Safety and Efficacy of Methoxyflurane for Treatment of Incident Pain

Inclusion Criteria: * Adult participants (18 years of age or older) * Able to give written informed consent * Anticipated episode(s) of incident pain related to planned BMB lasting no more than 30 minutes on average * Anticipated life expectancy of at least 1 month Pre-Exclusion Criteria: * Subjects with a clinical condition that may, in the opinion of the investigator, impact on the subject's ability to participate in the study, or on the study results * Participants who have had IV sedation/opioid on previous BMB and who wish to receive IV sedation/opioid on this occasion or who in the opinion of the BMB operator would be advised to receive IV sedation/opioid on this occasion * Concomitant use of other investigational agents * Concomitant use of nephrotoxic agents such as gentamicin * Uncontrolled INR (\>4) * Personal or familial hypersensitivity to fluorinated anaesthetics * Personal or familial malignant hyperthermia * Respiratory rate of less than 10 per minute * Has previously received methoxyflurane * Known pre-existing renal or hepatic impairment * Compromised Renal Function (creatinine ≥ 1.5 x ULNR) * Compromised Liver Function (bilirubin ≥ 2.5 x ULNR) Exclusion Criteria: * Premedication with anxiolytic (e.g. midazolam, diazepam) * Dosed with breakthrough dose of analgesic that may contribute to control of pain during the planned procedure