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.

Comparison of the effect of sevoflurane and propofol on the optic nerve sheath diameter in patients undergoing middle ear surgery.

PURPOSE: During middle ear surgery, the patient's head is turned away from the surgical site, which may increase the intracranial pressure. Anesthetics also affect the intracranial pressure. The optic nerve sheath diameter (ONSD) measured using ultrasonography is a reliable marker for estimating the intracranial pressure. This aim of this study was to investigate the effect of sevoflurane and propofol on the ONSD in patients undergoing middle ear surgery. METHODS: Fifty-eight adult patients were randomized into sevoflurane group (n = 29) or propofol group (n = 29). The ONSD was measured using ultrasound after anesthesia induction before head rotation (T0), and at the end of surgery (T1). The occurrence and severity of postoperative nausea and vomiting (PONV) were assessed 1 h after the surgery. RESULTS: The ONSD was significantly increased from T0 to T1 in the sevoflurane group [4.3 (0.5) mm vs. 4.9 (0.6) mm, respectively; P < 0.001] and the propofol group [4.2 (0.3) mm vs. 4.8 (0.5) mm, respectively; P < 0.001]. No significant difference was observed in the ONSD at T0 (P = 0.267) and T1 (P = 0.384) between the two groups. The change in the ONSD from T0 to T1 was not significantly different between the sevoflurane and propofol groups [0.6 (0.4) mm vs. 0.6 (0.3) mm, respectively; P = 0.972]. The occurrence and severity of PONV was not significantly different between the sevoflurane and propofol groups (18% vs. 0%, respectively; P = 0.053). CONCLUSION: The ONSD was significantly increased during middle ear surgery. No significant difference was observed in the amount of ONSD increase between the sevoflurane and propofol groups.

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.

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.

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.

Comparison of dynamic needle tip positioning versus conventional long-axis in-plane techniques for ultrasound-guided internal jugular venous catheterization: a randomized controlled trial.

BACKGROUND: Continuous visualization of the needle tip is essential for successful ultrasound-guided central venous catheterization, and the dynamic needle tip positioning (DNTP) technique enables it. The aim of this randomized, dual-center trial was to compare the first-attempt success rate of ultrasound-guided internal jugular catheterization between the DNTP and conventional long-axis in-plane (LAX-IP) techniques. METHODS: Patients undergoing cardiac surgery at two tertiary teaching hospitals were randomly allocated to either the DNTP or LAX-IP group. Internal jugular venous catheterization was performed by four anesthesiologists. The primary outcome was the first-attempt success rate of central venous catheterization. Procedural time and complications related to catheterization were compared as secondary outcomes. RESULTS: In total, 142 patients were analysed. The first-attempt success rate was significantly higher in the DNTP group (59/72, 81.9%) than in the LAX-IP group (46/70, 65.7%; odds ratio, 2.37; 95% confidence interval 1.09-5.15; P=0.028). In addition, the needle was redirected less frequently in the DNTP group than the LAX-IP group (P=0.026). Procedural time was comparable between the groups. No significant differences were observed in complications related to catheterization, including posterior wall puncture, carotid artery puncture, or hematoma. CONCLUSIONS: The DNTP technique resulted in a significantly higher success rate on the first attempt at internal jugular venous catheterization and required less frequent redirection of the needle during the procedure than the conventional LAX-IP technique.

Effect of intraoperative neuromuscular blockade on postoperative sore throat and hoarseness in patients undergoing spinal surgery: a prospective observational study.

Intraoperative neuromuscular blockade affects the resting tension between the vocal cords. We assessed the effect of neuromuscular blockade on postoperative sore throat and hoarseness following tracheal intubation in patients undergoing lumbar spinal surgery in the prone position. Altogether, 99 patients were included; 50 patients did not receive neuromuscular blockade, and 49 patients received moderate neuromuscular blockade during the maintenance of anesthesia. Neuromuscular blockade was performed depending on the use of intraoperative neurophysiological monitoring. The number of intubation attempts, time to achieve tracheal intubation, and duration of intubation were recorded accordingly. The incidence and severity of postoperative sore throat and hoarseness was assessed at 1, 6, and 24 h after surgery. The overall cumulative incidence of postoperative sore throat (60% vs. 59%, respectively; P = 1.000) and postoperative hoarseness (68% vs. 61%, respectively; P = 0.532) did not differ between the no neuromuscular blockade and moderate neuromuscular blockade. The incidence and severity of postoperative sore throat and hoarseness was also not different between the moderate and no neuromuscular blockade at each time point after surgery. Nevertheless, the incidences of postoperative sore throat and hoarseness were quite high. Further studies investigating strategies to alleviate them are warranted accordingly.

Effect of an endoscopic bite block on one-handed mask ventilation.

PURPOSE: An endoscopic bite block is a device to ensure that the patient's mouth remains wide open during endoscopic procedures. Wide opening of the mouth may facilitate the efficiency of one-handed mask ventilation. We evaluated the effect of an endoscopic bite block on mask ventilation among three ventilation techniques: one-handed ventilation, one-handed ventilation with an endoscopic bite block, and two-handed ventilation. METHODS: Fifty-nine anesthetized and paralyzed patients were included. After induction of anesthesia, one-handed ventilation, one-handed ventilation with an endoscopic bite block and two-handed ventilation were performed in a cross-over, randomized order. The primary outcome was the expiratory tidal volume (mL/kg of predicted body weight). Secondary outcomes included minute ventilation (L/min) and the incidence of inadequate mask ventilation or dead space ventilation. RESULTS: The expiratory tidal volume of one-handed ventilation with an endoscopic bite block was significantly improved when compared with that of one-handed ventilation (8.2 [6.8-10.2] mL/kg vs. 7.1 [4.5-9.0] mL/kg, respectively, difference = 1.1 mL/kg; 95% CI 0.8-2.4; P < 0.001), and was comparable to that of two-handed ventilation (8.9 [6.3-11.5] mL/kg; difference = 0.7 mL/kg; 95% CI - 0.7 to 1.5; P = 0.432). Minute ventilation was also significantly improved in one-handed ventilation with an endoscopic bite block compared with that in one-handed ventilation (7.4 [6.3-8.6] L/min vs. 6.7 [4.2-7.9] L/min, respectively, difference = 0.7 L/min; 95% CI 0.6-2.0; P < 0.001), and was comparable to that of two-handed ventilation (7.7 [6.5-9.5] L/min; difference = 0.3 L/min; 95% CI - 0.5 to 1.4; P = 0.390). The incidence of inadequate ventilation or dead space ventilation was not different among the ventilation techniques (P = 0.080). CONCLUSION: The use of an endoscopic bite block improved one-handed mask ventilation, showing comparable efficacy with two-handed mask ventilation.

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.

A Randomized Controlled Trial Comparing the Utility of Lighted Stylet and GlideScope for Double-Lumen Endobronchial Intubation.

OBJECTIVE: To compare GlideScope and lighted stylet for double-lumen endobronchial tube (DLT) intubation in terms of intubation time, success rate of first attempt at intubation, difficulty in DLT advancement toward the glottis, and postoperative sore throat and hoarseness. DESIGN: A prospective, randomized study. SETTING: Medical center governed by a university hostpial. PARTICIPANTS: Sixty-two adult patients undergoing thoracic surgery using DLT intubation. INTERVENTION: After the induction of anesthesia, DLT intubation was performed using GlideScope (n = 32) or lighted stylet (n = 32). MEASUREMENTS AND MAIN RESULTS: Number of intubation attempts, difficulty of DLT advancement toward the glottis, time taken for DLT intubation, and the incidence and severity of postoperative sore throat and hoarseness at 1 and 24 hours after surgery were evaluated. Time taken for DLT intubation was shorter in the lighted stylet group compared with the GlideScope group (30 [28-32] s v 45 [38-53] s, median [interquartile range], respectively; p < 0.001). DLT advancement toward the glottis was easier in the lighted stylet group than in the GlideScope group (p = 0.016). The success rate of DLT intubation in the first attempt (96.9% v 90.6% for lighted stylet and GlideScope, respectively), and the incidence and severity of postoperative sore throat and hoarseness were not different between the two groups. CONCLUSIONS: The use of lighted stylet allowed easier advancement of the DLT toward the glottis in the oropharyngeal space and reduced time for achieving DLT intubation compared with GlideScope.

Effect of the Macintosh curved blade size on direct laryngoscopic view in edentulous patients.

OBJECTIVE: In the present study, we compared the laryngoscopic view depending on the size of the Macintosh curved blade in edentulous patients. METHODS: Thirty-five edentulous adult patients scheduled for elective surgery were included in the study. After induction of anesthesia, two direct laryngoscopies were performed alternately using a standard-sized Macintosh curved blade (No. 4 for men and No. 3 for women) and smaller-sized Macintosh curved blade (No. 3 for men and No. 2 for women). During direct laryngoscopy with each blade, two digital photographs of the lateral view were taken when the blade tip was placed in the valleculae; the laryngoscope was lifted to achieve the best laryngeal view. Then, the best laryngeal views were assessed using the percentage of glottic opening (POGO) score. On the photographs of the lateral view of direct laryngoscopy, the angles between the line extending along the laryngoscopic handle and the horizontal line were measured. RESULTS: The POGO score was improved with the smaller-sized blade compared with the standard-sized blade (87.3% [11.8%] vs. 71.3% [20.0%], P<0.001, respectively). The angles between the laryngoscopic handle and the horizontal line were greater with the smaller-sized blade compared to the standard-sized blade when the blade tip was placed on the valleculae and when the laryngoscope was lifted to achieve the best laryngeal view (both P<0.001). CONCLUSIONS: Compared to a standard-sized Macintosh blade, a smaller-sized Macintosh curved blade improved the laryngeal exposure in edentulous patients.

Effect of Endotracheal Tube Cuff Shape on Postoperative Sore Throat After Endotracheal Intubation.

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.

Randomized comparison of three guidewire insertion depths on incidence of arrhythmia during central venous catheterization.

OBJECTIVE: Guidewire-induced arrhythmias that occur during central venous catheterization can progress to malignant arrhythmias in rare cases. This study compared the incidence of arrhythmia during central venous catheterization using three different depths of guidewire insertion into the right internal jugular vein. METHODS: Sixty-nine patients undergoing elective surgery requiring central venous catheterization through the right internal jugular vein were enrolled in this double-blind, prospective, randomized, and controlled study. Patients were randomly allocated to receive guidewire insertions to 15cm, 17.5cm, or 20cm before tissue dilation. Arrhythmic episodes were then monitored during dilation of the soft tissue. RESULTS: A total of 29 patients (42%) experienced arrhythmic episodes during tissue dilation. The guidewire-induced arrhythmia rates of the 15cm group, 17.5cm group, and 20cm group were 0.26 (95% confidence interval [CI]=0.10, 0.48), 0.35 (95% CI=0.16, 0.57), and 0.65 (95% CI=0.43, 0.84), respectively. The incidence of arrhythmic episodes was higher in the 20cm group than in the 15cm (odds ratio [OR]=5.31; 95% CI=1.50, 18.84) and 17.5cm (OR =3.52; 95% CI=1.05, 11.83) groups. There was no significant difference in arrhythmia rates between the 15cm group and 17.5cm group (p=0.542). CONCLUSIONS: During central venous catheterization through the right internal jugular vein, inserting guidewires to depths of 15 or 17.5cm before tissue dilation reduced the incidence of arrhythmic episodes compared to a depth of 20cm.

A comparison of single-handed chin lift and two-handed jaw thrust for tracheal intubation using a lightwand.

PURPOSE: In the present study, we evaluated the effects of single-handed chin lift and two-handed jaw thrust on lightwand-guided intubation and postoperative sore throat. METHODS: Sixty adult patients were included in the study. After induction of anesthesia, intubation was performed using a lightwand under single-handed chin lift or two-handed jaw thrust. In the single-handed chin lift group, the lightwand was inserted with the right hand after the mandible was lifted by placing the thumb of the left hand into the mouth. In the two-handed jaw thrust group, the lightwand was inserted while jaw thrust was achieved by an assistant using two hands. Lightwand search time, number of intubation attempts, and time to achieve intubation were assessed. Heart rate and mean arterial pressure were measured before and after intubation. Postoperative sore throat was evaluated at 1 and 24 h after surgery. RESULTS: Lightwand search time was significantly shorter in the two-handed jaw thrust group compared to the single-handed chin lift group (7.2 ± 4.6 vs. 12.1 ± 9.1 s, respectively; p = 0.016). The two-handed jaw thrust group had shorter intubation time than the single-handed chin lift group (21.0 ± 6.6 vs. 27.9 ± 9.9 s, respectively; p = 0.004). The number of intubation attempts and hemodynamic changes during intubation were similar between the two groups. The incidence and severity of postoperative sore throat were lower at 24 h after surgery in the two-handed jaw thrust group compared with the single-handed chin lift group (p = 0.011). CONCLUSIONS: The two-handed jaw thrust facilitated lightwand-guided intubation, and reduced the incidence and severity of postoperative sore throat compared to the single-handed chin lift.

A comparison of direct laryngoscopic views in different head and neck positions in edentulous patients.

OBJECTIVE: Proper head and neck positioning is an important factor for successful direct laryngoscopy, and the optimum position in edentulous patients is unclear. We compared direct laryngoscopic views in simple head extension, sniffing, and elevated sniffing positions in edentulous patients. METHODS: Eighteen adult edentulous patients scheduled for elective surgery were included in the study. After induction of anesthesia, the laryngeal view was assessed under direct laryngoscopy using the percentage of glottic opening (POGO) score in 3 different head and neck positions in a randomized order: simple head extension without a pillow, sniffing position with a pillow of 7 cm, and elevated sniffing position with a pillow of 10 cm. After assessment of the laryngeal views, tracheal intubation was performed. RESULTS: A significant difference was observed in the laryngeal views assessed at the 3 head positions (P= .001). The POGO scores (mean [SD]) in the sniffing position (78.9% [19.7%]) and elevated sniffing position (72.6% [20.8%]) were significantly improved compared to that with simple head extension (53.8% [25.9%]) (P= .001, respectively). The sniffing position provided the best laryngeal view. The mean POGO scores were higher in the sniffing position than the elevated sniffing position, but no significant difference was observed between these 2 positions (P= .268). CONCLUSIONS: The sniffing and elevated sniffing positions provide better laryngeal views during direct laryngoscopy compared to simple head extension in edentulous patients.