Search

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.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.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).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.

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

For safe nasotracheal intubation without middle turbinate injury, the tracheal tube should pass through the lower pathway, which is beneath the inferior turbinate and immediately above the nasal floor of the nostril. The purpose of this study was to assess the influence of nasal tip lifting on the incidence of passing preformed nasal Ring-Adair-Elwyn (RAE) tubes through the lower pathway during nasotracheal intubation.Patients were randomly assigned to a "nasal tip lifting group" or a "neutral group." For patients in the nasal tip lifting group, an investigator pulled the nasal tip in a cephalad direction when inserting a preformed nasal RAE tube into the nostril after induction of anesthesia. For patients in the neutral group, a tube was inserted with the nasal tip in a neutral position. The pathway by which the tube passed in each patient was identified using a fiberscope. The incidence of the tube passing through the lower pathway was compared between the 2 groups. The incidence of epistaxis was also evaluated.Eighty-six patients were enrolled and completed the study protocol. The incidence of the tracheal tube passing through the lower pathway was significantly higher in the nasal tip lifting group (79.1%) than in the neutral group (51.2%) (relative risk, 1.55; 95% confidence interval, 1.11-2.15; P = .007). Although the incidence of epistaxis was not different between the groups (18.6% vs 32.6%; P = .138), it was lower when the tracheal tube passed nasal cavity through the lower pathway (14.3%) than the upper pathway (46.7%), regardless of the randomized group with adjustment for potentially confounding variables (odds ratio, 0.19; 95% confidence interval, 0.07-0.54; P = .002).The nasal tip lifting maneuver helped to guide preformed nasal RAE tubes into the lower pathway during nasotracheal intubation.

In 41 healthy volunteers, we investigated the cross-sectional area (CSA) of the subclavian vein (SCV) in the following head positions: neutral and 30° head rotation toward the contralateral or ipsilateral sides. Significant differences were observed in the CSA of the SCV at 3 different head positions: contralateral 30° versus neutral, -0.05 cm (95% confidence interval, -0.08 to -0.03); contralateral 30° versus ipsilateral 30°, -0.15 cm (-0.19 to -0.12); neutral versus ipsilateral 30°, -0.10 cm (-0.13 to -0.07); all Pcorrected< .001). For SCV catheterization, 30° head rotation to the ipsilateral side provided significant improvements in the CSA compared with the other head positions.

BACKGROUND Although minor, a sore throat after endotracheal intubation can adversely affect patient satisfaction and postoperative function. We compared the effects of 2 endotracheal tube cuff shapes on postoperative sore throat. METHODS One hundred ninety-one adult patients were included in the study. After induction of anesthesia, patients were randomized to endotracheal intubation with a conventional cylindrical-shaped cuff (Group C, n = 95) or a tapered-shaped cuff (Group T, n = 96). The number of intubation attempts, time to achieve endotracheal intubation, and duration of intubation were recorded. Postoperative sore throat and hoarseness were assessed at 1, 6, and 24 hours after surgery. A 0- to 100-mm visual analog scale was used to evaluate sore throat severity. The primary outcome of this study was the overall cumulative incidence of postoperative sore throat in the 24-hour evaluation period in the 2 groups. RESULTS The overall incidence of postoperative sore throat was lower in Group T than in Group C (32% vs 54%; relative risk = 0.60, 95% confidence interval: 0.43-0.85; P= .003). At 6 hours after surgery, the incidence and severity of postoperative sore throat were lower in Group T compared with Group C (Bonferroni-corrected P< .05). Postoperative hoarseness also occurred less frequently in Group T compared with Group C (19% vs 37%; P= .006). Group T had lower incidence of hoarseness at 1 and 6 hours after surgery than Group C (Bonferroni-corrected P< .05), but the incidence of hoarseness at 24 hours after surgery did not differ between groups. CONCLUSIONS Intubation using an endotracheal tube with a tapered cuff reduced the incidence and severity of postoperative sore throat and the incidence of hoarseness after surgery when compared with an endotracheal tube with a cylindrical cuff.