphasis on combat trauma care under fire and the role of the anesthesiologist and intensivist in this continuum of care. An important link in the chain of survival is the Air Force Critical Care Aeromedical Transport Team, which provides critical care while transporting casualties from the theater to higher levels of care outside the war zone and home.

Effectiveness of intravenous fluid resuscitation in hypotensive cats: 82 cases (2012-2019)

OBJECTIVE

To evaluate the effectiveness of intravenous fluid resuscitation in hypotensive cats in an emergency room setting. Secondary objectives were to investigate changes in heart rate (HR) and body temperature (BT) in response to fluid resuscitation, and the association of these changes with patient survival.

DESIGN

Retrospective study.

SETTING

University teaching hospital.

ANIMALS

Eighty-two cats with confirmed hypotension.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Medical records from 2012 to 2019 were searched for cats that had documented systemic arterial hypotension (blood pressure measured using a Doppler ultrasonic flow probe [DBP] < 90 mm Hg) on presentation to the emergency room. Data collected included patient characteristics and DBP, HR, and BT before and after fluid resuscitation, type and volume of fluids administered, and outcome. The median DBP before and after resuscitative fluid therapy in all cats was 65 mm Hg (range, 20-85 mm Hg) and 80 mm Hg (range, 20-128 mm Hg), respectively (P < 0.001). However, only 30 cats (37%) were classified as responders to fluid resuscitation (DBP ≥ 90 mm Hg following bolus therapy). The mean HR and median BT before resuscitative fluid therapy was 159/min and 36.7°C. Following fluid resuscitation, where measured, the mean HR and median BT was 154/min (P = 1.00) and 35.9°C (P = 1.00). No significant differences in HR and BT were identified between responders and non-responders. Cats had a low survival rate of 7%. All survivors (n = 5) were initially bradycardic (HR < 160/min), compared to only 45% of non-survivors (P = 0.4).

CONCLUSIONS

Bolus fluid resuscitation effectively increases blood pressure in hypotensive cats; however, it does not result in normalization of blood pressure, HR, or BT in the majority of cases.

The effect of targeting Tie2 on hemorrhagic shock-induced renal perfusion disturbances in rats

BACKGROUND

Hemorrhagic shock is associated with acute kidney injury and increased mortality. Targeting the endothelial angiopoietin/Tie2 system, which regulates endothelial permeability, previously reduced hemorrhagic shock-induced vascular leakage. We hypothesized that as a consequence of vascular leakage, renal perfusion and function is impaired and that activating Tie2 restores renal perfusion and function.

METHODS

Rats underwent 1 h of hemorrhagic shock and were treated with either vasculotide or PBS as control, followed by fluid resuscitation for 4 h. Microcirculatory perfusion was measured in the renal cortex and cremaster muscle using contrast echography and intravital microscopy, respectively. Changes in the angiopoietin/Tie2 system and renal injury markers were measured in plasma and on protein and mRNA level in renal tissue. Renal edema formation was determined by wet/dry weight ratios and renal structure by histological analysis.

RESULTS

Hemorrhagic shock significantly decreased renal perfusion (240 ± 138 to 51 ± 40, p < 0.0001) and cremaster perfusion (12 ± 2 to 5 ± 2 perfused vessels, p < 0.0001) compared to baseline values. Fluid resuscitation partially restored both perfusion parameters, but both remained below baseline values (renal perfusion 120 ± 58, p = 0.08, cremaster perfusion 7 ± 2 perfused vessels, p < 0.0001 compared to baseline). Hemorrhagic shock increased circulating angiopoietin-1 (p < 0.0001), angiopoietin-2 (p < 0.0001) and soluble Tie2 (p = 0.05), of which angiopoietin-2 elevation was associated with renal edema formation (r = 0.81, p < 0.0001). Hemorrhagic shock induced renal injury, as assessed by increased levels of plasma neutrophil gelatinase-associated lipocalin (NGAL: p < 0.05), kidney injury marker-1 (KIM-1; p < 0.01) and creatinine (p < 0.05). Vasculotide did not improve renal perfusion (p > 0.9 at all time points) or reduce renal injury (NGAL p = 0.26, KIM-1 p = 0.78, creatinine p > 0.9, renal edema p = 0.08), but temporarily improved cremaster perfusion at 3 h following start of fluid resuscitation compared to untreated rats (resuscitation + 3 h: 11 ± 3 vs 8 ± 3 perfused vessels, p < 0.05).

CONCLUSION

Hemorrhagic shock-induced renal impairment cannot be restored by standard fluid resuscitation, nor by activation of Tie2. Future treatment strategies should focus on reducing angiopoietin-2 levels or on activating Tie2 via an alternative strategy.

Prehospital Whole Blood Resuscitation Reduces Fluid Requirement While Maintaining Critical Physiology in a Model of Penetrating Traumatic Brain Injury and Hemorrhage: Implications on Resource-Limited Combat Casualty Care

ABSTRACT

Prehospital resuscitation using whole blood (WB) is the standard of care for hemorrhagic shock (HS) but there is no consensus recommendation for resuscitation in the presence of traumatic brain injury (TBI) due to a lack of sufficient evidence. In order to evaluate the optimal resuscitation strategies for TBI+HS, Sprague-Dawley rats were randomized into four groups based on resuscitation fluid and prehospital mean arterial pressure (MAP) threshold (n = 9-10/group): Lactated Ringer's (LR)-60 mm Hg (LR60), LR-70 mm Hg (LR70), WB-60 mm Hg (WB60), WB-70 mm Hg (WB70). All groups received a frontal penetrating ballistic-like brain injury followed by a 35-min period of HS. During the prehospital phase, rats received an initial bolus of resuscitation fluid (WB or LR) followed by LR as needed to maintain MAP above the designated threshold for 90 min. During the in-hospital phase, rats received definitive resuscitation with shed WB. Physiological parameters were recorded continuously and cerebral edema was measured at 3 and 24 h postinjury. The WB60 group demonstrated a significantly lower prehospital fluid requirement compared WB70, LR60, and LR70 (P < 0.05). Compared to the respective LR groups, both the WB60 and WB70 groups also demonstrated improved MAP, cerebral perfusion pressure, brain tissue oxygen tension, and cerebral edema. The edema benefits were observed at 3 h, but not 24 h postinjury, and were localized to the injury site. Together, these results provide evidence that prehospital WB resuscitation and lower MAP resuscitation thresholds can reduce the prehospital fluid requirement while still maintaining critical cerebral physiology in a model of HS and concomitant TBI.

Physiology of Human Hemorrhage and Compensation

Hemorrhage is a leading cause of death following traumatic injuries in the United States. Much of the previous work in assessing the physiology and pathophysiology underlying blood loss has focused on descriptive measures of hemodynamic responses such as blood pressure, cardiac output, stroke volume, heart rate, and vascular resistance as indicators of changes in organ perfusion. More recent work has shifted the focus toward understanding mechanisms of compensation for reduced systemic delivery and cellular utilization of oxygen as a more comprehensive approach to understanding the complex physiologic changes that occur following and during blood loss. In this article, we begin with applying dimensional analysis for comparison of animal models, and progress to descriptions of various physiological consequences of hemorrhage. We then introduce the complementary side of compensation by detailing the complexity and integration of various compensatory mechanisms that are activated from the initiation of hemorrhage and serve to maintain adequate vital organ perfusion and hemodynamic stability in the scenario of reduced systemic delivery of oxygen until the onset of hemodynamic decompensation. New data are introduced that challenge legacy concepts related to mechanisms that underlie baroreflex functions and provide novel insights into the measurement of the integrated response of compensation to central hypovolemia known as the compensatory reserve. The impact of demographic and environmental factors on tolerance to hemorrhage is also reviewed. Finally, we describe how understanding the physiology of compensation can be translated to applications for early assessment of the clinical status and accurate triage of hypovolemic and hypotensive patients. © 2021 American Physiological Society. Compr Physiol 11:1531-1574, 2021.

Fluids of the Future

Fluids are a vital tool in the armament of acute care clinicians in both civilian and military resuscitation. We now better understand complications from inappropriate resuscitation with currently available fluids; however, fluid resuscitation undeniably remains a life-saving intervention. Military research has driven the most significant advances in the field of fluid resuscitation and is currently leading the search for the fluids of the future. The veterinary community, much like our civilian human counterparts, should expect the fluid of the future to be the fruit of military research. The fluids of the future not only are expected to improve patient outcomes but also be field expedient. Those fluids should be compatible with military environments or natural disaster environments. For decades, military personnel and disaster responders have faced the peculiar demands of austere environments, prolonged field care, and delayed evacuation. Large scale natural disasters present field limitations often similar to those encountered in the battlefield. The fluids of the future should, therefore, have a long shelf-life, a small footprint, and be resistant to large temperature swings, for instance. Traumatic brain injury and hemorrhagic shock are the leading causes of preventable death for military casualties and a significant burden in civilian populations. The military and civilian health systems are focusing efforts on field-expedient fluids that will be specifically relevant for the management of those conditions. Fluids are expected to be compatible with blood products, increase oxygen-carrying capabilities, promote hemostasis, and be easy to administer in the prehospital setting, to match the broad spectrum of current acute care challenges, such as sepsis and severe systemic inflammation. This article will review historical military and civilian contributions to current resuscitation strategies, describe the expectations for the fluids of the future, and describe select ongoing research efforts with a review of current animal data.

An Assessment of Research Priorities to Dampen the Pendulum Swing of Burn Resuscitation

On June 17 to 18, 2019, the American Burn Association, in conjunction with Underwriters Laboratories, convened a group of experts on burn resuscitation in Washington, DC. The goal of the meeting was to identify and discuss novel research and strategies to optimize the process of burn resuscitation. Patients who sustain a large thermal injury (involving >20% of the total body surface area [TBSA]) face a sequence of challenges, beginning with burn shock. Over the last century, research has helped elucidate much of the underlying pathophysiology of burn shock, which places multiple organ systems at risk of damage or dysfunction. These studies advanced the understanding of the need for fluids for resuscitation. The resultant practice of judicious and timely infusion of crystalloids has improved mortality after major thermal injury. However, much remains unclear about how to further improve and customize resuscitation practice to limit the morbidities associated with edema and volume overload. Herein, we review the history and pathophysiology of shock following thermal injury, and propose some of the priorities for resuscitation research. Recommendations include: studying the utility of alternative endpoints to resuscitation, reexamining plasma as a primary or adjunctive resuscitation fluid, and applying information about inflammation and endotheliopathy to target the underlying causes of burn shock. Undoubtedly, these future research efforts will require a concerted effort from the burn and research communities.

Dilemma of crystalloid resuscitation in non-exsanguinating polytrauma: what is too much?

Background

Aggressive crystalloid resuscitation increases morbidity and mortality in exsanguinating patients. Polytrauma patients with severe tissue injury and subsequent inflammatory response without major blood loss also need resuscitation. This study investigated crystalloid and blood product resuscitation in non-exsanguinating polytrauma patients and studied possible adverse outcomes.

Methods

A 6.5-year prospective cohort study included consecutive trauma patients admitted to a Level 1 Trauma Center intensive care unit (ICU) who survived 48 hours. Demographics, physiologic and resuscitation parameters in first 24 hours, Denver Multiple Organ Failure scores, adult respiratory distress syndrome (ARDS) data and infectious complications were prospectively collected. Patients were divided in 5 L crystalloid volume subgroups (0–5, 5–10, 10–15 and >15 L) to make clinically relevant comparisons. Data are presented as median (IQR); p value <0.05 was considered significant.

Results

367 patients (70% men) were included with median age of 46 (28–61) years, median Injury Severity Score was 29 (22–35) and 95% sustained blunt injuries. 17% developed multiple organ dysfunction syndrome (MODS), 4% ARDS and 14% died. Increasing injury severity, acidosis and coagulopathy were associated with more crystalloid administration. Increasing crystalloid volumes were associated with more blood products, increased ventilator days, ICU length of stay, hospital length of stay, MODS, infectious complications and mortality rates. Urgent laparotomy was found to be the most important independent predictor for crystalloid resuscitation in multinominal regression analysis. Further, fresh frozen plasma (FFP) <8 hours was less likely to be administered in patients >5 L compared with the group 0–5 L. With increasing crystalloid volume, the adjusted odds of MODS, ARDS and infectious complications increased 3–4-fold, although not statistically significant. Mortality increased 6-fold in patients who received >15 L crystalloids (p=0.03).

Discussion

Polytrauma patients received large amounts of crystalloids with few FFPs <24 hours. In patients with <10 L crystalloids, <24-hour mortality and MODS rates were not influenced by crystalloid resuscitation. Mortality increased 6-fold in patients who received >15 L crystalloids ≤24 hours. Efforts should be made to balance resuscitation with modest crystalloids and sufficient amount of FFPs.

Level of evidence

Level 3.

Study type

Population-based cohort study.

Involvement of TRPV1-containing peripheral sensory efferents in hemodynamic responses in a rat hemorrhagic shock model

BACKGROUND

Mechanisms underlying hemodynamic disturbance in hemorrhagic shock are not completely understood. Transient receptor potential vanilloid 1-expressing afferents are involved in hemorrhagic shock pathology, and transient receptor potential vanilloid 1 antagonist, capsazepine, acts on the central nervous system to improve mortality in a rat hemorrhagic shock model. In contrast, transient receptor potential vanilloid 1-positive efferents promote vasoactive reactions through the release of neuropeptides, including calcitonin gene-related peptides. This study aimed to investigate whether transient receptor potential vanilloid 1-positive peripheral sensory efferents are involved in hemodynamic responses after hemorrhagic shock.

METHODS

Male rats underwent hemorrhagic shock (mean arterial pressure 30 mm Hg for 90 min, followed by resuscitation for 30 min) and received capsazepine (5 μM/kg) 30 min after shock induction. A separate cohort of rats subjected to hemorrhagic shock received hCGRP_8-37 (300 μg/kg), a calcitonin gene-related peptide receptor antagonist, at 30, 60, or 90 minutes after shock induction. The 24-hour survival rate, mean arterial pressure, heart rate, arterial blood gas, and plasma calcitonin gene-related peptide levels were measured. Tissue blood flow and oxygenation both in the mesentery and skeletal muscle were also assessed.

RESULTS

Capsazepine treatment prevented the hemorrhagic shock-induced increase in plasma calcitonin gene-related peptide levels, and hCGRP_8-37 treatment improved the 24-h survival rates after hemorrhagic shock at a time-dependent manner. The hCGRP_8-37- or capsazepine-treated rats exhibited tissue oxygenation and metabolic conditions comparable to those in control rats at the end of the experiment.

CONCLUSION

Transient receptor potential vanilloid 1 plays a crucial role in hemodynamic responses to hemorrhagic shock, partly via calcitonin gene-related peptide release, involved in its peripheral sensory-efferent functions. The hCGRP_8-37 appears to improve peripheral circulatory failure, which may be useful as adjunct treatment after hemorrhagic shock.

Acute kidney injury in severely injured patients admitted to the intensive care unit

BACKGROUND

Our objective was to identify possible associations between clinical and laboratory variables and the risk of developing acute kidney injury (AKI) in severely injured patients admitted to the intensive care unit (ICU) for whom creatine kinase (CK) levels were available.

METHODS

For this retrospective observational study, we analyzed adult trauma patients admitted to the ICU from 2011 to 2015 at Fundación Valle del Lili (FVL) University Hospital. Our primary outcome was the incidence of AKI. Multivariate regression analysis was used to assess risk factors for this outcome.

RESULTS

A total of 315 patients were included. The trauma mechanisms were blunt (n = 130), penetrating (n = 66) and blast (n = 44) trauma. The median (interquartile range, IQR) of injury severity score (ISS) was 21 (16-29). AKI developed in 75 patients (23.8%). Multivariate regression analysis revealed that the thoracic abbreviated injury scale (AIS) value (median (IQR) in the AKI group: 3 (0-4)), Acute Physiology and Chronic Health Evaluation (APACHE II) score (median (IQR) in the AKI group: 18 (10-27)), CK greater than 5000 U/L, lactic acid concentration at admission, and dobutamine administration were independently associated with AKI.

CONCLUSION

We found that age, APACHE II score, thoracic trauma, lactic acidosis, and dobutamine administration were independently associated with AKI. Trauma surgeons need to be aware of the increased odds of AKI if one of these factors is identified during the evaluation and treatment of injured patients.

Immunopathophysiology of trauma-related acute kidney injury

Physical trauma can affect any individual and is globally accountable for more than one in every ten deaths. Although direct severe kidney trauma is relatively infrequent, extrarenal tissue trauma frequently results in the development of acute kidney injury (AKI). Various causes, including haemorrhagic shock, rhabdomyolysis, use of nephrotoxic drugs and infectious complications, can trigger and exacerbate trauma-related AKI (TRAKI), particularly in the presence of pre-existing or trauma-specific risk factors. Injured, hypoxic and ischaemic tissues expose the organism to damage-associated and pathogen-associated molecular patterns, and oxidative stress, all of which initiate a complex immunopathophysiological response that results in macrocirculatory and microcirculatory disturbances in the kidney, and functional impairment. The simultaneous activation of components of innate immunity, including leukocytes, coagulation factors and complement proteins, drives kidney inflammation, glomerular and tubular damage, and breakdown of the blood-urine barrier. This immune response is also an integral part of the intense post-trauma crosstalk between the kidneys, the nervous system and other organs, which aggravates multi-organ dysfunction. Necessary lifesaving procedures used in trauma management might have ambivalent effects as they stabilize injured tissue and organs while simultaneously exacerbating kidney injury. Consequently, only a small number of pathophysiological and immunomodulatory therapeutic targets for TRAKI prevention have been proposed and evaluated.

Effect of Low-Dose Supplementation of Arginine Vasopressin on Need for Blood Product Transfusions in Patients With Trauma and Hemorrhagic Shock: A Randomized Clinical Trial

Importance

Current therapies for traumatic blood loss focus on hemorrhage control and blood volume replacement. Severe hemorrhagic shock, however, is associated with a state of arginine vasopressin (AVP) deficiency, and supplementation of this hormone may decrease the need for blood products in resuscitation.

Objective

To determine whether low-dose supplementation of AVP in patients with trauma (hereinafter referred to as trauma patients) and with hemorrhagic shock decreases their need for transfused blood products during resuscitation.

Design, Setting, and Participants

This randomized, double-blind placebo-controlled clinical trial included adult trauma patients (aged 18-65 years) who received at least 6 U of any blood product within 12 hours of injury at a single urban level 1 trauma center from May 1, 2013, through May 31, 2017. Exclusion criteria consisted of prehospital cardiopulmonary resuscitation, emergency department thoracotomy, corticosteroid use, chronic renal insufficiency, coronary artery disease, traumatic brain injury requiring any neurosurgical intervention, pregnancy, prisoner status, or AVP administration before enrollment. Data were analyzed from May 1, 2013, through May 31, 2017, using intention to treat and per protocol.

Interventions

After administration of an AVP bolus (4 U) or placebo, participants received AVP (≤0.04 U/min) or placebo for 48 hours to maintain a mean arterial blood pressure of at least 65 mm Hg.

Main Outcomes

The primary outcome was total volume of blood product transfused. Secondary end points included total volume of crystalloid transfused, vasopressor requirements, secondary complications, and 30-day mortality.

Results

One hundred patients underwent randomization (49 to the AVP group and 51 to the placebo group). Patients were primarily young (median age, 27 years [interquartile range {IQR}, 22-25 years]) and male (n = 93) with penetrating trauma (n = 79). Cohort characteristics before randomization were well balanced. At 48 hours, patients who received AVP required significantly less blood products (median, 1.4 [IQR, 0.5-2.6] vs 2.9 [IQR, 1.1-4.8] L; P = .01) but did not differ in requirements for crystalloids (median, 9.9 [IQR, 7.9-13.0] vs 11.0 [8.9-15.0] L; P = .22) or vasopressors (median, 400 [IQR, 0-5900] vs 1400 [IQR, 200-7600] equivalent units; P = .22). Although the groups had similar rates of mortality (6 of 49 [12%] vs 6 of 51 [12%]; P = .94) and total complications (24 of 44 [55%] vs 30 of 47 [64%]; P = .37), the AVP group had less deep venous thrombosis (5 of 44 [11%] vs 16 of 47 [34%]; P = .02).

Conclusions and Relevance

Low-dose AVP during the resuscitation of trauma patients in hemorrhagic shock decreases blood product requirements. Additional research is necessary to determine whether including AVP improves morbidity or mortality.

Trial Registration

ClinicalTrials.gov identifier: NCT01611935.

Innate coagulability changes with age in stored packed red blood cells

BACKGROUND

Packed red blood cell (pRBC) units administered during resuscitation from hemorrhagic shock are of varied storage ages. We have previously shown that RBC-derived microparticles' impact on thrombogenesis. However, the impact of storage age on pRBC coagulability is unknown. Therefore, we sought to investigate the effect of storage age on innate coagulability and aggregability of stored pRBCs.

METHODS

pRBCs prepared from male C57BL/6J mice were stored in Additive Solution-3 according to our standardized murine blood banking protocols for 14 days. Rotational thromboelastometry (ROTEM) was used to assess the innate coagulation status of fresh and 14-day old pRBCs. Viscoelastic coagulation parameters of clotting time (CT), clot formation time (CFT), alpha angle, and maximum clot firmness (MCF) were analyzed to determine coagulability. Plasma was added to the fresh pRBCs and 15-day old pRBCs to determine if the storage-associated coagulopathy was reversible with plasma. Statistical analyses were conducted with a Student's t-test.

RESULTS

Fifteen-day old pRBCs demonstrated a significant reduction in MCF (10.3 vs. 24.4 mm, P-value <0.001) and alpha angle (6.0 vs. 27.2 degrees, P-value <0.001) as well as significant prolongation of CFT and CT (1126.5 vs. 571.4 s, P-value <0.001) compared to fresh pRBCs. FFP addition to 15-day old and fresh pRBCs, demonstrated a significant reduction in MCF and persistent prolongation of CFT. This suggests that pRBCs lost coagulability as they aged and this deficit was not completely corrected by plasma administration.

CONCLUSIONS

Storage duration may be an important factor in coagulation potential of pRBCs. Transfusion with older pRBCs may contribute to coagulopathy in massively transfused patients.

Superior Survival Outcomes of a Polyethylene Glycol-20k Based Resuscitation Solution in a Preclinical Porcine Model of Lethal Hemorrhagic Shock

OBJECTIVE

To compare early outcomes and 24-hour survival after LVR with the novel polyethylene glycol-20k-based crystalloid (PEG-20k), WB, or hextend in a preclinical model of lethal HS.

BACKGROUND

Posttraumatic HS is a major cause of preventable death. Current resuscitation strategies focus on restoring oxygen-carrying capacity (OCC) and coagulation with blood products. Our lab shows that PEG-20k is an effective non-sanguineous, LVR solution in acute models of HS through mechanisms targeting cell swelling-induced microcirculatory failure.

METHODS

Male pigs underwent splenectomy followed by controlled hemorrhage until lactate reached 7.5-8.5 mmol/L. They were randomized to receive LVR with PEG-20k, WB, or Hextend. Surviving animals were recovered 4 hours post-LVR. Outcomes included 24-hour survival rates, mean arterial pressure, lactate, hemoglobin, and estimated intravascular volume changes.

RESULTS

Twenty-four-hour survival rates were 100%, 16.7%, and 0% in the PEG-20k, WB, and Hextend groups, respectively (P = 0.001). PEG-20k significantly restored mean arterial press, intravascular volume, and capillary perfusion to baseline, compared to other groups. This caused complete lactate clearance despite decreased OCC. Neurological function was normal after next-day recovery in PEG-20k resuscitated pigs.

CONCLUSION

Superior early and 24-hour outcomes were observed with PEG-20k LVR compared to WB and Hextend in a preclinical porcine model of lethal HS, despite decreased OCC from substantial volume-expansion. These findings demonstrate the importance of enhancing microcirculatory perfusion in early resuscitation strategies.

3-Factor Versus 4-Factor PCC in Coagulopathy of Trauma: Four is Better Than Three

INTRODUCTION

Coagulopathy of trauma (COT) is common and highly lethal. Prothrombin complex concentrate (PCC) has been advocated for correction of COT. However, the difference in efficacy between three-factor PCC (3-PCC) versus four-factor PCC (4-PCC) remains unclear. The aim of our study was to compare efficacy of 3-PCC versus 4-PCC in COT.

METHODS

Five-year (2013-2017) review of coagulopathic trauma patients at our Level-I trauma center who received 3- or 4-PCC. Patients were divided into two groups (4-PCC and 3-PCC) and matched in 1:1 ratio using propensity-score-matching for demographics, injury parameters, admission vitals, and hematological parameters. Primary outcomes were time to correction of international normalized ratio (INR), blood products transfusion, thromboembolic complications, and mortality. Secondary outcomes were hospital-length of stay (LOS), intensive care unit (ICU)-LOS, cost of therapy, and total hospital cost.

RESULTS

Six hundred fifty-seven patients met inclusion criteria of whom 250 patients (4-PCC:125; 3-PCC:125) were matched. The mean age was 50 ± 19.4 y, 64% were male, and median-injury severity score was 24[15-33]. 4-PCC was associated with accelerated correction of INR (365 vs. 428 min, P = 0.01), decrease in red blood cells (7 units vs. 10 units, P = 0.04) and FFP (6 units vs. 8 units, P = 0.03) transfused. There was no difference in platelet transfusion, thromboembolic complications, mortality, hospital, and ICU-LOS. 4-PCC was associated with higher cost of PCC therapy, and lower cost of transfusion. There was no difference regarding the total hospital cost between the two groups.

CONCLUSION

Compared with 3-factor PCC, the use of 4-factor PCC is associated with a rapid reversal of INR and reduction in transfusion requirement without increasing the overall hospital cost or the risk of thromboembolic events. 4-PCC may be preferred as an adjunct for the resuscitation of coagulopathic trauma patients.

Damage Control Resuscitation Protocol and the Management of Open Abdomens in Trauma Patients

Although the use of damage control laparotomy (DCL) is well established, the effect of damage control resuscitation (DCR) on the management of open abdomens is relatively poorly studied. The aim of the present study was to determine the predictors for failure to achieve primary fascial closure (PFC) after DCL in the setting of a massive transfusion (MT) and DCR. This is a retrospective review over a 12-year period of all patients that underwent MT and DCL. Patients who achieved PFC were compared with those who did not (NPFC). Student's t tests were used to compare the two groups. A multiple logistic regression model was performed to identify independent risk factors for failure to attain PFC. Of 174 patients, 101 achieved PFC. Mean (6 standard deviation) age was 35.6 ± 14.9 years for PFC and 36.3 ± 14.0 years for NPFC ( P = 0.75). Admission Glasgow Coma Scale score was 11.4 ± 4.6 for PFC and 10.6 ± 5.0 for NPFC ( P = 0.25). Initial lactate (7.3 ± 3.8 vs 7.7 ± 4.1, P = 0.50), hemoglobin (11.3 ± 1.9 vs 11.0 ± 2.2, P = 0.43), systolic blood pressure (108 ± 44 vs 107 ± 35, P = 0.82), Injury Severity Score (34 ± 14 vs 36 ± 15, P = 0.32), and abdominal Abbreviated Injury Score (3.6 ± 1.1 vs 3.9 ± 1.0, P = 0.13) were similar between the two groups. There was no difference in total blood products administered at 24 hours (46 ± 26 vs 49 ± 29 units, P = 0.45). Logistic regression identified increasing volume of crystalloid at 24 hours (odds ratio, 0.86; 95% confidence interval, 0.74 to 0.99; P = 0.047), earlier operative year (2.1; 1.52 to 2.91; P < 0.001), and increased number of procedures (0.32, 0.18 to 0.58; P < 0.001) as independent predictors for failure to obtain PFC. Injury severity is not associated with failure to achieve PFC, whereas administration of large-volume crystalloid resuscitation, increasing number procedures, and earlier year of DCL are independent predictors for failure to achieve PFC. Application of DCR to DCL techniques results in an improvement in ability to achieve PFC.