Differential expression of extracellular matrix remodeling genes in rat model of hemorrhagic shock and resuscitation1,2

Major venous injury and large volume crystalloid resuscitation: A limb threatening combination

INTRODUCTION

Major venous injury (MVI) affecting the lower extremity can result in subsequent amputation. The contribution of intraoperative resuscitation efforts on the need for amputation is not well defined. We hypothesized that intraoperative large volume crystalloid resuscitation (LVCR) increases the risk of amputation after MVI, while massive transfusion (MT) does not.

METHODS

We performed a retrospective review of patients with infrarenal MVI from 2005 to 2015 at seven urban level I trauma centers. The outcome of interest was the need for secondary amputation.

RESULTS

478 patients were included. 31 (6.5%) patients with MVI required amputation. LVCR(p < 0.001), combined arterial/venous injury (p = 0.001), and associated fracture (p = 0.001) were significant risk factors for amputation. MT did not significantly increase amputation risk (p = 0.44). Multivariable logistic regression model demonstrated that patients receiving ≥5L LVCR(aOR (95% CI): 9.7 (2.9, 33.0); p < 0.001), with combined arterial/venous injury (aOR (95% CI):3.6 (1.5, 8.5); p = 0.004), and with an associated fracture (aOR (95% CI):3.2 (1.5, 7.1); p = 0.004) were more likely to require amputation.

CONCLUSION

Patients with MVI who receive LVCR, have combined arterial/venous injuries and have associated fractures are more likely to require amputation. MT was not associated with delayed amputation.

Hemorrhagic Shock and the Microvasculature

The microvasculature plays a central role in the pathophysiology of hemorrhagic shock and is also involved in arguably all therapeutic attempts to reverse or minimize the adverse consequences of shock. Microvascular studies specific to hemorrhagic shock were reviewed and broadly grouped depending on whether data were obtained on animal or human subjects. Dedicated sections were assigned to microcirculatory changes in specific organs, and major categories of pathophysiological alterations and mechanisms such as oxygen distribution, ischemia, inflammation, glycocalyx changes, vasomotion, endothelial dysfunction, and coagulopathy as well as biomarkers and some therapeutic strategies. Innovative experimental methods were also reviewed for quantitative microcirculatory assessment as it pertains to changes during hemorrhagic shock. The text and figures include representative quantitative microvascular data obtained in various organs and tissues such as skin, muscle, lung, liver, brain, heart, kidney, pancreas, intestines, and mesentery from various species including mice, rats, hamsters, sheep, swine, bats, and humans. Based on reviewed findings, a new integrative conceptual model is presented that includes about 100 systemic and local factors linked to microvessels in hemorrhagic shock. The combination of systemic measures with the understanding of these processes at the microvascular level is fundamental to further develop targeted and personalized interventions that will reduce tissue injury, organ dysfunction, and ultimately mortality due to hemorrhagic shock. Published 2018. Compr Physiol 8:61-101, 2018.

Dynamic changes in rat mesenteric lymph proteins following trauma using label-free mass spectrometry

Early events triggered by posttrauma/hemorrhagic shock currently represent a leading cause of morbidity and mortality in these patients. The causative agents of these events have been associated with increased neutrophil priming secondary to shock-dependent alterations of mesenteric lymph. Previous studies have suggested that unknown soluble components of the postshock mesenteric lymph are main drivers of these events. In the present study, we applied a label-free proteomics approach to further delve into the early proteome changes of the mesenteric lymph in response to hemorrhagic shock. Time-course analyses were performed by sampling the lymph every 30 min after shock up until 3 h (the time window within which a climax in neutrophil priming was observed). There are novel, transient early post-hemorrhagic shock alterations to the proteome and previously undocumented postshock protein alterations. These results underlie the triggering of coagulation and proinflammatory responses secondary to trauma/hemorrhagic shock, metabolic deregulation and apoptosis, and alterations to proteases/antiproteases homeostasis, which are suggestive of the potential implication of extracellular matrix proteases in priming neutrophil activation. Finally, there is a likely correlation between early postshock mesenteric lymph-mediated neutrophil priming and proteomics changes, above all protease/antiproteases impaired homeostasis (especially of serine proteases and metalloproteases).

The effect of Chaiqin Chengqi Decoction () on modulating serum matrix metalloproteinase 9 in patients with severe acute pancreatitis

OBJECTIVE

To investigate the effect of Chaiqin Chengqi Decoction (, CQCQD) on regulating serum matrix metalloproteinase 9 (MMP-9) in patients with severe acute pancreatitis (SAP).

METHODS

Thirty-five SAP patients hospitalized in West China Hospital from September 1, 2008 to February 28, 2009 were randomly assigned to two groups using a computer-derived random number sequence in a ratio of 1:1, treatment group (18 patients) and the placebo control group (17 patients). The patients in the treatment group were administered with CQCQD by gastric perfusion (50 mL/2 h) and retention enema (200 mL/6 h) for 7 days. The two groups had similar baseline information. The clinical indicators, including the initial Balthazar's computed tomography (CT) score, acute physiology and chronic health evaluation II (APACHE II) scores on 1st, 3rd, 5th and 7th day, incidences and durations of complications and the serum C-reactive protein (CRP), levels of MMP-9 on the 1st, 3rd, 5th and 7th day, were recorded and compared between the two groups.

RESULTS

The serum MMP-9, CRP and the APACHE II scores on the 3rd, 5th and 7th day in the treatment group were lower than those in the control group (P<0.05). The serum MMP-9 was positively correlated with the APACHE II score on the 1st day (r=0.430, P=0.01). The durations of acute respiratory distress syndrome (5.4±2.4 vs. 2.9±1.3), acute hepatitis (4.6±0.8 vs. 1.9±0.6) and acute heart failure (3.9±1.6 vs. 1.3±0.6, <0.05) in the control group were longer than those in the treatment group.

CONCLUSION

CQCQD could decrease the serum MMP-9 to relieve the severity of clinical symptoms and prevent the development of multiple organ dysfunction syndrome in patients with SAP.

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.

Acute pancreatitis: hypertonic saline increases heat shock proteins 70 and 90 and reduces neutrophil infiltration in lung injury

OBJECTIVES

Acute pancreatitis (AP) protease release induces lung parenchymal destruction via matrix metalloproteinases (MMPs), a neutrophil (polymorphonuclear leukocyte)-dependent process. Recent studies in hemorrhagic shock revealed that hypertonic saline (HTS) has an anti-inflammatory effect and can inhibit a variety of neutrophil functions. The aim of this study was to determine whether HTS and its actions in the pathway of neutrophil migration, MMPs, and heat shock proteins (HSPs) are effective in protecting the lung from injury associated with AP.

METHODS

We determined neutrophil infiltration and expressions of MMPs and HSPs in the lung tissue after AP induced by retrograde infusion of 2.5% of sodium taurocholate.

RESULTS

Animals submitted to AP that received HTS compared with those who received normal saline presented with increased HSP70 and HSP90 expressions and reduced myeloperoxidase levels and MMP-9 expression and activity.

CONCLUSIONS

Our data raised the hypothesis that a sequence of HTS lung protection events increases HSP70 and HSP90, inhibiting infiltration of neutrophils and their protease actions in the lung.

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.

Small volume hypertonic resuscitation of circulatory shock

Small volume hypertonic resuscitation is a relatively new conceptual approach to shock therapy. It was originally based on the idea that a relatively large blood volume expansion could be obtained by administering a relatively small volume of fluid, taking advantage of osmosis. It was soon realized that the physiological vasodilator property of hypertonicity was a useful byproduct of small volume resuscitation in that it induced reperfusion of previously ischemic territories, even though such an effect encroached upon the malefic effects of the ischemia-reperfusion process. Subsequent research disclosed a number of previously unsuspected properties of hypertonic resuscitation, amongst them the correction of endothelial and red cell edema with significant consequences in terms of capillary blood flow. A whole set of actions of hypertonicity upon the immune system are being gradually uncovered, but the full implication of these observations with regard to the clinical scenario are still under study. Small volume resuscitation for shock is in current clinical use in some parts of the world, in spite of objections raised concerning its safety under conditions of uncontrolled bleeding. These objections stem mainly from experimental studies, but there are few signs that they may be of real clinical significance. This review attempts to cover the earlier and the more recent developments in this field.