Wang H, et al. - As the optimum sevoflurane concentration for supraglottic airway device insertion allowing spontaneous breathing in 50% of obese patients (ED₅₀) remained unknown, researchers performed this study to determine the ED₅₀ of sevoflurane for supraglottic airway device Blockbuster insertion with spontaneous breathing in obese patients requiring general anesthesia. In this work, 2.5 ± 0.6% was identified as the optimum end-tidal sevoflurane concentration needed for the supraglottic airway device Blockbuster insertion permitting spontaneous breathing in 50% of obese patients (ED₅₀).