Monteserín-Matesanz C, et al. - Among patients receiving a remifentanil infusion without a neuromuscular blocking agent, researchers assessed the optimal end-tidal (ET) sevoflurane concentration for successful insertion of ProSeal laryngeal mask airway (PLMA) vs Supreme laryngeal mask airway (SLMA). There were 45 patients ASA (American Society Anaesthesiologists) physical status I–II, aged 18–60 years who were scheduled for elective ambulatory surgery. Cases with a difficult airway, recent respiratory infection, reactive airway, obstructive sleep apnoea syndrome, gastric aspiration’s risk factors, pregnancy, and lactation were excluded. In a random manner, the participants were assigned to receive the SLMA or the PLMA. The ET₅₀ (ET concentration in 50%) sevoflurane concentration co-delivered with remifentanil needed for PLMA insertion was found to be 1.20 ± 0.41%. It was identified to be 0.55 ± 0.38% for SLMA insertion. This implies that the end-tidal sevoflurane concentration with co-delivered remifentanil needed to permit the insertion of the SLMA was 54% lower compared with that required for inserting the PLMA.