Methoxyflurane for Procedural Analgesia at 4470 m Altitude

Methoxyflurane is a volatile, fluorinated anesthetic agent with analgesic properties. Although no longer used as an anesthetic due to concerns regarding renal toxicity in high doses, it has enjoyed a resurgence as an inhaled analgesic in prehospital care and in the emergency department. The agent is nonflammable and leads to rapid, titratable analgesia without intravenous access. The Penthrox inhaler device is light, robust, and straightforward to administer. Consequently, it has been proposed as an ideal analgesic for the remote high altitude setting. We report its use for procedural analgesia during suprapubic aspiration for acute urinary retention at a remote rescue post at night, in cold winter conditions, at 4470 m altitude in Machermo, Nepal. We found that methoxyflurane provided rapid, effective analgesia for our patient’s visceral and procedural pain. The inhaler was easy to administer, and the patient remained responsive to voice, with satisfactory oxygen saturation and respiratory rate throughout. We also briefly review the administration, dosing, efficacy, and safety of methoxyflurane and its role in remote medical care.