Prehospital Inhaled Methoxyflurane Non-Clinical Occupational Exposure Study
Status:
Not yet recruiting
Trial end date:
2023-07-01
Target enrollment:
Participant gender:
Summary
Methoxyflurane is an anesthetic gas and at low doses has shown to help with pain.
Methoxyflurane was approved in Canada in 2018. Low-dose methoxyflurane is self-administered
by patients via a handheld inhaler. Exhaled methoxyflurane is captured by an activated carbon
(AC) chamber fitted to the inhaler in order to minimize environmental and occupational
exposure. It provides rapid (<1 minute), short-term (30-45 minutes) pain relief within six to
ten inhalations and has been shown to be effective and safe in emergency care and for minor
surgical, radiological, and dental procedures.
The current dosing recommendation is 3 ml bottle. However, the frequency at which
methoxyflurane treatment can be safely used by paramedics is not established. From the
product monograph, a patient's maximum daily dose of 6 mLs and weekly 15 mLs of
methoxyflurane. The treatment course of methoxyflurane for patients should not be repeated at
an interval of less than 3 months. Despite the activated carbon chamber to capture the
exhaled methoxyflurane, when paramedics are supervising patients receiving inhaled analgesia
within a confined area (like the back of an ambulance), it is possible that a paramedic may
experience intermittent exposure to methoxyflurane vapour. Multiple use of the methoxyflurane
Inhaler, with or without the AC chamber, creates additional risk. Elevation of liver enzymes,
blood urea nitrogen, and serum uric acid, have been reported in healthcare professionals
regularly exposed to methoxyflurane inhalational products. 8 A formal limit regarding levels
of occupational exposure to methoxyflurane has not been established.
The risk of occupational exposure of methoxyflurane will be evaluated in a controlled
laboratory setting, recruiting 30 health, screened (history and blood work) volunteers to
participate in the back of an ambulance which meets the Ontario Ministry of Health Standards.
The participants will consent and follow a protocol while active samplers are placed in the
rear of the ambulance to capture the off-gassing of the methoxyflurane. This will inform the
risk of occupational exposure of methoxyflurane to paramedics, as well as, hoping to inform
the risk of multiple administrations by paramedics to different patients during a single
shift, to ensure a medical directive can be created to support patient care and evaluate and
support paramedic safety.