Cannabinoids, elective surgery, MH FHx

38yo female for elective TKR.


  • Severe CP with spastic paraparesis
  • Asthma
  • 4WW
  • Seizure disorder


  • Cannabinoid use – prescribed
  • Family member (1st cousin) with muscle biopsy-proven MH


  • How was her cannabinoid use managed perioperatively?
  • MH family hx, how to proceed?
    • This patient had had previous surgeries using volatile anaesthetic with no issues, making her very low risk
    • Given this is a procedure normally undertaken under SAB and sedation, easy to provide a trigger-free anaesthetic
    • Should we do a muscle Bx on this patient while she’s under anaesthetic?
      • Dedicated team normally reviews each case individually and formulates a plan (if indicated) for investigation. Takes time to organise.
      • If the genetic variant affecting the patient is known, then the other family members can have genetic testing alone.


  • Proceed to OT.
  • Cannabinoids to be prescribed in hospital through the appropriate pathway.
  • Trigger-free anaesthetic.