Nonetheless, the affected muscles may have become more sensitive to non-depolarizing muscle relaxants and, therefore, the dose administered has to be carefully chosen. Muscle break down leads to the release of high concentrations of potassium, CK and myoglobin in the circulation. As mentioned previously, high concentrations of potassium in the blood may result in cardiac arrest and the high concentrations of muscle-proteins may severely impair the kidney function. In addition, the use of succinylcholine and inhalational anesthetics may results in a syndrome called malignant hyperthermia. Succinylcholine and inhalational anesthetics are particularly renowned for causing this syndrome.
Malignant hyperthermia occurs relatively frequent in patients with muscular dystrophy.
Malignant hyperthermia is characterized by an extremely elevated metabolism within the muscle cell. As a result the temperature of the entire body rises to life-threatening levels, oxygen consumption and carbon dioxide production of the body increase dramatically and waste products are released into the circulation. It is of extreme importance that this syndrome is readily recognized so that the appropriate measures can be taken, including drastic cooling of the body and prompt initiation of therapy with the drug dantroleen. Unfortunately, despite appropriate measures, the course of this syndrome is often fatal. Children with muscular dystrophy should always be considered of being at high risk for the development of malignant hyperthermia and, therefore, the high risk anesthetics should be avoided.