What is Malignant Hyperthermia?
Malignant Hyperthermia (MH) is a reaction to commonly used anaesthesia drugs (which we refer to as triggering agents) where the body produces too much heat. If it is not recognised and treated in its early stages, MH can lead to death. The risk of developing MH is associated with a change in the genes that are responsible for controlling the release of calcium in muscle cells.
An MH reaction is a rare event, occurring in about one in every ten thousand general anaesthetics. Triggering anaesthetics do not necessarily cause an MH crisis every time someone at risk is given them.
MH is hereditary; it is passed on through the family. It can occur in every ethnicity. A person with MH has a 50% chance of passing that risk on to each child that they have.
The drugs necessary to avoid in MH are volatile anaesthetic agents and a muscle relaxant drug called suxamethonium (succinylcholine). These drugs would only be administered by an anaesthetist or in a medical emergency by appropriately trained personnel. They do not exist in tablet form.
There is no cure for the predisposition to MH.
A drug called Dantrolene is available that can help in the treatment of MH. It can be very effective in treating MH if used early in the developing syndrome but it may not provide complete resolution in a crisis.
Alternative general anaesthetic agents are available for those at risk of MH.
