Muscle biopsy for malignant hyperthermia screening in children.

Malignant Hyperthermia (MH) remains a life-threatening event in anaesthetic practice. In paediatric patients, triggering agents such as volatile anaesthetics and other succinylcholine are widely used. For children with a positive family history or previous clinical signs of MH, muscle biopsy for the halothane and caffeine in vitro muscle contracture tests is the only reliable procedure for diagnosis of MH susceptibility. Here we investigated outcome and compliance of patients and parents involved in the test. Twenty-four children between 6 and 14 yrs of age were admitted to hospital for biopsy. Muscle withdrawal was performed at the upper leg from lateral vastus muscle using regional or trigger-free general anaesthesia. Outcome and compliance were controlled by a telephone interview or direct physical re-evaluation. Seventeen patients out of 24 were diagnosed as clinically MH-susceptible according to the protocol of the European MH Group. Seven children were excluded as MH-negative by the test. Twenty-one children were evaluated postoperatively. Minor side effects of wound healing occurred, but none of the patients showed any abnormalities of muscle contracture or movement performance. Considering the high risk of fatal complications in the presence of MH-susceptibility, muscle biopsy of the upper leg for in-vitro diagnosis is a justified procedure that is acceptable to children and their parents.