Rhabdomyolysis

Megalin-related mechanism of hemolysis-induced acute kidney injury and the therapeutic strategy

Hemolysis-induced acute kidney injury (AKI) is attributed to heme-mediated proximal tubule epithelial cell (PTEC) injury and tubular cast formation due to intratubular protein condensation. Megalin is a multiligand endocytic receptor for proteins, peptides, and drugs in PTECs and mediates the uptake of free hemoglobin and the heme-scavenging protein α1-microglobulin. However, understanding of how megalin is involved in the development of hemolysis-induced AKI remains elusive. Here, we investigated the megalin-related pathogenesis of hemolysis-induced AKI and a therapeutic strategy using cilastatin, a megalin blocker. A phenylhydrazine-induced hemolysis model developed in kidney-specific mosaic megalin knockout (MegKO) mice confirmed megalin-dependent PTEC injury revealed by the co-expression of kidney injury molecule-1 (KIM-1). In the hemolysis model in kidney-specific conditional MegKO mice, the uptake of hemoglobin and α1-microglobulin as well as KIM-1 expression in PTECs was suppressed, but tubular cast formation was augmented, likely due to the nonselective inhibition of protein reabsorption in PTECs. Quartz crystal microbalance analysis revealed that cilastatin suppressed the binding of megalin with hemoglobin and α1-microglobulin. Cilastatin also inhibited the specific uptake of fluorescent hemoglobin by megalin-expressing rat yolk sac tumor-derived L2 cells. In a mouse model of hemolysis-induced AKI, repeated cilastatin administration suppressed PTEC injury by inhibiting the uptake of hemoglobin and α1-microglobulin and also prevented cast formation. Hemopexin, another heme-scavenging protein, was also found to be a novel ligand of megalin, and its binding to megalin and uptake by PTECs in the hemolysis model were suppressed by cilastatin. Mass spectrometry-based semiquantitative analysis of urinary proteins in cilastatin-treated C57BL/6J mice indicated that cilastatin suppressed the reabsorption of a limited number of megalin ligands in PTECs, including α1-microglobulin and hemopexin. Collectively, cilastatin-mediated selective megalin blockade is an effective therapeutic strategy to prevent both heme-mediated PTEC injury and cast formation in hemolysis-induced AKI. © 2024 The Pathological Society of Great Britain and Ireland.

The 2023 Türkiye-Syria earthquakes: analysis of pediatric victims with crush syndrome and acute kidney Injury

BACKGROUND

On February 6th, 2023, two consecutive earthquakes struck southeastern Türkiye with magnitudes of 7.7 and 7.6, respectively. This study aimed to analyze the clinical and laboratory findings, as well as management of pediatric victims with Crush Syndrome (CS) and Acute Kidney Injury (AKI).

METHODS

The study included pediatric earthquake victims who were presented to Mersin University Hospital. Clinical and laboratory characteristics of the patients were collected retrospectively.

RESULTS

Among 649 patients, Crush injury (CI), CS and AKI was observed in 157, 59, and 17 patients, respectively. White blood cell count (12,870 [IQR: 9910-18700] vs. 10,545 [IQR: 8355-14057] /µL, P < 0.001), C-reactive protein (51.27 [IQR: 14.80-88.78] vs. 4.59 [1.04-18.25] mg/L, P < 0.001) and myoglobin levels (443.00 [IQR: 198.5-1759.35] vs. 17 [11.8-30.43] ng/ml) were higher in patients with CS, while their sodium (IQR: 134 [131-137] vs. 136 [134-138] mEq/L, P < 0.001) levels were lower compared to non-CS patients. An increase in myoglobin levels was identified as an independent risk factor for developing CS (OR = 1.017 [1.006-1.027]). Intravenous fluid replacement was administered to the patients with CS at a dose of 4000 cc/m2/day. Hypokalemia was observed in 51.9% of the CS patients on the third day. All patients with AKI showed improvement and no deaths were reported.

CONCLUSIONS

Hyponatremia and increase in inflammation markers associated with CS may be observed. An increase in myoglobin levels was identified as a risk factor for CS. Hypokalemia may be seen as a complication of vigorous fluid therapy during hospitalization.

Investigating skeletal muscle biomarkers for the early detection of Australian myotoxic snake envenoming: an animal model pilot study

INTRODUCTION

Myotoxicity is an important toxidrome that can occur with envenoming from multiple Australian snake types. Early antivenom administration is an important strategy to reduce the incidence and severity of myotoxicity. The current gold standard biomarker, serum creatine kinase activity, does not rise early enough to facilitate early antivenom administration. Several other skeletal muscle biomarkers have shown promise in other animal models and scenarios. The aim of this study was to examine the predictive values of six skeletal muscle biomarkers in a rat model of Australian snake myotoxicity.

METHODS

Sprague-Dawley rats were anaesthetised and administered either Pseudechis porphyriacus (red-bellied black snake) or Notechis scutatus (tiger snake) venom, or normal saline via intramuscular injection. Blood samples were collected. Assays were performed for serum creatine kinase skeletal muscle troponin-I concentration, skeletal muscle troponin-C concentration, myoglobin activity, skeletal muscle myosin light chain-1 concentration, and creatine kinase-MM activity. Serum markers were plotted against time, with comparison of area under the concentration (or activity)-time curve. The predictive values of six skeletal muscle biomarkers were examined using receiver operating characteristic curves.

RESULTS

There was no difference in area under the serum creatine kinase activity-time curve between venom and control groups. Serum creatine kinase-MM activity rose early in the venom treated rats, which had a significantly greater area under the serum activity-time curve. No difference in area under the serum concentration-time curve was demonstrated for the other biomarkers. Creatine kinase-MM activity had a superior predictive values than creatine kinase activity at 0-4 hours and 0-10 hours after venom administration, as indicated by area under the receiver operating characteristic curves (95 per cent confidence intervals) of 0.91 (0.78-1.00) and 0.88 (0.73-1.00) versus 0.79 (0.63-0.95) and 0.66 (0.51-0.80).

DISCUSSION

The limitations of serum creatine kinase activity in early detection of myotoxicity were demonstrated in this rat model.

CONCLUSION

Serum creatine kinase-MM activity was superior for early detection of Australian myotoxic snake envenoming.

Stress biomarker changes following a series of repeated static and dynamic apneas in non-divers

PURPOSE

This study examined the magnitude of physiological strain imposed by repeated maximal static and dynamic apneas through assessing a panel of stress-related biomarkers.

METHODS

Eleven healthy men performed on three separate occasions (≥72-h apart): a series of five repeated maximal (i) static (STA) or (ii) dynamic apneas (DYN) or (iii) a static eupneic protocol (CTL). Venous blood samples were drawn at 30, 90, and 180-min after each protocol to determine ischaemia modified albumin (IMA), neuron-specific enolase (NSE), myoglobin, and high sensitivity cardiac troponin T (hscTnT) concentrations.

RESULTS

IMA was elevated after the apnoeic interventions (STA,+86%;DYN,+332%,p ≤ 0.047) but not CTL (p = 0.385). Myoglobin was higher than baseline (23.6 ± 3.9 ng/mL) 30-min post DYN (+70%,38.8 ± 13.3 ng/mL,p = 0.030). A greater myoglobin release was recorded in DYN compared with STA and CTL (p ≤ 0.035). No changes were observed in NSE (p = 0.207) or hscTnT (p = 0.274).

CONCLUSIONS

Five repeated maximal DYN led to a greater muscle injury compared with STA but neither elicited myocardial injury or neuronal-parenchymal damage.

Incidence of Electrolyte Imbalances Following Traumatic Rhabdomyolysis: A Systematic Review and Meta-Analysis

Rhabdomyolysis, a medical condition caused by the destruction of striated muscle fibers, can have many etiologies, with the most common one being traumatic etiologies, that is, crushing injuries, heavy exertion, and being trapped under rubbles, and so forth. Rhabdomyolysis causes many complications, including acute kidney injury and different electrolyte imbalances, which later can cause cardiac dysrhythmia and even death as a result. This systematic review and meta-analysis investigate the incidence of imbalances of four important electrolytes among patients diagnosed with traumatic rhabdomyolysis. PubMed, Scopus, Web of Science, and Embase databases were searched for any article related to traumatic rhabdomyolysis using keywords related to the topic of our study, excluding case studies and case series. Relevant data were extracted from the included articles, and finally, a meta-analysis was performed on them to calculate the pooled incidence of each electrolyte imbalance. Collectively, 32 articles were included in our study (through the database and citation checking). The following were the pooled incidence of each electrolyte imbalance: hyperkalemia, 31% (95%CI 22%-41%); hypokalemia, 10% (95%CI 4%-17%); hypernatremia, 3% (95%CI 0%-8%); hyponatremia, 23% (95%CI 7%-44%); hypercalcemia, 0% (95%CI 0%-1%); hypocalcemia, 57% (95%CI: 22%-88%); hyperphosphatemia, 33% (95%CI 11%-59%); hypophosphatemia, 4% (95%CI 0%-16%). According to the meta-analyses, the rate of hyperkalemia, hyponatremia, hypocalcemia, and hyperphosphatemia is higher than their counterpart in patients diagnosed with traumatic rhabdomyolysis.

Alcoholism and Immobility Induced Rhabdomyolysis Culminating in Hemodialysis

Rhabdomyolysis is characterised by muscle breakdown and the release of myoglobin. It is a potentially serious condition that can lead to acute kidney injury (AKI). Factors, such as ischemia, trauma, muscle compression and drug toxicity, can trigger muscle breakdown. Treatment involves aggressive fluid resuscitation to maintain urine output and prevent renal injury. Severe cases with AKI may require temporary renal replacement therapy, such as haemodialysis. It has also been proposed that dialysis can speed up recovery by removing myoglobin that is secreted into the circulation by injured muscles. We present a case of a patient with alcohol abuse and prolonged immobility leading to severe rhabdomyolysis requiring hemodialysis. Our aim is to emphasise the importance of timely identification, and appropriate management of severe rhabdomyolysis not improving on fluids may require HD as soon as possible in order to minimise complications.

Single-cell RNA sequencing identifies senescence as therapeutic target in rhabdomyolysis-induced acute kidney injury

BACKGROUND

The role of macrophages in the development of rhabdomyolysis-induced acute kidney injury (RM-AKI) has been established, but an in-depth understanding of the changes in the immune landscape could help to improve targeted strategies. Whereas senescence is usually associated with chronic kidney processes, we also wished to explore whether senescence could also occur in AKI and whether senolytics could act on immune cells.

METHODS

Single-cell RNA sequencing was used in the murine glycerol-induced RM-AKI model to dissect the transcriptomic characteristics of CD45+ live cells sorted from kidneys 2 days after injury. Public datasets from murine AKI models were reanalysed to explore cellular senescence signature in tubular epithelial cells (TECs). A combination of senolytics (dasatinib and quercetin, DQ) was administered to mice exposed or not to RM-AKI.

RESULTS

Unsupervised clustering of nearly 17 000 single-cell transcriptomes identified seven known immune cell clusters. Sub-clustering of the mononuclear phagocyte cells revealed nine distinct cell sub-populations differently modified with RM. One macrophage cluster was particularly interesting since it behaved as a critical node in a trajectory connecting one major histocompatibility complex class IIhigh (MHCIIhigh) cluster only present in Control to two MHCIIlow clusters only present in RM-AKI. This critical cluster expressed a senescence gene signature, that was very different from that of the TECs. Senolytic DQ treatment blocked the switch from a F4/80highCD11blow to F4/80lowCD11bhigh phenotype, which correlated with prolonged nephroprotection in RM-AKI.

CONCLUSIONS

Single-cell RNA sequencing unmasked novel transitional macrophage subpopulation associated with RM-AKI characterized by the activation of cellular senescence processes. This work provides a proof-of-concept that senolytics nephroprotective effects may rely, at least in part, on subtle immune modulation.

Evaluating injuries and illnesses that occurred during the Yukon Quest International sled dog race, 2018-2020

Introduction

The purpose of this study was to evaluate medical record data from the 2018-2020 Yukon Quest International Sled Dog race to examine injury patterns and risk factors for dogs competing in multi-day ultra-endurance events. Specifically, we summarized injuries and illnesses that resulted in canine athletes being removed ("dropped") from competition, and in orthopedic injuries diagnosed in both dropped and finished dogs.

Methods

The records of 989 dogs that started the race were examined, but only records from dogs in teams that went on to finish the race were included, for a total of 711 records.

Results and discussion

Three hundred and sixty five dogs (51.3%) were noted to have at least one abnormal finding in their veterinary medical record during the race. Orthopedic injuries were most common, and 291 injuries were ultimately diagnosed in 234 dogs (32.9%). Ultimately, 206 dogs (29%) were dropped from competition, for any reason. The most common reasons for dropping dogs were orthopedic injuries (156 dogs; 188 injuries), gastrointestinal illness (22 dogs), and cardiorespiratory disease (7 dogs). Most orthopedic injuries in dropped dogs occurred in the thoracic limb (n = 121 dogs; 151 injuries). Of those, injuries to the shoulder were most common (n = 77), followed by injuries to the carpus (n = 59), and injury to the pelvic limb (n = 32). Carpal injuries were the most prevalent injury diagnosed in dogs that went on to finish the race (71 of 85 injuries). Carpal injuries were the most prevalent injuries overall in 2018 (51%) and 2019 (52%). In 2020, shoulder injuries were most prevalent (27%), suggesting that trail conditions may have differed between years. The majority of dogs with an orthopedic injury ultimately were removed from competition (156 of 234, or 66.6%), but the likelihood of finishing the race with an injury depended on the type of injury sustained; 71 of 130 dogs (54.6%) with a carpal injury went on to finish the race, whereas only 9 of 86 dogs with a shoulder injury (10.5%) went on to finish. The results of this study can assist mushers and veterinarians in preparing for races, and in decision making during endurance sled dog races.

Contrast Agent-Free 3D Renal Ultrafast Doppler Imaging Reveals Vascular Dysfunction in Acute and Diabetic Kidney Diseases

To combat the irreversible decline in renal function associated with kidney disease, it is essential to establish non-invasive biomarkers for assessing renal microcirculation. However, the limited resolution and/or vascular sensitivity of existing diagnostic imaging techniques hinders the visualization of complex cortical vessels. Here, a 3D renal ultrafast Doppler (UFD) imaging system that uses a high ultrasound frequency (18 MHz) and ultrahigh frame rate (1 KHz per slice) to scan the entire volume of a rat's kidney in vivo is demonstrated. The system, which can visualize the full 3D renal vascular branching pyramid at a resolution of 167 µm without any contrast agent, is used to chronically and noninvasively monitor kidneys with acute kidney injury (AKI, 3 days) and diabetic kidney disease (DKD, 8 weeks). Multiparametric UFD analyses (e.g., vessel volume occupancy (VVO), fractional moving blood volume (FMBV), vessel number density (VND), and vessel tortuosity (VT)) describe rapid vascular rarefaction from AKI and long-term vascular degeneration from DKD, while the renal pathogeneses are validated by in vitro blood serum testing and stained histopathology. This work demonstrates the potential of 3D renal UFD to offer valuable insights into assessing kidney perfusion levels for future research in diabetes and kidney transplantation.

Factors predicting kidney replacement therapy in pediatric earthquake victims with crush syndrome in the first week following rescue

Crush syndrome due to traumatic rhabdomyolysis is one of the most significant problems to occur following earthquakes. On February 6, 2023, millions of people in Turkey were affected by two consecutive Kahramanmaraş earthquakes. The present study reports the analysis of clinical and laboratory findings of crush syndrome in pediatric earthquake victims admitted to our hospital from our region where the earthquake had a devastating effect. Clinical and laboratory findings concerning earthquake victims with crush syndrome were analyzed within the first week to determine what factors are predictive of kidney replacement therapy (KRT). The data of patients were retrospectively collected from medical records. A total of 310 children were admitted as earthquake victims to the pediatric emergency department. Ninety-seven (31%) of these patients had crush syndrome. Fifty-three (55%) of those with crush syndrome were female. The mean age was 10.9 ± 4.7 years, and the mean time under the rubble was 30.6 ± 23.8 h. Twenty-two patients (23%) required KRT. Hemodialysis was applied to 16 (73%) of them, and hemodiafiltration was applied to the other six (27%) in the pediatric intensive care unit. Regarding creatine kinase (CK) levels, the area under the receiver operating characteristic (ROC) curve (AUC) for predicting KRT was 0.905 (95% confidence interval [CI] 0.848-0.963; p < 0.001). The optimal cut-off value was 40,000 U/L with a sensitivity of 86% and a specificity of 83%. In terms of the percentage of body area crushed, the AUC for predicting KRT was 0.907 (95% CI 0.838-0.976; p < 0.001). The optimal cut-off value was 30% with a sensitivity of 86% and a specificity of 88%. Multiple logistic regression analysis showed that each 10% increase in body area crushed (OR 4.16, 95% CI 1.58-10.93, p = 0.004) and 1 mg/dl increase in the serum phosphorus level (OR 4.19, 95% CI 1.71-10.28, p = 0.002) were significant risk factors for dialysis treatment.

CONCLUSIONS

Crush syndrome and kidney problems are common following disasters like earthquakes. Clinical and laboratory findings at admission can predict dialysis requirement in earthquake victims. While CK elevation, body area crushed percentage, and increased phosphorus level were predictive of dialysis treatment, time under the rubble was not. Even if the patients were under the rubble for a short time, acute kidney injury (AKI) may develop as a result of severe hypovolemia due to crush injuries, and patients may need KRT.

WHAT IS KNOWN

•Crush syndrome after earthquakes needs to be treated carefully in victims and can cause AKI and mortality when not treated timely and appropriately.

WHAT IS NEW

•CK level elevation, body area crushed percentage, and increased phosphorus level are predictive of dialysis treatment. •The time under the rubble may not be predictive of dialysis requirement.

Rhabdomyolysis-Induced Acute Kidney Injury Treated with Medium Cut-Off Membrane: A Case Report

Acute kidney injury can complicate rhabdomyolysis in 10-40% patients. Myoglobinuria and elevated creatine kinase (CK) form the basis of diagnosis. When associated with azotemia and/or oliguria, intermittent hemodialysis is a treatment option. 31-year-old young man came with lower limb pain after doing 800 sit ups. At the presentation, blood pressure was high, serum creatinine was 15.7mg/dl and creatine kinase(CK)>20000 IU/L. Intermittent dialysis was initiated. He developed posterior reversible encephalopathy syndrome, generalized tonic clonic convulsions and a further rise in CK. He underwent extracorporeal removal of myoglobin with medium cut-off (MCO) membrane. After 3 sessions with MCO membrane, myoglobin and CK levels reduced. He was transitioned to conventional dialysis and discharged in a stable condition with complete renal recovery. Medium cut-off membrane effectively removes circulating myoglobin without significant albumin loss and is cost effective.

Rhabdomyolysis as cause, consequence, or mimicker of myocardial infarction: A case report

Key Clinical Message

A timely diagnosis is essential to start appropriate therapy and to reduce risks of life-threatening complications of rhabdomyolysis. Some cases can undergo differential diagnosis with other clinical conditions, e.g., myocardial infarction.

Abstract

We present the case of a 65-years-old male who was admitted to the emergency department with a clinical presentation related to myocardial infarction. The patient underwent coronary angioplasty and was then admitted to ICU due to hemodynamical instability, elevated potassium levels, and anuria. Further investigations revealed rhabdomyolysis. The patient received vasopressors, oxygenation support and renal replacement therapy. Outcomes at ICU discharge were favorable. The temporal association between rhabdomyolysis and myocardial infarction, together with an unclear pathophysiological relationship, made differential diagnosis difficult. We discuss this uncertainty in light of published literature.

Disasters and kidney care: pitfalls and solutions

Patients with kidney disease, especially those with kidney failure, are particularly susceptible to the adverse effects of disasters because their survival depends on functional infrastructure, advanced technology, the availability of specific drugs and well-trained medical personnel. The risk of poor outcomes across the entire spectrum of patients with kidney diseases (acute kidney injury, chronic kidney disease and kidney failure on dialysis or with a functioning transplant) increases as a result of disaster-related logistical challenges. Patients who are displaced face even more complex problems owing to additional threats that arise during travel and after reaching their new location. Overall, risks may be mitigated by pre-disaster preparedness and training. Emergency kidney disaster responses depend on the type and severity of the disaster and include medical and/or surgical treatment of injuries, treatment of mental health conditions, appropriate diet and logistical interventions. After a disaster, patients should be evaluated for problems that were not detected during the event, including those that may have developed as a result of the disaster. A retrospective review of the disaster response is vital to prevent future mistakes. Important ethical concerns include fair distribution of limited resources and limiting harm. Patients with kidney disease, their care-givers, health-care providers and authorities should be trained to respond to the medical and logistical problems that occur during disasters to improve outcomes.

A Comparative Analysis of Fasciotomy Results in Children and Adults Affected by Crush-Induced Acute Kidney Injury following the Kahramanmaraş Earthquakes

Background and Objectives: The current study aims to determine the impact of fasciotomy on mortality and morbidity in children and adults with crush-related AKI following the 2023 Kahramanmaraş earthquakes. Materials and Methods: The study included individuals who had suffered crush injuries after the 2023 Kahramanmaraş earthquakes and were identified as having an acute kidney injury (AKI). Patients with an AKI were divided into two groups based on age: those under 18 years and those over 18 years. A comparative analysis was conducted between the mortality and morbidity rates of patients who underwent fasciotomy and those who did not. Disseminated intravascular coagulopathy (DIC), sepsis, and adult respiratory distress syndrome (ARDS) have all been identified as contributors to morbidity. Results: The study was conducted with a total of 40 patients (21 males and 19 females) aged between 4 and 83 years. A total of 21 patients underwent fasciotomy, and the patients underwent varying numbers of fasciotomy, ranging from 0 to 11. The mortality rate was 12.5%, corresponding to five adult patients. No instances of mortality were reported in the paediatric cohort. The application of fasciotomy in instances of crush-induced AKI did not result in elevated levels of mortality in either the paediatric or adult demographic. Within the adult population, a substantial difference in the duration of dialysis was observed between individuals who underwent fasciotomy and those who did not. A statistically significant increase in the number of fasciotomy incisions was observed in patients diagnosed with sepsis compared with those without sepsis. The study found a significant positive correlation between the number of fasciotomy incisions and dialysis days. Conclusions: Neither adult nor paediatric patients with crush-induced AKI showed an increased risk of death after fasciotomy. The number of fasciotomy incisions significantly correlated with the development of sepsis. Despite experiencing delays in hospital admission for paediatric patients, the incidence of both crush syndrome and mortality rates among children remained relatively low.

The association between procalcitonin and acute kidney injury in patients stung by wasps

Introduction: The aim of this study was to investigate the status of serum procalcitonin (PCT) in patients stung by wasps and evaluate the association between PCT levels and acute kidney injury (AKI). Methods: Patients stung by wasps admitted to two tertiary hospitals between January 2017 and December 2020 were screened for enrollment. We evaluated serum PCT levels on admission in patients stung by wasps. The patients were divided into an AKI group and a non-AKI group. A logistic regression model was used to analyze the association between PCT status and AKI. The performance of PCT concentrations in predicting the occurrence of AKI was evaluated by the area under the receiver operating characteristic curve (AUROC). Results: A total of 138 patients were enrolled, and 66 patients suffered AKI. PCT levels were elevated in 78.99% of patients stung by wasps. Nearly half of the patients (47.83%) developed AKI. PCT levels were correlated with creatinine levels on admission (r = 0.787, 95% CI: 0.713-0.844). PCT levels in patients with AKI were higher than those in patients without AKI (p < 0.001). After adjustment for covariates, PCT levels on admission were independently associated with AKI (OR: 1.575, 95% CI: 1.071-2.317, p = 0.021). The AUROC of PCT levels on admission was 0.837 (95% CI, 0.771-0.902, p < 0.001). A PCT level of 0.57 μg/L was the cutoff for maximizing the Youden index; the specificity was 79.45%, and the sensitivity was 73.43%. Conclusion: Serum PCT levels may be a potential biomarker of AKI in patients stung by wasps.

A practical nomogram for predicting amputation rates in acute compartment syndrome patients based on clinical factors and biochemical blood markers

BACKGROUND

Amputation is a serious complication of acute compartment syndrome (ACS), and predicting the risk factors associated with amputation remains a challenge for surgeons. The aim of this study was to analyze the risk factors for amputation in patients with ACS and develop a nomogram to predict amputation risk more accurately.

METHODS

The study population consisted of 143 patients (32 in the amputation group and 111 in the limb preservation group) diagnosed with ACS. LASSO and multivariate logistic regression were used to screen predictors and create a nomogram. The model's accuracy was assessed by receiver operating characteristic (ROC) curves, C-index, calibration curves, and decision curve analysis (DCA).

RESULTS

The predictors included cause of injury, vascular damage, shock, and fibrinogen in the nomogram. The C-index of the model was 0.872 (95% confidence interval: 0.854-0.962), and the C-index calculated by internal validation was 0.838. The nomogram's area under the curve (AUC) was 0.849, and the calibration curve demonstrated a high degree of agreement between the nomogram's predictions and actual observations. Additionally, the DCA indicated good clinical utility for the nomogram.

CONCLUSION

The risk of amputation in ACS patients is associated with the cause of injury, vascular damage, shock, and fibrinogen. Our nomogram integrating clinical factors and biochemical blood markers enables doctors to more conveniently predict the risk of amputation in patients with ACS.

Drug induced nephrotoxicity- A mechanistic approach

The main goal of the treatment of patients is its effectiveness and safety. However, all currently prescribed drugs being used also have certain adverse effects, which might be seen as an unavoidable but necessary cost of pharmacotherapy. The kidney is the primary organ for xenobiotics elimination, making it particularly susceptible to the harmful effects of drugs and their metabolites during their excretion from the body. Moreover, certain medications have a preferential nephrotoxicity potential, which means that using them increases the risk of kidney injury. Drug nephrotoxicity is, therefore, both a significant problem and a complication of pharmacotherapy. It should be noted that, there is presently no accepted definition of drug-induced nephrotoxicity and no established diagnostic criteria. The current review briefly describes the pathogenic mechanism of drug-induced nephrotoxicity, the various basic drugs with nephrotoxicity potential and the renal biomarkers for the treatment of the drug-related kidney damage.

Rhabdomyolysis Secondary to Severe Hypothyroidism Due to Hashimoto's Thyroiditis: A Case Report

Hashimoto's thyroiditis, a chronic autoimmune inflammation of the thyroid glands, is the most common cause of hypothyroidism in iodine-sufficient areas, which can have varied clinical manifestations. It is more common in females and usually has an insidious course. Most patients present with mild clinical symptoms, such as constipation, fatigue, and weakness. Symptoms are associated with a slight increase in thyroid-stimulating hormone (TSH) levels and the presence of thyroid antibodies. However, overt hypothyroidism is uncommon. We hereby present an interesting case of rhabdomyolysis secondary to severe hypothyroidism due to Hashimoto's thyroiditis.

The pathophysiology of rhabdomyolysis in ungulates and rats: towards the development of a rodent model of capture myopathy

Capture myopathy (CM), which is associated with the capture and translocation of wildlife, is a life-threatening condition that causes noteworthy morbidity and mortality in captured animals. Such wildlife deaths have a significant impact on nature conservation efforts and the socio-economic wellbeing of communities reliant on ecotourism. Several strategies are used to minimise the adverse consequences associated with wildlife capture, especially in ungulates, but no successful preventative or curative measures have yet been developed. The primary cause of death in wild animals diagnosed with CM stems from kidney or multiple organ failure as secondary complications to capture-induced rhabdomyolysis. Ergo, the development of accurate and robust model frameworks is vital to improve our understanding of CM. Still, since CM-related complications are borne from biological and behavioural factors that may be unique to wildlife, e.g. skeletal muscle architecture or flighty nature, certain differences between the physiology and stress responses of wildlife and rodents need consideration in such endeavours. Therefore, the purpose of this review is to summarise some of the major etiological and pathological mechanisms of the condition as it is observed in wildlife and what is currently known of CM-like syndromes, i.e. rhabdomyolysis, in laboratory rats. Additionally, we will highlight some key aspects for consideration in the development and application of potential future rodent models.

Methamphetamine-induced profound rhabdomyolysis and myoglobin cast nephropathy: A case report and a literature review

A 46-year-old male with a history of substance abuse was found dead in custody 30 hours post incarceration for a minor offense. The scene demonstrates the body lying in a prone position in the cell room, locked from the outside. No signs of violence were found at the scene. External examination revealed no significant injuries, except for multiple minor contusions and abrasions. The autopsy demonstrated only a moderate degree of bilateral pulmonary edema. No internal injuries were found, except for fractures in the three lower left ribs. Dark reddish-brown urine was detected in the urinary bladder. Histological examination revealed a diffuse tubular injury with intraluminal eosinophilic granular casts. The myoglobin cast demonstrated pale PAS staining with a granular appearance, Masson Trichrome staining demonstrated fuschinophilic deposits on the casts, and immunoperoxidase staining for myoglobin was strongly positive in the casts (the images will be displayed). Blood myoglobin and creatine kinase levels were elevated. These findings revealed profound rhabdomyolysis caused by several factors. Blood toxicology tests revealed lethal methamphetamine and amphetamine levels. All the findings were consistent with methamphetamine-induced severe rhabdomyolysis. Therefore, forensic pathologists should carefully search for gross and histological findings and conduct thorough laboratory investigations to diagnose this condition for complete medicolegal examination.

Rhabdomyolysis and Acute Renal Dysfunction as Initial Manifestations of Monoclonal Gammopathy of Renal Significance

Monoclonal gammopathy of renal significance (MGRS) is a rare heterogeneous group of kidney disorders that encompasses all disorders caused by deposition of monoclonal protein (M-protein) and its light or heavy chain fragments secreted by pre-malignant or non-malignant B-cell clones in patients who do not meet the diagnostic criteria for multiple myeloma (MM) or other B-cell malignancies. MGRS can manifest as glomerular diseases, tubulopathies, or vascular involvement with varying clinical presentations, making the diagnosis of MGRS challenging. In patients with high clinical suspicion based on preliminary blood and urine studies, the evaluation of MGRS begins with a renal biopsy followed by monoclonal studies and cytogenetic analysis. There is no standard treatment protocol for MGRS, and the current consensus suggests a clone-directed approach. If not identified and treated early, MGRS often results in poor outcomes and can lead to extrarenal manifestations, such as cardiogenic shock. Herein, we present a case involving a 43-year-old male with a rare presentation of rhabdomyolysis, rapidly progressing renal dysfunction, and cardiac dysfunction. A bone marrow biopsy did not meet the diagnostic criteria for MM or other B-cell malignancies, while a renal biopsy revealed Kappa light chain cast nephropathy, which led to the final diagnosis of MGRS.

Inflammation balance in skeletal muscle damage and repair

Responding to tissue injury, skeletal muscles undergo the tissue destruction and reconstruction accompanied with inflammation. The immune system recognizes the molecules released from or exposed on the damaged tissue. In the local minor tissue damage, tissue-resident macrophages sequester pro-inflammatory debris to prevent initiation of inflammation. In most cases of the skeletal muscle injury, however, a cascade of inflammation will be initiated through activation of local macrophages and mast cells and recruitment of immune cells from blood circulation to the injured site by recongnization of damage-associated molecular patterns (DAMPs) and activated complement system. During the inflammation, macrophages and neutrophils scavenge the tissue debris to release inflammatory cytokines and the latter stimulates myoblast fusion and vascularization to promote injured muscle repair. On the other hand, an abundance of released inflammatory cytokines and chemokines causes the profound hyper-inflammation and mobilization of immune cells to trigger a vicious cycle and lead to the cytokine storm. The cytokine storm results in the elevation of cytolytic and cytotoxic molecules and reactive oxygen species (ROS) in the damaged muscle to aggravates the tissue injury, including the healthy bystander tissue. Severe inflammation in the skeletal muscle can lead to rhabdomyolysis and cause sepsis-like systemic inflammation response syndrome (SIRS) and remote organ damage. Therefore, understanding more details on the involvement of inflammatory factors and immune cells in the skeletal muscle damage and repair can provide the new precise therapeutic strategies, including attenuation of the muscle damage and promotion of the muscle repair.

Association between admission serum phosphate and risk of acute kidney injury in critically ill patients with rhabdomyolysis: A retrospective study based on MIMIC-Ⅲ

BACKGROUND

The incidence of acute kidney injury (AKI) is high in critically ill patients with rhabdomyolysis. Limited evidence was proved of the association between serum phosphate levels at intensive care unit (ICU) admission and the subsequent risk of AKI. Our study aims to assess if serum phosphate levels at admission were independently associated with AKI risk in these patients.

METHODS

This study extracted and analyzed data from Medical Information Mart for Intensive Care-Ⅲ (MIMIC-Ⅲ, version1.4). Rhabdomyolysis was defined as a peak creatine kinase (CK) level higher than 1000 U/L. Serum phosphate was measured within the first day into the ICU and was categorized to 4 groups (<2.6, 2.6-3.4, 3.5-4.5, >4.5mg/dl). AKI was defined according to the Kidney Disease Improving Global Outcome (KDIGO) guidelines. Adjusted smoothing spline plots and multivariable logistic regressions were carried out to explode the association between serum phosphate and risk of AKI. Subgroup analyse was applied to verify the consistency of the association.

RESULTS

Three hundred and twenty-one patients (68% male) diagnosed as rhabdomyolysis were eligible for this analysis. AKI occurred in 204 (64%) patients of total. Incidence of AKI with admission serum phosphate groups<2.6, 2.6-3.4, 3.5-4.5 and>4.5mg/dl were 53%, 57%, 68% and 76%, respectively. Smoothing spline curve showed that there was a positive curve between the elevated phosphate values and increasing risk of AKI, and there was no threshold saturation effect. In multivariable logistic regression, OR was 1.2 (95%CI 1.0-1.5, P=0.035, P trend=0.041) after adjusting confounders. Subgroup analyses proved the consistency of the relationship in these patients, possibly, except in the strata of potassium.

CONCLUSION

In rhabdomyolysis patients admitted to ICU, serum phosphate levels at admission were independently associated with an increased risk of AKI. As phosphate levels rise, the risk of AKI increased.

Myoglobin cast nephropathy following multiple bee stings

Bee stings usually result in mild allergic reactions; however, mass envenomation can cause severe complications such as rhabdomyolysis, hemolysis, shock, or multi-organ damage. Rhabdomyolysis can result in acute renal failure either by tubular obstruction by myoglobin casts or by direct cytotoxic injury. We present a case of a 12-year-old female child who presented with sudden onset anuria and hypertension following mass envenomation by bees. A renal biopsy was performed, the microscopic evaluation of which revealed tubular injury, with associated intratubular pigmented casts. The casts stained positive for myoglobin immunohistochemical stain, thus confirming a diagnosis of myoglobin cast nephropathy. The patient was given IV steroids and underwent seven sessions of hemodialysis, following which there was complete recovery of renal function.

Management of pediatric dialysis and kidney transplant patients after natural or man-made disasters

Pediatric patients on kidney replacement therapy (KRT) are among the most vulnerable during large-scale disasters, either natural or man-made. Hemodialysis (HD) treatments may be impossible because of structural damage and/or shortage of medical supplies, clean water, electricity, and healthcare professionals. Lack of peritoneal dialysis (PD) solutions and increased risk of infectious/non-infectious complications may make PD therapy challenging. Non-availability of immunosuppressants and increased risk of infections may result in graft loss and deaths of kidney transplant recipients. Measures to mitigate these risks must be considered before, during, and after the disaster including training of staff and patients/caregivers to cope with medical and logistic problems. Soon after a disaster, if the possibility of performing HD or PD is uncertain, patients should be directed to other centers, or the duration and/or number of HD sessions or the PD prescription adapted. In kidney transplant recipients, switching among immunosuppressants should be considered in case of non-availability of the medications. Post-disaster interventions target treating neglected physical and mental problems and also improving social challenges. All problems experienced by pediatric KRT patients living in the affected area are applicable to displaced patients who may also face extra risks during their travel and also at their destination. The need for additional local, national, and international help and support of non-governmental organizations must be anticipated and sought in a timely manner.

Remote ischaemic conditioning in necrotising enterocolitis: a phase I feasibility and safety study

OBJECTIVE

Remote ischaemic conditioning (RIC) improves the outcome of experimental necrotising enterocolitis (NEC) by preserving intestinal microcirculation. The feasibility and safety of RIC in preterm infants with NEC are unknown. The study aimed to assess the feasibility and safety of RIC in preterm infants with suspected or confirmed NEC.

DESIGN

Phase I non-randomised pilot study conducted in three steps: step A to determine the safe duration of limb ischaemia (up to 4 min); step B to assess the safety of 4 repeated cycles of ischaemia-reperfusion at the maximum tolerated duration of ischaemia determined in step A; step C to assess the safety of applying 4 cycles of ischaemia-reperfusion on two consecutive days.

SETTING

Level III neonatal intensive care unit, The Hospital for Sick Children (Toronto, Canada).

PATIENTS

Fifteen preterm infants born between 22 and 33 weeks gestational age.

INTERVENTION

Four cycles of ischaemia (varying duration) applied to the limb via a manual sphygmomanometer, followed by reperfusion (4 min) and rest (5 min), repeated on two consecutive days.

OUTCOMES

The primary outcomes were (1) feasibility defined as RIC being performed as planned in the protocol, and (2) safety defined as perfusion returning to baseline within 4 min after cuff deflation.

RESULTS

Four cycles/day of limb ischaemia (4 min) followed by reperfusion (4 min) and a 5 min gap, repeated on two consecutive days was feasible and safe in all neonates with suspected or confirmed NEC.

CONCLUSIONS

This study is pivotal for designing a future randomised controlled trial to assess the efficacy of RIC in preterm infants with NEC.

TRIAL REGISTRATION NUMBER

NCT03860701.

Relationship between Blood Parameters and Outcome in Rescued Roe Deer

Veterinary facility admissions of wild animals are increasing alongside the interest in wildlife diseases. To improve animal welfare, it is therefore important to increase veterinarians’ knowledge of wild animal medicine and to improve the clinical and diagnostic procedures, especially in the case of patients affected by trauma or multiple traumas. Blood analysis can be a quick and minimally invasive way of gathering useful clinical information for adequate treatment and management, and, together with a good clinical examination, to help predict hospitalisation outcomes. Few papers have reported reference ranges for the haematological and biochemical parameters of roe deer. This study evaluates the haematological and biochemical parameters in traumatised roe deer in relation to animal hospitalisation outcomes. The study was carried out on a cohort of 98 roe deer divided into groups according to their age and hospitalisation outcome. For each animal, a panel of haematological and biochemical parameters was performed. Significant differences were found between unweaned (<4 months old) groups in terms of MCV, MCH, CK, creatinine, total bilirubin, direct bilirubin, and indirect bilirubin, and between weaned (>4 months old) groups for total bilirubin. Creatine kinase, creatinine, and bilirubin may be useful indicators to correlate with the severity of trauma and help predict prognosis.

Antibiotic Therapy in the Critically Ill with Acute Renal Failure and Renal Replacement Therapy: A Narrative Review

The outcome for critically ill patients is burdened by a double mortality rate and a longer hospital stay in the case of sepsis or septic shock. The adequate use of antibiotics may impact on the outcome since they may affect the pharmacokinetics (Pk) and pharmacodynamics (Pd) of antibiotics in such patients. Acute renal failure (ARF) occurs in about 50% of septic patients, and the consequent need for continuous renal replacement therapy (CRRT) makes the renal elimination rate of most antibiotics highly variable. Antibiotics doses should be reduced in patients experiencing ARF, in accordance with the glomerular filtration rate (GFR), whereas posology should be increased in the case of CRRT. Since different settings of CRRT may be used, identifying a standard dosage of antibiotics is very difficult, because there is a risk of both oversimplification and failing the therapeutic efficacy. Indeed, it has been seen that, in over 25% of cases, the antibiotic therapy does not reach the necessary concentration target mainly due to lack of the proper minimal inhibitory concentration (MIC) achievement. The aim of this narrative review is to clarify whether shared algorithms exist, allowing them to inform the daily practice in the proper antibiotics posology for critically ill patients undergoing CRRT.

Uric Acid and Chronic Kidney Disease: Still More to Do

Gout and hyperuricemia are present in 25% and 60% of patients with chronic kidney disease (CKD), respectively. Despite the common association, the role of uric acid in the progression of kidney disease and in metabolic complications remains contested. Some authorities argue that the treatment of asymptomatic hyperuricemia in CKD is not indicated, and some have even suggested hyperuricemia may be beneficial. Here, we review the various arguments both for and against treatment. The weight of the evidence suggests asymptomatic hyperuricemia is likely injurious, but it may primarily relate to subgroups, those who have systemic crystal deposits, those with frequent urinary crystalluria or kidney stones, and those with high intracellular uric acid levels. We recommend carefully designed clinical trials to test if lowering uric acid in hyperuricemic subjects with cardiometabolic complications is protective.

Fluid Stewardship of Maintenance Intravenous Fluids

Despite the frequent use of maintenance intravenous fluids (mIVF) in critically ill patients, limited guidance is available. Notably, fluid overload secondary to mIVF mismanagement is associated with significant adverse patient outcomes. The Four Rights (right drug, right dose, right duration, right patient) construct of fluid stewardship has been proposed for the safe evaluation and use of fluids. The purpose of this evidence-based review is to offer practical insights for the clinician regarding mIVF selection, dosing, and duration in line with the Four Rights of Fluid Stewardship.

Molecular Mechanisms of Rhabdomyolysis-Induced Kidney Injury: From Bench to Bedside

Rhabdomyolysis-induced acute kidney injury (RIAKI) occurs following damage to the muscular sarcolemma sheath, resulting in the leakage of myoglobin and other metabolites that cause kidney damage. Currently, the sole recommended clinical treatment for RIAKI is aggressive fluid resuscitation, but other potential therapies, including pretreatments for those at risk for developing RIAKI, are under investigation. This review outlines the mechanisms and clinical significance of RIAKI, investigational treatments and their specific targets, and the status of ongoing research trials.

The management and diagnosis of rhabdomyolysis-induced acute kidney injury: a case study

Rhabdomyolysis is characterised by a rapid dissolution of damaged or injured skeletal muscle that can be the result of a multitude of mechanisms. It can range in severity from mild to severe, leading to multi-organ failure and death. Rhabdomyolysis causes muscular cellular breakdown, which can cause fatal electrolyte imbalances and metabolic acidosis, as myoglobin, creatine phosphokinase, lactate dehydrogenase and other electrolytes move into the circulation; acute kidney injury can follow as a severe complication. This article reflects on the case of a person who was diagnosed with rhabdomyolysis and acute kidney injury after a fall at home. Understanding the underpinning mechanism of rhabdomyolysis and the associated severity of symptoms may improve early diagnosis and treatment initiation.

Exercise-Induced Rhabdomyolysis Causing Acute Kidney Injury: A Potential Threat to Gym Lovers

Rhabdomyolysis, by definition, means the breakdown of muscles. The common causes are trauma, immobility, illicit drug use, medications, toxins, infections, potassium imbalance, hypothyroid or hyperthyroid states, hypothermia or hyperthermia, and some congenital muscular dystrophy. Exercise or exertion-induced rhabdomyolysis is a very uncommon entity and potentially rising among young generations amid getting perfect body shape as influenced by social platforms. However, rhabdomyolysis can lead to lethal complications, most commonly acute kidney injury leading to dialysis, disseminated intravascular coagulation (DIC), and acute compartment syndrome. Here we report a case of exertion-induced rhabdomyolysis causing acute renal failure in a young patient who presented to the emergency room at The Kidney Center, Karachi, after exercising at the gym. The patient was subsequently treated with hemodialysis and was discharged after six days of hospital admission.

Dexmethylphenidate-Induced Rhabdomyolysis by Interaction With Aromatase Inhibitor

Rhabdomyolysis secondary to prescription drug-drug interactions can be an overlooked life-threatening emergency. Amphetamines and similar substances have been associated with muscle lysis secondary to increased sympathetic activity that can cause myotoxicity, hyperthermia, and increased muscular activity. Anabolic steroids may also be a predisposing factor in developing rhabdomyolysis. A high index of suspicion for drug-induced rhabdomyolysis in a patient presenting with atraumatic extremity pain can facilitate rapid diagnosis and treatment. We present a case of drug-induced rhabdomyolysis likely secondary to a previously unreported medication interaction.

Clinical characteristics and outcomes of exertional rhabdomyolysis after indoor spinning: a systematic review

OBJECTIVES

An increasing number of patients are diagnosed with exertional rhabdomyolysis secondary to indoor spinning. We performed a systematic review to characterize the clinical features of this new clinical entity.

METHODS

We conducted a thorough literature search on PubMed, Embase, Web of Science, Scopus, and The Cumulative Index to Nursing and Allied Health Literature (CINAHL). Articles published from inception to 23 June 2021 were considered. A two-stage article selection process was performed. Articles that reported clinical characteristics and outcomes in patients with spin-induced exertional rhabdomyolysis (SIER) were included. Quality assessment was performed using the Joanna Briggs Institute checklists.

RESULTS

There were a total of 22 articles and 97 patients with SIER. Most patients were healthy females who had attended their first spinning session. The mean time to clinical presentation was 3.1 ± 1.5 days. The most common presenting symptoms were myalgia, dark urine, and muscle weakness in the thighs. Seven patients (7.2%) developed acute kidney injury, and two patients (2.1%) required temporary inpatient hemodialysis. Four patients (4.1%) developed thigh compartment syndrome and required fasciotomies. No long-term sequelae or mortality were observed. The mean length of stay was 5.6 ± 2.9 days.

CONCLUSIONS

Healthcare professionals must have a high index of suspicion for SIER when a patient presents with myalgia, dark urine, or weakness after a recent episode of indoor spinning. Fitness center owners, spinning instructors, and participants should also be better educated about the clinical features and manifestations of SIER.

Upper limb replantation: Surgical strategy and the prophylaxis of acute renal failure due to ischemia reperfusion injury – A report of two cases

Introduction. The arm replantation is an extremely rare and challenging procedure. The recognized risk is myoglobinuria and, consenquently, ischemia reperfusion-induced renal failure. Case report. We presented two patients aged 24 and 46 years who were admitted after traumatic arm amputation. Ischemia time was six and two hours, respectively. Postoperative intensive care treatment with assisted ventilation, sedation, and obtaining sufficient urine output prevented myoglobin-induced renal injury. In the case where ischemia time was shorter, there was only one delayed reconstruction of skin defects after fasciotomy, but in the case where ischemia lasted longer, the patient had two secondary look procedures with acceptable definitive results. Conclusion. Arm replantation is a safe procedure even in cases with longer ischemia time. Postoperative control of urine output, correction of acidosis, and preventing myoglobin-induced tubular injury are crucial for stable postoperative recovery and.

Donor rhabdomyolysis, acute kidney injury and kidney transplant outcomes

BACKGROUND

Donor rhabdomyolysis may constrain kidney utilization due to anticipated unfavorable graft outcomes-especially in combination with acute kidney injury (AKI). There is a paucity of empiric data to inform organ acceptance decision-making.

METHODS

A single-center retrospective cohort study of adult transplant recipients of deceased-donor kidneys with reported donor creatine phosphokinase (CPK) levels was conducted between 2014 and 2020. Recipients of CPK ≥ 1000 U/L kidneys were propensity matched to CPK < 1000 recipients according to outcome-predictive baseline covariates, except AKI.

RESULTS

A total of 254 kidney transplants were propensity matched into CPK ≥ 1000 (n = 90) vs CPK<1000 (n = 90) groups. Transplant outcomes with high versus low CPK kidneys were similar in terms of delayed graft function (p = 0.64), 1-year estimated glomerular filtration rate <25^th percentile (p = 0.69) and mean (p = 0.58), and time to all-cause graft failure (p = 0.58). There was no interaction between AKI and high CPK for these outcomes. Extreme CPK thresholds as high as >8672 U/L were not associated with overall graft survival in the unmatched sample (p = 0.81).

CONCLUSIONS

In a single center study, donor rhabdomyolysis was not associated with short-term kidney transplant graft outcomes, nor was there an additive effect of AKI. However, studies with greater CPK and AKI severity and longer follow-up are warranted. This article is protected by copyright. All rights reserved.

Dark urine as the initial manifestation of COVID-19: a case report

Background

Rhabdomyolysis is defined as a syndrome consisting of muscle necrosis and the release of intracellular muscle components into the bloodstream. Although rhabdomyolysis has been previously reported as an initial presentation or late complication of COVID-19, the data on it is still limited, and currently, there is no single case of COVID-19 in the literature that describes creatine kinase levels of more than 30,000 IU/L.

Case presentation

A 50-year-old African–American male presented to the hospital with decreased urine output, dark urine color, and constipation for the past couple of days. He was found to have acute kidney injury, liver injury, and creatinine kinase of 359,910 IU/L, for which aggressive intravenous fluid therapy was given. Infectious workup resulted in positive severe acute respiratory syndrome coronavirus 2 polymerase chain reaction. Two days after admission, the patient became symptomatic from a coronavirus disease 2019: he developed fever and hypoxia, and was placed on supplemental oxygen and started on a 10-day course of dexamethasone. The patient responded well to the treatment and supportive care for coronavirus disease 2019 and was successfully discharged.

Conclusion

Clinicians should be cognizant of atypical coronavirus disease 2019 presentations. The spectrum of damage of coronavirus disease 2019 is still an evolving topic, and more research is required to reveal the exact mechanisms by which severe acute respiratory syndrome coronavirus 2 leads to rhabdomyolysis.

Rare Causes of Hypercalcemia

This article discusses rare causes of hypercalcemia. Hypercalcemia can rarely be associated with immobilization, genetic diseases in children such as Williams-Beuren syndrome, Hypophosphatasia, Jansen Metaphyseal Chondrodysplasia (JMC), cosmetic injection, milk-alkali syndrome (MAS), calcium sulfate beads administration, manganese intoxication, postacute kidney failure recovery, and Paget's disease.

Elevated Neutrophil Gelatinase-Associated Lipocalin Is Associated With the Severity of Kidney Injury and Poor Prognosis of Patients With COVID-19

INTRODUCTION

Loss of kidney function is a common feature of COVID-19 infection, but serum creatinine (SCr) is not a sensitive or specific marker of kidney injury. We tested whether molecular biomarkers of tubular injury measured at hospital admission were associated with acute kidney injury (AKI) in those with COVID-19 infection.

METHODS

This is a prospective cohort observational study consisting of 444 consecutive patients with SARS-CoV-2 enrolled in the Columbia University emergency department (ED) at the peak of the pandemic in New York (March 2020-April 2020). Urine and blood were collected simultaneously at hospital admission (median time: day 0, interquartile range: 0-2 days), and urine biomarkers were analyzed by enzyme-linked immunosorbent assay (ELISA) and a novel dipstick. Kidney biopsies were probed for biomarker RNA and for histopathologic acute tubular injury (ATI) scores.

RESULTS

Admission urinary neutrophil gelatinase-associated lipocalin (uNGAL) level was associated with AKI diagnosis (267 ± 301 vs. 96 ± 139 ng/ml, P < 0.0001) and staging; uNGAL levels >150 ng/ml had 80% specificity and 75% sensitivity to diagnose AKI stages 2 to 3. Admission uNGAL level quantitatively associated with prolonged AKI, dialysis, shock, prolonged hospitalization, and in-hospital death, even when admission SCr level was not elevated. The risk of dialysis increased almost 4-fold per SD of uNGAL independently of baseline SCr, comorbidities, and proteinuria (odds ratio [OR] [95% CI]: 3.59 [1.83-7.45], P < 0.001). In the kidneys of those with COVID-19, NGAL mRNA expression broadened in parallel with severe histopathologic injury (ATI). Conversely, low uNGAL levels at admission ruled out stages 2 to 3 AKI (negative predictive value: 0.95, 95% CI: 0.92-0.97) and the need for dialysis (negative predictive value: 0.98, 95% CI: 0.96-0.99). Although proteinuria and urinary (u)KIM-1 were implicated in tubular injury, neither was diagnostic of AKI stages.

CONCLUSION

In the patients with COVID-19, uNGAL level was quantitatively associated with histopathologic injury (ATI), loss of kidney function (AKI), and severity of patient outcomes.

Forced running-induced rhabdomyolysis in the Sprague-Dawley rat: towards a rodent model of capture myopathy

Capture myopathy (CM) is a metabolic disease associated with mortality in mass boma captured (MBC) wildlife. The condition is induced by the forced pursuit, capturing, and restraint of wild animals, although its causal biology remains to be confirmed. A core feature of MBC-CM is rhabdomyolysis, which is associated with myoglobinuria and hyperthermia. Towards developing a translational model of CM-associated rhabdomyolysis, we investigated forced treadmill running to induce physical exhaustion and trigger rhabdomyolysis in Sprague Dawley (SD) rats. Twenty-four (24) SD rats (12 per sex) were subjected to treadmill habituation in a speed-tiered approach. Forty-eight hours after the last habituation session, one strenuous exercise (SE) session was performed at 75% of the theoretical VO_2MAX (30 m/min) until animals reached physical exhaustion. Core and skin surface temperatures were measured before the SE session and after rats reached exhaustion, after which a 1-h-cumulative urine sample was collected, and the myoglobin content assayed. We show that most SE, but not control-exposed (non-exercise) rats presented with myoglobinuria, while core and surface body temperatures in both male and female rats were significantly higher post-exercise. This pre-clinical model framework shows potential for investigating the pathophysiology of MBC-CM.

Admission serum myoglobin and the development of acute kidney injury after major trauma

BACKGROUND

Myoglobin and creatine kinase (CK) are both established markers of muscle injury but their hospital admission values have never been compared to predict post-traumatic acute kidney injury (AKI).

METHODS

An observational registry study of consecutive trauma patients admitted to a major regional trauma centre. The primary outcome was stage 1 or more AKI in the first 7 days after trauma. We assessed the association of hospital admission myoglobin or CK with development of AKI both alone and when added to two existing risk prediction models for post traumatic AKI.

RESULTS

Of the 857 trauma patients (median age 36 [25-52], 96% blunt trauma, median ISS of 20 [12-47]) included, 102 (12%) developed AKI. Admission myoglobin performed better than CK to predict AKI any stage with an AUC-ROC of 0.74 (95% CI 0.68-0.79) and 0.63 (95% CI 0.57-0.69), respectively (p < 0.001). Admission myoglobin also performed better than CK to predict AKI stage 2 or 3 [AUC-ROC of 0.79 (95% CI 0.74-0.84) and 0.74 (95% CI 0.69-0.79), respectively (p < 0.001)] with a best cutoff value of 1217 µg/L (sensitivity 74%, specificity 77%). Admission myoglobin added predictive value to two established models of AKI prediction and showed significant ability to reclassify subjects regarding AKI status, while admission CK did not. Decision curve analysis also revealed that myoglobin added net benefit to established predictive models. Admission myoglobin was better than CK at predicting development of significant rhabdomyolysis.

CONCLUSIONS

Admission myoglobin better predicts the development of AKI and severe rhabdomyolysis after major trauma. Admission myoglobin should be added in established predictive models of post-traumatic AKI to early identify high-risk patients.

Influenza A-induced rhabdomyolysis with acute renal failure following a deep tissue massage

We describe a unique case of severe influenza A-induced rhabdomyolysis in a previously healthy 39-year-old man, who developed symptoms immediately following a 2-hour deep-tissue massage and improved with oseltamivir and intravenous fluids. This case describes a possible temporal association between tissue damage secondary to deep tissue massage and the subsequent exacerbation of rhabdomyolysis in the setting of an influenza A infection. Biological evidence of muscle cell viral invasion with massage supports the possibility of elevated influenza A pathogenicity.

Rhabdomyolysis Following Ad26.COV2.S COVID-19 Vaccination

We report the case of a 19-year-old male who complained of myalgia, muscle weakness, and darkened urine two days after receiving his Ad26.COV2.S (Johnson & Johnson, New Brunswick, New Jersey, United States) COVID-19 vaccination. Blood examination revealed an increased creatine kinase (CK) level, and his urinary dipstick tested positive for blood, indicative of acute rhabdomyolysis. Serum creatinine levels were normal. Rhabdomyolysis due to strenuous physical activity was ruled out and further diagnostics excluded an autoimmune cause. Under repeated treatment with intravenous fluid resuscitation (outpatient treatment), his symptoms resolved and peak CK levels of 44,180 U/L returned to almost normal levels within two weeks. Rhabdomyolysis is a rare, potentially fatal vaccine-induced reaction. Further research is needed to better understand the underlying pathomechanism and to investigate whether subcutaneous injection of vaccines may be able to prevent rhabdomyolysis.

Umbelliferone attenuates glycerol-induced myoglobinuric acute kidney injury through peroxisome proliferator-activated receptor-γ agonism in rats

Rhabdomyolysis is a clinical syndrome caused by damage to skeletal muscle, which consequently releases breakdown products into circulation and causes acute kidney injury (AKI) in humans. Intramuscular injection of glycerol mimics rhabdomyolysis and associated AKI. In this study, we explored the role of umbelliferone against glycerol-induced AKI in rats. Kidney function was assessed by measuring serum creatinine, urea, electrolytes, and microproteinuria. Renal oxidative stress was quantified using thiobarbituric acid reactive substances, superoxide anion generation, and reduced glutathione assay. Renal histological changes were determined using periodic acid Schiff and hematoxylin-eosin staining, and immunohistology of apoptotic markers (Bax, Bcl-2) was done. Serum creatine kinase was quantified to assess glycerol-induced muscle damage. Umbelliferone attenuated glycerol-induced change in biochemical parameters, oxidative stress, histological alterations, and renal apoptosis. Pretreatment with bisphenol A diglycidyl ether, a peroxisome proliferator-activated receptor-γ (PPAR-γ) antagonist, attenuated umbelliferone-mediated protection. It is concluded that umbelliferone attenuates glycerol-induced AKI possibly through PPAR-γ agonism in rats.