From the Guidelines
Muscle breakdown is medically known as muscle wasting or sarcopenia, and in severe cases, it can lead to rhabdomyolysis, which occurs when damaged muscle tissue releases proteins and electrolytes into the bloodstream. The term rhabdomyolysis is more specific to the condition where muscle tissue damage leads to the release of myoglobin, potentially causing kidney damage 1. Muscle breakdown or wasting can result from various factors including immobilization, reduced oral intake, anesthesia, tissue damage, and subsequent immune system activation and metabolic changes 1. Treatment and prevention strategies for muscle breakdown focus on addressing the underlying cause, whether it's immobilization, malnutrition, or other factors, and may include resistance exercise, dietary interventions such as increased protein intake, and administration of essential amino acid mixtures 1. For example, a study found that beta-hydroxy-beta-methylbutyrate (HMB) supplementation resulted in a significant reduction in muscle loss and increase in muscle mass gain during rehabilitation 1. In cases of rhabdomyolysis, treatment primarily involves aggressive intravenous fluid administration to prevent kidney failure, monitoring of kidney function and electrolytes, and addressing the underlying cause 1. Some key points to consider in treating and preventing muscle breakdown include:
- Early institution of physical therapy to avoid joint contractures and muscle atrophy 1
- Goals of therapy should be to regain muscle strength and function 1
- Patients should meet regularly with a therapist to embark on a routine that incorporates both stretching and strengthening activities 1
- Intensive resistance training can be beneficial and safe in patients with muscle disease 1
- Referral to a physiatrist is essential early in the disease course to determine whether assistive devices are needed 1
- Assessment tools such as the Functional Index-2, Childhood Myositis Assessment Scale, and Childhood HAQ can be used to assess muscle impairment and functional capacity 1.
From the Research
Definition of Muscle Breakdown
- Muscle breakdown is also known as rhabdomyolysis, a complex medical condition involving the rapid dissolution of damaged or injured skeletal muscle 2.
- It occurs when skeletal muscle cells disrupt and release creatine phosphokinase (CK), lactate dehydrogenase (LDH), and myoglobin into the interstitial space and plasma 3.
Causes of Muscle Breakdown
- Rhabdomyolysis can be caused by direct muscular injury, strenuous exercise, drugs, toxins, infections, hyperthermia, seizures, metabolic and/or electrolyte abnormalities, and endocrinopathies 3.
- 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) 4.
Treatment of Muscle Breakdown
- Cessation of physical activity, relative rest during clinical recovery, and early aggressive fluid replacement are mainstays of treatment for exertional rhabdomyolysis (ER) 4.
- Early fluid resuscitation with ≥12 l daily intravenous infusion of alkaline solution started at the scene of injury can help prevent myoglobinuric acute kidney injury (AKI) and reduce mortality 5.
- The decision to initiate renal replacement therapy in clinical practice should not be made on the basis of the myoglobin or creatine phosphokinase serum concentrations, but rather on the basis of better knowledge of the pathophysiology of rhabdomyolysis and following AKI 6.