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.

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 head and neck positions on tracheal intubation using a McGRATH MAC video laryngoscope: A randomised, prospective study.

BACKGROUND: Different head and neck positions may affect video laryngoscopy in terms of laryngeal exposure, intubation difficulty, advancement of the tracheal tube into the glottis and the occurrence of palatopharyngeal mucosal injury. OBJECTIVE: We investigated the effects of simple head extension, head elevation without head extension and the sniffing position on tracheal intubation using a McGRATH MAC video laryngoscope. DESIGN: A randomised, prospective study. SETTING: Medical centre governed by a university tertiary hospital. PATIENTS: A total of 174 patients undergoing general anaesthesia. METHODS: Patients were randomly allocated to one of three groups: simple head extension (neck extension without a pillow), head elevation only (head elevation with a pillow of 7 cm and no neck extension) and sniffing position (head elevation with a pillow of 7 cm and neck extension). MAIN OUTCOMES: During tracheal intubation using a McGRATH MAC video laryngoscope in three different head and neck positions, we assessed intubation difficulty by several methods: a modified intubation difficulty scale score, time taken for tracheal intubation, glottic opening, number of intubation attempts, requirements for other manoeuvres (lifting force or laryngeal pressure) for laryngeal exposure and advancement of the tracheal tube into the glottis. The occurrence of palatopharyngeal mucosal injury was evaluated after tracheal intubation. RESULTS: Tracheal intubation was significantly easier in the head elevation group than in the simple head extension ( P  = 0.001) and sniffing positions ( P  = 0.011). Intubation difficulty did not differ significantly between the simple head extension and sniffing positions ( P  = 0.252). The time taken for intubation in the head elevation group was significantly shorter than that in the simple head extension group ( P  < 0.001). A lifting force or laryngeal pressure was required less frequently for tube advancement into the glottis in the head elevation group than in the simple head extension ( P  = 0.002) and sniffing position groups ( P  = 0.012). The need for a lifting force or laryngeal pressure for tube advancement into the glottis was not significantly different between the simple head extension and sniffing positions ( P  = 0.498). Palatopharyngeal mucosal injury occurred less frequently in the head elevation group than in the simple head extension group ( P  = 0.009). CONCLUSION: The head elevation position facilitated tracheal intubation using a McGRATH MAC video laryngoscope compared with a simple head extension or sniffing position. TRIAL REGISTRY NUMBER: ClinicalTrials.gov (NCT05128968).

Comparison of the needle tip location with the operator's position during ultrasound-guided internal jugular vein catheterization: A randomized controlled study.

OBJECTIVE: We hypothesized that when a right-handed operator catheterizes the left internal jugular vein (IJV), the tip of the needle might be positioned closer to the center of the vessel after puncture if the operator is standing in the patient's left axillary line, rather than standing cephalad to the patient. METHODS: The study randomly allocated 44 patients undergoing elective surgery under general anesthesia with planned left central venous catheterization to either conventional (operator stood cephalad to the patient) or intervention (operator stood in the patient's axillary line) groups. The left IJV was catheterized by 18 anesthesiologists. The distance between the center of the vessel and the needle tip, first-attempt success rate, and procedure time were compared. RESULTS: The distance from the needle tip to the center of the IJV after needle puncture was 3.5 (1.9-5.5) and 3.2 (1.7-4.9) cm in the conventional and intervention groups, respectively (P = .47). The first-attempt success rate was significantly higher in the intervention group (100% vs 68.2%, P = .01). Overall time to successful guidewire insertion was faster in the intervention group (P = .007). CONCLUSIONS: There was no significant difference in needle tip position when the right-handed operator was standing in the patient's left axillary line compared to standing cephalad to the patient during left IJV catheterization. However, it increased the first-attempt success rate and reduced the overall time for guidewire insertion.

Effectiveness of Cricoid and Paratracheal Pressures in Occluding the Upper Esophagus Through Induction of Anesthesia and Videolaryngoscopy: A Randomized, Crossover Study.

BACKGROUND: Maneuvers for preventing passive regurgitation of gastric contents are applied to effectively occlude the esophagus throughout rapid sequence induction and intubation. The aim of this randomized, crossover study was to investigate the effectiveness of cricoid and paratracheal pressures in occluding the esophagus through induction of anesthesia and videolaryngoscopy. METHODS: After the induction of anesthesia in 40 adult patients, the location of the esophageal entrance relative to the glottis and location of the upper esophagus relative to the trachea at the low paratracheal region were assessed using an ultrasonography, and the outer diameter of the esophagus was measured on ultrasound before and during application of cricoid and paratracheal pressures of 30 N. Then, videolaryngoscopy was performed with the application of each pressure. During videolaryngoscopy, location of the esophageal entrance relative to the glottis under cricoid pressure was examined on the screen of videolaryngoscope, and the upper esophagus under paratracheal pressure was evaluated using ultrasound. The occlusion rate of the esophagus, and the best laryngeal view using the percentage of glottic opening scoring system were also assessed during videolaryngsocopy. Esophageal occlusion under each pressure was determined by inserting an esophageal stethoscope into the esophagus. If the esophageal stethoscope could not be advanced into the esophagus under the application of each pressure, the esophagus was regarded to be occluded. RESULTS: During videolaryngoscopy, esophagus was occluded in 40 of 40 (100%) patients with cricoid pressure and 23 of 40 (58%) patients with paratracheal pressure (difference, 42%; 95% confidence interval, 26-58; P < .001). Both cricoid and paratracheal pressures significantly decreased the diameter of the esophagus compared to no intervention in the anesthetized paralyzed state ( P < .001, respectively). Ultrasound revealed that the compressed esophagus by paratracheal pressure in the anesthetized paralyzed state was partially released during videolaryngoscopy in 17 of 40 patients, in whom esophageal occlusion was unsuccessful. The best laryngeal view was not significantly different among the no intervention, cricoid pressure, and paratracheal pressure (77 [29] % vs 79 [30] % vs 76 [31] %, respectively; P = .064). CONCLUSIONS: The occlusion of the upper esophagus defined by inability to pass an esophageal stethoscope was more effective with cricoid pressure than with paratracheal pressure during videolaryngoscopy, although both cricoid and paratracheal pressures reduced the diameter of the esophagus on ultrasound in an anesthetized paralyzed state.

Association Between Anesthetics and Postoperative Delirium in Elderly Patients Undergoing Spine Surgery: Propofol Versus Sevoflurane.

STUDY DESIGNS: Retrospective Observational StudyObjectives: To compare the incidence of POD after propofol- and sevoflurane-based anesthesia in elderly patients undergoing spine surgery. METHODS: In this study, the medical records of elderly patients ≥ 65 years of age who underwent spine surgery under total intravenous anesthesia with propofol or inhalational anesthesia with sevoflurane were reviewed. The primary outcome was the incidence of POD after propofol- and sevoflurane-based anesthesia. Secondary outcomes included postoperative 30-day complications, length of postoperative hospital stay, associations of patient characteristics, and surgery- and anesthesia-related data with the development of POD, and associations of anesthetics with clinical outcomes such as postoperative 30-day complications, and length of postoperative hospital stay. RESULTS: Of the 281 patients, POD occurred in 29 patients (10.3%). POD occurred more frequently in the sevoflurane group than in the propofol group (15.7% vs. 5.0%, respectively; P=.003). The multivariable logistic regression analysis showed that sevoflurane-based anesthesia was associated with an increased risk of POD compared with propofol-based anesthesia (odds ratio [OR], 4.120; 95% confidence interval [CI], 1.549-10.954; P = .005), whereas anesthetics were not associated with postoperative 30-day complications and the length of postoperative hospital stay. Older age (OR, 1.242 CI, 1.130-1.366; P < .001) and higher mean pain score at postoperative day 1 (OR, 1.338 CI, 1.056-1.696; P = .016) were also associated with an increased risk of POD. CONCLUSIONS: Propofol-based anesthesia was associated with a lower incidence of POD than sevoflurane-based anesthesia in elderly patients after spine surgery.

Evaluation of the conventional and modified aerosol boxes during tracheal intubation in normal and difficult airways: a randomized, crossover, manikin simulation study.

The aim of this study was to evaluate conventional and modified aerosol boxes in terms of intubation time, first-pass intubation success, and mouth-to-mouth distance between the laryngoscopist and patient during tracheal intubation in simulated patients with normal and difficult airways. Sixteen anesthesiologists performed tracheal intubations with direct laryngoscope or three different videolaryngoscopes (McGRATH MAC videolaryngoscope, C-MAC videolaryngoscope, and Pentax-AWS) without an aerosol box or with a conventional or a modified aerosol boxes in simulated manikins with normal and difficult airways. Intubation time, first-pass intubation success, and mouth-to-mouth distance during tracheal intubation were recorded. Compared to no aerosol box, the use of a conventional aerosol box significantly increased intubation time in both normal and difficult airways (Bonferroni-corrected P-value (Pcorrected) = 0.005 and Pcorrected = 0.003, respectively). Intubation time was significantly shorter with the modified aerosol box than with the conventional one for both normal and difficult airways (Pcorrected = 0.003 and Pcorrected = 0.011, respectively). However, no significant differences were found in intubation time between no aerosol box and the modified aerosol box for normal and difficult airways (Pcorrected = 0.336 and Pcorrected = 0.112, respectively). The use of conventional or modified aerosol boxes significantly extended the mouth-to-mouth distances compared to not using an aerosol box during tracheal intubation with each laryngoscope (all Pcorrected < 0.05), and the distances were not different between the conventional and modified boxes in normal and difficult airways. The use of modified aerosol box did not increase intubation time and could help maintain a distance from the simulated patients with normal and difficult airways.

Comparison of the Conventional Downward and Modified Upward Laryngeal Handshake Techniques to Identify the Cricothyroid Membrane: A Randomized, Comparative Study.

BACKGROUND: Accurate identification of the cricothyroid membrane is crucial for successful cricothyroidotomy. The aim of this study was to compare the conventional downward and modified upward laryngeal handshake techniques in terms of accuracy to identify the cricothyroid membrane in nonobese female patients. METHODS: In 198 anesthetized female patients, the cricothyroid membrane was identified by either the conventional downward laryngeal handshake technique (n = 99) or the modified upward laryngeal handshake technique (n = 99). According to the conventional downward laryngeal handshake technique, the cricothyroid membrane was identified by palpating the neck downward from the greater cornu of the hyoid bone, thyroid laminae, and cricoid cartilage. According to the modified upward laryngeal handshake technique, the cricothyroid membrane was located by moving up from the sternal notch. The primary outcome was the accuracy of identifying the cricothyroid membrane. Secondary outcomes included the accuracy of midline identification and time taken to locate what participants believed to be the cricothyroid membrane. The primary and secondary outcomes according to the technique were analyzed using generalized estimating equations. RESULTS: The cricothyroid membrane could be identified more accurately by the modified upward laryngeal handshake technique than by the conventional downward technique (84% vs 56%, respectively; odds ratio [OR], 4.36; 95% confidence interval [CI], 2.13-8.93; P < .001). Identification of the midline was also more accurate by the modified laryngeal handshake than by the conventional technique (96% vs 83%, respectively; OR, 4.98; 95% CI, 1.65-15.01; P = .004). The time taken to identify the cricothyroid membrane was not different between the conventional and modified techniques (20.2 [16.2-26.6] seconds vs 19.0 [14.5-26.4] seconds, respectively; P = .83). CONCLUSIONS: The modified upward laryngeal handshake technique that involved tracing the trachea and laryngeal structures upward from the sternal notch was more accurate in identifying the cricothyroid membrane than the conventional downward technique in anesthetized female patients.

Effect of head and shoulder positioning on the cross-sectional area of the subclavian vein in obese subjects.

OBJECTIVE: Head and shoulder positioning may affect cross-sectional area (CSA) and location of the subclavian vein (SCV). We investigated the CSA of the SCV and the depth of the SCV, depending on the head and shoulder positions. METHODS: In 24 healthy obese volunteers, the short axis ultrasound images of the SCV and adjacent structures were obtained in three different head positions (neutral, 30° turned to the contralateral side, and 30° turned to the ipsilateral side) and two different shoulder positions (neutral and lowered). Images of the right and left SCVs were obtained in the supine and Trendelenburg positions. Subsequently, the CSA and depth of the SCV were measured. RESULTS: Significant differences were found in the CSA of the SCV in different head positions (30° turned to contralateral side vs. neutral: -0.06 cm2, 95% confidence interval [CI], -0.10 to -0.02; Pcorrected = 0.002, 30° turned to contralateral side vs. 30° turned to ipsilateral side: -0.16 cm2, 95% CI, -0.22 to -0.11; Pcorrected < 0.001, Neutral vs. 30° turned to ipsilateral side: -0.10 cm2, 95% CI, -0.14 to -0.07; Pcorrected < 0.001). The CSA of the SCV was significantly different, depending on shoulder positions (neutral vs. lowered: 0.44 cm2, 95% CI, 0.33 to 0.54; Pcorrected < 0.001), and body position (supine vs. Trendelenburg: -0.15 cm2, 95% CI, -0.19 to -0.12; Pcorrected < 0.001). However, the depth of the SCV did not differ with respect to head, shoulder, and body positions. CONCLUSIONS: Ipsilateral 30° head rotation, neutral shoulder position, and Trendelenburg position significantly enhanced the CSA of the SCV in obese participants.

Effect of Paratracheal Pressure on the Glottic View During Direct Laryngoscopy: A Randomized Double-Blind, Noninferiority Trial.

BACKGROUND: Cricoid pressure has been used as a component of the rapid sequence induction and intubation technique. However, concerns have been raised regarding the effectiveness and safety of cricoid pressure. Paratracheal pressure, a potential alternative to cricoid pressure to prevent regurgitation of gastric contents or aspiration, has been studied to be more effective to cricoid pressure in preventing gastric insufflation during positive pressure ventilation. However, to adopt paratracheal compression into our practice, adverse effects including its effect on the glottic view during direct laryngoscopy should be studied. We conducted a randomized, double-blind, noninferiority trial comparing paratracheal and cricoid pressures for any adverse effects on the view during direct laryngoscopy, together with other secondary outcome measures. METHODS: In total, 140 adult patients undergoing general anesthesia randomly received paratracheal pressure (paratracheal group) or cricoid pressure (cricoid group) during anesthesia induction. The primary end point was the incidence of deteriorated laryngoscopic view, evaluated by modified Cormack-Lehane grade with a predefined noninferiority margin of 15%. Secondary end points included percentage of glottic opening score, ease of mask ventilation, change in ventilation volume and peak inspiratory pressure during mechanical mask ventilation, ease of tracheal intubation, and resistance encountered while advancing the tube into the glottis. The position of the esophagus was assessed by ultrasound in both groups to determine whether pressure applied to the respective area would be likely to result in esophageal compression. All secondary outcomes were tested for superiority, except percentage of glottic opening score, which was tested for noninferiority. RESULTS: Paratracheal pressure was noninferior to cricoid pressure regarding the incidence of deterioration of modified Cormack-Lehane grade (0% vs 2.9%; absolute risk difference, -2.9%; 95% confidence interval, -9.9 to 2.6, P <.0001). Mask ventilation, measured on an ordinal scale, was found to be easier (ie, more likely to have a lower score) with paratracheal pressure than with cricoid pressure (OR, 0.41; 95% confidence interval, 0.21-0.79; P = .008). The increase in peak inspiratory pressure was significantly less in the paratracheal group than in the cricoid group during mechanical mask ventilation (median [min, max], 0 [-1, 1] vs 0 [-1, 23]; P = .001). The differences in other secondary outcomes were nonsignificant between the groups. The anatomical position of the esophagus was more suitable for compression in the paratracheal region, compared to the cricoid cartilage region. CONCLUSIONS: Paratracheal pressure was noninferior to cricoid pressure with respect to the effect on glottic view during direct laryngoscopy.

A pilot study comparing three bend angles for lighted stylet intubation.

BACKGROUND: For successful lighted stylet intubation, bending the lighted stylet with an appropriate angle is a prerequisite. The purpose of this study was to compare three different bend angles of 70, 80, and 90 degrees for lighted stylet intubation. METHODS: The patient trachea was intubated with a lighted stylet bent at 70, 80, or 90 degrees according to the randomly allocated groups (group I, II, and III, respectively). A lighted stylet combined with a tracheal tube was prepared with a bend angle of 70, 80, or 90 degrees according to the assigned group. We checked the success rate at the first attempt and overall success rate for the two attempts. Additionally, we measured search time, which was time from insertion of the bent union into the patient mouth to the start of advancing the tracheal tube while separating it from the lighted stylet, and evaluated postoperative sore throat (POST) at 2, 4, and 24 h after the recovery from anesthesia. RESULTS: There was no statistically significant difference between group I, II, and III for success rate at first attempt (73.9 %, 88.2 %, and 94.7 %, respectively, p = 0.178), even though there was a trend of increasing success rate with increasing bend angles. For overall success rate, there was similar result to that in the first attempt between the groups I, II, and III (82.6 %, 94.1 %, and 100 %, respectively, p = 0.141). However, search time took significantly longer in group I than groups II and III (p < 0.001). When group II and III were compared for POST with numeric rating scale (0-10), it was significantly lower in group II than III at 2, 4 h after the recovery (0.5 vs. 2.3, p = 0.016, and 0.4 vs. 1.8, p = 0.011, respectively). CONCLUSIONS: The bend angle of the lighted stylet affected the time required for tracheal intubation and POST in our study. 80 and 90 degrees as a bend angle seem to be acceptable for clinicians in regard to success rate of lighted stylet intubation. Considering the success rate of lighted stylet intubation and POST, the bend angle of 80 degrees might be better than 70 and 90 degrees. TRIAL REGISTRATION: ClinicalTrials.gov Identifier NCT03693235 , registered on 30 September 2018.

Comparison of Sugammadex Dose for Intraoperative Neuromonitoring in Thyroid Surgery: A Randomized Controlled Trial.

OBJECTIVES/HYPOTHESIS: To compare effect of 1 and 2 mg/kg of sugammadex on the incidence of intraoperative bucking and intraoperative neuromonitoring (IONM) quality in thyroid surgery. STUDY DESIGN: Randomized controlled trial. METHODS: Patients qualified for thyroid surgery with IONM were eligible for this double-blind, randomized, controlled trial. After tracheal intubation with 0.6 mg/kg rocuronium, 1 or 2 mg/kg of sugammadex was administered to patients in group I or II, respectively. The quality of the IONM for the external branch of the superior laryngeal nerve (EBSLN) was evaluated (strong/intermediate/weak). The initial amplitude of electromyography for the vagus nerve (V1) and the recurrent laryngeal nerve (R1) were recorded. Intraoperative bucking movements was recorded. RESULTS: A total of 102 patients (51 in each group) completed the study. Time from sugammadex administration to initial checking for the EBSLN was not different between group I and II (25.0 ± 7.9 vs. 25.5 ± 9.0 minutes, P = .788). There was no difference in the neuromonitoring quality for the EBSLN between group I and II (strong/intermediate/weak: 46/5/0 vs. 50/1/0, P = .205). The amplitudes of V1 (1,086.3 ± 673.3 µV vs. 1,161.8 ± 727.5 µV, P = .588) and R1 (1,328.2 ± 934.1 µV vs. 1,410.5 ± 919.6 µV, P = .655) were comparable between the groups. Patients who experienced bucking were significantly fewer in the group I than the group II (13.7% vs. 35.3%, P = .020). CONCLUSION: A dose of 1 mg/kg sugammadex induced less bucking than 2 m/kg while providing comparable IONM quality during thyroid surgery. LEVEL OF EVIDENCE: 2 Laryngoscope, 131:2154-2159, 2021.

Effect of bevel direction on the tracheal tube pathway during nasotracheal intubation: A randomised trial.

BACKGROUND: For nasotracheal intubation, the nasal pathway between the inferior turbinate and hard palate (lower pathway) is preferred for patient safety. However, selecting the lower pathway can be challenging because passage of the tube through the nasal pathway is usually performed blindly. OBJECTIVES: We investigated whether facing the bevel of the tracheal tube in the cephalad direction of the patient could help in advancing the tracheal tube through the lower pathway during nasotracheal intubation. DESIGN: A randomised, blinded trial. SETTING: SMG-SNU Boramae Medical Center, Seoul National University College of Medicine, Seoul, Korea from January 2019 to March 2020. PATIENTS: Sixty-eight adult patients undergoing oromaxillary surgeries were enrolled in this study. INTERVENTIONS: Patients were randomly allocated to undergo nasotracheal intubation with the bevel of the tube facing the cephalad direction (intervention group) or to the left (conventional group). MAIN OUTCOME MEASURES: The effects of bevel direction on the pathway of the tube in the nasal cavity, and the incidence of epistaxis were evaluated by fibreoptic bronchoscopy. RESULTS: The success rate of the tracheal tube passing through the lower pathway was significantly higher in the intervention group than the conventional group (79.4 vs. 55.9%, relative risk 1.421, 95% CI 1.007 to 2.005, P = 0.038). The incidence of epistaxis was also lower in the intervention group than in the conventional group (41.2 vs. 73.5%, relative risk 0.560, 95% CI 0.357 to 0.878, P = 0.007). CONCLUSIONS: Facing the bevel of the tracheal tube in the cephalad direction of the patient facilitated selection of the lower pathway and reduced the incidence of epistaxis during nasotracheal intubation in patients undergoing oromaxillary surgery. TRIAL REGISTRATION: ClinicalTrial.gov, NCT03740620.

Ultrasound assessment of gastric content in fasted patients before elective laparoscopic cholecystectomy: a prospective observational single-cohort study.

BACKGROUND: Patients with symptomatic gallbladder diseases exhibit delayed gastric emptying. We evaluated the residual gastric content in fasted patients scheduled for elective laparoscopic cholecystectomy because of symptomatic gallbladder disease using ultrasonography. METHODS: This prospective observational single-cohort study was approved by the Institutional Review Board, and written informed consent was obtained from all included patients. Before anesthesia induction, the gastric antrum was examined by ultrasound. Once the presence of solid content was excluded, the patients were classified using a three-point grading system (grade 0: no fluid; grade 1: fluid in the right lateral decubitus position; grade 2: fluid in both the supine and right lateral decubitus positions), and the fluid volume was measured. A stomach was considered empty if it had no contents or ≤ 1.5 mL·kg-1 of fluid, and was considered full if solid content or > 1.5 mL·kg-1 of fluid was detected. RESULTS: Among 138 patients, 18 patients (13%) presented with a full stomach, 12 (9%) of whom had solid content, and six (4%) of whom had >1.5 mL·kg-1 of fluid in their stomach. Among the remaining 120 patients with an empty stomach, 65 patients presented with a grade 0 antrum, and 55 patients with a grade 1 or 2 antrum with ≤ 1.5 mL·kg-1 of fluid. CONCLUSION: The gastric ultrasound assessment revealed that 13% of patients scheduled for elective cholecystectomy because of symptomatic gallbladder disease had a full stomach despite following the fasting guidelines. This was higher than the reported incidence of a full stomach among the general surgical population. Further studies are required to delineate the clinical implications of our findings. TRIAL REGISTRATION: www.ClinicalTrials.gov (NCT03259841); registered 4 August, 2017.

RéSUMé: CONTEXTE: Les patients atteints de maladies vésiculaires symptomatiques souffrent de retard de la vidange gastrique. Nous avons évalué par échographie le contenu gastrique résiduel chez des patients à jeun devant subir une cholécystectomie non urgente par laparoscopie en raison de maladie vésiculaire symptomatique. MéTHODE: Cette étude prospective observationnelle sur une cohorte unique a été approuvée par le Comité d'éthique indépendant et le consentement éclairé écrit a été obtenu de tous les patients inclus. Avant l'induction de l'anesthésie, l'antre gastrique a été examiné par échographie. Une fois la présence de solides exclue, les patients ont été catégorisés selon un système de notation de 3 grades (0 : aucun liquide; 1 : liquides détectés en position de décubitus latéral droit; 2 : liquides détectés en décubitus dorsal et en décubitus latéral droit), et le volume liquidien a été mesuré. Un estomac était considéré comme vide s'il n'avait aucun contenu solide et ≤ 1,5 mL·kg−1 de liquides, et considéré comme plein si du contenu solide ou > 1,5 mL·kg−1 de liquides était détecté. RéSULTATS: Parmi 138 patients, 18 (13 %) se sont présentés avec un estomac plein, parmi lesquels 12 (9 %) avaient du contenu solide, et six (4 %) avaient > 1,5 mL·kg−1 de liquides dans l'estomac. Parmi les 120 patients restants avec un estomac vide, 65 présentaient un antre gastrique de grade 0 et 55 présentaient un antre de grade 1 ou 2 avec ≤ 1,5 mL·kg−1 de liquides. CONCLUSION: L'évaluation gastrique par échographie a révélé que 13 % des patients devant subir une cholécystectomie non urgente en raison de maladie vésiculaire symptomatique avaient un estomac plein tout en ayant respecté les directives de jeûne. Ce chiffre était plus élevé que l'incidence rapportée d'estomac plein parmi la population chirurgicale générale. Des études supplémentaires sont nécessaires pour déterminer les implications cliniques de nos résultats. ENREGISTREMENT DE L'éTUDE: www.ClinicalTrials.gov (NCT03259841); enregistrée le 4 août 2017.

A Meta-Analysis on the Effect of Dexamethasone on the Sugammadex Reversal of Rocuronium-Induced Neuromuscular Block.

Sugammadex reverses the rocuronium-induced neuromuscular block by trapping the cyclopentanoperhydrophenanthrene ring of rocuronium. Dexamethasone shares the same steroidal structure with rocuronium. The purpose of this study was to evaluate the influence of dexamethasone on neuromuscular reversal of sugammadex after general anesthesia. Electronic databases were searched to identify all trials investigating the effect of dexamethasone on neuromuscular reversal of sugammadex after general anesthesia. The primary outcome was time for neuromuscular reversal, defined as the time to reach a Train-of-Four (TOF) ratio of 0.9 after sugammadex administration. The secondary outcome was the time to extubation after sugammadex administration. The mean difference (MD) and 95% CI were used for these continuous variables. Six trials were identified; a total of 329 patients were included. The analyses indicated that dexamethasone did not influence the time for neuromuscular reversal of sugammadex (MD -3.28, 95% CI -36.56 to 29.99, p = 0.847) and time to extubation (MD 25.99, 95% CI -4.32 to 56.31, p = 0.093) after general anesthesia. The results indicate that dexamethasone did not influence the neuromuscular reversal of sugammadex in patients after general anesthesia. Therefore, the dexamethasone does not appear to interfere with reversal of neuromuscular blockade with sugammadex in patients undergoing general anesthesia for elective surgery.

Effect of neck extension on the advancement of tracheal tubes from the nasal cavity to the oropharynx in nasotracheal intubation: a randomized controlled trial.

BACKGROUND: Clinicians sometimes encounter resistance in advancing a tracheal tube, which is inserted via a nostril, from the nasal cavity into the oropharynx during nasotracheal intubation. The purpose of this study was to investigate the effect of neck extension on the advancement of tracheal tubes from the nasal cavity into the oropharynx during nasotracheal intubation. METHODS: Patients were randomized to the 'neck extension group (E group)' or 'neutral position group (N group)' for this randomized controlled trial. After induction of anesthesia, a nasal RAE tube was inserted via a nostril. For the E group, an anesthesiologist advanced the tube from the nasal cavity into the oropharynx with the patient's neck extended. For the N group, an anesthesiologist advanced the tube without neck extension. If the tube was successfully advanced into the oropharynx within two attempts by the same maneuver according to the assigned group, the case was defined as 'success.' We compared the success rate of tube advancement between the two groups. RESULTS: Thirty-two patients in the E group and 33 in the N group completed the trial. The success rate of tube passage during the first two attempts was significantly higher in the E group than in the N group (93.8% vs. 60.6%; odds ratio = 9.75, 95% CI = [1.98, 47.94], p = 0.002). CONCLUSION: Neck extension during tube advancement from the nasal cavity to the oropharynx before laryngoscopy could be helpful in nasotracheal intubation. TRIAL REGISTRATION: ClinicalTrials.gov Identifier NCT03377114 , registered on 13 December 2017.

A prospective, randomized comparison of the LMA-protector™ and i-gel™ in paralyzed, anesthetized patients.

BACKGROUND: In the present study, we compare the LMA-Protector™ and the i-gel™ in terms of adequacy of the airway seal, insertion time, ease and accuracy of insertion, and the incidence of postoperative sore throat. METHODS: In 110 anesthetized and paralyzed adult patients, the i-gel™ (n = 55) or the LMA-Protector™ (n = 55) was inserted. The primary outcome was airway leak pressure. The secondary outcomes included the first-attempt success rate, insertion time, ease and accuracy of the device insertion, ease of gastric tube placement, blood staining on the device after removal, and incidence and severity of postoperative sore throat. RESULTS: The airway leak pressure was higher with the LMA-Protector™ than with the i-gel™ (31 [7] cmH2O vs. 27 [6] cmH2O, respectively; P = 0.016). Insertion time was longer with the LMA-Protector™ than with the i-gel™ (27 [16] sec vs. 19 [16] sec, respectively, P < 0.001), but ease of insertion and the first-attempt success rate were not different between the two groups. The LMA-Protector™ provided a worse fiberoptic view of the vocal cords and more difficult gastric tube insertion than the i-gel™ (both P < 0.001). Blood staining on the device was more frequent with the LMA-Protector™ than with the i-gel™ (P = 0.033). The incidence and severity of postoperative sore throat were not different between the two groups. CONCLUSION: The LMA-Protector™ provided a better airway sealing effect than the i-gel™. However, it required a longer insertion time, provided a worse fiberoptic view of the vocal cords, and caused more mucosal injury compared to the i-gel™. TRIAL REGISTRATION: ClinicalTrials.gov (NCT03078517). Registered prior to patient enrollment, Date of registration: Mar 13, 2017.

Ultrasound assessment of the anatomic landmarks for spinal anesthesia in elderly patients with hip fracture: A prospective observational study.

Tuffier line is a common landmark for spinal anesthesia. The 10th rib line has been suggested as a new landmark to predict the intervertebral levels. We evaluated the accuracy of these 2 anatomic landmarks for identifying the L4-L5 intervertebral space using ultrasonography in elderly patients with hip fracture.Seventy-nine elderly patients scheduled for hip fracture surgery under spinal anesthesia were included. In the lateral decubitus position with the fracture side up, the L4-L5 intervertebral space was identified alternately using Tuffier line, a line drawn between the highest points of both iliac crests, and the 10th rib line. The 10th rib line, an imaginary line that joints the 2 lowest points of the rib cage, passes through the L1-L2 intervertebral space or the body of L2. The L4-L5 intervertebral space was determined by the counting-down method from the 10th rib line. Then, the estimated intervertebral spaces were evaluated using ultrasonography.The L4-L5 intervertebral space was correctly identified in 47 (59%) patients with Tuffier line and 45 (57%) patients with the 10th rib line (P = .87). The estimation ratio related to the intervertebral levels was not different between the 2 landmarks (P = .40). The wrong identifications of intervertebral level with Tuffier line and the 10th rib line was observed in the following order: L3-L4 intervertebral space: 27% vs 24%, L5-S1 intervertebral space: 9% vs 16%, and L2-L3 intervertebral space: 5% vs 3%, respectively.Tuffier line and the 10th rib line may be unreliable to estimate the intervertebral space for spinal anesthesia in elderly patients with hip fracture.

Comparison of standard versus 90° rotation technique for LMA Flexible™ insertion: a randomized controlled trial.

BACKGROUND: Insertion of a flexible laryngeal mask airway (LMA Flexible) is known to be more difficult than that of a conventional laryngeal mask airway. The 90° rotation technique can improve the success rate with a conventional laryngeal mask airway but its effect with the LMA Flexible remains unknown. We assessed whether the 90° rotation technique increased the first-attempt success rate of LMA Flexible insertion versus the standard technique. METHODS: In total, 129 female patients undergoing breast surgery were analyzed. The primary endpoint was success at the first attempt. The insertion time, number of trials, number of manipulations required, and oropharyngeal leak pressure were also evaluated. Heart rate and mean blood pressure were recorded 1 min before and 1 min after insertion. Blood staining on the LMA Flexible after removal and postoperative sore throat were checked. RESULTS: The first-attempt success rates were comparable between the groups (93% vs. 98.3%, P = .20). The insertion time, number of trials and manipulations, hemodynamic variables, and complications, such as blood staining and sore throat, did not differ between the groups. CONCLUSIONS: The 90° rotation technique is a good alternative to the standard technique for insertion of the LMA Flexible. TRIAL REGISTRATION: ClinicalTrials.gov ( NCT03028896 ). It was registered retrospectively at Jan 19th, 2017.