Prophylaxis of acute renal failure in patients with rhabdomyolysis

A Review of Bicarbonate Use in Common Clinical Scenarios

BACKGROUND

The use of sodium bicarbonate to treat metabolic acidosis is intuitive, yet data suggest that not all patients benefit from this therapy.

OBJECTIVE

In this narrative review, we describe the physiology behind commonly encountered nontoxicologic causes of metabolic acidosis, highlight potential harm from the indiscriminate administration of sodium bicarbonate in certain scenarios, and provide evidence-based recommendations to assist emergency physicians in the rational use of sodium bicarbonate.

DISCUSSION

Sodium bicarbonate can be administered as a hypertonic push, as a resuscitation fluid, or as an infusion. Lactic acidosis and cardiac arrest are two common scenarios where there is limited benefit to routine use of sodium bicarbonate, although certain circumstances, such as patients with concomitant acute kidney injury and lactic acidosis may benefit from sodium bicarbonate. Patients with cardiac arrest secondary to sodium channel blockade or hyperkalemia also benefit from sodium bicarbonate therapy. Recent data suggest that the use of sodium bicarbonate in diabetic ketoacidosis does not confer improved patient outcomes and may cause harm in pediatric patients. Available evidence suggests that alkalinization of urine in rhabdomyolysis does not improve patient-centered outcomes. Finally, patients with a nongap acidosis benefit from sodium bicarbonate supplementation.

CONCLUSIONS

Empiric use of sodium bicarbonate in patients with nontoxicologic causes of metabolic acidosis is not warranted and likely does not improve patient-centered outcomes, except in select scenarios. Emergency physicians should reserve use of this medication to conditions with clear benefit to patients.

Administration of a single dose of lithium ameliorates rhabdomyolysis-associated acute kidney injury in rats

Rhabdomyolysis is characterized by muscle damage and leads to acute kidney injury (AKI). Clinical and experimental studies suggest that glycogen synthase kinase 3β (GSK3β) inhibition protects against AKI basically through its critical role in tubular epithelial cell apoptosis, inflammation and fibrosis. Treatment with a single dose of lithium, an inhibitor of GSK3β, accelerated recovery of renal function in cisplatin and ischemic/reperfusion-induced AKI models. We aimed to evaluate the efficacy of a single dose of lithium in the treatment of rhabdomyolysis-induced AKI. Male Wistar rats were allocated to four groups: Sham, received saline 0.9% intraperitoneally (IP); lithium (Li), received a single IP injection of lithium chloride (LiCl) 80 mg/kg body weight (BW); glycerol (Gly), received a single dose of glycerol 50% 5 mL/kg BW intramuscular (IM); glycerol plus lithium (Gly+Li), received a single dose of glycerol 50% IM plus LiCl IP injected 2 hours after glycerol administration. After 24 hours, we performed inulin clearance experiments and collected blood / kidney / muscle samples. Gly rats exhibited renal function impairment accompanied by kidney injury, inflammation and alterations in signaling pathways for apoptosis and redox state balance. Gly+Li rats showed a remarkable improvement in renal function as well as kidney injury score, diminished CPK levels and an overstated decrease of renal and muscle GSK3β protein expression. Furthermore, administration of lithium lowered the amount of macrophage infiltrate, reduced NFκB and caspase renal protein expression and increased the antioxidant component MnSOD. Lithium treatment attenuated renal dysfunction in rhabdomyolysis-associated AKI by improving inulin clearance and reducing CPK levels, inflammation, apoptosis and oxidative stress. These therapeutic effects were due to the inhibition of GSK3β and possibly associated with a decrease in muscle injury.

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.

Rhabdomyolysis: an American Association for the Surgery of Trauma Critical Care Committee Clinical Consensus Document

Rhabdomyolysis is a clinical condition characterized by destruction of skeletal muscle with release of intracellular contents into the bloodstream. Intracellular contents released include electrolytes, enzymes, and myoglobin, resulting in systemic complications. Muscle necrosis is the common factor for traumatic and non-traumatic rhabdomyolysis. The systemic impact of rhabdomyolysis ranges from asymptomatic elevations in bloodstream muscle enzymes to life-threatening acute kidney injury and electrolyte abnormalities. The purpose of this clinical consensus statement is to review the present-day diagnosis, management, and prognosis of patients who develop rhabdomyolysis.

Role of bicarbonate and volume therapy in the prevention of acute kidney injury in rhabdomyolysis: a retrospective propensity score-matched cohort study

Background

Although bicarbonate has traditionally been used to treat patients with rhabdomyolysis at high risk of acute kidney injury (AKI), it is unclear whether this is beneficial. This study compared bicarbonate therapy to non-bicarbonate therapy for the prevention of AKI and mortality in rhabdomyolysis patients.

Methods

In a propensity score-matched cohort study, patients with a creatine kinase (CK) level of >1,000 U/L during hospitalization were divided into bicarbonate and non-bicarbonate groups. Patients were subgrouped based on low-volume (<3 mL/kg/hr) or high-volume (≥3 mL/kg/hr) fluid resuscitation in the first 72 hours. Logistic regression analyses were used to identify the impacts of bicarbonate use and fluid resuscitation on AKI risk and need for dialysis. The Kaplan-Meier method was used to estimate survival. Volume overload and electrolyte imbalances were assessed.

Results

Among 4,077 patients, we assembled a cohort of 887 pairs of patients treated with and without bicarbonate. Bicarbonate group had a higher incidence of AKI, higher rate of dialysis dependency, higher 30-day mortality, and longer hospital stay than the non-bicarbonate group. Further, patients who received high-volume fluid therapy had worse renal outcomes and a higher mortality than those who received low-volume fluids regardless of bicarbonate use. Bicarbonate use, volume overload, and AKI were associated with higher mortality. Volume overload was significantly higher in the bicarbonate group than in the non-bicarbonate group.

Conclusion

Bicarbonate or high-volume fluid therapy for patients with rhabdomyolysis did not reduce AKI or improve mortality compared to non-bicarbonate or low-volume fluid therapy. Limited use of bicarbonate and adjustment of fluid volume may improve the short- and long-term outcomes of patients with rhabdomyolysis.

Management of rhabdomyolysis: A practice management guideline from the Eastern Association for the Surgery of Trauma

BACKGROUND

The treatment of rhabdomyolysis remains controversial. Although there is no question that any associated compartment syndrome needs to be identified and released, debate persists regarding the benefit of further therapy including aggressive intravenous fluid resuscitation (IVFR), urine alkalization with bicarbonate, and the use of mannitol. The goal of this practice management guideline was to evaluate the effects of bicarbonate, mannitol, and aggressive intravenous fluids on patients with rhabdomyolysis.

METHODS

A systematic review and meta-analysis comparing treatments in patients with rhabdomyolysis was performed. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology was applied to assess the quality of evidence and to create evidence-based recommendations regarding the use of bicarbonate, mannitol, and aggressive IVFR in patients with rhabdomyolysis.

RESULTS

A total of 12 studies were identified for analysis. On quantitative analysis, IVFR decreased the incidence of acute renal failure (ARF) and need for dialysis in patients with rhabdomyolysis. Neither bicarbonate nor mannitol administration improved the incidence of acute renal failure and need for dialysis in patients with rhabdomyolysis. Quality of evidence was deemed to be very low, with the vast majority of the literature being retrospective studies.

CONCLUSION

In patients with rhabdomyolysis, we conditionally recommend for aggressive IVFR to improve outcomes of ARF and lessen the need for dialysis. We conditionally recommend against treatment with bicarbonate or mannitol in patients with rhabdomyolysis.

Role of Bicarbonates and Mannitol in Rhabdomyolysis: A Comprehensive Review

Rhabdomyolysis is characterized by rapid muscle breakdown and release of intracellular muscle components into the circulation. Acute renal injury is the most common and fatal complication of rhabdomyolysis. The current literature emphasizes the importance of preventing rhabdomyolysis and finding the benefits of sodium bicarbonates and mannitol in its prevention. A PubMed database search for the keywords "Rhabdomyolysis," "Sodium bicarbonate use in rhabdomyolysis," "Mannitol use in rhabdomyolysis," and a Medical Subject Headings (MeSH) search using the keyword "Rhabdomyolysis; Acute Kidney Injury (Subheading-Prevention and control)" generated 10,005 articles overall. After a thorough application of inclusion/exclusion criteria, 37 relevant studies were selected for this literature study. This analysis demonstrates that aggressive early volume resuscitation with normal saline should continue being the principal focus of therapy, and the use of sodium bicarbonate and mannitol in practical situations is not entirely justified. This article also emphasizes the need for future research on this topic and provides recommendations for future research. 

A "crush" course on rhabdomyolysis: risk stratification and clinical management update for the perioperative clinician

Rhabdomyolysis, the release of myoglobin and other cellular breakdown products from necrotic muscle tissue, is seen in patients with crush injuries, drug overdose, malignant hyperthermia, muscular dystrophy, and with increasing frequency in obese patients undergoing routine procedures. For the perioperative clinician, managing the resultant shock, hyperkalemia, acidosis, and myoglobinuric acute kidney injury can present a significant challenge. Prompt recognition, hydration, and correction of metabolic disturbances may reduce or eliminate the need for long-term renal replacement therapy. This article reviews the pathophysiology and discusses key issues in the perioperative diagnosis, risk stratification, and management of rhabdomyolysis.

Volume Resuscitation in Patients With High-Voltage Electrical Injuries

Volume resuscitation of patients with high-voltage electrical injuries (>1000 V) is a more complex challenge than standard burn resuscitation. High voltages penetrate deep tissues. These deep injuries are not accounted for in resuscitation formulae dependent on percentage of cutaneous burn. Myonecrosis occurring from direct electrical injury and secondary compartment syndromes can result in rhabdomyolysis, compromising renal function and urine output. Urine output is the primary end point, with a goal of 1 mL/kg/h for adult patients with high-voltage electrical injuries. As such, secondary resuscitation end points of laboratory values, such as lactate, base deficit, hemoglobin, and creatinine, as well as hemodynamic monitoring, such as mean arterial pressure and thermodilution techniques, can become crucial in guiding optimum administration of resuscitation fluids. Mannitol and bicarbonates are available but have limited support in the literature. High-voltage electrical injury patients often develop acute kidney injury requiring dialysis and have increased risks of chronic kidney disease and mortality. Continuous venovenous hemofiltration is a well-supported adjunct to clear the myoglobin load that hemodialysis cannot from circulation.

Prevention of rhabdomyolysis-induced acute kidney injury - A DASAIM/DSIT clinical practice guideline

BACKGROUND

Rhabdomyolysis-induced acute kidney injury (AKI) is a common and serious condition. We aimed to summarise the available evidence on this topic and provide recommendations according to current standards for trustworthy guidelines.

METHODS

This guideline was developed using Grading of Recommendations Assessment, Development, and Evaluation (GRADE). The following preventive interventions were assessed: (a) fluids, (b) diuretics, (c) alkalinisation, (d) antioxidants, and (e) renal replacement therapy. Exclusively patient-important outcomes were assessed.

RESULTS

We suggest using early rather than late fluid resuscitation (weak recommendation, very low quality of evidence). We suggest using crystalloids rather than colloids (weak recommendation, low quality of evidence). We suggest against routine use of loop diuretics as compared to none (weak recommendation, very low quality of evidence). We suggest against use of mannitol as compared to none (weak recommendation, very low quality of evidence). We suggest against routine use of any diuretic as compared to none (weak recommendation, very low quality of evidence). We suggest against routine use of alkalinisation with sodium bicarbonate as compared to none (weak recommendation, low quality of evidence). We suggest against the routine use of any alkalinisation as compared to none (weak recommendation, low quality of evidence). We suggest against routine use of renal replacement therapy as compared to none (weak recommendation, low quality of evidence). For the remaining PICO questions, no recommendations were issued.

CONCLUSION

The quantity and quality of evidence supporting preventive interventions for rhabdomyolysis-induced AKI is low/very low. We were able to issue eight weak recommendations and no strong recommendations.

Rhabdomyolysis - Go big or go home

OBJECTIVE

To evaluate the occurrence of renal injury in hospitalized patients with the diagnosis of rhabdomyolysis among a series of patients presenting to an urban emergency department.

METHODS

A retrospective chart review between January 2006 and February 2017 was conducted on patients aged 21-65 years old that were admitted with a diagnosis of Rhabdomyolysis. We included patients with an initial serum creatinine (Cr) level < 1.3 mg/dL and an initial serum creatine phosphokinase (CPK) level > 1000 U/L. We excluded patients with preexisting renal disease, hypertension, diabetes, patients currently on medications in the statin class, patients with muscular dystrophy and neuromuscular disorders.

RESULTS

One hundred and fifteen patients (100 men, 15 women) were enrolled, with a mean age of 36 years old. The mean CPK at presentation was 18,965 U/L and the highest CPK was 168,300 U/L. The mean Cr upon presentation was 0.95 mg/dL. The average length of stay of our patients was 4.6 days. The longest length of stay was 30 days and the shortest was 1 day. Seven patients had hospital stays longer than 10 days. None of the patients had prolonged admissions due to rhabdomyolysis alone. The patient admitted for 30 days had a protracted admission due to liver failure and sepsis thought to be unrelated to Rhabdomyolysis. No patients that fit our inclusion criteria developed renal insufficiency (Cr > 1.3 mg/dL) or failure regardless of their CPK upon presentation, peak CPK or therapies received during their hospitalization.

CONCLUSION

Patients in our data set that presented to the Emergency Department with a CPK of >1000 U/L and a Cr of <1.3 mg/dL that were hospitalized with a diagnosis of rhabdomyolysis are not at risk for developing renal insufficiency or failure if treated promptly with fluid rehydration, regardless of their initial CPK values.

Rhabdomyolysis After Prolonged Surgery: Report of 2 Cases and Review of Literature

Rhabdomyolysis is a condition in which damaged muscle tissue breaks down and intracellular contents, including myoglobin, are released into the circulation. This produces a nonspecific clinical syndrome including electrolyte disturbances, hypovolemia, metabolic acidosis, coagulopathies, and risk of acute kidney injury. Rhabdomyolysis has been reported as a complication of prolonged surgical procedures but has rarely been reported in the oral and maxillofacial surgery literature. Early diagnosis and treatment of rhabdomyolysis are important to avoid long-term complications such as renal failure. We present 2 cases of postoperative rhabdomyolysis after prolonged maxillofacial surgical procedures in which the patients were managed without long-term sequelae. The pathophysiology, risk factors, diagnosis, and treatment of postoperative rhabdomyolysis are discussed, with a brief review of the literature.

Fluids for Prevention and Management of Acute Kidney Injury

Fluids are the only known method of attenuating renal injury. Furthermore, whether for hydration, resuscitation or renal replacement therapy, fluid prescriptions must be tailored to the fluid and electrolyte, cardiovascular status and residual renal function of the patient. Different fluids have significantly different effects both on volume expansion as well as on the electrolyte and acid-base balance; while controversial, different fluids may even influence renal function differently. This systematic review focuses on fluids for prevention and management of acute kidney injury. We have reviewed the available evidence and have made recommendations for clinical practice and future studies.

Acute kidney injury in the perioperative period and in intensive care units (excluding renal replacement therapies)

Acute kidney injury (AKI) is a syndrome that has progressed a great deal over the last 20 years. The decrease in urine output and the increase in classical renal biomarkers, such as blood urea nitrogen and serum creatinine, have largely been used as surrogate markers for decreased glomerular filtration rate (GFR), which defines AKI. However, using such markers of GFR as criteria for diagnosing AKI has several limits including the difficult diagnosis of non-organic AKI, also called "functional renal insufficiency" or "pre-renal insufficiency". This situation is characterized by an oliguria and an increase in creatininemia as a consequence of a reduction in renal blood flow related to systemic haemodynamic abnormalities. In this situation, "renal insufficiency" seems rather inappropriate as kidney function is not impaired. On the contrary, the kidney delivers an appropriate response aiming to recover optimal systemic physiological haemodynamic conditions. Considering the kidney as insufficient is erroneous because this suggests that it does not work correctly, whereas the opposite is occurring, because the kidney is healthy even in a threatening situation. With current definitions of AKI, normalization of volaemia is needed before defining AKI in order to avoid this pitfall.

An increase in the number of admitted patients with exercise-induced rhabdomyolysis

BACKGROUND

Rhabdomyolysis may lead to serious complications, and treatment is both time-consuming and costly. The condition can be caused by many factors, including intense exercise. The purpose of this study was to investigate whether the number of hospitalisations due to exercise-induced rhabdomyolysis has changed in recent years. We describe the disease course in hospitalised patients, and compare disease course in individuals with exercise-induced rhabdomyolysis and rhabdomyolysis due to other causes.

MATERIAL AND METHOD

The study is a systematic review of medical records from Akershus University Hospital for the years 2008 and 2011 – 14. All hospitalised patients with diagnostic codes M62.8, M62.9 and T79.6 and creatine kinase levels > 5 000 IU/l were included. The cause of the rhabdomyolysis was recorded in addition to patient characteristics and the results of various laboratory tests.

RESULTS

Of 161 patients who were hospitalised with rhabdomyolysis during the study period, 44 cases (27  %) were classified as exercise-induced. In 2008 there were no admissions due to exercise-induced rhabdomyolysis; in 2011 and 2012 there were six and four admissions respectively, while in 2014 there were 22. This gives an estimated incidence of 0.8/100 000 in 2012 and 4.6/100 000 in 2014. Strength-training was the cause of hospitalisation in 35 patients (80  % of the exercise-induced cases). Three patients (7  % of the exercise-induced cases) had transient stage 1 kidney injury, but there were no cases with stage 2 or stage 3 injury. By comparison, 52  % of patients with rhabdomyolysis due to another cause had kidney injury, of which 28  % was stage 2 or 3.

INTERPRETATION

The number of persons hospitalised with exercise-induced rhabdomyolysis has increased four-fold from 2011 to 2014, possibly due to changes in exercise habits in the population. None of the patients with exercise-induced rhabdomyolysis had serological signs of kidney injury upon hospital discharge.

Rhabdomyolysis and acute kidney injury in patients with traumatic spinal cord injury

Background:

Patients with acute traumatic spinal cord injuries (SCIs) exhibit factors that, in other populations, have been associated with rhabdomyolysis.

Purpose:

The aim of the study is to determine the incidence of rhabdomyolysis in patients with acute traumatic SCI admitted to the Intensive Care Unit (ICU), as well as the development of secondary acute kidney injury and associated factors.

Study Design and Setting:

This was an observational, retrospective study.

Patient Sample:

All adult patients admitted to the ICU with acute traumatic SCI who presented rhabdomyolysis, diagnosed through creatine phosphokinase (CPK) levels >500 IU/L.

Outcome Measures:

Incidence of rhabdomyolysis and subsequent renal dysfunction was calculated.

Materials and Methods:

Data about demographic variables, comorbidity, rhabdomyolysis risk factors, and variables involving SCI, severity scores, and laboratory parameters were obtained from clinical records. Multivariate logistic regression was used to identify renal injury risk factors.

Results:

In 2006–2014, 200 patients with acute SCI were admitted to ICU. Of these, 103 had rhabdomyolysis (incidence = 51.5%; 95% confidence interval [CI]: 44.3%–58.7%). The most typical American Spinal Injury Association classification was A (70.3%). The injury severity score was 30.3 ± 12.1 and sequential organ failure assessment (SOFA) score was 5.6 ± 3.3 points. During their stay, 57 patients (55.3%; 95% CI: 45.2%–65.4%) presented renal dysfunction (creatinine ≥1.2 mg/dL). In the multivariate analysis, variables associated with renal dysfunction were creatinine at admission (odds ratio [OR] = 9.20; P = 0.006) and hemodynamic SOFA score the day following admission (OR = 1.33; P = 0.024). Creatinine was a better predictor of renal dysfunction than the peak CPK value during the rhabdomyolysis (area under the receiver operating characteristic curve: 0.91 vs. 0.63, respectively).

Conclusions:

Rhabdomyolysis is a frequent condition in patients with acute traumatic SCI admitted to the ICU, and renal dysfunction occurs in half of the cases. Creatinine values should be requested starting at the admission while neither the peak CPK values nor the hemodynamic SOFA scores could be used to properly discriminate between patients with and without renal dysfunction.

Rhabdomyolysis and acute kidney injury in the injured war fighter

BACKGROUND

Rhabdomyolysis is a recognized complication of traumatic injury. The correlation of an elevated creatine kinase (CK) level and the development of acute kidney injury (AKI) has been studied in the civilian population. We sought to review the prevalence of rhabdomyolysis in injured war fighters and determine if peak CK levels correlate with AKI.

METHODS

This is a retrospective cohort study of patients admitted at a US military treatment facility from January to November 2010. Inclusion criteria were active duty patients transported after explosive, penetrating, or blunt injury. Patients with burns or non-trauma-related admissions were excluded. Rhabdomyolysis was defined as a CK level greater than 5,000 U/L. AKI was defined using the Kidney Disease: Improving Global Outcomes classification. Mann-Whitney U-tests were used to determine the significance for continuous data. Correlations were determined using Spearman's ρ. Significance was set at p < 0.05.

RESULTS

Of the 318 patients included in our analysis, 310 (98%) were male, and the median age was 24 years (21-28 years). Blast was the predominant mechanism of injury (71%), with a median Injury Severity Score (ISS) of 22 (16-29). Rhabdomyolysis developed in 79 patients (24.8%). The median peak CK for all patients was 4,178 U/L and ranged from 208 U/L to 120,000 U/L. Stage 1, 2, and 3 AKI developed in 56 (17.6%), 3 (0.9%), and 7 (2.2%) patients, respectively. There was a weak but statistically significant correlation between peak CK and AKI (r = 0.26, p < 0.05).

CONCLUSION

Elevated peak CK levels in the injured war fighter are weakly associated with the development of AKI but are not predictive. The development of clinical practice guidelines would help standardize treatment for rhabdomyolysis in combat casualties and would allow for standardized comparisons in future work.

LEVEL OF EVIDENCE

Epidemiologic/prognostic study, level III.

Nontraumatic rhabdomyolysis with short-term alcohol intoxication - a case report

Alcohol-induced rhabdomyolysis is a potentially life-threatening condition due to the probability of progression to acute renal injury. Patients admitted to emergency department with acute alcohol intoxication should always undergo blood and urine tests for early recognition and treatment of rhabdomyolysis.

[Perioperative acute kidney injury and failure]

Perioperative period is very likely to lead to acute renal failure because of anesthesia (general or perimedullary) and/or surgery which can cause acute kidney injury. Characterization of acute renal failure is based on serum creatinine level which is imprecise during and following surgery. Studies are based on various definitions of acute renal failure with different thresholds which skewed their comparisons. The RIFLE classification (risk, injury, failure, loss, end stage kidney disease) allows clinicians to distinguish in a similar manner between different stages of acute kidney injury rather than using a unique definition of acute renal failure. Acute renal failure during the perioperative period can mainly be explained by iatrogenic, hemodynamic or surgical causes and can result in an increased morbi-mortality. Prevention of this complication requires hemodynamic optimization (venous return, cardiac output, vascular resistance), discontinuation of nephrotoxic drugs but also knowledge of the different steps of the surgery to avoid further degradation of renal perfusion. Diuretics do not prevent acute renal failure and may even push it forward especially during the perioperative period when venous retourn is already reduced. Edema or weight gain following surgery are not correlated with the vascular compartment volume, much less with renal perfusion. Treatment of perioperative acute renal failure is similar to other acute renal failure. Renal replacement therapy must be mastered to prevent any additional risk of hemodynamic instability or hydro-electrolytic imbalance.

Rhabdomyolysis

Rhabdomyolysis is a well-known clinical syndrome of muscle injury associated with myoglobinuria, electrolyte abnormalities, and often acute kidney injury (AKI). The pathophysiology involves injury to the myocyte membrane and/or altered energy production that results in increased intracellular calcium concentrations and initiation of destructive processes. Myoglobin has been identified as the primary muscle constituent contributing to renal damage in rhabdomyolysis. Although rhabdomyolysis was first described with crush injuries and trauma, more common causes in hospitalized patients at present include prescription and over-the-counter medications, alcohol, and illicit drugs. The diagnosis is confirmed by elevated creatine kinase levels, but additional testing is needed to evaluate for potential causes, electrolyte abnormalities, and AKI. Treatment is aimed at discontinuation of further skeletal muscle damage, prevention of acute renal failure, and rapid identification of potentially life-threatening complications. Review of existing published data reveals a lack of high-quality evidence to support many interventions that are often recommended for treating rhabdomyolysis. Early and aggressive fluid resuscitation to restore renal perfusion and increase urine flow is agreed on as the main intervention for preventing and treating AKI. There is little evidence other than from animal studies, retrospective observational studies, and case series to support the routine use of bicarbonate-containing fluids, mannitol, and loop diuretics. Hyperkalemia and compartment syndrome are additional complications of rhabdomyolysis that must be treated effectively. A definite need exists for well-designed prospective studies to determine the optimal management of rhabdomyolysis.

Hypothyroidism and acute kidney injury: an unusual association

Association between severe hypothyroidism and acute kidney injury (AKI) is rare. A 40-year-old woman presented with 15 days history of generalised muscle pain, weakness, weight gain and oedema.

MEDICAL HISTORY

hypertension and hypothyroidism.

PHYSICAL EXAMINATION

dry skin, peripheral/periorbital oedema, slow thought and speaking, thyroid increased. Laboratory examinations: high levels of creatine kinase , creatinine, uric acid and lactate dehydrogenase. Free T4 was very low (<0.3 ng/dL) and thyroid-stimulating hormone was high (21.7 µIU/mL). Urinalysis showed haem pigment without haematuria. We performed the diagnosis of AKI secondary to hypothyroidism-induced rhabdomyolysis. Intravenous fluids were started, urinary alkalisation and increased l-thyroxine dose replacement. On the day after admission, forced diuresis with furosemide was introduced leading to a progressive improvement of symptoms. Although hypothyroidism and AKI is unusual, it should be suspected in patients presenting decrease of renal function and high creatine kinase in the absence of other causes of rhabdomyolysis.

Prevention of kidney injury following rhabdomyolysis: a systematic review

OBJECTIVE

To conduct a systematic literature review to evaluate evidence-based recommendations for the prevention of rhabdomyolysis-associated acute renal failure (ARF).

DATA SOURCES

PubMed (1966-December 2012), International Pharmaceutical Abstracts, Science Citation Index, and Cochrane databases (1970-December 2012) were searched. There were no language restrictions.

STUDY SELECTION AND DATA EXTRACTION

Studies selected dealt with treatment of rhabdomyolysis (crush syndrome) or prevention of ARF in patients with rhabdomyolysis. Articles excluded did not present original data or described only the management of ARF after it developed. Single case reports were excluded. Extracted data included study type; population; definitions of rhabdomyolysis and ARF; fluid, sodium bicarbonate, and mannitol dosages; and study findings.

DATA SYNTHESIS

Twenty-seven studies met the inclusion criteria. No controlled trials compared intravenous fluid administration plus sodium bicarbonate to fluid administration alone. Three concluded that there was no significant difference in the rates of ARF between patients receiving and those not receiving sodium bicarbonate; however, urine alkalinization was not documented. Eight investigations concluded that delayed fluid administration increased the risk of ARF. No controlled study compared volumes of fluid administered or targeted urine output goals. Fluid type, therapy duration, and monitoring parameters varied widely; 4 used a urine output goal in adults of more than 300 mL/h or 300 mL/h or more. No evidence supported a preferred fluid type or that sodium bicarbonate with or without mannitol was superior to fluid therapy alone.

CONCLUSIONS

Intravenous fluids should be initiated as soon as possible, preferably within the first 6 hours after muscle injury, at a rate that maintains a urine output in adults of 300 mL/h or more for at least the first 24 hours. Sodium bicarbonate should be administered only if necessary to correct systemic acidosis and mannitol only to maintain urine output of 300 mL/h or more despite adequate fluid administration.

Perioperative Management of Peripheral Vascular Trauma

Peripheral vascular trauma is not uncommon in the civilian setting, and it can be uniquely challenging because of the limited time during which intervention can salvage an ischemic extremity. Injuries can be from a blunt or penetrating mechanism, and these injuries can be isolated or can be in the setting of a complex multisystem trauma. The intent of this review is to discuss the perioperative management of peripheral vascular trauma with an emphasis of predicting, preventing, and managing common postoperative complications.

A potentially life-threatening complication of university orientation activities

BACKGROUND

This case report describes a university student who participated in an orientation activity and developed exertional rhabdomyolysis.

METHODS

With prompt intravenous volume expansion started in the accident and emergency department, he made an uneventful recovery despite a marked elevation of creatine kinase. The riskfactors of developing exertional rhabdomyolysis were reviewed. Suggestions based on these risk factors were made to the organizers of such orientation programmes.

RESULTS

He was discharged on day 6. On follow-up on day 8 after presentation at theaccident and emergency department, the CK level was 46 000 U/L and it fell to 2600 U/L in another 2 weeks. On follow-up 3 weeks after the incident, he remained well without symptoms.

CONCLUSION

For the clinicians, once rhadbomyolysis is suspected or diagnosed, intravenous fluid therapy with a crystalloid should be initiated as soon as possible to prevent the occurrence of acute renal faiure.

Mechanism-based therapeutic approaches to rhabdomyolysis-induced renal failure

Rhabdomyolysis-induced renal failure represents up to 15% of all cases of acute renal failure. Many studies over the past 4 decades have demonstrated that accumulation of myoglobin in the kidney is central in the mechanism leading to kidney injury. However, some discussion exists regarding the mechanism mediating this oxidant injury. Although the free-iron-catalyzed Fenton reaction has been proposed to explain the tissue injury, more recent evidence strongly suggests that the main cause of oxidant injury is myoglobin redox cycling and generation of oxidized lipids. These molecules can propagate tissue injury and cause renal vasoconstriction, two of the three main conditions associated with acute renal failure. This review presents the evidence supporting the two mechanisms of oxidative injury, describes the central role of myoglobin redox cycling in the pathology of renal failure associated with rhabdomyolysis, and discusses the value of therapeutic interventions aiming at inhibiting myoglobin redox cycling for the treatment of rhabdomyolysis-induced renal failure.

Late-onset rhabdomyolysis in burn patients in the intensive care unit

Rhabdomyolysis (RML), defined as creatine phosphokinase (CPK) >1000 U/L, is relatively common immediately after a significant burn. Late-onset RML, occurring a week or more after a burn, is less well understood and recognised. All patients admitted to the Intensive Care Unit (ICU) following an acute burn between May 2006 and December 2009 were retrospectively identified. Patients with CPK>1000 U/L a week or more after their burn had a detailed notes review. Seventy-six patients were admitted during 43 months. Late-onset RML was demonstrated in 7/76 (9%) patients. They had a similar pattern of normal or mildly raised CPK on admission that resolved over the following days, but suddenly increased sharply to over 1000 U/L, a week or more after their burn, usually around day ten. A severe late-onset RML occurred in 5/76 (7%) patients, with a CPK rise of over 5000 U/L, and all required haemodialysis. Potential triggering factors for late-onset RML include sepsis, nephrotoxic drugs and hypophosphataemia. It is important to consider measuring CPK in all patients with the above complications, even after it has previously been observed to be normal, in order to initiate early treatment.

Rhabdomyolysis in the intensive care unit

Rhabdomyolysis is a clinical syndrome defined by muscle breakdown and subsequent release of intracellular contents. There are many etiologies of rhabdomyolysis, classified here as congenital and acquired; compartment syndrome secondary to trauma with reperfusion injury is one common precipitating factor. Regardless of the underlying etiology, the pathophysiology follows a similar pathway via myocyte destruction and release of myoglobin into the systemic circulation. Rhabdomyolysis-induced renal failure is caused by the precipitation of myoglobin in the renal tubules which is enhanced under acidic conditions. A high index of clinical suspicion is required to promptly recognize rhabdomyolysis, especially in the unconscious patient. Presenting symptoms include tea-colored urine and muscle weakness or fatigue. The diagnosis is confirmed most reliably with the finding of elevated serum creatine kinase levels. Early, aggressive resuscitation with either normal saline or lactated Ringer's solution to maintain an adequate urine output is the most important intervention in preventing the development of acute renal failure. There is insufficient clinical evidence supporting the routine administration of diuretics and bicarbonate to protect against the development of acute renal failure.

Metabolic consequences of acute limb ischemia and their clinical implications

Acute limb ischemia is a common medical condition resulting from arterial embolization, in situ thrombosis, trauma, and other causes. The severity of injury is related to the duration of ischemia and the effects of reperfusion. Metabolic consequences of reperfusion injury can be variable, ranging from transient symptoms in the lower extremity to systemic inflammation with multiple organ dysfunction. This article provides an overview of some of the key mediators of reperfusion injury. Additional discussion is focused on the clinical effects of reperfusion in the extremity, as well as the pulmonary, cardiac, and renal organ systems. A better understanding of these processes may result in improved patient outcomes and decreased mortality.

Exertional rhabdomyolysis and acute kidney injury

Skeletal muscle breakdown occurs normally with exercise, followed by muscle repair and physiologic adaptation. Strenuous, unaccustomed, prolonged, and repetitive exercise, particularly when associated with other risk factors such as hot and humid climate or sickle cell trait can cause clinically significant exertional rhabdomyolysis (ER). Although most cases are asymptomatic and resolve without sequelae, ER is the most common cause of exercise-related myoglobinuric acute renal injury and acute renal failure in athletes. Exercise-related muscle pain, elevated serum creatine kinase (CK), and "cola-colored" urine have been described as a classic presentation of ER. The exact mechanism of ER has not been clearly elucidated. Most studies suggest a cascade of events that include depletion of adenosine triphosphate (ATP), impaired function of the Na+- K+ ATPase system, intracellular excess calcium accumulation, sarcolemma damage, and release of intracellular proteins and other substances into blood. Excess myoglobin that is filtered at the glomerulus can lead to myoglobinuric acute renal injury. Cessation of physical activity, relative rest during clinical recovery, and early aggressive fluid replacement are mainstays of treatment. Return to play after recovery from ER is influenced by associated risk factors that may predispose the athlete to recurrence and is guided by signs, symptoms, and CK levels. This article reviews the definitions, pathophysiology, diagnosis, and management of ER with specific relevance to acute kidney injury.

Factors associated with acute renal failure in children with rhabdomyolysis

Pigment nephropathy accounts for approximately 3% of all cases of acute renal failure (ARF) in children. Studies of risk factors associated with ARF and the need for renal replacement therapy (RRT) in children with rhabdomyolysis-associated pigment nephropathy consist of retrospective case series with variable inclusion criteria. Our objective was to evaluate clinical and laboratory characteristics, etiology, initial fluid therapy, prevalence of ARF and the requirement for RRT in pediatric patients with acute rhabdomyolysis. Twenty-eight patients (19 male) with a mean age of 11.1 +/- 5.6 years were studied. Acute renal failure occurred in 11 patients (39%), seven of whom (64%) required RRT. Features associated with the need for RRT included history of fever, persistent oliguria, admission blood urea nitrogen level, creatinine, Ca(2+), K(+), bicarbonate and aspartate aminotransferase. Most of these factors are related to the level of renal insufficiency and degree of muscle injury. There was no difference in admission and peak creatine kinase (CK) levels between those who did or did not require RRT. However, all who required RRT had a peak CK level > 5000 U/L.