Lactated ringer's solution and hetastarch but not plasma resuscitation after rat hemorrhagic shock is associated with immediate lung apoptosis by the up-regulation of the Bax protein

Plasma for prevention and treatment of glycocalyx degradation in trauma and sepsis

The endothelial glycocalyx, a gel-like layer that lines the luminal surface of blood vessels, is composed of proteoglycans, glycoproteins, and glycosaminoglycans. The endothelial glycocalyx plays an essential role in vascular homeostasis, and its degradation in trauma and sepsis can lead to microvascular dysfunction and organ injury. While there are no proven therapies for preventing or treating endothelial glycocalyx degradation, some initial literature suggests that plasma may have a therapeutic role in trauma and sepsis patients. Overall, the literature suggesting the use of plasma as a therapy for endothelial glycocalyx degradation is non-clinical basic science or exploratory. Plasma is an established therapy in the resuscitation of patients with hemorrhage for restoration of coagulation factors. However, plasma also contains other bioactive components, including sphingosine-1 phosphate, antithrombin, and adiponectin, which may protect and restore the endothelial glycocalyx, thereby helping to maintain or restore vascular homeostasis. This narrative review begins by describing the endothelial glycocalyx in health and disease: we discuss the overlapping disease mechanisms in trauma and sepsis that lead to its damage and introduce plasma transfusion as a potential therapy for prevention and treatment of endothelial glycocalyx degradation. Second, we review the literature on plasma as an exploratory therapy for endothelial glycocalyx degradation in trauma and sepsis. Third, we discuss the safety of plasma transfusion by reviewing the adverse events associated with plasma and other blood product transfusions, and we examine modern transfusion precautions that have enhanced the safety of plasma transfusion. We conclude that the literature proposes that plasma may have the potential to prevent and treat endothelial glycocalyx degradation in trauma and sepsis, indicating the need for further research.

Shock lung is not "wet" but characterized as necroptotic inflammation in a mouse model of hypotension

OBJECTIVES

Hypotension episodes before or after donor brain death are assumed to trigger hypoxia-reoxygenation, causing diffuse alveolar-capillary damage via necrosis. However, alveolar-capillary membranes have direct access to oxygen in alveoli. We hypothesized hypotension-induced lung injury is not diffuse alveolar-capillary damage but interstitial inflammation resulting from nonhypoxic lung ischemia and systemic responses to hypoxic extrapulmonary ischemia.

METHODS

The 4-hour hypotension model was established by subjecting C57BL/6J mice to 4-hour hypotension at 15 ± 5 mm Hg of mean artery pressure and resuscitated with whole shed blood and norepinephrine. Nonhypoxic lung ischemia model was established by 4-hour left pulmonary artery ligation. At 24 hours postprocedure, an arterial blood gas analysis and a gastroduodenal occult blood test were conducted. Lung samples were assessed for histology, cytokine transcripts, regulated cell death, and alveolar-capillary permeability.

RESULTS

The 4-hour hypotension model had an intraoperative mortality rate of 17.7% (41/231) and a stress-ulcer bleeding rate of 15.3% (29/190). No signs of alveolar flooding were observed in both models. Four-hour hypotension without stress ulcer showed normal oxygenation and permeability but increased interstitial infiltration, transcription of Tnf and Il1b, phosphorylation of MLKL and RIPK3, and cleaved caspase 3 compared with 4-hour pulmonary artery ligation and naïve control. Animals that developed stress ulcer presented with worse pulmonary infiltration, intracellular edema, and oxygenation but just slightly increased permeability. Immunoblotting showed significant upregulations of protein expression and phosphorylation of MLKL and RIPK3, cleaved Caspase-3, but not its prototype in 4-hour hypotension with stress ulcer.

CONCLUSIONS

Hypotensive lung injury is essentially a nonhypoxic ischemia-reperfusion injury enhanced by systemic responses. It is predominated by necroptosis-induced inflammation rather than necrosis-induced diffuse alveolar-capillary damage.

Mesenteric Lymph Duct Drainage Attenuates Lung Inflammatory Injury and Inhibits Endothelial Cell Apoptosis in Septic Rats

The present study was to investigate the effect of mesenteric lymph duct drainage on lung inflammatory response, histological alteration, and endothelial cell apoptosis in septic rats. Animals were randomly assigned into four groups: control, sham surgery, sepsis, and sepsis plus mesenteric lymph drainage. We used the colon ascendens stent peritonitis (CASP) procedure to induce the septic model in rats, and mesenteric lymph drainage was performed with a polyethylene (PE) catheter inserted into mesenteric lymphatic. The animals were sacrificed at the end of CASP in 6 h. The mRNA expression levels of inflammatory mediators were measured by qPCR, and the histologic damage were evaluated by the pathological score method. It was found that mesenteric lymph drainage significantly reduced the expression of TNF-α, IL-1β, and IL-6 mRNA in the lung. Pulmonary interstitial edema and infiltration of inflammatory cells were alleviated by mesenteric lymph drainage. Moreover, increased mRNA levels of TNF-α, IL-1β, IL-6 mRNA, and apoptotic rate were observed in PMVECs treated with septic lymph. These results indicate that mesenteric lymph duct drainage significantly attenuated lung inflammatory injury by decreasing the expression of pivotal inflammatory mediators and inhibiting endothelial apoptosis to preserve the pulmonary barrier function in septic rats.

Toxic medications in Leber's hereditary optic neuropathy

Leber's hereditary optic neuropathy (LHON) is a maternally inherited mitochondrial disorder characterized by acute bilateral vision loss. The pathophysiology involves reactive oxygen species (ROS), which can be affected by medications. This article reviews the evidence for medications with demonstrated and theoretical effects on mitochondrial function, specifically in relation to increased ROS production. The data reviewed provides guidance when selecting medications for individuals with LHON mutations (carriers) and are susceptible to conversion to affected. However, as with all medications, the proven benefits of these therapies must be weighed against, in some cases, purely theoretical risks for this unique patient population.

Plasma Transfusion: History, Current Realities, and Novel Improvements

Traumatic hemorrhage is the leading cause of preventable death after trauma. Early transfusion of plasma and balanced transfusion have been shown to optimize survival, mitigate the acute coagulopathy of trauma, and restore the endothelial glycocalyx. There are a myriad of plasma formulations available worldwide, including fresh frozen plasma, thawed plasma, liquid plasma, plasma frozen within 24 h, and lyophilized plasma (LP). Significant equipoise exists in the literature regarding the optimal plasma formulation. LP is a freeze-dried formulation that was originally developed in the 1930s and used by the American and British military in World War II. It was subsequently discontinued due to risk of disease transmission from pooled donors. Recently, there has been a significant amount of research focusing on optimizing reconstitution of LP. Findings show that sterile water buffered with ascorbic acid results in decreased blood loss with suppression of systemic inflammation. We are now beginning to realize the creation of a plasma-derived formulation that rapidly produces the associated benefits without logistical or safety constraints. This review will highlight the history of plasma, detail the various types of plasma formulations currently available, their pathophysiological effects, impacts of storage on coagulation factors in vitro and in vivo, novel concepts, and future directions.

Plasma Transfusion

The resuscitation of the injured patient continues to be a highly debated topic. Multiple studies have been performed with the intent to determine the optimal strategy to combat, and ultimately prevent, trauma induced coagulopathy. This chapter discusses the risks and benefits of resuscitation protocols utilizing plasma.

Plasma is the aqueous portion of blood that contains coagulation factors, fibrinolytic proteins, albumin, immunoglobulins, and up to 6000 other proteins. Multiple methods of collection and storage have been developed, each one affecting the plasma and its proteins differently. Once collected, plasma can be frozen for storage. If frozen within 8 h, the product is labelled as fresh frozen plasma (FFP). If frozen more than 6 h, but less than 24 h, it is labelled as plasma frozen within 24 h (FP24). When FFP and FP24 are mobilized from the blood bank, they are thawed in a water bath to create thawed plasma (TP) which can be stored in liquid form for up to 4 days prior to transfusion. Liquid plasma (LQP) is derived from whole blood and is never frozen. It can be stored for up to 30 days by some reports prior to transfusion. Each of these forms of plasma has been extensively studied for efficacy of coagulation and are all useful in the resuscitation of a traumatically injured patient.

There is much more than coagulation factors in plasma that are useful to patients. Studies looking at the endotheliopathy associated with hemorrhagic shock have shown a decrease in the inflammatory response, promotion of endothelial repair, and decreased edema. Transfusion protocols utilizing plasma at the time of presentation have shown a decrease in the amount of blood products transfused, as well as an improvement in mortality. Transfusion ratios of platelets–red blood cells–plasma units in a 1:1:1 ratio have shown a significant improvement in mortality at 3 h post-admission over 1:1:2. There has not been an increase in the incidence of adverse events with the increase usage of plasma.

The early administration of plasma to the massively hemorrhaging traumatically injured patient improves mortality, decreases total blood product usage, and promotes the resolution of trauma induced endotheliopathy without increasing adverse events.

Histologic changes of the fetal membranes after fetoscopic laser surgery for twin-twin transfusion syndrome

BACKGROUND

Preterm premature rupture of membranes remains a major complication after fetoscopic laser surgery (FLS) for twin-twin transfusion syndrome (TTTS). We studied the histologic changes of fetal membranes post-FLS and investigated a possible impact of amniotic fluid (AF) dilution.

METHODS

Fetal membranes of 31 pregnancies that underwent FLS for TTTS were investigated histologically at delivery at different sites: trocar site of recipient sac and at distance, donor sac, and inter-twin membrane.

RESULTS

The trocar insertion site on the recipient sac showed no signs of histologic hallmarks of healing. Wide-spread alteration in collagen organization and higher apoptotic index in the amnion of the recipient sac which were absent in donor's and reference membranes. To explain the mechanisms, we analyzed the AF composition of recipient sacs from TTTS pregnancies vs. GA-matched healthy singleton controls and found glucose, protein and lactate dehydrogenase activity were all significantly lower in TTTS sacs consistent with over-dilution of recipient's AF (~2-fold). In-vitro exposure of healthy amniochorion to analogous dilutional stress conditions recapitulated the histologic changes and induced apoptosis and autophagy.

CONCLUSION

Alteration in structural integrity of the recipient's amniochorion, possibly in response to dilution stress, along with ineffective repair mechanisms may explain the increased incidence of preterm birth post-FLS.

Protective effects of polyethylene oxide on the vascular and organ function of rats with severe hemorrhagic shock

This study examined the effects of polyethylene oxide (PEO) on the survival rate, hemodynamics, blood gas indexes, lactic acid levels, microcirculation, and inflammatory cytokine levels in rats subjected to severe hemorrhagic shock. The shocked rats were resuscitated with either Ringer's lactate solution or 20 ppm of PEO in Ringer's lactate solution for 1 h. It was found that infusion of PEO effectively improved the survival, metabolic acidosis, oxygen delivery, hyperlactacidemia, tissue perfusion, and inflammatory responses of rats subjected to hemorrhagic shock. In addition, we found, for the first time, that PEO showed protective effects on hepatic and renal injury, as evidenced by the significant decreases in the elevated levels of alanine aminotransferase, aspartate aminotransferase, blood urea nitrogen, and creatinine caused by shock induction after infusion of PEO (p < 0.05, 60 min post-resuscitation by comparison with pre-resuscitation). All of these findings indicate that PEO exhibits strong therapeutic effects under conditions of severe hemorrhagic shock,which also provides theoretical and experimental bases for the clinical use of PEO.

Aggressive early crystalloid resuscitation adversely affects outcomes in adult blunt trauma patients: an analysis of the Glue Grant database

BACKGROUND

Evidence suggests that aggressive crystalloid resuscitation is associated with significant morbidity in various clinical settings. We wanted to assess whether aggressive early crystalloid resuscitation adversely affects outcomes in adult blunt trauma patients.

METHODS

Data were derived from the Glue Grant database. Our primary outcome measure was all-cause in-hospital mortality. Secondary outcomes included days on mechanical ventilation; intensive care unit (ICU) and hospital length of stay (LOS); inflammatory (acute lung injury and adult respiratory distress syndrome, or multiple-organ failure) and resuscitation-related morbidity (abdominal and extremity compartment syndromes or acute renal failure) and nosocomial infections (ventilator-associated pneumonia, bloodstream, urinary tract, and surgical site infections).

RESULTS

In our sample of 1,754 patients, in-hospital mortality was not affected, but ventilator days (p < 0.001) as well as ICU (p = 0.009) and hospital (p = 0.002) LOS correlated strongly with the amount of crystalloids infused in the first 24 hours after injury. Amount of crystalloid resuscitation was also associated with the development of adult respiratory distress syndrome (p < 0.001), multiple-organ failure (p < 0.001), bloodstream (p = 0.001) and surgical site infections (p < 0.001), as well as abdominal (p < 0.001) and extremity compartment syndromes (p = 0.028) in a dose-dependent fashion, when age, Glasgow Coma Scale (GCS), severity of injury and acute physiologic derangement, comorbidities, as well as colloid and blood product transfusions were controlled for.

CONCLUSION

Crystalloid resuscitation is associated with a substantial increase in morbidity, as well as ICU and hospital LOS in adult blunt trauma patients.

Impact of fluid therapy on apoptosis and organ injury during haemorrhagic shock in an oxygen-debt-controlled pig model

INTRODUCTION

Apoptosis, or programmed cell death, seems to play a role in the physiology of shock. The influence of fluid resuscitation on the occurrence of apoptosis during haemorrhage is still unclear. Using an experimental randomised study, the goal of this investigation was to find a relation between different frequently used resuscitation fluids and evidence of apoptosis.

MATERIALS AND METHODS

Sixty female pigs with a mean body weight of 20 kg were randomised into six groups, each receiving a different resuscitation fluid therapy: malated Ringer, lactated Ringer, hypertonic saline, hypertonic saline solution/Dextran 60, carbonate/gelatine and a sham group (no shock, no resuscitation). A haemorrhagic shock with a predefined oxygen debt with high mortality expected was induced for a period of 60 min. Then, the resuscitation fluid therapy within each group was initiated. At the beginning, after 1 h of shock and 1 and 2 h after resuscitation, biopsies from the liver were taken, as one of the most important metabolism organs of shock. Three hours after the beginning of the resuscitation period, the animals were allowed to recover under observation for 3 days. At the end of this period, a state of narcosis was induced and another liver biopsy was taken. Finally, the animals were sacrificed and samples were taken from the liver, kidney, heart and hippocampus. The TUNEL method was used for identifying apoptosis. Impairment of liver function was indicated by the measurement of transaminase levels.

RESULTS

There was no observed difference in the rate of apoptosis in all groups and a low number of apoptotic cells were found in all the organs sampled. The sham group also showed a low count of apoptosis. The hypoxia-sensitive neurons within the hippocampus did not show any signs of apoptosis. The high oxygen debt during haemorrhage led to a high mortality. The non-treated animals died very quickly, as an indicator for severe shock. Animals treated with hypertonic saline showed a significant increase in aspartate transaminase (AST) plasma levels on the first day after shock.

CONCLUSION

The different resuscitation fluids used in the treatment of haemorrhagic shock in this experimental model showed no evidence of a different apoptosis rate in the end organs.

Effect of N-acetylcysteine on pulmonary cell death in a controlled hemorrhagic shock model in rats

PURPOSE

To evaluate the effect of N-acetylcysteine (NAC) combined with fluid resuscitation on pulmonary cell death in rats induced with controlled hemorrhagic shock (HS).

METHODS

Two arteries (MAP calculation and exsanguination) and one vein (treatments) were catheterized in 22 anesthetized rats. Two groups of male albino rats were induced with controlled HS at 35mmHg MAP for 60 min. After this period, the RL group was resuscitated with Ringer's lactate and the RL+NAC group was resuscitated with Ringer's lactate combined with 150mg/Kg NAC. The control group animals were cannulated only. The animals were euthanized after 120 min of fluid resuscitation. Lung tissue samples were collected to evaluate the following: histopathology, TUNEL and imunohistochemical expression of caspase 3.

RESULTS

RL showed a greater number of cells stained by TUNEL than RL + NAC, but there was no change in caspase 3 expression in any group.

CONCLUSION

N-acetylcysteine associate to fluid resuscitation, after hemorrhagic shock, decreased cell death attenuating lung injury.

Impact of inverse ratios on patients with exsanguinating vascular injuries: should more be the new paradigm?

BACKGROUND

Resuscitation strategies in patients with severe hemorrhage have evolved throughout the years. Optimal resuscitation ratios for civilian exsanguinating vascular injuries has not been determined. We hypothesize improved outcomes in patients with exsanguinating vascular injuries when an aggressive hemostatic resuscitation is used with an inverse ratio of fresh frozen plasma (FFP) to packed red blood cell (PRBC).

METHODS

This is a 5-year retrospective analysis of vascular injuries requiring hemostatic resuscitation. Resuscitation groups by ratios of FFP/PRBC were inverse (>1:1), high (1-1:2), and low (<1:2). Patients with 10 or greater units of PRBC (massively transfused patients) were evaluated in each of the resuscitation groups. Demographics and complications throughout hospital length of stay and were compared between the resuscitation groups. Survivability Kaplan-Meier curves were generated at 6 hours and 5 days.

RESULTS

A total of 258 patients with vascular injuries required component therapy resuscitation (low, n = 78; high, n = 156; inverse, n = 24). Massively transfused patients (n = 162, 62.7%) showed a significant Kaplan-Meier survivability difference at 6 hours (low, 65.0% vs. high, 75.0% vs. inverse, 100%, p = 0.024) and at 5 days (low, 52.5% vs. high, 62.0% vs. inverse, 100%, p = 0.008). Moreover, for massively transfused patients with extremity vascular injuries (n = 65, 39%), a relationship between resuscitation ratio and amputations was significant (low vs. high vs. inverse was 36.8% vs. 12.8% vs. 0%, respectively; p = 0.033).

CONCLUSION

This is the first study that highlights the potential outcomes benefits of an inverse ratio of FFP-PRBC in patients with exsanguinating vascular injuries. Multi-institutional prospective analysis is needed to potentially elucidate the cytoprotective effect of FFP to validate these results.

LEVEL OF EVIDENCE

Therapeutic study, level IV; diagnostic study, level III.

Spray-dried plasma and fresh frozen plasma modulate permeability and inflammation in vitro in vascular endothelial cells

BACKGROUND

After major traumatic injury, patients often require multiple transfusions of fresh frozen plasma (FFP) to correct coagulopathy and to reduce bleeding. A spray-dried plasma (SDP) product has several logistical benefits over FFP use in trauma patients with coagulopathy. These benefits include ease of transport, stability at room temperature, and rapid reconstitution for infusion. Our past work suggests that FFP promotes endothelial stability by inhibiting endothelial permeability.

STUDY DESIGN AND METHODS

The main goal of this project is to determine if solvent-detergent-treated SDP is equivalent to FFP in inhibiting vascular endothelial cell (EC) permeability and inflammation in vitro. Furthermore, this study aimed to determine if solvent-detergent treatment and spray drying of plasma alters the protective effects of FFP on EC function. The five groups tested in our studies are the following: 1) fresh frozen-thawed plasma (FFP); 2) solvent-detergent-treated FFP; 3) solvent-detergent-treated SDP; 4) lactated Ringer's solution; and 5) Hextend.

RESULTS

This study demonstrates that in vitro SDP and FFP equivalently inhibit vascular EC permeability, EC adherens junction breakdown, and endothelial white blood cell binding, an effect that is independent of changes in Vascular Cell Adhesion Molecule 1, Intracellular Adhesion Molecule 1, or E-selectin expression on ECs. Solvent-detergent treatment of FFP does not alter the protective effects of FFP on endothelial cell function in vitro.

CONCLUSION

These data suggest the equivalence of FFP and SDP on modulation of endothelial function and inflammation in vitro.

Optimal trauma resuscitation with plasma as the primary resuscitative fluid: the surgeon's perspective

Over the past century, blood banking and transfusion practices have moved from whole blood therapy to components. In trauma patients, the shift to component therapy was achieved without clinically validating which patients needed which blood products. Over the past 4 decades, this lack of clinical validation has led to uncertainty on how to optimally use blood products and has likely resulted in both overuse and underuse in injured patients. However, recent data from both US military operations and civilian trauma centers have shown a survival advantage with a balanced transfusion ratio of RBCs, plasma, and platelets. This has been extended to include the prehospital arena, where thawed plasma, RBCs, and antifibrinolytics are becoming more widely used. The Texas Trauma Institute in Houston has followed this progression by putting RBCs and thawed plasma in the emergency department and liquid plasma and RBCs on helicopters, transfusing platelets earlier, and using thromboelastogram-guided approaches. These changes have not only resulted in improved outcomes, but have also decreased inflammatory complications, operations, and overall use of blood products. In addition, studies have shown that resuscitating with plasma (instead of crystalloid) repairs the "endotheliopathy of trauma," or the systemic endothelial injury and dysfunction that lead to coagulation disturbances and inflammation. Data from the Trauma Outcomes Group, the Prospective Observational Multicenter Major Trauma Transfusion (PROMMTT) study, and the ongoing Pragmatic Randomized Optimal Platelet and Plasma Ratios (PROPPR) trial represent a decade-long effort to programmatically determine optimal resuscitation practices, balancing risk versus benefits. With injury as the leading cause of death in patients age 1 to 44 years and hemorrhage the leading cause of potentially preventable death in this group, high-quality data must be obtained to provide superior care to the civilian and combat injured.

Resuscitation after hemorrhagic shock: the effect on the liver--a review of experimental data

The liver is currently considered to be one of the first organs to be subjected to the hypoxic insult inflicted by hemorrhagic shock. The oxidative injury caused by resuscitation also targets the liver and can lead to malfunction and the eventual failure of this organ. Each of the various fluids, vasoactive drugs, and pharmacologic substances used for resuscitation has its own distinct effect(s) on the liver, and the anesthetic agents used during surgical resuscitation also have an impact on hepatocytes. The aim of our study was to identify the specific effect of these substances on the liver. To this end, we conducted a literature search of MEDLINE for all types of articles published in English, with a focus on articles published in the last 12 years. Our search terms were "hemorrhagic shock," "liver," "resuscitation," "vasopressors," and "anesthesia." Experimental studies form the majority of articles found in bibliographic databases. The effect of a specific resuscitation agent on the liver is assessed mainly by measuring apoptotic pathway regulators and inflammation-induced indicators. Apart from a wide range of pharmacological substances, modifications of Ringer's Lactate, colloids, and pyruvate provide protection to the liver after hemorrhage and resuscitation. In this setting, it is of paramount importance that the treating physician recognize those agents that may attenuate liver injury and avoid using those which inflict additional damage.

The role of toll-like receptor-4 in the development of multi-organ failure following traumatic haemorrhagic shock and resuscitation

Haemorrhagic shock and resuscitation (HS/R) following major trauma results in a global ischaemia and reperfusion injury that may lead to multiple organ dysfunction syndrome (MODS). Systemic activation of the immune system is fundamental to the development of MODS in this context, and shares many features in common with the systemic inflammatory response syndrome (SIRS) that complicates sepsis. An important advancement in the understanding of the innate response to infection involved the identification of mammalian toll-like receptors (TLRs) expressed on cells of the immune system. Ten TLR homologues have been identified in humans and toll-like receptor-4 (TLR4) has been studied most intensively. Initially found to recognise bacterial lipopolysaccharide (LPS), it has also recently been discovered that TLR4 is capable of activation by endogenous 'danger signal' molecules released following cellular injury; this has since implicated TLR4 in several non-infectious pathophysiologic processes, including HS/R. The exact events leading to multi-organ dysfunction following HS/R have not yet been clearly defined, although TLR4 is believed to play a central role as has been shown to be expressed at sites including the liver, lungs and myocardium following HS/R. Multi-organ dysfunction syndrome remains an important cause of morbidity and mortality in trauma patients, and current therapy is based on supportive care. Understanding the pathophysiology of HS/R will allow for the development of targeted therapeutic strategies aimed at minimising organ dysfunction and improving patient outcomes following traumatic haemorrhage. A review of the pathogenesis of haemorrhagic shock is presented, and the complex, yet critical role of TLR4 as both a key mediator and therapeutic target is discussed.

Establishment of an experimental mouse model of trauma-hemorrhagic shock

This study established an experimental mouse model of trauma-hemorrhagic shock (THS). THS-induced mice (C57BL/6J, n=33) were subjected to femoral fracture, ischemia for 90 min, and resuscitation for 15 min. The sham-operated mice (C57BL/6J, n=33) underwent the same anesthetic and surgical procedures, but neither trauma-hemorrhage nor fluid resuscitation were performed. Mean arterial pressure (MAP) and microvascular tissue perfusion over the small intestine, liver, and left kidney were longitudinally measured in all mice. Blood was collected for analysis at baseline and 3, 6, 12, and 24 h post resuscitation, and the small intestine, liver, and left kidney were resected for hematoxylin and eosin staining 24 h post resuscitation. Compared with the sham group, MAP and microvascular tissue perfusion over the small intestine, liver, and left kidney were all significantly reduced in the THS group at the end of hemorrhage. Following resuscitation, no significant differences were observed between the groups. THS induction was associated with significantly increased plasma concentrations of Cr, AST, CPK, IL-6, IL-10, and TNF-α from the baseline values by two- to three-fold after the hemorrhage phase, and THS-induced mice demonstrated significantly increased histological injury scores. The rapid drop in MAP and microvascular tissue perfusion observed following THS induction, and the gradual recovery post resuscitation, reflects the successful establishment of a THS experimental mouse model.

Early blood product and crystalloid volume resuscitation: risk association with multiple organ dysfunction after severe blunt traumatic injury

BACKGROUND

Elements of volume resuscitation from hemorrhagic shock, such as amount of blood product and crystalloid administration, have been shown to be associated with multiple organ dysfunction (MOD). However, it is unknown whether these are causative factors or merely markers of an underlying requirement for large-volume resuscitation. We sought to further delineate the relevance of the major individual components of early volume resuscitation to onset of MOD after severe blunt traumatic injury.

METHODS

We performed a secondary analysis of a large, multicenter prospective observational cohort of severely injured blunt trauma patients, the NIGMS Trauma Glue Grant, to assess the relevance of individual components of resuscitation administered in the first 12 hours of resuscitation including packed red blood cells (PRBC), fresh frozen plasma (FFP), and isotonic crystalloid, to the onset of MOD within the first 28 days after injury. Deaths within 48 hours of injury were excluded. We used a two tiered, exhaustive logistic regression model search technique to adjust for potential confounders from clinically relevant MOD covariates, including indicators of shock severity, injury severity, comorbidities, age, and gender.

RESULTS

The study cohort consisted of 1,366 severely injured blunt trauma patients (median new Injury Severity Score = 34). Incidence of 28-day Marshall MOD was 19.6%. Transfusion of ≥10 Units of PRBC in the first 12 hours (odds ratio, 2.06; 95% confidence interval 1.44-2.94), but not FFP (≥8 U) or large volume crystalloid administration (≥12 L), was independently associated with onset of 28-day Marshall MOD. PRBC:FFP ratio in the first 12 hours was not significantly associated with MOD.

CONCLUSIONS

When controlling for all major components of acute volume resuscitation, massive-transfusion volumes of PRBC's within the first 12 hours of resuscitation are modestly associated with MOD, whereas FFP and large volume crystalloid administration are not independently associated with MOD. Previous reported associations of blood products and large-volume crystalloid with MOD may be reflecting overall resuscitation requirements and burden of injury rather than independent causation.

Protective effects of fresh frozen plasma on vascular endothelial permeability, coagulation, and resuscitation after hemorrhagic shock are time dependent and diminish between days 0 and 5 after thaw

BACKGROUND

Clinical studies have shown that resuscitation with fresh frozen plasma (FFP) is associated with improved outcome after severe hemorrhagic shock (HS). We hypothesized that in addition to its effects on hemostasis, FFP has protective and stabilizing effects on the endothelium that translate into diminished endothelial cell (EC) permeability and improved resuscitation in vivo after HS. We further hypothesized that the beneficial effects of FFP would diminish over 5 days of routine storage at 4 degrees C.

METHODS

EC permeability was induced by hypoxia and assessed by the passage of 70-kDa Dextran between monolayers. Thrombin generation time and coagulation factor levels or activity were assessed in FFP. An in vivo rat model of HS and resuscitation was used to determine the effects of FFP on hemodynamic stability.

RESULTS

Thawed FFP inhibits EC permeability in vitro by 10.2-fold. Protective effects diminish (to 2.5-fold) by day 5. Thrombin generation time is increased in plasma that has been stored between days 0 and 5. In vivo data show that day 0 FFP is superior to day 5 FFP in maintaining mean arterial pressure in rats undergoing HS with resuscitation.

CONCLUSION

Both in vitro and in vivo studies show that FFP has beneficial effects on endothelial permeability, vascular stability, and resuscitation in rats after HS. The benefits are independent of hemostasis and diminish between days 0 and 5 of storage.

Coagulation management in massive bleeding

PURPOSE OF REVIEW

To update readers on recent literature regarding treatment of coagulopathy for patients with life-threatening bleeding, highlighting emerging therapeutic options, controversial topics, and ongoing clinical trials.

RECENT FINDINGS

Massive transfusion protocols featuring immediate availability of blood products and multidisciplinary communication reduce mortality and conserve resources. There is a growing consensus that immediate administration of plasma and platelet units in a 1: 1: 1 ratio with red cell units reduces early mortality. Lyophilized and recombinant blood product components may have advantages over traditional blood products in certain clinical circumstances.

SUMMARY

Massive transfusion protocols standardize treatment of the coagulopathy of massive bleeding, leading to rapid restoration of hemostasis and decrease in early mortality.

Anesthetic concerns in trauma victims requiring operative intervention: the patient too sick to anesthetize

Trauma is the third leading cause of death in the U.S. Timely acute care anesthetic management of patients following traumatic injury may improve outcome. Recognition of highly-mortal injuries to the brain, heart, lungs, liver, and pelvis should guide trauma-specific management strategies. Rapid intraoperative treatment of life-threatening conditions following injury includes the use of 'controlled-under resuscitation' of fluid administration until surgical hemorrhage control, early factor replacement in addition to transfusion of packed red blood cells, and use of adjuvant therapies such as recombinant factor VIIa. These treatment strategies, other recent developments in acute trauma resuscitation, and a review of associated co-existing medical conditions that may impact mortality, are presented.

First report on safety and efficacy of hetastarch solution for initial fluid resuscitation at a level 1 trauma center

BACKGROUND

For logistics, the US Army recommends Hextend (Hospira; 6% hetastarch in buffered electrolyte, HET) for battlefield resuscitation. To support this practice, there are laboratory data, but none in humans. To test the hypothesis that HET is safe and effective in trauma, we reviewed our first 6 months of use at a civilian level 1 trauma center.

STUDY DESIGN

From June 2008 to December 2008, trauma patients received standard of care (SOC) +/- 500 to 1,000 mL of HET within 2 hours of admission at surgeon discretion. Each case was reviewed, with waiver of consent.

RESULTS

There were 1,714 admissions; 805 received HET and 909 did not. With HET versus SOC, overall mortality was 5.2% versus 8.9% (p = 0.0035) by univariate analysis. Results were similar after penetrating injury only (p = 0.0016) and in those with severe injury, defined by Glasgow Coma Scale <9 (p = 0.0013) or Injury Severity Score >26 (p = 0.0142). After HET, more patients required ICU admission (40.9% vs. 34.5%; p = 0.0334) and transfusions of blood (34.4% vs. 20.2%; p = 0.0014) or plasma (20.7% vs. 12.2%; p = 0.0251), but there were no treatment-related differences in prothrombin time or partial thromboplastin time. The 24-hour urine outputs and requirements for blood, plasma, and other fluids were similar. However, increased early deaths with SOC implicate possible selection bias. If that factor was controlled for with multivariate analysis, the same trends were present, but the apparent treatment effects of HET were no longer statistically significant.

CONCLUSIONS

In the first trial to date in hemodynamically unstable trauma patients, and the largest trial to date in any population of surgical patients, initial resuscitation with HET was associated with reduced mortality and no obvious coagulopathy. A randomized blinded trial is necessary before these results can be accepted with confidence.

Fluid resuscitation: past, present, and the future

Hemorrhage remains a major cause of preventable death following both civilian and military trauma. The goals of resuscitation in the face of hemorrhagic shock are restoring end-organ perfusion and maintaining tissue oxygenation while attempting definitive control of bleeding. However, if not performed properly, resuscitation can actually exacerbate cellular injury caused by hemorrhagic shock, and the type of fluid used for resuscitation plays an important role in this injury pattern. This article reviews the historical development and scientific underpinnings of modern resuscitation techniques. We summarized data from a number of studies to illustrate the differential effects of commonly used resuscitation fluids, including isotonic crystalloids, natural and artificial colloids, hypertonic and hyperoncotic solutions, and artificial oxygen carriers, on cellular injury and how these relate to clinical practice. The data reveal that a uniformly safe, effective, and practical resuscitation fluid when blood products are unavailable and direct hemorrhage control is delayed has been elusive. Yet, it is logical to prevent this cellular injury through wiser resuscitation strategies than attempting immunomodulation after the damage has already occurred. Thus, we describe how some novel resuscitation strategies aimed at preventing or ameliorating cellular injury may become clinically available in the future.

Effects of the Resuscitation Fluid and the Hemoglobin Based Oxygen Carrier (HBOC) Excipient on the Toxicity of the HBOC: Ringer'sD,L-Lactate, Ringer'sL-Lactate, and Ringer's Ketone Solutions

Hemoglobin based oxygen carriers (HBOC) are resuspended in "excipients" consisting of Ringer's D,L-lactate containing antioxidants to prevent methemoglobin formation during storage. Investigators have reported cardiac arrhythmias following infusion of Ringer's D,L-lactate solution. Studies have shown that D-lactate stimulates human granulocytes to generate oxygen free radicals and L-lactate inhibits glycolysis. Patients receiving HBOC in Ringer's D,L-lactate excipient are also resuscitated or hemodiluted with Ringer's lactate solution. Oxygen-free radicals generated by Ringer's D,L-lactate and HBOC may oxidize nitric oxide in endothelial cells, causing the vasoconstrictor effects reported following HBOC infusion, and activate NF-kappab and the apoptotic cascade. The combination of Ringer's D,L-lactate and HBOC in Ringer's D,L-lactate excipient may be responsible for the severe adverse events observed in clinical studies of HBOC.Veech has recommended replacing the 27 mM of lactate in Ringer's with 27 mM D-betahydroxybutyrate (BHB). BHB reduces the generation of oxygen free radicals by mitochondria and human granulocytes.

Albumin resuscitation protects against traumatic/hemorrhagic shock-induced lung apoptosis in rats

OBJECTIVE

To determine the effects of albumin administration on lung injury and apoptosis in traumatic/hemorrhagic shock (T/HS) rats.

METHODS

Studies were performed on an in vivo model of spontaneously breathing rats with induced T/HS; the rats were subjected to femur fracture, ischemia for 30 min, and reperfusion for 20 min with Ringer's lactate solution (RS) or 5% (w/v) albumin (ALB), and the left lower lobes of the lungs were resected.

RESULTS

Albumin administered during reperfusion markedly attenuated injury of the lung and decreased the concentration of lactic acid and the number of in situ TdT-mediated dUTP nick-end labelling (TUNEL)-positive cells. Moreover, immunohistochemistry performed 24 h after reperfusion revealed increases in the level of nuclear factor kappaB (NF-kappaB), and phosphorylated p38 mitogen-activated protein kinase (MAPK) in the albumin-untreated group was down-regulated by albumin treatment when compared with the sham rats.

CONCLUSION

Resuscitation with albumin attenuates tissue injury and inhibits T/HS-induced apoptosis in the lung via the p38 MAPK signal transduction pathway that functions to stimulate the activation of NF-kappaB.

Apoptosis and haemorrhagic shock

Abstract

This is a review paper that provides an overview of current information on programmed cell death in haemorrhagic shock, including the identification of different molecular receptor signals. A PubMed search for all dates was undertaken using the search terms apoptosis, trauma and haemorrhagic shock. Original research, sentinel and review papers from peer-reviewed journals were included for identification of key concepts. Haemorrhagic shock remains a primary cause of death in civilian and military trauma. Apoptosis is accelerated following haemorrhagic shock. Many methods are used to detect and quantify apoptosis. Fluid resuscitation regimens vary in their effect on the extent of apoptosis. Investigators are examining the effects of haemorrhagic shock and fluid resuscitation on apoptotic signalling pathways. Molecular information is becoming available and being applied to the care of patients experiencing haemorrhagic shock, making it essential for nurses and other health care providers to consider the mechanisms and consequences of apoptosis.

Trauma-hemorrhagic shock-induced pulmonary epithelial and endothelial cell injury utilizes different programmed cell death signaling pathways

Intestinal ischemia after trauma-hemorrhagic shock (T/HS) results in gut barrier dysfunction and the production/release of biologically active and tissue injurious factors in the mesenteric lymph, which, in turn, causes acute lung injury and a systemic inflammatory state. Since T/HS-induced lung injury is associated with pulmonary endothelial and epithelial cell programmed cell death (PCD) and was abrogated by mesenteric lymph duct ligation, we sought to investigate the cellular pathways involved. Compared with trauma-sham shock (T/SS) rats, a significant increase in caspase-3 and M30 expression was detected in the pulmonary epithelial cells undergoing PCD, whereas apoptosis-inducing factor (AIF), but not caspase-3, was detected in endothelial cells undergoing PCD. This AIF-mediated pulmonary endothelial PCD response was validated in an in situ femoral vein assay where endothelial cells were found to express AIF but not caspase-3. To complement these studies, human umbilical vein endothelial cell (HUVEC), human lung microvascular endothelial cell (HLMEC), and human alveolar type II epithelial cell (A549) lines were used as in vitro models. T/HS lymph induced the nuclear translocation of AIF in HUVEC and HLMEC, and caspase inhibition in these cells did not afford any cytoprotection. For proof of principle, AIF silencing in HUVEC reversed the cytotoxic effects of T/HS on cell viability and DNA fragmentation. In A549 cells, T/HS lymph activated caspase-3-mediated apoptosis, which was partially abrogated by N-benzyloxycarbonyl-Val-Ala-Asp (zVAD). Additionally, T/HS lymph did not cause the nuclear translocation of AIF in A549 cells. Collectively, T/HS-induced pulmonary endothelial PCD occurs via an AIF-dependent caspase-independent pathway, whereas epithelial cells undergo apoptosis by a caspase-dependent pathway.

Allicin, a major component of garlic, inhibits apoptosis in vital organs in rats with trauma/hemorrhagic shock

OBJECTIVE

Allicin is believed to be the main component responsible for the biological activity of garlic. The regulation of cell apoptosis may have therapeutic potential for trauma/hemorrhagic shock, and previous studies have demonstrated that allicin exerts protective effects against tissue ischemia-reperfusion injury. Therefore, this study examined the effects of allicin on apoptosis-related organ damage, induced by trauma/hemorrhagic shock.

METHODS

Studies were performed on an in vivo model of spontaneously breathing rats with induced trauma/hemorrhagic shock; the left lower lobe of the lungs, left kidney, and intestine were resected, and the rats were subjected to femur fracture, ischemia for 30 mins, and reperfusion for 20 mins. Allicin (30 microg/kg) was administered during reperfusion.

RESULTS

Allicin administered during reperfusion markedly attenuated injury and apoptosis of the lungs, kidneys, and intestine and decreased the concentrations of lactic acid and creatinine, the number of in situ TdT-mediated dUTP nick-end labeling-positive cells, and the activity and expression of caspase-3 and -9 (as determined by Western blot). Furthermore, immunohistochemistry and Western blot performed 24 hrs after reperfusion revealed increases in the levels of nuclear factor kappaB, phosphorylated p38, and extracellular signal-regulated kinase 1 mitogen-activated protein kinase in the allicin-untreated group when compared with the sham rats. Allicin treatment downregulated the levels of nuclear factor kappaB and phosphorylated p38 mitogen-activated protein kinase but did not modify those of phosphorylated extracellular signal-regulated kinase 1 mitogen-activated protein kinase.

CONCLUSION

Allicin attenuates tissue injury and inhibits trauma/hemorrhagic shock- and reperfusion-induced apoptosis in several important organs via the p38 mitogen-activated protein kinase signal transduction pathway that functions to stimulate the activation of nuclear factor-kappaB, caspase-3 and -9, but not of extracellular signal-regulated kinase 1 mitogen-activated protein kinase.

Increased plasma and platelet to red blood cell ratios improves outcome in 466 massively transfused civilian trauma patients

OBJECTIVE

To determine the effect of blood component ratios in massive transfusion (MT), we hypothesized that increased use of plasma and platelet to red blood cell (RBC) ratios would result in decreased early hemorrhagic death and this benefit would be sustained over the ensuing hospitalization.

SUMMARY BACKGROUND DATA

Civilian guidelines for massive transfusion (MT > or =10 units of RBC in 24 hours) have typically recommend a 1:3 ratio of plasma:RBC, whereas optimal platelet:RBC ratios are unknown. Conversely, military data shows that a plasma:RBC ratio approaching 1:1 improves long term outcomes in MT combat casualties. There is little consensus on optimal platelet transfusions in either civilian or military practice. At present, the optimal combinations of plasma, platelet, and RBCs for MT in civilian patients is unclear.

METHODS

Records of 467 MT trauma patients transported from the scene to 16 level 1 trauma centers between July 2005 and June 2006 were reviewed. One patient who died within 30 minutes of admission was excluded. Based on high and low plasma and platelet to RBC ratios, 4 groups were analyzed.

RESULTS

Among 466 MT patients, survival varied by center from 41% to 74%. Mean injury severity score varied by center from 22 to 40; the average of the center means was 33. The plasma:RBC ratio ranged from 0 to 2.89 (mean +/- SD: 0.56 +/- 0.35) and the platelets:RBC ratio ranged from 0 to 2.5 (0.55 +/- 0.50). Plasma and platelet to RBC ratios and injury severity score were predictors of death at 6 hours, 24 hours, and 30 days in multivariate logistic models. Thirty-day survival was increased in patients with high plasma:RBC ratio (> or =1:2) relative to those with low plasma:RBC ratio (<1:2) (low: 40.4% vs. high: 59.6%, P < 0.01). Similarly, 30-day survival was increased in patients with high platelet:RBC ratio (> or =1:2) relative to those with low platelet:RBC ratio (<1:2) (low: 40.1% vs. high: 59.9%, P < 0.01). The combination of high plasma and high platelet to RBC ratios were associated with decreased truncal hemorrhage, increased 6-hour, 24-hour, and 30-day survival, and increased intensive care unit, ventilator, and hospital-free days (P < 0.05), with no change in multiple organ failure deaths. Statistical modeling indicated that a clinical guideline with mean plasma:RBC ratio equal to 1:1 would encompass 98% of patients within the optimal 1:2 ratio.

CONCLUSIONS

Current transfusion practices and survival rates of MT patients vary widely among trauma centers. Conventional MT guidelines may underestimate the optimal plasma and platelet to RBC ratios. Survival in civilian MT patients is associated with increased plasma and platelet ratios. Massive transfusion practice guidelines should aim for a 1:1:1 ratio of plasma:platelets:RBCs.

Prevention of hypovolemic circulatory collapse by IL-6 activated Stat3

Half of trauma deaths are attributable to hypovolemic circulatory collapse (HCC). We established a model of HCC in rats involving minor trauma plus severe hemorrhagic shock (HS). HCC in this model was accompanied by a 50% reduction in peak acceleration of aortic blood flow and cardiomyocyte apoptosis. HCC and apoptosis increased with increasing duration of hypotension. Apoptosis required resuscitation, which provided an opportunity to intervene therapeutically. Administration of IL-6 completely reversed HCC, prevented cardiac dysfunction and cardiomyocyte apoptosis, reduced mortality 5-fold and activated intracardiac signal transducer and activator of transcription (STAT) 3. Pre-treatment of rats with a selective inhibitor of Stat3, T40214, reduced the IL-6-mediated increase in cardiac Stat3 activity, blocked successful resuscitation by IL-6 and reversed IL-6-mediated protection from cardiac apoptosis. The hearts of mice deficient in the naturally occurring dominant negative isoform of Stat3, Stat3β, were completely resistant to HS-induced apoptosis. Microarray analysis of hearts focusing on apoptosis related genes revealed that expression of 29% of apoptosis related genes was altered in HS vs. sham rats. IL-6 treatment normalized the expression of these genes, while T40214 pretreatment prevented IL-6-mediated normalization. Thus, cardiac dysfunction, cardiomyocyte apoptosis and induction of apoptosis pathway genes are important components of HCC; IL-6 administration prevented HCC by blocking cardiomyocyte apoptosis and induction of apoptosis pathway genes via Stat3 and warrants further study as a resuscitation adjuvant for prevention of HCC and death in trauma patients.

Histidine inhibits the degradation of cells suspended in Ringer's lactate

BACKGROUND

We previously demonstrated that the degradation of a suspension of Jurkat cells in Ringer's lactate (RL) was inhibited by the addition of a 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid/Tris buffer. Given the ability of histidine to buffer protons in the physiologic range (pKa = 6.0), we hypothesized that this amino acid would have the same effect.

METHODS

RL was made in our laboratory using sodium l-lactate. Jurkat cells were suspended in RL alone or RL with various concentrations of histidine or other test reagents at 37 degrees C for 4 hours or 24 hours in an atmosphere of 95% air and 5% CO2. Using flow cytometry, we measured cell shrinkage, phosphatidylserine translocation, propidium iodide uptake, and intracellular oxygen free radical production.

RESULTS

Cell shrinkage was induced by suspension in RL after 4 hours incubation. At 4 hours, cell shrinkage was inhibited by all concentrations of histidine tested, 7.8 mumol/L to 10 mmol/L. There was no statistical difference between cells suspended in medium and cells suspended in 1 mmol/L or 10 mmol/L histidine. After 24 hours incubation, 100% of the cells in RL had undergone cell shrinkage whereas in 10 mmol/L histidine only a mean of 20% of the cells had undergone cell shrinkage. The inhibitory effect of 1 mmol/L histidine at pH 7.4 was compared with that at pH 6.8. After 4 hours incubation, there was no difference. After 24 hours incubation, the inhibitory effect at pH 7.4 was significantly greater that that at pH 6.8. Histidine at 1 mmol/L to 10 mmol/L significantly reduced the percentage of cells that underwent phosphatidylserine translocation and propidium iodide uptake. The effect of the dipeptide buffer, glycylglycine, and the two other positively charged amino acids, arginine and lysine, after 4 hours incubation was compared with histidine at 1 mmol/L. At 1 mmol/L, histidine was superior to arginine and lysine and indistinguishable from glycylglycine. Intracellular free radical production was measured at 0.5 mmol/L, 1.0 mmol/L, and 10 mmol/L histidine concentrations. There was significant inhibition only at 10 mmol/L.

CONCLUSIONS

Characteristics of apoptotic cell death that occur in cells suspended in RL are inhibited by the addition of histidine, arginine, and lysine as well as the dipeptide glycylglycine, which, with a pKa of 8.25, also buffers in the physiologic range. Histidine is superior to lysine and arginine at 1 mmol/L. The salutary effect of histidine at 0.5 mmol/L and 1 mmol/L is caused by a mechanism other than the inhibition of oxygen free radicals. Moreover, the buffering of protons may play a role at 24 hours but made no difference at 4 hours.

Biphasic onset of splenic apoptosis following hemorrhagic shock: critical implications for Bax, Bcl-2, and Mcl-1 proteins

Introduction

The innate immune response to trauma hemorrhage involves inflammatory mediators, thus promoting cellular dysfunction as well as cell death in diverse tissues. These effects ultimately bear the risk of post-traumatic complications such as organ dysfunction, multiple organ failure, or adult respiratory distress syndrome. In this study, a murine model of resuscitated hemorrhagic shock (HS) was used to determine the apoptosis in spleen as a marker of cellular injury and reduced immune functions.

Methods

Male C57BL-6 mice were subjected to sham operation or resuscitated HS. At t = 0 hours, t = 24 hours, and t = 72 hours, mice were euthanized and the spleens were removed and evaluated for apoptotic changes via DNA fragmentation, caspase activities, and activation of both extrinsic and intrinsic apoptotic pathways. Spleens from untreated mice were used as control samples.

Results

HS was associated with distinct lymphocytopenia as early as t = 0 hours after hemorrhage without regaining baseline levels within the consecutive 72 hours when compared with sham and control groups. A rapid activation of splenic apoptosis in HS mice was observed at t = 0 hours and t = 72 hours after hemorrhage and predominantly confirmed by increased DNA fragmentation, elevated caspase-3/7, caspase-8, and caspase-9 activities, and enhanced expression of intrinsic mitochondrial proteins. Accordingly, mitochondrial pro-apoptotic Bax and anti-apoptotic Bcl-2 proteins were inversely expressed within the 72-hour observation period, thereby supporting significant pro-apoptotic changes. Solely at t = 24 hours, expression of the anti-apoptotic Mcl-1 protein shows a significant increase when compared with sham-operated and control animals. Furthermore, expression of extrinsic death receptors were only slightly increased.

Conclusion

Our data suggest that HS induces apoptotic changes in spleen through a biphasic caspase-dependent mechanism and imply a detrimental imbalance of pro- and anti-apoptotic mitochondrial proteins Bax, Bcl-2, and Mcl-1, thereby promoting post-traumatic immunosuppression.

Fluid management of the trauma patient

Hemodynamic instability in the trauma patient is most commonly secondary to blood loss and the accumulation of fluid in injured tissue. The etiologies of shock unrelated to hypovolemia must also be investigated. The treatment of hypovolemia in patients with non-cerebral trauma should begin with Ringer's lactate solution. Normal saline (0.9% sodium chloride) is appropriate for patients with head injury, alkalosis, or hyponatremia, but in large volumes may lead to metabolic acidosis. The role of colloids, hypertonic saline, and hemoglobin solutions in trauma resuscitation is unclear at the present time. Base deficit and lactate levels are useful as predictors of morbidity and mortality and can be used to guide resuscitation.

RESUSCITATION WITH HYDROXYETHYL STARCH SOLUTION PREVENTS NUCLEAR FACTOR κB ACTIVATION AND OXIDATIVE STRESS AFTER HEMORRHAGIC SHOCK AND RESUSCITATION IN RATS

Fluid resuscitation is vital for treating traumatic hemorrhagic shock (HS), but reperfusion is believed to have the adverse consequences of generating reactive oxygen species and inflammatory cytokines, both of which cause multiple organ dysfunctions. We investigated the effects of various resuscitation fluids on the changes of redox-sensitive molecules after HS and fluid resuscitation (HS/R). We induced HS by bleeding male Sprague-Dawley rats to a blood pressure of 30 to 40 mmHg for 60 minutes. Thirty minutes later, the rats were killed (HS group) or immediately resuscitated with shed blood (HS + BL group), L-isomer lactated Ringer's solution (HS + LR group), or hydroxyethyl starch (HS + HES group). After HS, we found a significant increase in nuclear factor kappaB DNA binding activity, which was effectively inhibited using HES solution or blood resuscitation. Moreover, resuscitation with blood or LR solution, but not HES solution, induced significant oxidative stress, manifested by a high ratio of oxidized glutathione to reduced glutathione in the lungs, liver, and spleen. HS alone, however, did not increase the ratio of the oxidized glutathione to reduced glutathione in all organs. Although the protein expression of anti-apoptotic Bcl-2 and pro-apoptotic Bax varied in different organs, we found that resuscitation using HES solution prevented the HS-induced reduction of the Bcl-2/Bax ratio in the heart. HES solution was an appropriate resuscitation fluid in reversing nuclear factor kappaB activation, maintaining the Bcl-2/Bax ratio, and preventing oxidative stress after acute HS.

New developments in fluid resuscitation

Hemorrhagic shock is the leading cause of death in civilian and military trauma. Effective hemorrhage control and optimal resuscitation are the main goals in the management of severely injured patients. This article addresses the changing trends in fluid resuscitation in regards to who, when, and how. Much of these changing trends are caused by the recognition that the current method of resuscitation with crystalloid fluids may not be optimal and may even have detrimental consequences. This article summarizes a number of studies that have evaluated the cellular toxicities of commonly used resuscitation fluids, to highlight the need for the development of new fluids.

An update on fluid resuscitation

Hemorrhagic shock is the leading cause of death in civilian and military trauma. Effective hemorrhage control and better resuscitation strategies have the potential of saving lives. However, if not performed properly, resuscitation can actually exacerbate cellular injury caused by hemorrhagic shock, and the type of fluid used for resuscitation plays an important role in this injury pattern. It is logical to prevent this cellular injury through wiser resuscitation strategies than attempting immunomodulation after the damage has already occurred. It is important to recognize that unlike numerous other variables, resuscitation is completely under our control. We decide who, when and how should get resuscitated. This paper summarizes data from a number of studies to illustrate the differential effects of commonly used resuscitation fluids on cellular injury, and how these relate to clinical practice. In addition, some novel resuscitation strategies are described that may become clinically available in the near future.

Hepatic and Pulmonary Apoptosis After Hemorrhagic Shock in Swine Can Be Reduced Through Modifications of Conventional Ringer???s Solution

BACKGROUND

Cytotoxic properties of racemic (D-,L-isomers) lactated Ringer's solution detected in vitro and in small animal experiments, have not been confirmed in large animal models. Our hypothesis was that in a clinically relevant large animal model of hemorrhage, resuscitation with racemic lactated Ringer's solution would induce cellular apoptosis, which can be attenuated by elimination of d-lactate.

METHODS

Yorkshire swine (n = 49, weight 40-58 kg) were subjected to uncontrolled (iliac arterial and venous injuries) and controlled hemorrhage, totaling 40% of estimated blood volume. They were randomized (n = 7/group) to control groups, which consisted of (1) no hemorrhage (NH), (2) no resuscitation (NR), or resuscitation groups, which consisted of (3) 0.9% saline (NS), (4) racemic lactated Ringer's (DL-LR), (5) L-isomer lactated Ringer's (L-LR), (6) Ketone Ringer's (KR), (7) 6% hetastarch in 0.9% saline (Hespan). KR was identical to LR except for equimolar substitution of lactate with beta-hydroxybutyrate. Resuscitation was performed in three phases, simulating (1) prehospital, (2) operative, (3) postoperative/recovery periods. Arterial blood gasses, circulating cytokines (TNF-alpha, IL-1, -6, -10), and markers of organ injury were serially measured. Metabolic activity of brain, and liver, was measured with microdialysis. Four hours postinjury, organs were harvested for Western blotting, ELISA, TUNEL assay, and immunohistochemistry.

RESULTS

All resuscitation strategies restored blood pressure, but clearance of lactic acidosis was impeded following DL-LR resuscitation. Metabolic activity decreased during shock and improved with resuscitation, without any significant inter-group differences. Levels of cytokines in circulation were similar, but tissue levels of TNF in liver and lung increased six- and threefolds (p < 0.05) in NR group. In liver, all resuscitation strategies significantly decreased TNF levels compared with the NR group, but in the lung resuscitation with lactated Ringer (DL and L isomers) failed to decrease tissue TNF levels. DL-LR resuscitation also increased apoptosis (p < 0.05) in liver and lung, which was not seen after resuscitation with other solutions.

CONCLUSIONS

In this large animal model of hemorrhagic shock, resuscitation with conventional (racemic) LR solution increased apoptotic cell death in liver and lung. This effect can be prevented by simple elimination of D-lactate from the Ringer's solution.

Hepatic apoptosis after hemorrhagic shock in rats can be reduced through modifications of conventional Ringer's solution

BACKGROUND

Resuscitation with racemic lactated Ringer's solution induces cellular apoptosis. This study was conducted to determine if the elimination of D-lactate isomer would attenuate apoptosis in the liver, and to investigate the possible mechanisms.

STUDY DESIGN

Sprague Dawley rats (n=30, 5 per group) were subjected to modified volume-controlled hemorrhage and randomized to the following groups: no hemorrhage (sham); no resuscitation (NR); resuscitation with racemic lactated Ringer's (DL-LR); L-isomer LR (L-LR); ketone (beta-hydroxybuturate) Ringer's (KR); or pyruvate Ringer's (PR). Animals were sacrificed 2 hours later and expressions of proapoptotic proteins (BAD), antiapoptotic (bcl-2) proteins, and poly-ADP ribose polymerase (PARP) cleavage in liver were analyzed by Western blotting. Contribution of the phosphatidylinositol 3-kinase/serine/threonine kinase (PI3k/Akt) pathway was assessed by measuring total and phosphorylated PI3K, Akt, BAD, and endothelial nitric oxide synthase (eNOS) proteins. The terminal deoxynucleotidyl transferase mediated dUTP nick end labeling (TUNEL) assay was used to detect the apoptotic cells. Liver ATP levels were measured using a luciferase reaction assay.

RESULTS

Hemorrhage significantly decreased the hepatic ATP level and resuscitation improved it, but it returned to normal only in the L-isomer lactated Ringer's and ketone Ringer's groups. Expression of proapoptotic proteins was significantly lower in the pyruvate Ringer's and ketone Ringer's groups; L-isomer lactated Ringer's and pyruvate Ringer's resuscitation significantly increased bcl-2 expression. Poly-ADP ribose polymerase fragmentation and total number of apoptotic cells were significantly increased in the racemic lactated Ringer's group. There was no significant induction of Akt activity or changes in phosphorylated BAD, Akt, or eNOS levels.

CONCLUSIONS

Resuscitation with racemic lactated Ringer's induces hepatic apoptosis, which is decreased if the D-isomer of lactate is eliminated. Apoptosis is reduced even more when lactate is substituted with beta-hydroxybutyrate or pyruvate. The beneficial effects are not through improvements in the energy status or activation of the PI3K/Akt pathway.

The epidemiology and modern management of traumatic hemorrhage: US and international perspectives

Trauma is a worldwide problem, with severe and wide ranging consequences for individuals and society as a whole. Hemorrhage is a major contributor to the dilemma of traumatic injury and its care. In this article we describe the international epidemiology of traumatic injury, its causes and its consequences, and closely examine the role played by hemorrhage in producing traumatic morbidity and mortality. Emphasis is placed on defining situations in which traditional methods of hemorrhage control often fail. We then outline and discuss modern principles in the management of traumatic hemorrhage and explore developing changes in these areas. We conclude with a discussion of outcome measures for the injured patient within the context of the epidemiology of traumatic injury.

Combat casualty care research: from bench to the battlefield

Hemorrhagic shock is the leading cause of death in civilian and combat trauma. Effective hemorrhage control and better resuscitation strategies have the potential of saving lives. The Trauma Readiness and Research Institute for Surgery (TRRI-Surg) was established to address the core mission of the Uniformed Services University, "Learning to Care for Those in Harm's Way," by conducting research to improve the outcome of combat casualties. This article highlights the salient achievements of this research effort in the areas of hemorrhage control, resuscitation, design and testing of devices, and some novel concepts such as the use of profound hypothermia. The impact of these basic science research findings on changes in military medical care and outcome of injured soldiers is also described.

Progress in Postoperative ICU Management

The clinical case presented in this article illustrates how many of the more recent advances in the management of critically ill patients apply to current clinical practice. Simple cost-effective general measures (eg, optimal sterile precautions during procedures; hand washing; early goal-directed resuscitation with appropriate fluids, inotropes, and antibiotics; and surgical source control of infected foci) still should form the basis of clinical practice, however. There has been renewed interest in blood transfusion therapy and its associated risks. Lower tidal volume ventilation now is practiced almost universally in patients with ARDS, and several new selective pulmonary vasodilators have extended the armamentarium when taking care of these patients. High-frequency oscillatory ventilation and ECMO remain challenging options in patients with refractory hypoxemia. Appropriate patient selection is important when corticosteroid therapy is considered. Tight blood glucose control and monitoring improve outcome and should be part of ICU care of septic patients. The role of the PAC is controversial. Other techniques to measure cardiac output, hemodynamics, and perfusion are available and should be considered. Sedation and analgesia form an integral part of critical care. Because of its immediate and long-term risks, neuromuscular blockade should be used sparingly and only when all other options have been exhausted. Ongoing education regarding sedation protocols and the effect of sedation on outcome is needed among physicians and nurses caring for these patients.

The effect of shock resuscitation fluids on apoptosis

BACKGROUND

Recent data suggest that the type of resuscitation fluid used to treat hemorrhagic shock contributes to cellular dysfunction

METHODS

Rats were hemorrhaged, exposed to a hypovolemic shock period for 75 minutes, and then resuscitated for 1 hour. Treatment animals were assigned randomly to lactate Ringer's solution, normal saline solution, bicarbonate Ringer's solution, hypertonic saline solution, rat plasma solution, ketone Ringer's solution, or nonresuscitation. After resuscitation, lung and liver samples were collected and evaluated for apoptosis by using ligation-mediated polymerase chain reaction.

RESULTS

Nonresuscitated shock rats had significantly higher levels of apoptosis in lung and liver. Rats treated with normal saline solution, bicarbonate Ringer's solution, ketone Ringer's solution, and hypertonic saline solution had significantly lower levels of apoptosis in lung compared with nonresuscitated animals. Rats treated with bicarbonate Ringer's solution and ketone Ringer's solution had significantly lower levels of apoptosis in liver tissue when compared with nonresuscitated animals.

CONCLUSIONS

Cellular damage results from hemorrhagic shock. The use of resuscitation fluids decreases apoptosis during shock.