Early Therapeutic Intervention for Crush Syndrome: Characterization of Intramuscular Administration of Dexamethasone by Pharmacokinetic and Biochemical Parameters in Rats

Cardiovascular events in crush syndrome: on-site therapeutic strategies and pharmacological investigations

Crush syndrome often occurs after severe crush injury caused by disasters or accidents, and is associated with high mortality and poor prognosis. Cardiovascular complications, such as cardiac arrest, hypovolemic shock, and hyperkalemia-related cardiac dysfunction, are the primary causes of on-site death in crush syndrome. Prehospital evaluation, together with timely and correct treatment, is of great benefit to crush syndrome patients, which is difficult in most cases due to limited conditions. Based on current data and studies, early fluid resuscitation remains the most important on-site treatment for crush syndrome. Novel solutions and drugs used in fluid resuscitation have been investigated for their effectiveness and benefits. Several drugs have proven effective for the prevention or treatment of cardiovascular complications in crush syndrome, such as hypovolemic shock, hyperkalemia-induced cardiac complications, myocardial ischemia/reperfusion injury, ventricular dysfunction, and coagulation disorder experimentally. Moreover, these drugs are beneficial for other complications of crush syndrome, such as renal dysfunction. In this review, we will summarize the existing on-site treatments for crush syndrome and discuss the potential pharmacological interventions for cardiovascular complications to provide clues for clinical therapy of crush syndrome.

Systemic Review of Animal Models Used in the Study of Crush Syndrome

ABSTRACT

Crush syndrome (CS), also known as traumatic rhabdomyolysis, is the leading cause of death following extrication from structural collapse due to earthquakes. Due to the unfeasibility of human studies, animal models are used to study crush syndrome pathophysiology, including biochemistry and treatment regimes. The aim of this systematic literature review was to identify the differences and benefits of various animal models used in the study of CS and provide valuable information for design of future research. A systematic search was conducted in two methods: with the filters "(crush syndrome) AND (crush muscle injury)" and with the keywords "(crush syndrome) AND (animal model)" covering all articles in the PubMed databases. The search generated 378 articles. After screening abstracts, 91 articles were retrieved and read, then 11 repeated articles were removed and 2 reference papers were included. We finally reviewed 82 original articles. There appear to be two primary methods employed for inducing crush syndrome in animal models, which are chemically induced injury and physically induced injury. Chemical method mainly includes intramuscular (IM) injection of tissue extract solution and IM injection of 50% glycerine. Physical method can be classified into invasive and non-invasive physical compression by elasticated material, inflatable band and heavy load. Various species of animals have been used to study CS, including mice (13.4%), rats (68.3%), rabbits (11.0%), canines (4.9%), goats (1.2%), and pigs (1.2%). Small animals are suitable for researches exploring the mechanism of disease or drug efficacy while large animals can work better with clinical application-related researches. In regard to the choice of modeling method, compressing the certain muscle of animals by heavy things is superior to others to cause systemic trauma-related rhabdomyolysis signs. In addition, due to the significant burden of crush injuries on animals, further attention shall be paid to the selection of the most suitable anesthetics and appropriate analgesics.

Protective effects of ischemic postconditioning on skeletal muscle following crush syndrome in the rat

Purpose

To investigate the effect of ischemic postconditioning (IPostC) on skeletal muscle and its optimal protocol.

Methods

This article is about an animal study of rat model of crush syndrome. Sixty rats were randomized into nine different IPostC intervention groups and a control group. The anesthetized rats were subjected to unilateral hindlimb 3-kg compression with a compression device for 6 h, followed by nine different IPostC intervention protocols.

Results

Serum levels of creatine kinase (CK) at 3 h post-crush became 2.3-3.9 times among all 10 groups after crush. At 72 h post-crush, serum CK level was reduced to 0.28-0.53 time in all intervention groups. The creatinine (CREA) level in the control group was elevated to 3.11 times at 3 h post-crush and reduced to1.77 time at 72 h post-crush. The potassium (K+) level in the control group was elevated to 1.65 and 1.41 time at 3 and 72 h post-crush, respectively.

Conclusions

Our IPostC intervention protocols can effectively protect rats from crush-induced elevation of serum CK, CREA, and K+ levels. The timing of IPostC intervention should be as early as possible, to ensure the protective effect.

Emerging medical therapies in crush syndrome - progress report from basic sciences and potential future avenues

Crush injury is a disease that is commonly found in victims of earthquakes, debris flows, mine disasters, explosions, terrorist attacks, local wars, and other accidents. The complications that arise due to the crush injury inflicted on victims give rise to crush syndrome (CS). If not treated in time, the mortality rate of CS is very high. The most important measure that can be taken to reduce mortality in such situations is to immediately start treatment. However, the traditional treatment methods such as fluid resuscitation, diuresis, and hemodialysis are not feasible enough to be carried out at the disaster scene. So there is a need for developing new treatments that are efficient and convenient. Because it is difficult to diagnose in the disaster area and reach the treatment equipment and treat on time. It has become a new research needs to be directed into identifying new medical treatment targets and methods using the etiology and pathophysiological mechanisms of CS. In recent years, a large number of new anti-oxidant and anti-inflammatory drug therapies have been shown to be highly efficacious in CS rat/mouse models. Some of them are expected to become specific drugs for the emergency treatment of a large number of patients who may develop CS in the aftermath of earthquakes, wars, and other disasters in the future. Hence, we have reviewed the latest research on the medical therapy of CS as a source for anyone wishing to pursue research in this direction.

Effect of Hydrogen Sulfide on Kidney Injury in Rat Model of Crush Syndrome

BACKGROUND

Acute kidney injury is the most serious complication of crush syndrome. Hydrogen sulfide (H₂S) is an endogenously produced gaseous signaling molecule. It is involved in homeostatic functions, such as blood pressure control, apoptosis, oxidative stress, and inflammation. In this study, effects of H₂S on kidney injury were investigated in a rat model of crush syndrome.

METHODS

Rats were divided into six groups (n = 8): Sham (steril saline ip), crush (sterile saline ip), crush + NaHS (sodium hydrosulfide, an H₂S donor) (100 μmol/kg ip). All these groups were also separated as 3 and 24 h after decompression. Crush injury was induced by 6 h of direct compression to both hindlimbs of anesthetized rats with blocks weighing 3.6 kg each sides, followed by 3 or 24 h of decompression. Kidney injury molecule-1, neutrophil gelatinase-associated lipocalin, tumor-necrotizing factor-α, transforming growth factor-β, tissue total oxidant status, and total antioxidant status levels were measured in kidney homogenates 3 and 24 h after decompression. Serum creatine kinase, blood urea nitrogen, and creatinine levels were also measured. Apoptosis was assessed by TUNEL method. Bcl-2 was assessed by immunohistochemistry. Glomerular and tubular structures were also examined histopathologically.

RESULTS

NaHS reduced kidney injury molecule-1, neutrophil gelatinase-associated lipocalin, tumor-necrotizing factor-α, transforming growth factor-β, total oxidant status levels, and increased total antioxidant status levels in kidney 3 and 24 h after decompression. Serum urea, creatinine, and creatine kinase levels also reduced with NaHS. NaHS decreased renal damage and apoptosis in crush-related acute kidney injury.

CONCLUSIONS

These results suggest that H₂S could reduce crush-related acute kidney injury via anti-inflammatory, antioxidant, and antiapoptotic effects.

Astragaloside-IV prevents acute kidney injury and inflammation by normalizing muscular mitochondrial function associated with a nitric oxide protective mechanism in crush syndrome rats

Background

Crush syndrome (CS) is a serious medical condition characterized by muscle cell damage resulting from decompression after compression (i.e., ischemia/reperfusion injury). A large number of CS patients develop cardiac failure, kidney dysfunction, and systemic inflammation, even when fluid therapy is administered. We evaluated whether the administration of astragaloside-IV (AS)-containing fluid improved survival by preventing kidney and muscular mitochondrial dysfunction in a rat model of CS.

Results

The CS model was generated by subjecting anesthetized rats to bilateral hind limb compression with a rubber tourniquet for 5 h. Rats were then randomly divided into four groups: (1) sham; (2) CS with no treatment; (3) CS with normal saline treatment; and (4) CS with normal saline + 10 mg/kg AS. AS-containing fluid improved kidney function by improving shock and metabolic acidosis in CS rats. In addition, there was a reduction in oxidative damage. The attenuation of hyperkalemia was significantly related to improving muscle injury via preventing mitochondrial dysfunction. Moreover, this mitochondria protection mechanism was related to the nitric oxide (NO) generated by activation of endothelial nitric oxide synthase, which provided an anti-oxidative and anti-inflammatory effect.

Conclusions

Treatment with AS-containing fluid led to a dramatic improvement in survival following CS because of direct and indirect anti-oxidative effects in the kidney, and improvements in mitochondrial dysfunction and inflammation owing to AS acting as an NO donor in injured muscle.

Electronic supplementary material

The online version of this article (doi:10.1186/s13613-017-0313-2) contains supplementary material, which is available to authorized users.