Tracheal tube fusion in Drosophila involves release of extracellular vesicles from multivesicular bodies

Extracellular vesicles (EVs) comprise diverse types of cell-released membranous structures that are thought to play important roles in intercellular communication. While the formation and functions of EVs have been investigated extensively in cultured cells, studies of EVs in vivo have remained scarce. We report here that EVs are present in the developing lumen of tracheal tubes in Drosophila embryos. We defined two distinct EV subpopulations, one of which contains the Munc13-4 homologue Staccato (Stac) and is spatially and temporally associated with tracheal tube fusion (anastomosis) events. The formation of Stac-positive luminal EVs depends on the tracheal tip-cell-specific GTPase Arl3, which is also required for the formation of Stac-positive multivesicular bodies, suggesting that Stac-EVs derive from fusion of Stac-MVBs with the luminal membrane in tip cells during anastomosis formation. The GTPases Rab27 and Rab35 cooperate downstream of Arl3 to promote Stac-MVB formation and tube fusion. We propose that Stac-MVBs act as membrane reservoirs that facilitate tracheal lumen fusion in a process regulated by Arl3, Rab27, Rab35, and Stac/Munc13-4.

Tracheal Tube-Mounted Camera Assisted Intubation vs. Videolaryngoscopy in Expected Difficult Airway: A Prospective, Randomized Trial (VivaOP Trial)

Background: Tracheal intubation in patients with an expected difficult airway may be facilitated by videolaryngoscopy (VL). The VL viewing axis angle is specified by the blade shape and visualization of the larynx may fail if the angle does not meet anatomy of the patient. A tube with an integrated camera at its tip (VST, VivaSight-SL) may be advantageous due to its adjustable viewing axis by means of angulating an included stylet.Methods: With ethics approval, we studied the VST vs. VL in a prospective non-inferiority trial using end-tidal oxygen fractions (etO2) after intubation, first-attempt success rates (FAS), visualization assessed by the percentage of glottis opening (POGO) scale, and time to intubation (TTI) as outcome parameters.Results: In this study, 48 patients with a predicted difficult airway were randomized 1:1 to intubation with VST or VL. Concerning oxygenation, the VST was non-inferior to VL with etO2 of 0.79 ± 0.08 (95% CIs: 0.75–0.82) vs. 0.81 ± 0.06 (0.79–0.84) for the VL group, mean difference 0.02 (−0.07 to 0.02), p = 0.234. FAS was 79% for VST and 88% for VL (p = 0.449). POGO was 89 ± 21% in the VST-group and 60 ± 36% in the VL group, p = 0.002. TTI was 100 ± 57 s in the VST group and 68 ± 65 s in the VL group (p = 0.079). TTI with one attempt was 84 ± 31 s vs. 49 ± 14 s, p < 0.001.Conclusion: In patients with difficult airways, tracheal intubation with the VST is feasible without negative impact on oxygenation, improves visualization but prolongs intubation. The VST deserves further study to identify patients that might benefit from intubation with VST.

A COMPARATIVE ANALYSIS FOR REDUCTION OF POST-SURGICAL SORE THROAT BY APPLYING OF KETAMINE-NEBULIZATION & BETAMETHASONE-GEL OVER THE ENDO-TRACHEAL TUBE CUFF

Background: In general anaesthesia (GA), endo-tracheal -intubation is required to control respiration & to protect the airway. The commonest locations of injury while intubation are the larynx & trachea, which typically manifest as regional pain, inflammation & even necrosis. Aims & objectives: This research was carried out to contrast the efficaciousness of ketamine-nebulization & betamethasone-gel on the cuff of the endo-tracheal -tube to alleviate post-surgical throat pain (POST). Materials & methods: This is a randomized, prospective research assessing the efficaciousness of betamethasone-gel & lignocaine-jelly ketamine-nebulisation applied over the endo-tracheal -tube cuff to decrease post-surgical sore throat nebulisation (POST). The study subjects were divided randomly into ketamine (category K), betamethasone (category B) & lignocaine category (category L). Study subjects were observed immediately after extubation (0 hr), 2 hrs, 6 hrs, 12 hrs & 24 hours after the post-surgical time for POST, which was rated on a four-point ranking. Results: In this research, the total occurrence of POST was 30 %. Out of this, POST occurred only in 20 % of study subjects in the (K) category, 23 % of study subjects in the (B) category, contrasted to 47% in the (L) (control) category. The occurrence of POST at 0 hr, 2 hrs, 6 hrs, 12 hrs, 24 hours was 10 %, 10 %, 17 %, 10 % & 7 % respectively in the ketamine-nebulisation category. Conclusion: This research culminates that pre-surgical nebulization with ketamine & betamethasone-gel applied over the cuff of the endo-tracheal -tube is equally successful in reducing POST. Key Word: ketamine-nebulization, betamethasone-gel, lignocaine, Endo-tracheal -intubation

Efficacy of stylet angulation at the holding position during tracheal intubation with a videolaryngoscope: a randomized controlled trial

The aim of this randomized controlled trial was to determine the efficacy of stylet angulation at the holding position during tracheal intubation with a McGRATH MAC videolaryngoscope. Patients were randomized to a group for intubation without stylet angulation at the holding position (non-angulation group) and to a group for intubation with stylet angulation at the holding position (angulation group). The primary outcome was the time for placement of the tracheal tube. Sixty patients were analyzed. The mean (standard deviation) times for tube placement were 21.3 (5.6) s in the non-angulation group and 16.9 (3.8) s in the angulation group (P < 0.001). The scores of operator's perception of difficulty in tube delivery, number of attempts for tube delivery, and degrees of extension, abduction, internal rotation of the right upper arm and extension of the right wrist during tube placement in the angulation group were significantly smaller than those in the non-angulation group (P < 0.001, P = 0.002, P < 0.001, P < 0.001, P < 0.001, P < 0.001, respectively). Our results suggest that stylet angulation at the holding position improves maneuverability of the tracheal tube and enables easy, smooth, and swift tube placement during tracheal intubation with a McGRATH MAC videolaryngoscope.