how is rhabdomyolysis characterized? course hero

What is rhabdomyolysis in the body?

Rhabdomyolysis is a state of muscle injury that can lead to several forms of systemic insult, with the most important being acute kidney injury, electrolyte imbalance, and disseminated intravascular coagulation. The systemic complications associated with rhabdomyolysis result from the leakage of muscle intracellular components into the bloodstream. This activity reviews the causes, pathophysiology, and presentation of rhabdomyolysis and highlights the role of the interprofessional team in its management.

What is the hallmark of acute rhabdomyolysis?

The hallmark of acute rhabdomyolysis is elevated CPK levels. In addition, reddish-brown urine from myoglobinuria may be present a 50% of cases. After triage and obtaining vital signs, basic labs including complete blood count, basic metabolic panel, liver function test, CRP, ESR, CPK levels, urinalysis, EKG, and chest X-ray should be obtained.

What is rhabdomyolysis in skeletal muscle?

Rhabdomyolysis means dissolution of skeletal muscle , and it is characterized by leakage of muscle cell contents, myoglobin, sarcoplasmic proteins (creatinine kinase, lactate dehydrogenase, aldolase, alanine, and aspartate aminotransferase), and electrolytes into the extracellular fluid and the circulation. The word rhabdomyolysis is derived from the Greek words rhabdos (rod-like/striated), mus (muscle), and Lucis (breakdown). [1] The common symptoms and signs are muscle weakness, pain/myalgia, local swelling and may be associated with dark red color urine/myoglobinuria. It can range from mild elevation in creatinine phosphokinase to medical emergencies like compartment syndrome, intravascular fluid depletion, Disseminated intravascular coagulation, pigment induced acute kidney injury (AKI), and cardiac arrhythmias. Laboratory diagnosis of rhabdomyolysis shows elevations in serum creatine phosphokinase (CPK), and there is no specific established serum level cut-off. Many physicians use three-five times the upper limit of normal Values of 100 to 400 IU/L (approximately 1000 IU/liter) for diagnosis. Rhabdomyolysis is one of the major causes of acute renal failure. [2] If identified early, the prognosis of acute kidney injury with rhabdomyolysis is relatively benign. [3] The etiology of rhabdomyolysis can be classified as traumatic and nontraumatic. Important causes of traumatic rhabdomyolysis are crush syndrome from accidents, earthquakes, and other natural and manufactured disasters. Not every muscle trauma leads to rhabdomyolysis and renal failure. Alternative causes for acute renal failure like dehydration, sepsis, drugs should always be evaluated. Seizures, alcohol use, drugs, prolonged bedridden state are common causes of nontraumatic rhabdomyolysis. [4]

What is the normal CPK level?

Normal CPK levels are 20 to 200 IU/L. Elevated levels usually at least five times the upper limit of normal is considered rhabdomyolysis. CPK exists in four significant isoenzymes, CK- MM, CK-MB, and CK-BB. The CK-MM is specific for skeletal muscle, CK-MB 1 and 2 specific for cardiac muscle, and CK BB for the brain. Its half-life is 36 hours. Serum CPK levels begin to rise within 2 to 12 hours after the injury peaks within 1 to 5 days. It declines after 3 to 5 days in the absence of muscle injury. The suspect continued muscle injury and compartment syndrome in cases of Persistently elevated CPK levels [39]

How long does it take to recover from rhabdomyolysis?

With better treatment, the mortality rates have decreased over the recent years, but the disorder still carries significant morbidity. Rapid intervention with aggressive hydration is the key to prevent renal injury and renal failure. Many patients take months to recover the muscle mass even after recovery, and some even have residual pain for a few years. [54] [55] [Level 5] With an interprofessional healthcare team approach to diagnosis and care that includes clinicians (MDs, DOs, PAs, NPs), specialists, nurses, and pharmacists, patients with rhabdomyolysis can achieve good outcomes and avoid the long-term sequelae of this condition. [Level 5]

What causes rhabdomyolysis?

The common causes of rhabdomyolysis are trauma, exertion, muscle hypoxia, infections, metabolic and electrolyte disorders, drugs, toxins, and genetic defects. [10] Recurrent episodes of rhabdomyolysis should prompt workup to identify underlying defects seen in muscle metabolism. The muscle damage can be from direct injury/trauma or by metabolic inequalities resulting in direct sarcolemmic injury or ATP depletion within the muscle fiber. Depletion of ATP impairs intracellular calcium regulation (usually, muscle cells maintain low levels of calcium at rest and increased calcium necessary for actin–myosin-binding during contraction), resulting in a persistent increase in sarcoplasmic calcium, causing persistent contraction, energy depletion, and activation of calcium-dependent proteases, phospholipases and eventual destruction of myofibrillar, cytoskeletal, and membrane proteins, followed by lysosomal digestion of fiber contents.

Is myoglobinuria a nephrotoxic condition?

Myoglobin is freely filtered through the glomerulus and reabsorbed in the renal tubule by endocytosis in a normal healthy state. Myoglobin has no nephrotoxic effect in the tubules in alkaline urine. The proximal convoluted tubule (PCT) of the kidney has limited ability to convert iron to ferritin. Urine acidification in rhabdomyolysis and excess myoglobin delivery to PCT causes ferrihemate accumulation. The globin chain readily dissociates from the iron-containing ferrihemate portion of myoglobin and is rapidly converted to ferritin. Ferritin generates oxygen-free radicals leading to excess oxidative stress and Proximal convoluted tubular cell injury. [33] The reabsorption of excess myoglobin is limited in distal convoluted tubule (DCT) in rhabdomyolysis. The presence of vasoconstriction, hypovolemia with excess water reabsorption in DCT further concentrates myoglobin in DCT; all of these promote cast formation and obstruction of DCT. [6]

What is rhabdomyolysis?

Rhabdomyolysis is a state of muscle injury that can lead to several forms of systemic insult, with the most important being acute kidney injury, electrolyte imbalance, and disseminated intravascular coagulation. The systemic complications associated with rhabdomyolysis results from the leakage of mu …. Rhabdomyolysis is a state of muscle injury ...

What are the complications of rhabdomyolysis?

The systemic complications associated with rhabdomyolysis results from the leakage of muscle intracellular components into the bloodstream. Several etiologies and conditions, such as trauma and drug use , can lead to the development of rhabdomyolysis. It is important to understand how to identify and treat rhabdomyolysis because, in most cases, ...

What is rhabdomyolysis in the body?

Rhabdomyolysis is a syndrome characterized by breakdown of muscle tissue, followed by dispersing its intracellular components into the circulatory system. These components include electrolytes, purines, enzymes (such as creatine kinase) and myoglobin. This syndrome is associated with many diseases, drugs, medications, toxins and injuries.

How to diagnose rhabdomyolysis?

Diagnosing rhabdomyolysis must be followed by a search for the cause. A careful history and physical examination are crucial, but may not always help in concluding definitively the underlining etiology. In such cases there is not a clear protocol for which tests should be attempted. If drugs or toxins are suspected, toxicological screening should be done. If infection is a possibility, appropriate cultures, complete blood count (CBC) and serological studies should be performed. If an endocrine or a metabolic disorder is suspected, blood chemistry and endocrine assay is to be done to confirm this.

What are the factors that increase the risk of exertional rhabdomyolysis?

Factors increasing the risk of exertional rhabdomyolysis are hypokalemia (often resulting from excessive sweating), sickle-cell trait (especially in combination with high altitude)15, extreme heat and humidity9, exercise-induced asthma, or pre-exertion fatigue.

What causes hyperthermia in the body?

Malignant hyperthermia is a condition usually ascribed as a genetic susceptibility to anesthetic drugs, causing hyperthermia, increased metabolic rate, elevated respiratory rate, pulse, rigidity and rhabdomyolysis. It may also be triggered by exercise (exercise induced malignant hyperpyrexia)40.

What happens when more than 100g of muscle tissue is degraded?

When more than 100g of muscle tissue is degraded the plasma’s myoglobin binding capacity is overwhelmed and free myoglobin causes renal morbidity by several mechanisms3–5. Causes. There is a large variety of causes for rhabdomyolysis, all leading to muscle ischemia and cell breakdown.

Why do rhabdomyolysis patients have arrhythmias?

Arrhythmiasmay occur due to electrolytes abnormalities, chiefly hyperkalemia and hypocalcemia. Since both abnormalities, as well as others described, can present themselves very early in the pathogenesis involving rhabdomyolysis, especially hypocalcemia of the early phase4, monitoring and early intervention are indicated in order to prevent arrhythmias and cardiac arrest.

Is rhabdomyolysis an incidental finding?

Rhabdomyolysis could be an incidental finding of a laboratory test. Anyhow, purposeful efforts should be made to identify an underlying cause.