Overview of the disease
A disease of muscle tissue damage and lysis often caused by strenuous exercise, hyperthermia, drugs, and toxins that manifests itself as muscle pain, weakness, and deepening of the color of the urine. The cause of the disease is removed and treated with fluid replacement, hemodialysis, or filtration.
Definition
Rhabdomyolysis syndrome is a series of clinical syndromes affecting the rhabdomyocellular membrane, membrane channels, and their energy supply.
The integrity of the rhabdomyocellular membrane is altered, and cellular contents (e.g., myoglobin, creatine kinase, etc.) are released into the extracellular fluid and circulation, most often accompanied by acute renal failure and metabolic disturbances.
The muscles of the human body are divided into three categories. They are smooth muscle, which forms the walls of internal organs; skeletal muscle, which is responsible for various movements of the body; and cardiac muscle, which constitutes the heart. Skeletal muscle and cardiac muscle are two types of muscles that, when viewed under a microscope, show light and dark transverse stripes on the muscle fibers, hence the name transverse muscle.
Epidemiology
Rhabdomyolysis syndrome tends to be disseminated, and no authoritative, comprehensive epidemiologic information is available.
Types
There are no types of the disease.
Causes
Common causes of this disease include muscle compression, strenuous exercise, hyperthermia, heat stroke, drugs, poisons, and infections.
Causes
The causes of rhabdomyolysis syndrome are complex, and the common causes are listed below.
Physical factors
Muscle injury or over-activity from any cause can cause rhabdomyolysis syndrome.
Muscle crush injuries
Mostly seen in situations such as earthquakes, wars, and traffic accidents.
Drowsiness and prolonged limb compression due to carbon monoxide poisoning, alcohol poisoning, cerebrovascular accidents, etc.
Various muscle traumas caused by other traumatic injuries and other reasons, such as self-abuse or abuse, severe torture, electric shock injuries.
Strenuous exercise, especially sudden exercise of people who usually do not exercise or strenuous exercise in high temperature, high humidity environment and high altitude, such as marathon running, armed cross-country, mountaineering and frog jumping.
Extreme body temperature, e.g. hyperthermia, heat stroke.
Non-physical factors
Drugs
Sedative-hypnotics, e.g., Phenazepam, chlorpromazine, benzodiazepines.
Statins and beta-lipid-lowering drugs.
Addictive drugs such as cocaine and methadone.
Other drugs, such as diuretics, anti-infectives, immunosuppressive drugs, etc.
Poisons: organophosphorus pesticides, heavy metals, insect venom and snake venom.
Infections: viral and bacterial infections, commonly influenza A and B viruses, pneumococcal and Legionella pneumophila infections.
Autoimmune diseases: autoimmune diseases such as polymyositis and dermatomyositis, including dermatomyositis overlapping systemic scleroderma and dermatomyositis secondary to dry syndrome.
Endocrine disorders or metabolic abnormalities: diabetic hyperosmolar nonketotic coma, thyroid crisis and pheochromocytoma, hypothyroidism.
Electrolyte abnormalities: the presence of electrolyte-losing disorders leading to metabolic disturbances such as hypokalemia, hypophosphatemia, hyponatremia, and hypocalcemia.
Inherited metabolic disorders: inherited metabolic disorders such as hereditary disorders of glucose metabolism, muscle phosphorylase deficiency, congenital phosphofructokinase deficiency.
Ischemia: blockage or poor perfusion of muscle blood vessels, e.g., thrombosis or vasospasm, shock states.
Pathogenesis
The pathogenesis of rhabdomyolysis varies with different causes.
Crush, trauma, strenuous exercise or excessive muscle activity, electric shock, mainly direct damage to muscle cell membranes.
Vascular occlusion, compression, shock, hyperthermia and other causes of myocyte ischemia and hypoxia, mainly myocyte ATP depletion, which in turn affects the exchange of sodium and potassium ions.
Electrolyte disorders such as hypokalemia and hyponatremia also affect enzyme function.
Symptoms
Typical symptoms are pain in the calf and lower back muscles, weakness, and strong tea-colored urine, accompanied by systemic symptoms such as fever, nausea, vomiting, and tachycardia. The disease is also associated with hemorrhagic oliguria, edema, and loss of consciousness in severe cases.
Main Symptoms
The typical “triad” of rhabdomyolysis is muscle pain, muscle weakness and dark-colored urine, as follows.
Muscle pain, tenderness, and swelling. The most commonly affected muscle groups are the calf and lower back muscles, which can be painful and swollen.
Muscle weakness and generalized weakness, about half of the patients have no muscle pain or muscle weakness.
Tea-colored urine or soy sauce-colored urine.
Secondary symptoms
Severe cases may present with fever, general malaise, tachycardia, nausea, vomiting and abdominal pain.
Complications
Acute renal failure: rhabdomyolysis syndrome leads to decreased blood flow through renal vasoconstriction, direct blockage of renal tubules by myoglobin, and direct cytotoxicity of myoglobin, triggering acute renal failure. It can cause severe electrolyte abnormalities and acid-base imbalance. Manifestations include a sharp decrease in urine, edema, and elevated blood pressure. In severe cases, unconsciousness or shock may occur, which may be life-threatening.
Disseminated intravascular coagulation (DIC): manifested by bleeding from multiple sites such as skin, mucous membranes, wounds, etc., respiratory distress, cyanosis, and shock.
Consultation
Generally consult the nephrology department and emergency department. Patients should not be strenuously active before seeking medical treatment.
Department of Medicine
Nephrology
When tea-colored or soy sauce-colored urine occurs, especially when it is accompanied by muscle pain and general weakness, it is recommended to consult a doctor immediately.
Emergency Department
If the condition is serious or even life-threatening, such as change of consciousness or shock, it is recommended to call “120” or the emergency department immediately.
Preparing for medical treatment
Preparing for medical treatment: registration, preparation of documents, and common problems.
Tips for medical treatment
It is recommended to wear loose-fitting clothes to make it easier to complete the examination.
Don’t do any strenuous activities before the visit so as not to influence the judgment or aggravate the condition.
Medical Preparation Checklist
Symptom list
Especially need to pay attention to the time of symptom onset, special performance, etc.
Any muscle pain? Where does it occur?
Does it feel difficult to move arms and legs, or is there muscle weakness?
Is there a change in the color of the urine? Is there tea- or soy-colored urine?
Are there any symptoms such as fever, rapid heartbeat, nausea, or vomiting?
How long have these symptoms lasted?
Medical History Checklist
Has there been any previous heavy exercise?
Has there been any sustained crushing?
Has there been heavy alcohol consumption?
What medications have been used recently?
Are there any medical conditions such as diabetes or hypothyroidism?
Checklist
Test results of the last six months, which can be brought to the doctor’s office
Laboratory tests: blood biochemistry, blood routine, urine routine
Others: Electrocardiogram
Medication List
Medication used in the last 3 months, if available, bring along the box or package to the doctor
Sedative-hypnotics: Phenazepam, Diazepam
Addictive drugs: cocaine, methadone
Lipid-lowering drugs: atorvastatin, gemfibrozil
Antibiotics: erythromycin, clarithromycin
Diagnosis
Diagnosis is based on
Diagnosis is made on the basis of clinical symptoms, history, and laboratory tests. Biochemical tests may reveal elevated serum creatine kinase and urine tests may show elevated urinary myoglobin; these laboratory findings may assist in the diagnosis of the disease.
Medical history
A typical history (including suspected etiology, muscular manifestations, and changes in urine color) is highly suspicious.
Clinical manifestations
Muscle pain, muscle weakness, soy sauce or tea-colored urine, oliguria, vomiting, and confusion are present.
Laboratory Tests
Blood tests
Biochemical tests show an elevated serum myosin profile (creatine kinase, aspartate aminotransferase, lactate dehydrogenase, etc.). Myoglobin is elevated.
Creatinine, urea nitrogen, and uric acid levels are elevated. Hyperkalemia, hypocalcemia, and metabolic acidosis are seen in the acute phase.
Thrombocytopenia and other hematologic abnormalities.
Urine examination
Urine volume is reduced and urine is soy sauce-like or tea-colored.
Urine routine is characterized by myoglobinuria, which is manifested by positive urinary occult blood, but urine sediment microscopy is free of erythrocytes or a small number of erythrocytes, granular tubular, and often positive for urinary protein.
Imaging
On MRI, swelling of the involved muscles is seen.
Other
Muscle examination
Electromyography shows myogenic muscle damage at the site of involvement.
Electrocardiogram
Examination focuses on myocardial damage from hyperkalemia.
Differential Diagnosis
Care should be taken to differentiate from other conditions that cause muscle weakness.
Dermatomyositis
Similarities: muscle pain, elevated serum creatine kinase.
Differences: dermatomyositis skin abnormalities are obvious, there may be periorbital erythema and Corron’s rash on the extensor side of the knuckles and elbows.
Angina pectoris and myocardial infarction
Similarities: Chest pain, increased serum creatine kinase.
Differences: angina pectoris or myocardial infarction, more pronounced elevation of serum troponin, and dynamic changes in the electrocardiogram. History, electrocardiogram, CK isoenzyme analysis, and blood and urine myoglobin tests are helpful in the differential diagnosis.
Myofasciitis
Similarities: muscle pain.
Differences: myofasciitis has no urine color changes and few complications.
Treatment
The main treatments are removal of the cause, fluid replacement, hemodialysis or filtration therapy. Massive fluid replacement and diuretic dehydration are used to maintain body stability. Hemodialysis or filtration therapy prevents deterioration of kidney function. Surgery is also used to relieve fascial pressure if necessary.
Etiologic treatment
The main aim of etiologic treatment is to protect kidney function.
Removal of the cause of the disease
Remove the trigger for rhabdomyolysis; avoid risk factors that aggravate rhabdomyolysis.
Release muscle compression in those who have been squeezed.
For those with high fever, lower the temperature promptly.
Discontinue the suspected drug if it is caused by drugs.
Actively treat dermatomyositis.
When subjected to prolonged, extensive, and severe compression, the risk of sudden and massive entry of intracellular substances such as potassium ions into the bloodstream after decompression needs to be considered, evaluated, and prevented before decompression is lifted.
Protection of renal function
Stabilize the patient’s vital signs, replenish isotonic fluids and sodium bicarbonate in large quantities, pay attention to the monitoring of access, and avoid pulmonary edema.
Replenish fluids as early as possible and as soon as possible, start with isotonic saline, and give a certain amount of hypotonic glucose saline after fluid resuscitation to maintain sufficient urine output.
Those with myoglobinuria should apply appropriate amount of sodium bicarbonate to alkalinize the urine, to promote the excretion of myoglobin and metabolic wastes, and to maintain urine pH＞6.5 and plasma pH＜7.5.
Safeguard renal perfusion and prevent acute tubular necrosis.
Hemodialysis or hemofiltration: if acute renal failure and hyperkalemia have occurred, renal replacement therapy may be required until renal function is restored.
Symptomatic treatment
Management of hyperkalemia, hypokalemia
Hyperkalemia: calcium can be used to antagonize the cardiotoxicity of potassium, diuresis and cation-exchange resin polysulfostyrene can be taken orally to promote the excretion of potassium, glucose and insulin can promote the transfer of extracellular potassium to intracellular cells, and if there is no urine, dialysis should be used to actively remove potassium from the blood.
Hypocalcemia: generally does not require special treatment, calcium supplementation as appropriate when symptoms of hypocalcemia occur.
Maintaining the stability of vital signs and internal environment
Aggressively replenish fluids, fully hydrate, remove harmful substances, maintain water electrolyte and acid-base balance.
Maintain adequate urine output, meanwhile, alkalize urine with appropriate amount of sodium bicarbonate to promote the excretion of Mb and metabolic wastes, and also use a small amount of mannitol to diuretics and reduce the swelling of damaged muscles.
Blood purification therapy
Continuous blood filtration not only removes metabolic wastes such as urea, creatinine and excess potassium ions, but also removes harmful substances such as myoglobin and inflammatory factors, which helps to stabilize the internal environment of the body.
Complications and comorbidities treatment
Interfascial compartment syndrome
If there is a wound, the wound should be actively and thoroughly cleared.
If there is no trauma, conservative treatment should be given as far as possible.
Fasciotomy should be performed if the difference between diastolic and intraventricular pressure is less than 20 millimeters of mercury (mmHg), and if there is no improvement within 6 hours after mannitol infusion and hyperbaric oxygen therapy.
Fasciotomy should be performed with caution to prevent massive exudate, bleeding, and infection.
Disseminated intravascular coagulation
According to the coagulation index and coagulation situation, heparin treatment should be given.
Hemorrhagic shock
Immediate volume expansion treatment.
Apply platelets, vitamin K and fresh frozen plasma.
Prompt transfusion support in case of heavy bleeding.
Multi-organ dysfunction syndrome
Give appropriate management according to the guidelines and norms of MODS as follows.
Avoid infection.
Correct the abnormalities of circulatory function, cardiac function, respiratory function, renal function, gastrointestinal function, hepatic function, hematologic function, and central nervous system function.
Prognosis
If there are no complications, the prognosis is good after active treatment. When complications such as acute renal failure are combined, the mortality rate increases dramatically. The cause of the disease and the presence or absence of complications are crucial in determining the prognosis of the patient.
Cure
The prognosis of rhabdomyolysis syndrome is related to the cause and complications. With early treatment, most patients have a better prognosis and impaired renal function can be restored.
Hazards
If the patient develops acute renal failure and disseminated intravascular coagulation, it may lead to death in severe cases.
Daily
After finishing the treatment patients can eat normally, but avoid alcohol, accidental injuries and exposure to morbid factors, stay away from poisons and reduce physical activity. Preventive measures for this disease include avoiding prolonged and intense exercise, avoiding heat stroke, and staying away from poisons.
Daily management
Diet
Avoid alcohol abuse and take care to identify foods where poisoning may occur.
Lifestyle
After finishing treatment, reduce physical activity to minimize muscle loading.
Reduce accidental injuries, e.g. trauma, poisonous insect bites.
Avoid exposure to morbidity factors.
Daily monitoring
If rhabdomyolysis syndrome is caused by a genetic disorder, etc., daily life monitoring is needed to avoid recurrence of the same symptoms.
Prevention
Drink plenty of water after strenuous exercise.
In case of heat stroke, remove excess clothing and immerse your body in cold water.
People who usually do not exercise should avoid sudden exercise of high intensity, and after strenuous exercise they should drink a lot of electrolyte water and regularly monitor the relevant indicators as prescribed by the doctor.
Stay away from poisons.