This prospective, randomized, cross-over study compared the performance of the novel Flexible Tip Bougie™ (FTB) with a conventional bougie as an intubation aid in a simulated difficult airway manikin model among anaesthesiology trainees with regards of first pass success rate, time to intubation, number of attempts and ease of use. Sixty-two anesthesiology trainees, novice to the usage of FTB, participated in this study. Following a video demonstration, each participant performed endotracheal intubation on a manikin standardized to a difficult airway view. Each participant performed direct laryngoscopy and intubated the manikin using a conventional bougie and FTB, at least 1 day in between devices, in a randomized order. The first pass success rate was significantly higher with FTB (98.4%) compared to conventional bougie (85.5%), p = 0.008. The median time to intubation was significantly faster when using FTB, median = 32.0 s [Interquartile range (IQR): 23.8-41.3 s] compared to when using conventional bougie, median = 41.5 s (IQR: 31.8-69.5 s), p < 0.001. The FTB required significantly less intubation attempts compared to conventional bougie, p = 0.024. The overall ease of use, scored on a Likert scale from 1 to 5, was significantly higher in the FTB (4.26 ± 0.53) compared to the conventional bougie (3.19 ± 0.83), p < 0.001. This simulated difficult airway manikin study finding suggested that FTB is a useful adjunct for difficult airway intubation. The FTB offered a higher first pass success rate with a faster time to intubation and less required attempts.
Melting permafrost mounds in subarctic palsa mires are thawing under climate warming and have become a substantial source of N2O emissions. However, mechanistic insights into the permafrost thaw-induced N2O emissions in these unique habitats remain elusive. We demonstrated that N2O emission potential in palsa bogs was driven by the bacterial residents of two dominant Sphagnum mosses especially of Sphagnum capillifolium (SC) in the subarctic palsa bog, which responded to endogenous and exogenous Sphagnum factors such as secondary metabolites, nitrogen and carbon sources, temperature, and pH. SC's high N2O emission activity was linked with two classes of distinctive hyperactive N2O emitters, including Pseudomonas sp. and Enterobacteriaceae bacteria, whose hyperactive N2O emitting capability was characterized to be dominantly pH-responsive. As the nosZ gene-harboring emitter, Pseudomonas sp. SC-H2 reached a high level of N2O emissions that increased significantly with increasing pH. For emitters lacking the nosZ gene, an Enterobacteriaceae bacterium SC-L1 was more adaptive to natural acidic conditions, and N2O emissions also increased with pH. Our study revealed previously unknown hyperactive N2O emitters in Sphagnum capillifolium found in melting palsa mound environments, and provided novel insights into SC-associated N2O emissions.