News release

From: The University of Queensland

A less invasive way to test for a potential life-threatening reaction to anaesthetic has been developed by University of Queensland researchers.

Malignant hyperthermia (MH), a condition which causes some people exposed to anaesthetics to experience muscle rigidity, dangerously high body temperature, increased heart rate and build-up of acid in the blood, can be fatal.

Professor Bradley Launikonis from UQ’s School of Biomedical Sciences said susceptibility to MH is genetic, and anyone with a family history of the condition needs to be tested before going under anaesthetic.

“Currently the only way to accurately assess susceptibility to MH is an invasive muscle tissue biopsy that involves taking a sample for testing, and leaving patients with a 10cm cut to their thigh,” Professor Launikonis said.

“The process is invasive, expensive and time-consuming and causes significant discomfort and scarring.

“The test can’t be done on children and there are some adults who are fearful of large biopsies, or don’t want to be left with a huge scar as well as the potential for several days of recovery.’’

A new diagnostic test, Calcium Wave Frequency Assay, has shown potential for detecting MH susceptibility with just a single muscle fibre – about 1,000 times less muscle tissue than currently required.

MH was first recognised by anaesthetist Dr Michael Denborough in Melbourne in the 1960s when multiple members of the same family died after undergoing general anaesthetic.

There are now 3 MH Diagnostic Units in Australia and others worldwide, with about 10 people a week in Australia undergoing the invasive open biopsy.

Professor Launikonis said while a blood test was available for the genetic mutation, the risk of a false negative was considered too high because of the many possible mutations that can lead to MH susceptibility.

“We hope the new test can eventually be done with a minimally invasive needle biopsy and that it could ultimately have implications for other muscle conditions such as Muscular dystrophy,” he said.

“While MH is a rare condition, anaesthetists need to know if a patient is susceptible so they can take extra precautions, otherwise the person could die during an operation.

“A muscle relaxant drug can be administered to someone having an MH reaction, but even if the person survives, they can still have permanent neurological damage.

“It is vital people know this information.’’

Professor Launikonis said the next step would be a full clinical validation of the new test.

The research is published in Anaesthesiology.