Comparison of the effects of paratracheal pressure and cricoid pressure on placement of the i-gel® supraglottic airway: a randomized clinical trial.

PURPOSE: Anesthesiologists can use supraglottic airway devices as a rescue technique for failed intubation even in patients with an increased risk of gastric regurgitation. In this randomized study, we aimed to evaluate the effects of cricoid pressure and paratracheal pressure on placement of the i-gel® (Intersurgical Ltd., Wokingham, Berkshire, UK). METHODS: After induction of anesthesia in 76 adult patients, we inserted the i-gel under paratracheal or cricoid pressure, and assessed the success rate of i-gel insertion, resistance during insertion, time required for insertion, accuracy of the insertion location, tidal volumes, and peak inspiratory pressure with or without each maneuver after i-gel insertion. RESULTS: The overall success rate of insertion was significantly higher under paratracheal pressure than under cricoid pressure (36/38 [95%] vs 27/38 [71%], respectively; difference, 24%; 95% confidence interval [CI], 8 to 40; P = 0.006]. Resistance during insertion was significantly lower under paratracheal pressure than under cricoid pressure (P < 0.001). The time required for insertion was significantly shorter under paratracheal pressure than under cricoid pressure (median [interquartile range], 18 [15-23] sec vs 28 [22-38] sec, respectively; difference in medians, -10; 95% CI, -18 to -4; P < 0.001). Fibreoptic examination of the anatomical alignment of the i-gel in the larynx revealed no significant difference in the accuracy of the insertion location between the two maneuvers (P = 0.31). The differences in tidal volume and peak inspiratory pressure with or without the maneuvers were significantly lower with paratracheal pressure than with cricoid pressure (P = 0.003, respectively). CONCLUSIONS: Insertion of the i-gel supraglottic airway was significantly more successful, easier, and faster while applying paratracheal pressure than cricoid pressure. STUDY REGISTRATION: ClinicalTrials.gov (NCT05377346); first submitted 11 May 2022.

RéSUMé: OBJECTIF: Les anesthésiologistes peuvent utiliser des dispositifs supraglottiques comme technique de sauvetage en cas d'échec de l'intubation, même chez les personnes présentant un risque accru de régurgitation gastrique. Dans cette étude randomisée, nous avons cherché à évaluer les effets de la pression cricoïdienne et de la pression paratrachéale sur le positionnement du dispositif i-gel® (Intersurgical Ltd., Wokingham, Berkshire, Royaume-Uni). MéTHODE: Après l'induction de l'anesthésie chez 76 adultes, nous avons inséré l'i-gel en utilisant une pression paratrachéale ou cricoïdienne, et avons évalué le taux de réussite de l'insertion de l'i-gel, la résistance pendant l'insertion, le temps nécessaire à l'insertion, la précision de l'emplacement d'insertion, les volumes courants ainsi que la pression inspiratoire maximale avec ou sans chacune des manœuvres après l'insertion de l'i-gel. RéSULTATS: Le taux global de réussite de l'insertion était significativement plus élevé avec une pression paratrachéale qu'avec une pression cricoïdienne (36/38 [95 %] vs 27/38 [71 %], respectivement; différence, 24 %; intervalle de confiance [IC] à 95 %, 7,6 à 39,8; P = 0,006]. La résistance lors de l'insertion était significativement plus faible en utilisant une pression paratrachéale par rapport à une pression cricoïdienne (P < 0,001). Le temps nécessaire à l'insertion était significativement plus court après avoir exercé une pression paratrachéale plutôt que cricoïdienne (médiane [écart interquartile], 18,4 [15,3­23,1] secondes vs 28,4 [22,3 à 37,8] secondes, respectivement; différence dans les médianes, −10,0; IC 95 %, −18,4 à −3,6; P < 0,001). L'examen par fibre optique de l'alignement anatomique de l'i-gel dans le larynx n'a révélé aucune différence significative dans la précision de l'emplacement d'insertion entre les deux manœuvres (P = 0,31). Les différences de volume courant et de pression inspiratoire maximale avec ou sans les manœuvres étaient significativement plus faibles avec la pression paratrachéale qu'avec la pression cricoïdienne (P = 0,003, respectivement). CONCLUSION: L'insertion du dispositif supraglottique i-gel a été significativement plus réussie, plus facile et plus rapide lors de l'application d'une pression paratrachéale que d'une pression cricoïdienne. ENREGISTREMENT DE L'éTUDE: ClinicalTrials.gov (NCT05377346); soumis pour la première fois le 11 mai 2022.

Prediction for Perioperative Stroke Using Intraoperative Parameters.

BACKGROUND: Perioperative stroke is a severe complication following surgery. To identify patients at risk for perioperative stroke, several prediction models based on the preoperative factors were suggested. Prediction models often focus on preoperative patient characteristics to assess stroke risk. However, most existing models primarily base their predictions on the patient's baseline characteristics before surgery. We aimed to develop a machine-learning model incorporating both pre- and intraoperative variables to predict perioperative stroke. METHODS AND RESULTS: This study included patients who underwent noncardiac surgery at 2 hospitals with the data of 15 752 patients from Seoul National University Hospital used for development and temporal internal validation, and the data of 449 patients from Boramae Medical Center used for external validation. Perioperative stroke was defined as a newly developed ischemic lesion on diffusion-weighted imaging within 30 days of surgery. We developed a prediction model composed of pre- and intraoperative factors (integrated model) and compared it with a model consisting of preoperative features alone (preoperative model). Perioperative stroke developed in 109 (0.69%) patients in the Seoul National University Hospital group and 11 patients (2.45%) in the Boramae Medical Center group. The integrated model demonstrated superior predictive performance with area under the curve values of 0.824 (95% CI, 0.762-0.880) versus 0.584 (95% CI, 0.499-0.667; P<0.001) in the internal validation; and 0.716 (95% CI, 0.560-0.859) versus 0.505 (95% CI, 0.343-0.654; P=0.018) in the external validation, compared to the preoperative model. CONCLUSIONS: We suggest that incorporating intraoperative factors into perioperative stroke prediction models can improve their accuracy.

Usefulness of video laryngoscopy in tracheal intubation at thyroid surgical position for intraoperative neuromonitoring.

This observational study aimed to compare the glottic view between video and direct laryngoscopy for tracheal intubation in the surgical position for thyroid surgery with intraoperative neuromonitoring. Patients scheduled for elective thyroid surgery with intraoperative neuromonitoring were enrolled. After the induction of anesthesia, patients were positioned in the thyroid surgical posture with a standard inclined pillow under their head and back. An investigator assessed the glottic view using the percentage of glottic opening (POGO) scale and the modified Cormack-Lehane grade in direct laryngoscopy and then video laryngoscopy sequentially while using the same McGRATH™ MAC video laryngoscope at once, with or without external laryngeal manipulation, at the surgical position. A total of thirty-nine patients were participated in this study. Without external laryngeal manipulation, the POGO scale significantly improved during video laryngoscopy compared to direct laryngoscopy in the thyroid surgical position (60.0 ± 38.2% vs. 22.4 ± 23.8%; mean difference (MD) 37.6%, 95% confidence interval (CI) = [29.1, 46.0], P < 0.001). Additionally, with external laryngeal manipulation, the POGO scale showed a significant improvement during video laryngoscopy compared to direct laryngoscopy (84.6 ± 22.9% vs. 58.0 ± 36.3%; MD 26.7%, 95% CI = [18.4, 35.0] (P < 0.001). The superiority of video laryngoscopy was also observed for the modified Cormack-Lehane grade. In conclusion, video laryngoscopy with the McGRATH™ MAC video laryngoscope, when compared to direct laryngoscopy with it, improved the glottic view during tracheal intubation in the thyroid surgical position. This enhancement may potentially facilitate the proper placement of the electromyography tracheal tube and prevent tube displacement due to positional change for thyroid surgery.

Effect of Nitrogen Doping on the Photocatalytic Properties and Antibiofilm Efficacy of Reduced TiO2 Nanoparticles.

Nanomaterial-mediated antibacterial photodynamic therapy (aPDT) emerges as a promising treatment against antibiotic-resistant bacterial biofilms. Specifically, titanium dioxide nanoparticles (TiO2 NPs) are being investigated as photosensitizers in aPDT to address biofilm related diseases. To enhance their photocatalytic performance in the visible spectral range for biomedical applications, various strategies have been adopted, including reduction of TiO2 NPs. However, despite improvements in visible-light photoactivity, reduced TiO2 NPs have yet to reach their expected performance primarily due to the instability of oxygen vacancies and their tendency to reoxidize easily. To address this, we present a two-step approach to fabricate highly visible-light active and stable TiO2 NP photocatalysts, involving nitrogen doping followed by a magnesium-assisted reductive annealing process. X-ray photoelectron spectroscopy analysis of the synthesized reduced nitrogen-doped TiO2 NPs (H:Mg-N-TiO2 NPs) reveals that the presence of nitrogen stabilizes oxygen vacancies and reduced Ti species, leading to increased production of reactive oxygen species under visible-light excitation. The improved aPDT efficiency translates to a 3-fold enhancement in the antibiofilm activity of nitrogen-doped compared to undoped reduced TiO2 NPs against both Gram-positive (Streptococcus mutans) and Gram-negative (Porphyromonas gingivalis, Fusobacterium nucleatum) oral pathogens. These results underscore the potential of H:Mg-N-TiO2 NPs in aPDT for combating bacterial biofilms effectively.