Analysis of predictive factors for difficult ProSeal laryngeal mask airway insertion and suboptimal positioning

Jun, Joo Hyun; Kim, Jong Hak; Baik, Hee Jung; Kim, Youn Jin; Yun, Doo Gyun

Abstract

BACKGROUND
There has been controversy about predicting difficult LMA insertion and suboptimal position. Our aim was to evaluate bedside predictors for difficult LMA ProSeal(TM) (PLMA) insertion and suboptimal position.
METHODS
As the potential predictive factors for difficult PLMA insertion and suboptimal position, we considered male gender, increased body mass index (BMI), seven individual items suggesting difficult airway [modified Mallampati classification > or = III, inter-incisor distance < or = 5 cm, thyromental distance < or = 6.5 cm, head/neck movement < or = 90degrees, history of difficult intubation, buck of teeth > or = moderate, upper lip bite test (ULBT) > or = II] and > or = 3 of total airway score which is the sum of scores assessed by a score of 0, 1, 2 in seven individual items. The PLMA position was assessed by fiberoptic bronchoscopy to determine whether these predictors predict suboptimal position of PLMA (fiberoptic score < 3, as graded on a standard fiberopitc scale). We also investigated the effect of predictive factors on the failure of the first insertion of PLMA and time required for successful Proseal LMA insertion on the first attempt.
RESULTS
154 patients were enrolled in the study. The total airway score did have a significant relationship with the fiberoptic findings. The male gender and ULBT I of investigated predictors did significantly correlate with failure on the first insertion of PLMA. We did not find any significant relationship between the predictive factors and PLMA insertion time on the first attempt.
CONCLUSIONS
The male gender and ULBT I indicate difficult PLMA insertion, and the total airway score > or = 3 indicates suboptimal position of PLMA.