[Background and Goal of Study]
It is important to manage the tracheal cuff (TC) and the bronchial cuff (BC) of a double lumen tube (DLT) appropriately during one lung ventilation. The relationship between the TC pressure and the BC pressure under general anesthesia is still unclear. We hypothesized that there are no differences between TC pressure and BC pressure caused by the clinical experience of the anesthesiologist. The aim of our study is to investigate relationships between cuff pressures and clinical experience of the anesthesiologist. 

[Materials and Methods]
This study was performed with the approval of the Institutional Review Board (IRB). A total of 31 adult patients with insertion of left-DLTs were retrospectively investigated from anesthesia records between Sep. 2016 and Mar. 2017. Anesthesiologists inflated cuffs without using a manometer. BC was inflated while direct looking with a bronchoscopy through a tracheal lumen. Anesthesiologists were divided into the fellow group and non-fellow group based on their career paths. The cuff pressures were measured using a manometer at 5 cm H2O of positive end-expiratory pressure. The patient characteristics, TC pressures and BC pressures were statistically evaluated. A p value < 0.05 was considered a significant difference. Statistical analysis was performed using JMP®12.0.1 software (SAS Institute Inc., Cary, NC, USA).

[Results and Discussion]
The number of DLTs measured in fellow and non-fellow group were 17 and 14, respectively. The number of anesthesiologists in the fellow and non-fellow group were 9 and 5, respectively. There were no statistically significant differences in patient characteristics. The difference between the TC and BC pressure (mean ± standard deviation: SD) in each group was 14.4 ± 4.1cm H2O (p = 0.003) in the fellow and 7.4 ± 8.7cm H2O (p = 0.41) in the non-fellow group. The BC pressure was statistically lower than the TC pressure in the fellow group despite there was no significant difference between the BC pressure and TC pressure in the non-fellow group. The experienced anesthesiologists tend to avoid excessive BC pressures. It may be supposed that clinical experience contributes to adjustment of the cuff pressure.

[Conclusion]
The clinical experiences affect a difference between TC pressure and BC pressure.

02 / Does clinical experience affect the relationship between tracheal and bronchial cuff pressures of double-lumen tubes?