Disaster nephrology: crush injury and beyond

February 6th, Kahramanmaraş earthquakes and the disaster management algorithm of adult emergency medicine in Turkey: An experience review

This compilation covers emergency medical management lessons from the February 6th Kahramanmaraş earthquakes. The objective is to review relevant literature on emergency services patient management, focusing on Koenig's 1996 Simple Triage and Rapid Treatment (START) and Secondary Assessment of Victim Endpoint (SAVE) frameworks. Establishing a comprehensive seismic and mass casualty incident (MCI) protocol chain is the goal. The prehospital phase of seismic MCIs treats hypovolemia and gets patients to the nearest hospital. START-A plans to expedite emergency patient triage and pain management. The SAVE algorithm is crucial for the emergency patient secondary assessment. It advises using Glasgow Coma Scale, Mangled Extremity Severity Score, Burn Triage Score, and Safe Quake Score for admission, surgery, transfer, discharge, and outcomes. This compilation emphasizes the importance of using diagnostic tools like bedside blood gas analyzers and ultrasound devices during the assessment process, drawing from 6 February earthquake research. The findings create a solid framework for improving emergency medical response strategies, making them applicable in similar situations.

Sudden-Onset Disaster Mass-Casualty Incident Response: A Modified Delphi Study on Triage, Prehospital Life Support, and Processes

The application and provision of prehospital care in disasters and mass-casualty incident response in Europe is currently being explored for opportunities to improve practice. The objective of this translational science study was to align common principles of approach and action and to identify how technology can assist and enhance response. To achieve this objective, the application of a modified Delphi methodology study based on statements derived from key findings of a scoping review was undertaken. This resulted in 18 triage, eight life support and damage control interventions, and 23 process consensus statements. These findings will be utilized in the development of evidence-based prehospital mass-casualty incident response tools and guidelines.

Wilderness Rescue of a Hiker with Multiple Trapped Limbs by a Combined Wilderness and Urban Rescue Team Using High-Pressure Airbags

We report on the case of a 28-y-old man with both legs and left arm trapped for nearly 6 h after falling and subsequently being trapped by a boulder during a hike in the wilderness. Extrication required equipment designed for urban environments and was operated by an unconventional team of rescue professionals. The patient experienced multiple right lower-extremity orthopedic injuries, acute kidney injury secondary to rhabdomyolysis, and bilateral segmental pulmonary emboli. In this article, we detail the extrication and review the treatment guidelines for crush injuries that focus on aggressive fluid resuscitation prior to and during extrication and medication administration only if hyperkalemia presents. Wilderness rescuers should plan for the use of unconventional rescue equipment in austere prolonged rescue scenarios.

High risk and low prevalence diseases: Blast injuries

INTRODUCTION

Blast injury is a unique condition that carries a high rate of morbidity and mortality, often with mixed penetrating and blunt injuries.

OBJECTIVE

This review highlights the pearls and pitfalls of blast injuries, including presentation, diagnosis, and management in the emergency department (ED) based on current evidence.

DISCUSSION

Explosions may impact multiple organ systems through several mechanisms. Patients with suspected blast injury and multisystem trauma require a systematic evaluation and resuscitation, as well as investigation for injuries specific to blast injuries. Blast injuries most commonly affect air-filled organs but can also result in severe cardiac and brain injury. Understanding blast injury patterns and presentations is essential to avoid misdiagnosis and balance treatment of competing interests of patients with polytrauma. Management of blast victims can also be further complicated by burns, crush injury, resource limitation, and wound infection. Given the significant morbidity and mortality associated with blast injury, identification of various injury patterns and appropriate management are essential.

CONCLUSIONS

An understanding of blast injuries can assist emergency clinicians in diagnosing and managing this potentially deadly disease.

Delayed step-by-step decompression with DSF alleviates skeletal muscle crush injury by inhibiting NLRP3/CASP-1/GSDMD pathway

Crush injury (CI) is a common disease in earthquake and traffic accidents. It refers to long-term compression that induces ischemia and hypoxia injury of skeletal muscle rich parts, leading to rupture of muscle cells and release of contents into the blood circulation. Crush syndrome (CS) is the systemic manifestation of severe, traumatic muscle injury. CI rescue faces a dilemma. Ischemic reperfusion due to decompression is a double-edged sword for the injured. Death often occurs when the injured are glad to be rescued. Programmed cell death (PCD) predominates in muscle CI or ischemia-reperfusion injury. However, the function and mechanism of pyroptosis and apoptosis in the pathogenesis of skeletal muscle injury in CI remain elusive. Here, we identified that pyroptosis and apoptosis occur independently of each other and are regulated differently in the injured mice's skeletal muscle of CI. While in vitro model, we found that glucose-deprived ischemic myoblast cells could occur pyroptosis. However, the cell damage degree was reduced if the oxygen was further deprived. Then, we confirmed that delayed step-by-step decompression of CI mice could significantly reduce skeletal muscle injury by substantially inhibiting NLRP3/Casp-1/GSDMD pyroptosis pathway but not altering the Casp-3/PARP apoptosis pathway. Moreover, pyroptotic inhibitor DSF therapy alone, or the combination of delayed step-by-step decompression and pyroptotic inhibitor therapy, significantly alleviated muscle injury of CI mice. The new physical stress relief and drug intervention method proposed in this study put forward new ideas and directions for rescuing patients with CI, even CS-associated acute kidney injury (CS-AKI).

Crush injury and syndrome: A review for emergency clinicians

INTRODUCTION

Primary disasters may result in mass casualty events with serious injuries, including crush injury and crush syndrome.

OBJECTIVE

This narrative review provides a focused overview of crush injury and crush syndrome for emergency clinicians.

DISCUSSION

Millions of people worldwide annually face natural or human-made disasters, which may lead to mass casualty events and severe medical issues including crush injury and syndrome. Crush injury is due to direct physical trauma and compression of the human body, most commonly involving the lower extremities. It may result in asphyxia, severe orthopedic injury, compartment syndrome, hypotension, and organ injury (including acute kidney injury). Crush syndrome is the systemic manifestation of severe, traumatic muscle injury. Emergency clinicians are at the forefront of the evaluation and treatment of these patients. Care at the incident scene is essential and focuses on treating life-threatening injuries, extrication, triage, fluid resuscitation, and transport. Care at the healthcare facility includes initial stabilization and trauma evaluation as well as treatment of any complication (e.g., compartment syndrome, hyperkalemia, rhabdomyolysis, acute kidney injury).

CONCLUSIONS

Crush injury and crush syndrome are common in natural and human-made disasters. Emergency clinicians must understand the pathophysiology, evaluation, and management of these conditions to optimize patient care.

Remote ischemic postconditioning protects against crush-induced acute kidney injury via down-regulation of apoptosis and senescence

BACKGROUND

Acute renal failure due to crush syndrome is one of the leading causes of death in disasters. Ischemic Postconditioning (IPC) is a potentially effective strategy to protect against ischemic reperfusion injury, but a few studies noted its protective effect in crush induced acute kidney injury (AKI). Hence, this study investigated the optimal IPC strategy to prevent crush induced AKI and reveal related cellular mechanisms.

METHODS

The right lower extremities of rabbits were constantly compressed for 8 h and then performed five cycles of clamping and releasing the femoral artery and vein before depression using a clip. In terms of the duration of clamping and releasing, the animals were randomly divided into 5 groups, Control, IPC-5sec, IPC-30sec, IPC-1min, and IPC-5min groups; 6 rabbits for each group. Biomarkers of inflammation, renal function, renal tubular injury, and muscular injury, apoptosis, and cellular senescence in kidney were detected.

RESULTS

Six hours after decompression, the levels of Serum Creatine (SCr), Blood Urea Nitrogen (BUN), K+, and Interleukin-6 (IL-6) in IPC-1min and IPC-5min groups were lower than Control, with a statistically significant difference. The morphological study of Periodic Acid-Schiff (PAS) staining demonstrated that 6 h after decompression, IPC-1min can attenuate renal tubular damage renal tubule. Meanwhile, the level of Neutrophil Gelatinase-Associated Lipocalin (NGAL) in circulation in the IPC-30sec, IPC-1min, and IPC-5min groups was significantly decreased compared with the Control group, 2 h after decompression. On the other hand, the levels of serum Creatine Kinase (CK) and Myoglobin (Mb), and the morphological change of muscular damage detected by hematoxylin and eosin (H&E) staining in IPC-1min-treated group were significantly lower than Control group 6 hours after decompression. Further results of the cellular mechanism showed that the apoptotic markers of Terminal deoxynucleotidyl Transferase-mediated dUTP Nick End Labeling (TUNEL) and Caspase3 and the cell senescent markers of senescence-associated β-galactosidase (SA-β-Gal) and nuclear LAMNB1 have changed significantly in the IPC-1min group, compared with the control group.

CONCLUSIONS

Performing 5 cycles of 1-min IPC would be a convenient, time-saving, and effective method to prevent crush-induced AKI by attenuating the release of nephrotoxic substances after decompression and downregulation of the expression of apoptosis and cellular senescence biomarkers.

Rescue Robots for the Urban Earthquake Environment

Robotics have important applications in the field of disaster medical rescue. The deployment of urban rescue robots at the earthquake site can help shorten response time, improve rescue efficiency and keep rescue personnel away from danger. This discussion introduces the performance of some robots in actual rescue scenarios, focuses on the current research status of robots that can provide medical assistance, and analyzes the merits and shortcomings of each system. Based on existing studies, the limitations and development directions of urban rescue robots are also discussed.

Myoglobin promotes macrophage polarization to M1 type and pyroptosis via the RIG-I/Caspase1/GSDMD signaling pathway in CS-AKI

Crush syndrome (CS) is a life-threatening illness in traffic accidents and earthquakes. Crush syndrome-induced acute kidney injury (CS-AKI) is considered to be mainly due to myoglobin (Mb) circulation and deposition after skeletal muscle ruptures and releases. Macrophages are the primary immune cells that fight foreign substances and play critical roles in regulating the body's natural immune response. However, what effect does myoglobin have on macrophages and the mechanisms involved in the CS-AKI remain unclear. This study aims to look into how myoglobin affects macrophages of the CS-AKI model. C57BL/6 mice were used to construct the CS-AKI model by digital crush platform. Biochemical analysis and renal histology confirmed the successful establishment of the CS-AKI mouse model. Ferrous myoglobin was used to treat Raw264.7 macrophages to mimic the CS-AKI cell model in vitro. The macrophage polarization toward M1 type and activation of RIG-I as myoglobin sensor were verified by real-time quantitative PCR (qPCR), Western blotting (WB), and immunofluorescence (IF). Macrophage pyroptosis was observed under light microscopy. The interaction between RIG-I and caspase1 was subsequently explored by co-immunoprecipitation (Co-IP) and IF. Small interfering RNA (siRIG-I) and pyroptosis inhibitor dimethyl fumarate (DMF) were used to verify the role of macrophage polarization and pyroptosis in CS-AKI. In the kidney tissue of CS-AKI mice, macrophage infiltration and M1 type were found. We also detected that in the cell model of CS-AKI in vitro, ferrous myoglobin treatment promoted macrophages polarization to M1. Meanwhile, we observed pyroptosis, and myoglobin activated the RIG-I/Caspase1/GSDMD signaling pathway. In addition, pyroptosis inhibitor DMF not only alleviated kidney injury of CS-AKI mice but also inhibited macrophage polarization to M1 phenotype and pyroptosis via the RIG-I/Caspase1/GSDMD signaling pathway. Our research found that myoglobin promotes macrophage polarization to M1 type and pyroptosis via the RIG-I/Caspase1/GSDMD signaling pathway in CS-AKI.

RIG-I, a novel DAMPs sensor for myoglobin activates NF-κB/caspase-3 signaling in CS-AKI model

BACKGROUND

Acute kidney injury (AKI) is the main life-threatening complication of crush syndrome (CS), and myoglobin is accepted as the main pathogenic factor. The pattern recognition receptor retinoicacid-inducible gene I (RIG-I) has been reported to exert anti-viral effects function in the innate immune response. However, it is not clear whether RIG-I plays a role in CS-AKI. The present research was carried out to explore the role of RIG-I in CS-AKI.

METHODS

Sprague-Dawley rats were randomly divided into two groups: the sham and CS groups (n = 12). After administration of anesthesia, the double hind limbs of rats in the CS group were put under a pressure of 3 kg for 16 h to mimic crush conditions. The rats in both groups were denied access to food and water. Rats were sacrificed at 12 h or 36 h after pressure was relieved. The successful establishment of the CS-AKI model was confirmed by serum biochemical analysis and renal histological examination. In addition, RNA sequencing was performed on rat kidney tissue to identify molecular pathways involved in CS-AKI. Furthermore, NRK-52E cells were treated with 200 μmol/L ferrous myoglobin to mimic CS-AKI at the cellular level. The cells and cell supernatant samples were collected at 6 h or 24 h. Small interfering RNAs (siRNA) was used to knock down RIG-I expression. The relative expression levels of molecules involved in the RIG-I pathway in rat kidney or cells samples were measured by quantitative Real-time PCR (qPCR), Western blotting analysis, and immunohistochemistry (IHC) staining. Tumor necrosis factor-α (TNF-α) was detected by ELISA. Co-Immunoprecipitation (Co-IP) assays were used to detect the interaction between RIG-I and myoglobin.

RESULTS

RNA sequencing of CS-AKI rat kidney tissue revealed that the different expression of RIG-I signaling pathway. qPCR, Western blotting, and IHC assays showed that RIG-I, nuclear factor kappa-B (NF-κB) P65, p-P65, and the apoptotic marker caspase-3 and cleaved caspase-3 were up-regulated in the CS group (P < 0.05). However, the levels of interferon regulatory factor 3 (IRF3), p-IRF3 and the antiviral factor interferon-beta (IFN-β) showed no significant changes between the sham and CS groups. Co-IP assays showed the interaction between RIG-I and myoglobin in the kidneys of the CS group. Depletion of RIG-I could alleviate the myoglobin induced expression of apoptosis-associated molecules via the NF-κB/caspase-3 axis.

CONCLUSION

RIG-I is a novel damage-associated molecular patterns (DAMPs) sensor for myoglobin and participates in the NF-κB/caspase-3 signaling pathway in CS-AKI. In the development of CS-AKI, specific intervention in the RIG-I pathway might be a potential therapeutic strategy for CS-AKI.

Aetiologies and factors associated with poor clinical outcomes in rhabdomyolysis: a retrospective cohort study in an Australian trauma centre

Rhabdomyolysis is a clinical syndrome with significant morbidity and mortality that occurs as a result of traumatic and non-traumatic aetiologies. Acute kidney injury, the need for dialysis, and death, can occur due to rhabdomyolysis. This study explores the aetiologies, clinical outcomes and associated factors for poor outcomes in a cohort of patients with rhabdomyolysis in a tertiary trauma centre in Australia.

Kidney problems in disaster situations

Mass disasters, particularly earthquakes, cause many medical problems, including kidney problems, but an organized approach to cope with them was initiated only at the end of previous century, subsequent to the Armenian Spitak earthquake in 1988. Originally, interventions were focused on acute kidney injury (AKI) following crush injury and rhabdomyolysis in victims who had been trapped under the debris of collapsed buildings. However, similar problems were also registered in the context of other catastrophic events, especially man-made disasters like wars and torture. Other kidney-related problems, such as the preservation of treatment continuity in chronic kidney disease (CKD), especially in maintenance dialysis patients, deserved attention as well. Specific therapeutic principles apply to disaster-related kidney problems and these may differ from usual day-to-day clinical practice. Those approaches have been formulated in global and specific country-related guidelines and recommendations. It is clear that a well-conceived and organized management of kidney diseases in disasters benefits outcomes. Furthermore, it may be useful if the model and philosophy that were applied over the last three decades could be adapted by broadening the scope of disasters leading to intervention. Actions should be guided and coordinated by a panel of experts steering ad hoc interventions, rather than applying the "old" static model where a single coordinating center instructs and uses volunteers listed long before a potential event occurs.

Acute Kidney Injury Secondary to Rhabdomyolysis: A Rare Complication of Low-Energy Trauma

Introduction

Crush syndrome refers to the systemic manifestation of muscle cell injury following release of myocyte contents into the blood circulation. It is seen most commonly in patients sustaining high-energy trauma. Acute kidney injury is one of the most serious complications of crush syndrome and is an important cause of mortality in these patients. In contrast, the occurrence of rhabdomyolysis in patients sustaining low-energy trauma is sparsely reported in the literature. The authors report one such rare case.

Case Report

The patient was a 77-year-old hypertensive male who presented to the emergency following an episode of slip and fall at home. After prompt resuscitation, he was sent for radiological evaluation which revealed fractures of the left inter-trochanteric femur and left proximal humerus. Meanwhile, laboratory investigations showed grossly deranged renal parameters, along with elevated serum creatinine phosphokinase levels (more than 5 times the baseline). A diagnosis of acute kidney injury secondary to traumatic rhabdomyolysis was made. Medical management included adequate intravenous fluid administration combined with strict input-output monitoring. Subsequently, the patient underwent closed reduction and internal fixation of the inter-trochanteric femur fracture with a proximal femoral nail. However, fracture of the proximal humerus was managed non-operatively with sling immobilization as patient refused to give consent for a second surgery.

Conclusion

Although rare, acute kidney injury secondary to rhabdomyolysis can occur in patients with low-energy trauma. It is important not to confuse it with chronic renal insufficiency, especially in geriatrics many of whom are long-standing hypertensives.

Disasters, children and the kidneys

Following disasters, children are physically, psychologically and socially more vulnerable than adults; consequently, their morbidity and mortality are higher. The risks are especially high for orphans and unaccompanied children who are separated from their families, making them frequently victims of human trafficking, slavery, drug addiction, crime or sexual exploitation. Education of children and families about disaster-related risks and providing special protection in disaster preparedness plans may mitigate these threats. Kidney disease patients, both paediatric and adult, are extra vulnerable during disasters, because their treatment is dependent on technology and functioning infrastructure. Acute kidney injury, chronic kidney disease patients not on dialysis and dialysis and transplant patients are faced with extensive problems. Overall, similar treatment principles apply both for adults and paediatric kidney patients, but management of children is more problematic, because of substantial medical and logistic difficulties. To minimize drawbacks, it is vital to be prepared for renal disasters. Preparedness plans should address not only medical professionals, but also patients and their families. If problems cannot be coped with locally, calling for national and/or international help is mandatory. This paper describes the spectrum of disaster-related problems in children and the specific features in treating acute and chronic kidney disease in disasters.

Validity of Urine NGALds Dipstick for Acute Kidney Injury in a Malawian Trauma Cohort

Introduction

Acute kidney injury (AKI) is a major cause of mortality worldwide, particularly in low-resource settings with limited diagnostic testing. Neutrophil gelatinase-associated lipocalin (NGAL) has shown promise in predicting AKI. Nested within a larger, prospective cohort study evaluating AKI incidence in admitted trauma patients, our objective was to evaluate a novel dipstick, NGALds, for the prediction of AKI in Malawi, Africa.

Methods

Participants were >6 months of age. Spearman rank correlation coefficients (R) assessed NGAL categories (negative [≤50 ng/ml], low risk [51−149 ng/ml], moderate risk [150−299 ng/ml], and high risk [≥300 ng/ml]) for the urine NGALds dipstick and laboratory-based NGAL Test.

Results

We enrolled 285 participants (one-third children). Thirteen percent developed AKI. The dipstick captured 45 of 52 participants (86.5%) with moderate- or high-risk NGAL values on laboratory-based testing (R = 0.74). The dipstick had sensitivity of 44.4%, specificity of 73.5%, positive predictive value of 19.5%, and negative predictive value of 90.2% for predicting AKI. Acute kidney injury was associated with an increased risk of mortality (relative risk [RR] = 3.9, 95% confidence interval [CI] = 1.9−8.2), but mortality risk greatly increased among children who first had a positive (≥150 ng/ml) NGALds result (RR = 12.0, 95% CI = 1.8−78.4).

Conclusions

The NGALds dipstick performed similarly to the NGAL Test in this low-resource setting and may be a useful tool to rule out AKI. It may be even more important in predicting high mortality risk among children.

Ulinastatin ameliorates acute kidney injury induced by crush syndrome inflammation by modulating Th17/Treg cells

BACKGROUND

Acute kidney injury (AKI) is the main complication of crush syndrome (CS), and it is also a cause of lethality in CS. However, effective treatments for AKI are still lacking. Ulinastatin (UTI) is a broad-spectrum serine protease inhibitor extracted from human urine that reportedly modulates innate immunity and pro-inflammatory responses in sepsis. Here, we explored the effect and the potential mechanism of ulinastatin on crush syndrome-induced acute kidney injury (CSAKI).

METHODS

A CSAKI rat model was established by using a digital crush injury device platform. Forty-six male Wistar rats were randomly divided into five groups: the normal control (n = 6), CSAKI model (n = 10), CSAKI plus UTI1 (50,000 U/kg) (n = 10), CSAKI plus UTI2 (100,000 U/kg) (n = 10) and CSAKI plus UTI3 (200,000 U/kg) (n = 10) groups. Hematoxylin-eosin (HE) staining was used to investigate the reliability of the CSAKI model. The percentage of Th17/Treg lymphocytes in peripheral blood was measured by flow cytometry, and the expression of transcription factors associated with Th17/Treg cells was evaluated by quantitative real-time polymerase chain reaction (PCR). In addition, specific cytokines released by Th17/Treg cells in serum and kidney tissues were detected by enzyme-linked immunosorbent assay (ELISA).

RESULTS

Treatment with ulinastatin could significantly decrease serum BUN, CK, Scr, Mb and K⁺ levels compared with CSAKI group. HE staining results showed that ulinastatin could inhibit inflammatory cells infiltration, decrease sarcomere rupture in muscle tissues induced by extrusion, and alleviate the glomerular congestion and edema, as well as decrease myoglobin cast in kidney tissues. The proportion of CD4⁺CD25⁺Foxp3⁺ regulatory T (Treg) cells and Foxp3 expression levels were decreased in the CSAKI animals, while IL-17 expression levels were significantly increased, compared with those of the normal control group. Treatment with ulinastatin upregulated the proportion of Treg cells in CD4⁺ T cells and downregulated the expression of IL-17 compared with those of the CSAKI group.

CONCLUSION

The findings of our study indicate that UTI attenuates CS-induced AKI and alleviate the inflammatory response during the early stage. The mechanism of UTI may be due to regulating the balance between Th17/Treg cells. Our study provides a new mechanism for the beneficial effect of ulinastatin on CSAKI.

Carbon Monoxide Rescues the Developmental Lethality of Experimental Rat Models of Rhabdomyolysis-Induced Acute Kidney Injury

Many victims, after being extricated from a collapsed building as the result of a disaster, suffer from disaster nephrology, a term that is referred to as the crush syndrome (CS). Recommended treatments, which include dialysis or the continuous administration of massive amounts of fluid are not usually easy in cases of such mass natural disasters. In the present study, we examined the therapeutic performance of a biomimetic carbon monoxide (CO) delivery system, CO-enriched red blood cells (CO-RBCs), on experimental animal models of an acute kidney injury (AKI) induced by traumatic and nontraumatic rhabdomyolysis, including CS and rhabdomyolysis with massive hemorrhage shock. A single CO-RBC treatment was found to effectively suppress the pathogenesis of AKI with the mortality in these model rats being improved. In addition, in further studies using glycerol-induced rhabdomyolysis model rats, the pathogenesis of which is similar to that for the CS, AKI and mortality were also reduced as the result of a CO-RBC treatment. Furthermore, CO-RBCs were found to have renoprotective effects via the suppression of subsequent heme protein-associated renal oxidative injury; the oxidation of myoglobin in the kidneys, the generation of reactive oxygen species by free heme produced from degraded-cytochrome P450 and hemoglobin-associated renal injury. Because CO-RBCs can be prepared and used at both hospitals and at a disaster site, these findings suggest that CO-RBCs have the potential for use as a novel cell therapy against both nontraumatic and traumatic rhabdomyolysis including CS-induced AKI. SIGNIFICANCE STATEMENT: After mass natural and man-made disasters, people who are trapped in collapsed buildings are in danger of acute kidney injury (AKI), including crush syndrome (CS)-related AKI. This paper reports that carbon monoxide-enriched red blood cells (CO-RBCs), which can be prepared at both hospitals and disaster sites, dramatically suppressed the pathogenesis of CS-related AKI, thus improving mortality via suppressing heme protein-associated renal injuries. CO-RBCs have the potential for serving as a practical therapeutic agent against disaster nephrology associated with the CS.

Fluid resuscitation with preventive peritoneal dialysis attenuates crush injury-related acute kidney injury and improves survival outcome

Background

In-hospital renal replacement therapy (RRT) is widely used for the treatments of acute kidney injury (AKI) in crush injury (CI) victims. This study was designed to investigate whether preventive peritoneal dialysis (PPD) is useful for renal protection in CI.

Methods

Animals received hindlimb compressions for 6 h to induce CI. Then, animals were untreated or treated with PPD and/or massive fluid resuscitation (MFR) for 8 h since the onset of compression release. Blood and renal tissue samples were collected at various time points for biological and morphological analysis.

Results

PPD attenuated lactic acidosis and reduced serum K⁺ and myoglobin levels in CI animals. In addition, PPD was effective in removing blood urea nitrogen (BUN) and creatinine, and reduced renal expressions of neutrophil gelatinase-associated lipocalin (NGAL). The combination of PPD and MFR furtherly attenuated AKI with significantly decreased histological scores (p = 0.037) and reduced NGAL expressions (p = 0.0002) as compared with the MFR group. Moreover, MFR + PPD group had a significantly higher survival rate than that in the MFR and the PPD groups (p < 0.05, respectively).

Conclusion

The use of PPD at the onset of compression release is beneficial for renal protection and survival outcome in a rabbit model of CI.

Electronic supplementary material

The online version of this article (10.1186/s13049-019-0644-0) contains supplementary material, which is available to authorized users.

Extracorporeal Filtration of Potassium in a Swine Model of Bilateral Hindlimb Ischemia-Reperfusion Injury With Severe Acute Hyperkalemia

Introduction

Options for the treatment of hyperkalemia in the pre-hospital setting are limited, particularly in the context of natural disaster or during combat operations. Contemporary interventions require extensive resources and technical expertise. Here we examined the potential for a simple, field deployable bridge-dialysis as a countermeasure for acute hyperkalemia induced by prolonged ischemia-reperfusion.

Methods

Twenty female swine were randomized into two experimental groups undergoing a 2-hour bilateral hindlimb ischemia-reperfusion injury. Subsequent to injury, hemoperfusion was performed in the presence (Column) and absence (Sham Control) of a high-affinity potassium-binding column (CytoSorbents, Monmouth Junction, NJ, USA). Serial blood gas and chemistries were sampled. Primary endpoint was changed in serum potassium concentrations post-injury and filtration.

Results

Serum potassium was significantly elevated following ischemia-reperfusion injury in both groups (149% (12) and 150% (22), p < 0.05 vs respective baseline values). There were no differences observed between groups in respect to physiologic parameters; mean arterial pressure, heart rate, systemic vascular resistance, cardiac output, or central venous oxygenation. Filtration resulted in a significant relative decrease in potassium compared with controls after the first hour as determined by repeated measures two-way ANOVA (p < 0.0001) which continued through end of the study. Significant thrombocytopenia was observed in animals undergoing filtration with a mean reduction in platelets measured at T = 480 minutes (168 × 103μL, p < 0.0001 vs baseline).

Conclusions

We demonstrate that serum potassium can be filtered via hemoperfusion utilizing a simple extracorporeal potassium-binding platform, though evolution of this technology will be required to achieve meaningful reduction of potassium in clinically significant hyperkalemia after trauma.

Renal Failure Patients in Disasters

Disasters occur regularly, and frequently large numbers of patients treated with maintenance dialysis or with the recent onset of acute kidney injury are put at risk owing to the lack of access to dialysis care precipitating also a kidney failure disaster. The absence of necessary dialysis treatments can result in excessive emergency department visits, hospitalizations, morbidity, or an early death. Those with kidney failure are often evaluated in disaster medical locations or hospitals without nephrologists in attendance. Here we offer guidance for medical personnel evaluating such patients so that dialysis-dependent individuals can be properly assessed and managed with the need for urgent dialysis recognized. A disaster dialysis triage system is proposed. (Disaster Med Public Health Preparedness. 2019;13:782-790).

Non-machinery dialysis that achieves blood purification therapy without using full-scale dialysis machines

An electrical or water supply and a blood purification machine are required for renal replacement therapy. There is a possibility that acute kidney injury can occur in large numbers and on a wide scale in the case of a massive earthquake, and there is the potential risk that the current supply will be unable to cope with acute kidney injury cases. However, non-machinery dialysis requires exclusive circuits and has the characteristic of not requiring the full-scale dialysis machines. We performed perfusion experiments that used non-machinery dialysis and recent blood purification machines in 30-min intervals, and the effectiveness of non-machinery dialysis was evaluated by the assessing the removal efficiency of potassium, which causes lethal arrhythmia during acute kidney injury. The non-machinery dialysis potassium removal rate was at the same level as continuous blood purification machines with a dialysate flow rate of 5 L/h after 15 min and continuous blood purification machines with a dialysate flow rate of 3 L/h after 30 min. Non-machinery dialysis required an exclusive dialysate circuit, the frequent need to replace bags, and new dialysate exchanged once every 30 min. However, it can be seen as an effective renal replacement therapy for crush-related acute kidney injury patients, even in locations or facilities not having the full-scale dialysis machines.

Evaluation of Acute Kidney Injury Using Contrast Ultrasonography in a Rabbit Model of Crush Syndrome

This study aimed to investigate the feasibility of evaluating acute kidney injury (AKI) using contrast ultrasonography in a rabbit model of crush syndrome. Sixty-four New Zealand white rabbits were anesthetized and the left hind limb was wrapped and compressed for 4 h with a sphygmomanometer. Contrast ultrasonography of the left kidney using microbubbles as the contrast medium was performed. The serum levels of blood urea nitrogen (BUN), creatine (Cr), creatine kinase (CK) and lactate dehydrogenase (LDH) were significantly increased in comparison to before the compression. Correlation analysis showed that peak intensity was negatively correlated with the biochemical parameters and area under the curve (AUC) was positively correlated with these parameters. Contrast ultrasonography is thus sensitive to the changes in renal perfusion after limb crush injury in rabbits. The ultrasonography results correlated well with the biochemical parameters that are related to muscle injury and AKI.

PEGylated Artificial Antibodies: Plasmonic Biosensors with Improved Selectivity

Molecular imprinting, which involves the formation of artificial recognition elements or cavities with complementary shape and chemical functionality to the target species, is a powerful method to overcome a number of limitations associated with natural antibodies. An important but often overlooked consideration in the design of artificial biorecognition elements based on molecular imprinting is the nonspecific binding of interfering species to noncavity regions of the imprinted polymer. Here, we demonstrate a universal method, namely, PEGylation of the noncavity regions of the imprinted polymer, to minimize the nonspecific binding and significantly enhance the selectivity of the molecular imprinted polymer for the target biomolecules. The nonspecific binding, as quantified by the localized surface plasmon resonance shift of imprinted plasmonic nanorattles upon exposure to common interfering proteins, was found to be more than 10 times lower compared to the non-PEGylated counterparts. The method demonstrated here can be broadly applied to a wide variety of functional monomers employed for molecular imprinting. The significantly higher selectivity of PEGylated molecular imprints takes biosensors based on these artificial biorecognition elements closer to real-world applications.

Imaging technologies for monitoring the safety, efficacy and mechanisms of action of cell-based regenerative medicine therapies in models of kidney disease

The incidence of end stage kidney disease is rising annually and it is now a global public health problem. Current treatment options are dialysis or renal transplantation, which apart from their significant drawbacks in terms of increased morbidity and mortality, are placing an increasing economic burden on society. Cell-based Regenerative Medicine Therapies (RMTs) have shown great promise in rodent models of kidney disease, but clinical translation is hampered due to the lack of adequate safety and efficacy data. Furthermore, the mechanisms whereby the cell-based RMTs ameliorate injury are ill-defined. For instance, it is not always clear if the cells directly replace damaged renal tissue, or whether paracrine effects are more important. Knowledge of the mechanisms responsible for the beneficial effects of cell therapies is crucial because it could lead to the development of safer and more effective RMTs in the future. To address these questions, novel in vivo imaging strategies are needed to monitor the biodistribution of cell-based RMTs and evaluate their beneficial effects on host tissues and organs, as well as any potential adverse effects. In this review we will discuss how state-of-the-art imaging modalities, including bioluminescence, magnetic resonance, nuclear imaging, ultrasound and an emerging imaging technology called multispectral optoacoustic tomography, can be used in combination with various imaging probes to track the fate and biodistribution of cell-based RMTs in rodent models of kidney disease, and evaluate their effect on renal function.

Disaster nephrology: a new concept for an old problem

Natural and man-made mass disasters directly or indirectly affect huge populations, who need basic infrastructural help and support to survive. However, despite the potentially negative impact on survival chances, these health care issues are often neglected by the authorities.

Treatment of both acute and chronic kidney diseases (CKDs) is especially problematic after disasters, because they almost always require complex technology and equipment, whereas specific drugs may be difficult to acquire for the treatment of the chronic kidney patients. Since many crush victims in spite of being rescued alive from under the rubble die afterward due to lack of dialysis possibilities, the terminology of ‘renal disaster’ was introduced after the Armenian earthquake. It should be remembered that apart from crush syndrome, multiple aetiologies of acute kidney injury (AKI) may be at play in disaster circumstances.

The term ‘seismonephrology’ (or earthquake nephrology) was introduced to describe the need to treat not only a large number of AKI cases, but the management of patients with CKD not yet on renal replacement, as well as of patients on haemodialysis or peritoneal dialysis and transplanted patients. This wording was later replaced by ‘disaster nephrology’, because besides earthquakes, many other disasters such as hurricanes, tsunamis or wars may have a negative impact on the ultimate outcome of kidney patients.

Disaster nephrology describes the handling of the many medical and logistic problems in treating kidney patients in difficult circumstances and also to avoid post-disaster chaos, which can be made possible by preparing medical and logistic scenarios. Learning and applying the basic principles of disaster nephrology is vital to minimize the risk of death both in AKI and CKD patients.

Kidney care in Haiti--the role of partnerships

Establishing a programme for the prevention and treatment of acute kidney injury, chronic kidney disease and end-stage renal disease in a developing country involves unique challenges. We became involved in a collaborative effort to improve nephrology care in Haiti after participating in the emergency response to the 2010 earthquake. The focus of this ongoing project is overcoming barriers to implementation with the goal of improving training and resources for Haitian health-care workers and developing programmes for renal disease prevention and treatment in a setting of limited resources. Here, we offer practical advice for nephrologists who would like to help to advance medical care in developing countries. Rather than technical issues related to the prevention and treatment of renal disease, we focus on collaboration, education and the building of partnerships.

Wars, disasters and kidneys

This paper summarizes the impact that wars had on the history of nephrology, both worldwide and in the Ghent Medical Faculty notably on the definition, research and clinical aspects of acute kidney injury. The paper briefly describes the role of 'trench nephritis' as observed both during World War I and II, supporting the hypothesis that many of the clinical cases could have been due to Hantavirus nephropathy. The lessons learned from the experience with crush syndrome first observed in World War II and subsequently investigated over many decades form the basis for the creation of the Renal Disaster Relief Task Force of the International Society of Nephrology. Over the last 15 years, this Task Force has successfully intervened both in the prevention and management of crush syndrome in numerous disaster situations like major earthquakes.