Self-administered methoxyflurane for procedural analgesia: experience in a tertiary Australasian centre

Methoxyflurane, an agent formerly used as a volatile anaesthetic but that has strong analgesic properties, will soon become available again in the UK and Europe in the form of a small hand-held inhaler. We describe our experience in the use of inhaled methoxyflurane for procedural analgesia within a large tertiary hospital. In a small pilot crossover study of patients undergoing burns-dressing procedures, self-administered methoxyflurane inhalation was preferred to ketamine-midazolam patient-controlled analgesia by five of eight patients. Patient and proceduralist outcomes and satisfaction were recorded from a subsequent case series of 173 minor surgical and radiological procedures in 123 patients performed using inhaled methoxyflurane. The procedures included change of dressing, minor debridement, colonoscopy and incision-and-drainage of abscess. There was a 97% success rate of methoxyflurane analgesia to facilitate these procedures. Limitations of methoxyflurane include maximal daily and weekly doses, and uncertainty regarding its safety in patients with pre-existing renal disease.