Isoflurane as a cost-effective alternative to sevoflurane for short-duration gynaecological brachytherapy: a randomised non-inferiority trial of emergence.

Abstract

Purpose: The optimal anaesthetic choice for gynaecological brachytherapy remains uncertain. While sevoflurane offers rapid recovery due to favourable pharmacokinetics, its higher cost limits affordability in resource-constrained settings. Isoflurane, a less expensive volatile agent, may be a cost-effective alternative if recovery profiles are comparable.

Material and methods: We conducted a prospective, randomised, non-inferiority trial including 100 women with American Society of Anesthesiologists (ASA) physical status I-III undergoing ambulatory intracavitary brachytherapy. Participants were randomly allocated to maintenance anaesthesia with either isoflurane (n = 50) or sevoflurane (n = 50), with anaesthetic depth titrated to maintain a bi-spectral index (BIS) between 40 and 60. The primary outcome was emergence time, defined as the interval from discontinuation of anaesthesia to eye opening after verbal command. Secondary outcomes included time to supraglottic airway removal, haemodynamic stability, postoperative cognitive function, post-anaesthesia care unit (PACU) stay, adverse events, and anaesthetic agent cost. Non-inferiority was prespecified with a margin of 3.2 minutes.

Results: Emergence times were similar between isoflurane and sevoflurane groups (7.13 ±1.60 min vs. 7.24 ±1.70 min; mean difference 0.12 min; 97.5% CI: 0.86 to -0.63), confirming non-inferiority of isoflurane. Secondary outcomes, including airway removal time, haemodynamics, cognitive scores, PACU stay and adverse events, showed no significant differences. Isoflurane administration cost was 61.6% lower compared to sevoflurane (22.2 ±2.77 INR vs. 57.8 ±9.35 INR; p = 0.001).

Conclusions: Isoflurane is non-inferior to sevoflurane for emergence time in short-duration gynaecological brachytherapy, with comparable recovery profiles. Its substantial cost advantage supports its use as an economical anaesthetic option in high-volume, resource-limited oncology settings.