National Board of Chiropractic Examiners (NBCE) Practice Test

What is the primary characteristic of Rhabdomyolysis?

1. Severe muscle spasms

2. Elevation of creatine kinase levels

3. Decreased muscle tone

4. Muscle hypertrophy

The correct answer is: Elevation of creatine kinase levels

Rhabdomyolysis is primarily characterized by the elevation of creatine kinase (CK) levels in the blood. This condition occurs when muscle tissue breaks down, releasing myoglobin and other intracellular components into the bloodstream. The breakdown of muscle fibers leads to a significant increase in creatine kinase, which is an enzyme found predominantly in skeletal muscle. High levels of CK are often used as a diagnostic marker for rhabdomyolysis, making this option the most definitive characteristic of the condition. Understanding the underlying mechanism of rhabdomyolysis is essential; the process can be triggered by various factors, including trauma, excessive exercise, drug use, or metabolic disorders. The elevated CK not only indicates muscle damage but is also a potential predictor of complications such as acute kidney injury, which can occur when myoglobin is filtered through the kidneys. The other options, while they might present in certain patient scenarios, do not represent the primary diagnostic criterion for rhabdomyolysis. Thus, the elevation of creatine kinase levels is central to both the diagnosis and understanding of the severity of muscle damage associated with rhabdomyolysis.