Rhabdomyolysis: Causes, Symptoms, Treatment, Pathophysiology, Survival Rate, Prognosis, Epidemiology
Rhabdomyolysis is a very serious syndrome in which the muscle tissue breaks down due to direct or indirect injury of the muscle. The term refers to the breaking down of the muscle from the skeletal system – 'rhabdo' means the skeleton, 'myo' means the muscle and 'lysis' means the breakdown. The problem that is even more severe and associated with Rhabdomyolysis is that the contents of this broken down muscular tissue are rapidly spilled into the bloodstream.
What is Rhabdomyolysis?
Rhabdomyolysis is the death of muscle fibres caused by injury of skeletal muscle and the releasing of the potentially toxic intracellular contents into the bloodstream or the plasma. The results often lead to the damage of the kidney as these toxic intracellular contents are harmful to the kidney. The reason behind this is the spilling of myoglobin, the muscle protein that is released and spilled into the bloodstream when the muscles are broken down. The myoglobin clogs the filtering system of the kidneys and as a result, damages the function of the kidneys.
Signs and Symptoms of Rhabdomyolysis:
The symptoms of Rhabdomyolysis vary to a great extent and are largely dependent on the fact, whether kidney failure has occurred or not. The cause and the affected body part also manipulate the signs and symptoms of Rhabdomyolysis. The most common symptoms are –
- Muscle pain, mostly in the skeletal muscle that are associated with the movement of the body. Hence, the shoulder, lower back and thigh muscles ache mostly.
- Fatigues, feeling weak, nausea and vomiting are also the symptoms of Rhabdomyolysis
- Joint pain and seizures
- Fever and rapid heart rate
- Muscle tenderness and stiffness or myalgia is also a symptom of Rhabdomyolysis
- Tea-coloured urine
- Decreased quantity of urine can also be symptoms of Rhabdomyolysis.
However, there is possibility that none of these symptoms occur in patient suffering from Rhabdomyolysis. Many people with Rhabdomyolysis have had no symptoms at all or the symptoms may mimic other conditions as well.
Causes of Rhabdomyolysis:
The difficulty associated with Rhabdomyolysis is the breaking down of the skeletal tissue that leads to releasing the muscle protein called myoglobin into the bloodstream and gradually the kidneys fail due to damage to the filtering system. Why the muscle tissues of the skeletal system are broken, have several causes associated with it. The most common causes are –
- Crushing of the muscles or injury of the muscle tissue caused by car accident, physical torture and prolonged surgery, coma or lying down on the floor in unconscious state without waking up.
- Injuries caused by electrical shock, third degree burn and lightning strike can also cause Rhabdomyolysis.
- Severe muscle trauma caused by extreme physical exercise or due to withdrawal of alcohol
- Extreme muscle dehydration can also cause Rhabdomyolysis.
- Genetic diseases associated with muscle like McArdle's disease, familial paroxysmal rhabdomyolysis, Duchenne's muscular dystrophy, carnitine deficiency, lactate dehydrogenase deficiency can also cause Rhabdomyolysis
- Drug and alcohol intoxication
- Use of certain medication or statin drugs such as atorvastatin, simvastatin, lovastatin or pravastatin that are used to treat cholesterol can also cause Rhabdomyolysis.
- Medications that are used to treat Parkinson's disease and also anaesthesia medications, psychiatric medications and HIV medications. Cocaine and similar drug abuse also causes this condition
- Extreme body temperatures, especially low core body temperature or hypothermia caused by prolonged drowning and high body temperatures caused by heat stroke
- Disorders of the muscle like dermatomyositis, myositis, polymyositis or myopathies in short can cause Rhabdomyolysis
- Some kinds of viral and bacterial infection as well as snake bites can also cause Rhabdomyolysis
- Metabolic disorders like diabetic ketoacidosis, hypothyroidism problems with carbohydrate metabolism, lipid metabolism or purine metabolism can cause Rhabdomyolysis.
These are the most common causes of Rhabdomyolysis. Occurrence of any of these may cause or increase the risk of causing Rhabdomyolysis.
Epidemiology of Rhabdomyolysis:
Rhabdomyolysis is a common condition, especially amongst adults. It is less common amongst children. 26,000 cases of Rhabdomyolysis were annually registered in the United States of America, as per the reports of the National Hospital Discharge Survey. Although it is more common amongst adults, children (including infants, toddlers and adolescents) with metabolism disorders, inherited enzyme deficiencies and those, who are suffering from diseases like malignant hyperthermia and Duchenne muscular dystrophy, are also seen to suffer from Rhabdomyolysis.
24% of the patients, who are admitted to the emergency department due to cocaine abuse related conditions, are also seen to have Rhabdomyolysis. Otherwise, the most common causes are the illicit drug abuse, alcohol withdrawal, muscular trauma and prescribed drugs.
The rate of myoglobin-induced acute kidney injury or failure in adults ranges from 17-35%, whereas in paediatric patients, it is 42%. Amongst the 17-35% of adult patients with kidney failure, 28-37% patients need short-term hemodialysis. Of all the kidney failure cases, 5 to 20% cases are caused by Rhabdomyolysis.
Prognosis and Survival Rate of Rhabdomyolysis:
The mortality rate of Rhabdomyolysis is 5% of all the cases. However, it is largely dependent on the etiology or the cause that is associated with the condition. The severity of the existing comorbid condition largely controls the mortality rate. However, a 10-year retrospective paediatric review showed that of 191 patients suffering from Rhabdomyolysis, only 13 patients died that is only 6% of the entire case study. Of these 13 patients, 9 patients suffered cardiopulmonary arrest and hence, could not be resuscitated.
With rapid intervention, diagnosis and with proper supportive treatment, Rhabdomyolysis can well be managed. The Rhabdomyolysis cases that are caused by muscle trauma and crush injuries, and lead to Rhabdomyolysis-related kidney injury and renal failure, can significantly be improved. Survival rate in Rhabdomyolysis can be significantly increased and patients have even successfully and completely recovered from this condition with aggressive hydration and dialysis support services.
Pathophysiology of Rhabdomyolysis:
Adenosine triphosphate and myocyte in the muscle cells ensure that the calcium efflux and cell ion levels are balanced. When the myocyte membrane is damaged, there is an increase of the calcium levels in the cells. The proteolytic enzymes lead to apoptosis of this calcium and causes muscle necrosis as well as releasing of myoglobin, phosphate, potassium, urate and creatine kinase in the blood stream.
Diagnosis of Rhabdomyolysis:
Diagnosis of Rhabdomyolysis starts with the doctor clinically assessing if there has been any pain in the muscles, if the muscles are tender or if any of the muscles have died off or not. To confirm the condition, the doctor will run a urine and blood test that will show if the level of myoglobin in the blood and urine is high or not. If it is high, it will indicate the possibility of Rhabdomyolysis. The other tests that are done include –
- Creatine kinase or CK test: To check the CK level in blood. An increased CK level will indicate muscle damage
- Creatinine (in blood and urine): An increased level will indicate kidney damage
- Calcium and potassium level in the body. Increased level will indicate Rhabdomyolysis.
Treatments for Rhabdomyolysis:
If rapid diagnosis is done, Rhabdomyolysis can be completely treated, without any serious damage to the kidneys. The most effective treatment procedures for Rhabdomyolysis are –
- Fluid Administration and Recovery: The fluid content of the body must be increased significantly. For that the IV or intravenous fluid or isotonic saline solution must be given. The fluid must contain bicarbonate that will help the body to fight against the acid that the muscle injury causes. It also helps the myoglobin to flush out of the kidneys.
- Medications to Treat Rhabdomyolysis: The medications that are recommended for Rhabdomyolysis are mostly associated with kidney functioning. For this, the diuretics such as bicarbonate are prescribed.
- Dialysis: If acute renal failure and kidney dysfunction occurs, dialysis or "extracorporeal blood purification" is done to remove the excess potassium, sodium and phosphate levels in the blood, in a special machine.
Prevention for Rhabdomyolysis:
Rhabdomyolysis is a syndrome that is quite common amongst patients, who are on fibrate and statin medications or medications for high cholesterol control. Hence, when they are prescribed any of these medicines, they are warned and made aware of the possible risks of developing Rhabdomyolysis and its initial symptoms, so that the diagnosis is not delayed. Stressful exercise routine and too much of stress and strain should be avoided to prevent Rhabdomyolysis. If you are hydrated enough and the muscles do not face any dehydration, then Rhabdomyolysis can well be prevented.
Rhabdomyolysis is not an extremely difficult condition that cannot be treated. But like all other disorders, diseases and syndromes, this too can be fatal if not treated on time.