A learning curve of LMA® ProSeal™ insertion: a prospective analysis of cumulative sum method

Purpose LMA ® ProSeal™ (pLMA) has been used as an alternative to tracheal tubes. It is unclear how many cases are required to achieve proficiency in performing pLMA insertion among novice residents. Therefore, we analyzed the learning curve of pLMA insertion using a cumulative sum (CUSUM) chart and assessed the effects of learning. Methods In this single-center, prospective, observational study, we included 15 novice residents. Staff anesthesiologists recorded success or failure; insertion time; and incidences of bleeding or reflex including cough, hiccups, and limb movement. A successful pLMA insertion was defined as effective ventilation within two attempts with an insertion time of ≤ 120 s. Regarding CUSUM, we set acceptable and unacceptable failure rates as 20% and 40%, respectively. Further, α and β errors were designated as 0.1. We stratified the number of cases encountered by each resident into four groups of 10 cases each (1–10, 11–20, 21–30, and ≥ 31 cases) and evaluated the effects of learning. Results Each resident encountered 44 ± 5 (mean ± SD) cases of pLMA insertion, and 14/15 achieved proficiency in performing pLMA insertion after 20 ± 8 cases. Success rate (76%, 86%, 91%, and 93%; P