MH and COVID-19

COVID-19 is a new disease and MH susceptibility is a relatively rare condition. Although, therefore, there is no direct evidence for how the two conditions might interact, we can base advice on our experience of MH and the expanding number of publications on COVID-19.

  1. We can be almost certain that people who are susceptible to MH are not at increased risk of catching COVID-19.
  2. MH susceptibility, at least for the great majority of affected people, is not likely to increase the severity of COVID-19 infection or affect survival of those who are infected. Much more important is likely to be the presence of other chronic conditions, such as cardiovascular disease, diabetes, lung conditions and those with suppressed immune systems. 
  3. We strongly advise MH susceptible patients to wear a warning tag or bracelet to let doctors know about the MH risk in the emergency setting. At least in the UK, anaesthetists, intensive care doctors and emergency medicine physicians have been recommended to use a muscle relaxant drug called suxamethonium (succinylcholine) during insertion of a breathing tube should artificial ventilation of the lungs be required to treat COVID-19. Suxamethonium can trigger an MH reaction or cause potentially fatal muscle breakdown (rhabdomyolysis) in MH susceptible individuals. A range of warning tags/bracelet products are available through Amazon – search “malignant hyperthermia bracelet”.
  4. Some viral illnesses can cause rhabdomyolysis (breakdown of muscle tissue) which, if severe, can lead to kidney damage. COVID-19 is associated with myalgia (muscle aches or pain) but rhabdomyolysis does not seem to be a prominent feature of the infection. However, we know that a small proportion of MH susceptible patients have reported one or more episodes of rhabdomyolysis that are unrelated to anaesthesia – often related to severe exercise. It is possible that other MH susceptible patients are also more likely to develop rhabdomyolysis during COVID-19 infection than the general population. If you are MH susceptible with COVID-19 symptoms you should seek medical advice if you develop any one of the following: disabling muscle pain, muscle cramps or stiffness that limit bending or straightening of the limbs, dark urine (the colour of tea or cola). In the UK you should call the NHS 111 service who should arrange for you to be seen at hospital.