Rhabdomyolysis in Children

Rhabdomyolysis is a condition in which muscle cells break down, releasing a potentially harmful protein called myoglobin into the bloodstream. Myoglobin and its byproducts can impair kidney function. Because of this, rhabdomyolysis is a leading cause of acute renal failure in children.

Causes

• The leading causes of rhabdomyolysis in adults include trauma, excessive physical exertion and ingestion of toxins or medications. In children, the leading causes of rhabdomyolysis are viral muscle infections, trauma and hereditary disorders. Children with chronic conditions like asthma, diabetes and thyroid problems are at increased risk of developing rhabdomyolysis.

Features

• Most children with rhabdomyolysis present with generalized muscle weakness, muscle aches (a condition called myalgia) and tenderness. Children with rhabdomyolysis have dark or cola-colored urine. This happens because the kidneys attempt to excrete the excess myoglobin in the blood, and myoglobin has a dark-colored pigment in its chemical composition.

  Children can present with other, non-specific symptoms like fatigue, nausea, vomiting and joint pain. The typical symptoms of muscle injury, dark urine and kidney involvement do not appear at the same time in most children.

Effects

• Lab tests are necessary to diagnose rhabdomyolysis. One of the most useful tests is the CK blood test. CK stands for creatine kinase, a protein that is present in muscle cells. An increase in the level of creatine kinase in the blood signals muscle damage. Also important are detection of myoglobin in the urine and testing for the child's renal function, to make sure acute renal failure is not occurring.

Prevention/Solution

• Children with rhabdomyolysis require vigorous fluid therapy, usually with IV fluids, to flush out the myoglobin in the blood. It is also important to remove any potential causes of ongoing muscle breakdown. If urine is not produced in adequate quantities with fluid therapy, other medicines, including diuretics, can be used. In severe cases, dialysis is necessary to treat renal failure.

Warning

• Muscle cells also contain high levels of potassium. During muscle breakdown, potassium levels in the blood can increase. This can lead to life-threatening conditions, including abnormal heart rhythms. Other potential electrolyte problems include hypocalcemia (abnormally low calcium in the blood) and hyperphosphatemia (abnormally high levels of phosphate). These conditions usually resolve once the cause of the muscle breakdown goes away, and the child is well hydrated.