FCO-170 Patient experience using Methoxyflurane (Penthrox) inhalational analgesia within the ambulatory gynaecology unit

Methoxyflurane (Penthrox 99.9% 3mL) is a well-established self-administered inhalational analgesia for the emergency relief of moderate to severe pain in conscious adult patients.

We performed a single centre retrospective patient evaluation study to evaluate the efficacy of Penthrox within the ambulatory gynaecology setting (June 2022-July 2023). Included participants completed a post-procedure symptom questionnaire, with visual analogue pain scores recorded.

Results -In total, n=219 ambulatory procedures were included; n=179 hysteroscopic, 5 MVA and 35 ‘other’. Indications during hysteroscopy included patient anxiety, previous discomfort and discomfort during this index procedure. Overall, 9 (4.1%) procedures were not completed, with cervical stenosis, patient request and loss of hysteroscopic view reasons indicated. Pain score sub-analysis according to hysteroscopic procedure was as follows; endometrial biopsy (EB)(n=59; 33.3%; median pain score (PS)=3 [95% CI 1-3]), EB+intrauterine system insertion (IUS) (n=30; 16.8%; PS=3[1-3]), myomectomy (Myosure/Bigatti)+/-IUS (n=5; 0.6%, PS=2[0-5]), polypectomy (Myosure/Bigatti) ) +/-IUS (n=41; 22.9%, PS=3[2-5]) and polypectomy ‘other method’) +/-IUS (n=19; 10.6%, PS=4[3-6]).  The median pain score for MVA was (n=5; 0.6%, PS=2[0-7]). No significant difference in pain score was measured between diagnostic (n=63; PS=3[2-4]) and interventional (n=70; PS=4[2-4]) hysteroscopy procedures (p>0.05).

Conclusion- Penthrox appears an effective analgesic for diagnostic and operative hysteroscopy procedures. Further prospective, comparative data, including overall patient satisfaction assessment, is required. The potential value for women requiring early pregnancy complication management is also important.