A prospective assessment of methoxyflurane and other analgesic agents during bone marrow biopsy

Abstract

<h3>Aims</h3> Analgesic agents for use during bone marrow biopsy include lignocaine, nitrous oxide, intravenous midazolam and methoxyflurane. There are no published data regarding the use of methoxyflurane during bone marrow biopsy and thus no guidelines as to whether this agent should be provided to every patient. <h3>Methods</h3> A prospective audit was conducted via the use of questionnaires given to patients post-biopsy. Patients assessed the pain experienced on a 100 mm visual analogue scale. If applicable, the pain from previous biopsies was rated. Information was collected regarding side effects. The change in the number of biopsies requiring midazolam sedation was determined. <h3>Results</h3> 163 questionnaires were returned from 1034 biopsies performed during the collection period (16% response rate). There was no significant difference in pain score between the lignocaine (31 mm), nitrous oxide (34 mm) and methoxyflurane (37 mm) groups, however the patients in the methoxyflurane group were younger (53 years versus 68 years with lignocaine, p < 0.01). Side effects were more common in the methoxyflurane group (62%), predominantly dizziness. Since the introduction of methoxyflurane, midazolam use declined (9% to 2%, <i>p <</i> 0.01). <h3>Discussion</h3> Methoxyflurane is a potent adjuvant agent, with the drawbacks of cost and side effects. An approach of patient selection rather than universal usage does not result in increased pain perception.