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OBJECTIVES We investigated the safety and efficacy of continuous intraoperative neuromonitoring (CIONM) during video-assisted thoracoscopic lobectomy for left lung cancer in preventing recurrent laryngeal nerve injury. METHODS From August 2015 to March 2020, 22 patients with left lung cancer without CIONM (unmonitored) and 20 patients with left lung cancer with CIONM underwent thoracoscopic lobectomy with complete mediastinal lymph node dissection including 4L dissection. Clinical outcomes from these 2 groups were compared. RESULTS The incidence of 4L metastasis was 7.14% (3 patients). There was no significant difference in the total number of dissected 4L lymph nodes between the 2 groups (3.23 ± 2.2 in the unmonitored group, 3.95 ± 2.0 in the CIONM group). CIONM was successful in all of the cases. There was no significant difference in the incidence of postoperative vocal cord palsy (22.7% in the unmonitored group, 20% in the CIONM group, P = 1.000). All of the 5 patients (100%) had permanent vocal cord palsy in the unmonitored group. Although statistically insignificant, 75% (3 patients) had total recovery of the vocal cord function, with only 1 patient remaining in permanent vocal cord palsy in the CIONM group. CONCLUSIONS CIONM was safe and efficient. CIONM might be helpful to avoid permanent vocal cord palsy by immediately warning the surgeon about impending nerve injury, so the surgeon can stop delivering further injury to the recurrent laryngeal nerve.

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.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.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).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.

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.

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 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 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.

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.

This prospective, randomized controlled trial evaluated the effect of neostigmine for intraoperative neuromonitoring (IONM) during thyroid surgery. Forty subjects undergoing thyroidectomy with IONM, randomized into neostigmine administration after tracheal intubation (Group N, n = 20) or control treatment with normal saline (Group C, n = 20), completed the trial. Electromyography amplitudes of the vagus nerve (V1) were recorded before thyroid dissection. The time from the initial V1 signal check to successful V1 stimulation was recorded. In Group N, all the patients had a successful V1 signal at the first check, whereas ten (50%) patients in Group C had a time delay between the initial V1 check and successful V1 (p p = 0.003). In Groups N and C, the mean V1 amplitudes were 962.2 ± 434.5 μV vs. 802.3 ± 382.7 μV (p = 0.225), respectively, and the mean R1 amplitudes were 1240.0 ± 836.5 μV vs. 1023.4 ± 455.8 μV (p = 0.316), respectively. There was one bucking event in Group N. In conclusion, neostigmine administration immediately after tracheal intubation can be useful to reverse neuromuscular blockade for successful IONM in thyroid surgeries.

Background The cross-sectional area of the subclavian vein (csSCV) is a crucial factor in the successful catheterization of the subclavian vein. This randomized controlled study investigated the effects of the csSCV on landmark-based subclavian vein catheterization. Methods This study was performed using a two-stage protocol. During stage I, the csSCV was measured in 17 patients placed in the supine, 20° ipsilateral tilt, and 20° contralateral tilt positions in a random order. During stage II, landmark-based subclavian vein catheterization was randomly performed in patients placed in either the supine (group S, n = 107) or the ipsilateral tilt (group I, n = 109) position. The primary outcome measure was the csSCV in stage I and the primary venipuncture success rate in stage II. Secondary outcome measures were the time to successful venipuncture, the total catheterization time, the first-pass success rate, and the incidence of mechanical complications during catheterization. Results The csSCV was significantly larger in the ipsilateral tilt than in either the supine or contralateral tilt position (1.01 ± 0.35 vs. 0.84 ± 0.32 and 0.51 ± 0.26 cm2, P = .006 and P = .344). There were also no significant differences in the secondary outcome measures of the two groups. Conclusions The csSCV was significantly larger in patients placed in the ipsilateral tilt than in the supine position, but the difference did not result in better clinical performance of landmark-based subclavian vein catheterization. Trial registration NCT03296735 for stage I (ClinicalTrials.gov, September 28, 2017) and NCT03303274 for stage II (ClinicalTrials.gov, October 6, 2017).

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.

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.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·kgAmong 138 patients, 18 patients (13%) presented with a full stomach, 12 (9%) of whom had solid content, and six (4%) of whom had1.5 mL·kgThe 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.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

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. 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. 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

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

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

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 Conclusions Ipsilateral 30° head rotation, neutral shoulder position, and Trendelenburg position significantly enhanced the CSA of the SCV in obese participants.

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.

We applied continuous intraoperative neuromonitoring (CIONM) during video-assisted thoracoscopic surgery (VATS) lobectomy for left lung cancer and evaluated its safety and usefulness. An electrode was attached to a double-lumen tube, and placed at vocal cord level to detect the EMG signal evoked by vocal cord movement. Before 4 L lymph node dissection, an automatic periodic stimulation device was applied to the vagus nerve to stimulate vagus nerve continuously. Surgery was suspended if the amplitude decreased lower than the threshold and was resumed when the amplitude recovered. Ten patients (6 male, 4 female) were enrolled. CIONM was successfully performed in all patients without technical failure, and there was no hemodynamic instability. Amplitude decreased below the threshold in four patients. One patient did not recover amplitude and experienced transient vocal cord palsy. In the three other patients, the amplitude recovered above the threshold and no vocal cord palsy occurred. The six patients who did not exhibit amplitude decrease experienced no vocal cord palsy. Our results suggest that CIONM may be applied safely for VATS left lobectomy and may be used to predict postoperative vocal cord function. This approach may be helpful to prevent RLN injury during VATS left lobectomy.

Background We analyzed the influence of anesthesia methods on surgical outcomes and renal function in retrograde intrarenal surgery (RIRS) in a prospective, randomized controlled study. Methods Seventy patients who underwent RIRS from September 2015 to February 2017 were randomly allocated to general anesthesia (GA) or spinal anesthesia (SA) groups. Renal function was assessed using estimated glomerular filtration rate, and separate renal function was evaluated using nuclear medicine tests. Maneuverability and accessibility were evaluated after every surgery. All procedures were performed by a single experienced surgeon (SY Cho). Results Stone-free rate was higher in the GA (92.3%, 36 of 39) than the SA (71.0%, 22 of 31) (P = 0.019) group. Pain score was higher in the GA than in the SA group on the first postoperative morning (P = 0.025), but pain scores of the two groups were similar before discharge (P = 0.560). There were no differences in the changes of serum creatinine level (P = 0.792) and changes of estimated glomerular filtration rate (P = 0.807). Differences of separate renal function between operative and contralateral site increased significantly in patients under GA than under SA at postoperative 3 months (P = 0.014). Maneuverability and accessibility were better in SA with sedation than GA (P Conclusions RIRS under SA showed advantages in renal function change using renogram at postoperative 3 months and in lower pain score on the first postoperative morning. Performance of operator under SA was worse than that under GA and significantly improved with sedation. RIRS under SA showed advantages in lower pain score at postoperative first day. Trial registration Clinicaltrials.gov ID is NCT03957109, and registration date is 17th May 2019. This study was retrospectively registered.

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.A prospective, randomized study.Medical center governed by a university hostpial.Sixty-two adult patients undergoing thoracic surgery using DLT intubation.After the induction of anesthesia, DLT intubation was performed using GlideScope (n = 32) or lighted stylet (n = 32).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; p0.001). 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.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.

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 15 cm, 17.5 cm, or 20 cm 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 15 cm group, 17.5 cm group, and 20 cm 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 20 cm group than in the 15 cm (odds ratio [OR] = 5.31; 95% CI = 1.50, 18.84) and 17.5 cm (OR = 3.52; 95% CI = 1.05, 11.83) groups. There was no significant difference in arrhythmia rates between the 15 cm group and 17.5 cm group (p = 0.542). Conclusions During central venous catheterization through the right internal jugular vein, inserting guidewires to depths of 15 or 17.5 cm before tissue dilation reduced the incidence of arrhythmic episodes compared to a depth of 20 cm.

Central obesity may be related to the spread of spinal anesthesia in female patients. Fifty-seven female patients undergoing spinal anesthesia were allocated to either the central obesity or noncentral obesity group. After induction of spinal anesthesia, maximal sensory blockade (primary outcome), time for maximal sensory block, maximum motor block, time to maximum motor block, time to L2 regression, and time to Bromage scale 0 were evaluated. Multiple linear regression analyses showed that maximal sensory blockade was related to central obesity (P = .004). Central obesity is related to a more extensive spread of spinal anesthesia in female patients.

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. 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. 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). Neck extension during tube advancement from the nasal cavity to the oropharynx before laryngoscopy could be helpful in nasotracheal intubation. ClinicalTrials.gov Identifier NCT03377114 , registered on 13 December 2017.

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

Background Various interventions to reduce postreperfusion syndrome during liver transplantation have been explored, but the effect of volatile anesthetics used during liver transplantation on the incidence of postreperfusion syndrome has not been evaluated. A randomized controlled trial was performed to compare the incidence of postreperfusion syndrome between 2 commonly used volatile anesthetics, sevoflurane and desflurane. Methods Sixty-two adult liver recipients scheduled for living-donor liver transplantation were randomized to receive either sevoflurane or desflurane for general anesthesia. The incidence of postreperfusion syndrome, use of vasoactive drugs, and postoperative course were compared. The risk factors associated with postreperfusion syndrome were also analyzed. Results There was significantly less postreperfusion syndrome in the sevoflurane group compared to the desflurane group (38.7% vs 77.4%, P = 0.004) and less epinephrine was required in the sevoflurane group than the desflurane group (19.4% vs 45.2%, P = 0.030). Postoperative intensive care unit and hospital length of stay and postoperative course were similar between the groups. Multivariate analysis identified desflurane (compared to sevoflurane) as the only risk factor (odds ratio 7.314, P = 0.001) for reperfusion syndrome. Conclusions When using volatile anesthetics for elective living donor liver transplantation, sevoflurane seems to be a better option than desflurane for reducing the incidence of postreperfusion syndrome.

Objective The aim of this study was to evaluate the effect of jaw thrust on transesophageal echocardiography probe insertion and concomitant oropharyngeal injury. Design A prospective, randomized study Setting Medical center governed by a university hospital Participants Forty-two adult patients undergoing cardiovascular surgery were included. Interventions After the induction of anesthesia, a transesophageal echocardiography probe was inserted using an anterior jaw lift technique (conventional group, n = 21) or a jaw thrust-assisted technique (jaw thrust group, n = 21). Measurements and Main Results The incidence of oropharyngeal injury, number of insertion attempts, blood on the probe tip, and presence of persistent oropharyngeal bleeding were evaluated. In the conventional group, oropharyngeal injury occurred more frequently than in the jaw-thrust group (52.4% v 9.5%, respectively; p = 0.006). Regarding transesophageal echocardiography probe insertion, the conventional group required more attempts than the jaw-thrust group (p = 0.043). The incidence of blood on the probe tip was higher in the conventional group than in the jaw-thrust group (p = 0.020), but the presence of persistent oropharyngeal bleeding was similar between the 2 groups. Conclusions The jaw-thrust maneuver facilitated the insertion of the transesophageal echocardiography probe and reduced concomitant oropharyngeal injury.

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.

BACKGROUND The cricothyroid membrane is the most commonly accessed location for invasive surgical airway. Although the laryngeal handshake method is recommended for identifying the cricothyroid membrane, there is no clinical data regarding the utility of the laryngeal handshake method in cricothyroid membrane identification. The objective of this study was to compare the accuracy of cricothyroid membrane identification between the laryngeal handshake method and simple palpation. METHODS After anaesthesia induction, the otorhinolaryngology resident and anaesthesia resident identified and marked the needle insertion point for cricothyroidotomy using simple palpation and the laryngeal handshake method, respectively. The cricothyroid membrane was confirmed with ultrasonography. Identification was determined successful if the marked point was placed within the longitudinal area of the cricothyroid membrane and within 5 mm from midline transversely. The accuracy of cricothyroid membrane identification using the laryngeal handshake method and simple palpation was compared. RESULTS A total of 123 patients were enrolled. The cricothyroid membrane was correctly identified in 87 (70.7%, 95% confidence interval 61.8-78.6%) patients using the laryngeal handshake method compared to 78 (63.4%, 95% confidence interval 54.3-71.9%) patients using simple palpation (P = .188). The time required to identify the cricothyroid membrane was longer when using the laryngeal handshake method (15 [3-48] seconds vs 10.9 [3-55] seconds, P = .003). CONCLUSION The success rate of identifying the cricothyroid membrane was similar among the anesthesiologists who performed the laryngeal handshake method and also among otorhinolaryngologists who used simple palpation.

In the present study, we compared the laryngoscopic view depending on the size of the Macintosh curved blade in edentulous patients.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.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%], P0.001, 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 P0.001).Compared to a standard-sized Macintosh blade, a smaller-sized Macintosh curved blade improved the laryngeal exposure in edentulous patients.

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 Head fixation can induce hemodynamic instability. Remifentanil is commonly used with propofol for total intravenous anesthesia (TIVA) during neurosurgery. This study investigated the 90% effective concentration (EC90) of remifentanil for blunting of cardiovascular responses to head fixation during neurosurgery via bispectral index (BIS) monitoring. Methods Fifty patients undergoing neurosurgery requiring head fixation were enrolled. This study was performed using the biased coin up-and-down design sequential method (BCD). After tracheal intubation, the effect-site target concentration (Ce) of remifentanil was adjusted to achieve hemodynamic stability and reset to the level preoperatively assigned to each patient, according to the BCD method, approximately 10 min before head fixation. Baseline hemodynamic values were recorded before head fixation. An ineffective response was defined as a case with a > 20% increase in hemodynamic values from baseline. Otherwise, the response was determined to be effective. The EC90 of remifentanil was calculated as a modified isotonic estimator. Results Forty-three patients completed this study. The EC90 of remifentanil for blunting cardiovascular responses to head fixation was estimated to be 6.48 ng/mL (95% CI, 5.94–6.83 ng/mL). Conclusions Adjustment of the Ce of remifentanil to approximately 6.5 ng/mL before head fixation could prevent noxious cardiovascular responses in 90% of neurosurgical ASA I-II patients aged 20 to 65 years old during propofol target-controlled infusion titrated to maintain BIS between 40 and 50. Trial registration ClinicalTrials.gov Identifier NCT01489137, retrospectively registered 5 December 2011.

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.

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. 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. 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). 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.

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.

The correct position of double-lumen tubes (DLTs) is customarily confirmed after tracheal intubation by bronchoscopy with the patient supine on a headrest. However, displacement of DLTs usually occurs during lateral positioning because of neck extension. This study was undertaken to determine whether displacement of DLTs could be minimized during lateral positioning if DLTs were positioned without a headrest.One hundred patients scheduled for thoracic surgery were randomized into two groups (n = 50 each). After tracheal intubation using a headrest, adjustment of DLT position was performed according to group assignment, i.e., either with the headrest in place or without the headrest. Using a bronchoscope, distances from the tracheal opening to the main carina and from the bronchial opening to the left bronchial carina were measured in both the supine and lateral positions.Displacement of DLTs [mean (standard deviation)] during lateral positioning was greater in the headrest group than in the no-headrest group [12.3 (6.5) mm vs 6.8 (5.5) mm, respectively, in the trachea; 11.6 (6.7) mm vs 6.0 (4.6) mm, respectively, in the bronchus; P0.001]. The incidence of significant displacement, defined as10 mm from initial correct position, was greater in the headrest group than in the no-headrest group (64% vs 28%, respectively, in the trachea; 58% vs 20%, respectively, in the bronchus; P0.001).Displacement of DLTs during lateral positioning appears to be caused primarily by extension of the neck. Correct adjustment of DLT position without a headrest in the supine position is an easy and effective method to minimize DLT displacement during lateral positioning.

BACKGROUND: If lung deflation increases the distance from the subclavian vein (SCV) to the pleura and the diameter of the vein, it might decrease the risk of pneumothorax and increase the success rate of subclavian venous cannulation. We evaluated the effect of lung deflation on the distance from the SCV to the pleura (SCV-pleura distance) and on the cross-sectional area (CSA) of the SCV in mechanically ventilated pediatric patients. METHODS: Fifty patients (25 infants younger than 1 year and 25 children aged 1 to 8 years) were placed supine over a shoulder roll, and their lungs were ventilated with a tidal volume of 6 to 7 mL/kg. Lung deflation was achieved by opening the endotracheal tube to the atmosphere. The SCV-pleura distances and the SCV CSAs were measured using ultrasound at the end of inflation and 0, 30, 60, 90, and 120 seconds after lung deflation. A P value

Postreperfusion syndrome (PRS), an acute decrease in blood pressure after reperfusion of the liver graft, occurs frequently during liver transplantation surgery. We supposed that the activation of the kallikrein-kinin system leading to extensive systemic vasodilatation was a possible cause. The effect of pretreatment with nafamostat mesilate (NM), a broad spectrum serine protease inhibitor, on the occurrence of PRS was evaluated. Sixty-two adult liver recipients were randomized to receive an intravenous bolus of either 0.02 mg/kg of NM (NM group, n = 31) or an equal volume of normal saline (control group, n = 31) just before reperfusion of the liver graft. Occurrence of PRS and intraoperative use of vasoactive drugs were compared between the two groups. Postoperative recovery was also compared. PRS was significantly less frequent (48% vs. 81%, p = 0.016) requiring less vasopressors in the NM group compared to the control group. The NM group also showed faster recovery of the mean arterial pressure. Perioperative laboratory values were similar between the two groups. Pretreatment with 0.02 mg/kg of NM immediately before reperfusion decreases the frequency of PRS and vasopressor requirements during the reperfusion period in liver transplantation.

BACKGROUND: For facilitation of femoral venous cannulation, the larger cross-sectional area (CSA) of the vein is helpful and can be achieved by inguinal compression, Valsalva maneuver, or the reverse Trendelenburg position. In this study, we evaluated these methods using ultrasonography in children. METHODS: Ultrasound was used to measure the CSA of the common femoral vein of 50 anesthetized pediatric patients (Group L: 25 patients more than 2 yr, Group S: 25 patients younger than 2 yr). The following six measurements of the CSA of the femoral vein were made: 1) in the supine position (control), 2) with digital compression above the inguinal ligament, 3) in the Trendelenburg position 15 degrees , 4) in the Trendelenburg position 15 degrees plus inguinal compression, 5) with Valsalva maneuver, and 6) in the reverse Trendelenburg position 15 degrees . We defined 20% change of the CSA as clinically significant. RESULTS: Inguinal compression increased the CSA of the femoral vein by 40% in Group L and by 57% in Group S (each P < 0.001). Inguinal compression during the Trendelenburg position also increased the CSA by 43% in Group L and by 73% in Group S (each P < 0.001). Valsalva maneuver for increasing the CSA of the femoral vein was more effective in Group S (increased by 35%) than in Group L (by 19%). The changes in the CSA were not clinically significant during the Trendelenburg position or the reverse Trendelenburg position. CONCLUSIONS: Inguinal compression effectively increases the CSA of the femoral vein and its effect is also prominent in the Trendelenburg position. Valsalva maneuver is more effective in small children. Gravitational position changes have little effect on the size of the femoral vein in children.

Inexperienced physicians frequently have difficulty performing nasal fiberoptic intubation. A pre-inserted tracheal tube of the appropriate length allows an excellent view of the laryngeal opening. The purpose of this study was to determine the ideal length of a pre-inserted tracheal tube for nasal fiberoptic intubation and to investigate if it could be predicted from easily measureable patient parameters. This was an observational study in which data on adult patients (n = 150) requiring nasal intubation were collected and analyzed by stepwise regression. During the pre-anesthesia examination, a right-angled gauge was used to measure the distance from the mid-point of the lateral border of the nares to the tragus of the ear (NT distance) and to the mandibular angle (NM distance). The distance from the tragus to the mandibular angle (TM distance) was also measured. The age, sex, height, and weight of each patient were recorded. After induction of anesthesia, the minimum and maximum lengths of the pre-inserted tracheal tube that provided an excellent view of laryngeal opening during nasal fiberoptic intubation were measured. The optimal length was calculated, and an equation was derived through stepwise regression analysis. The optimal length for each patient could be reliably predicted using the equation (distances in cm, weight in kg): optimal length (cm) = 1.952 + 0.051 × height (cm) + 0.354 × NM distance (cm) − 0.011 × weight (kg) (r 2 = 0.460, P

We hypothesized that the assisted maintenance of head extension would reduce the frequency of direct contact between the laryngoscope blade and the maxillary incisors during tracheal intubation.Sixty-eight patients undergoing elective surgical procedures under general anesthesia were enrolled in this prospective, randomized, controlled crossover study. A single experienced anesthesiologist performed the simulated tracheal intubations with a classic Macintosh laryngoscope. After reaching the sniffing position during direct laryngoscopy, tracheal intubations with and without maintaining the head extension (by an assistant) were simulated twice in each patient in random order. The occurrence of dental contact with the laryngoscope blade was recorded during the simulated tracheal intubation. The distance between the laryngoscopic blade and maxillary central incisors was assessed using a digital caliper. The angle of head extension and the glottic view were also evaluated.The frequency of dental contact was lower with the assisted head extension than without it (25/68 [37%] vs 67/68 [99%], P.001). The blade-to-tooth distance was longer with assistance than without it (1.8 ± 1.9 [0-8] mm vs 0.0 ± 0.1 [0-1] mm, P.001). The angle of head extension was greater with assistance than without it (26.6° ± 5.8° [6.0°-37.4°] vs 19.9° ± 5.4° [3.4°-31.8°], P.001). No significant difference was observed between 2 simulated tracheal intubations with regard to the glottic views.The assisted maintenance of head extension during the simulation of tracheal intubation reduced the frequency of dental contact with the laryngoscopic blade without compromising the laryngoscopic views. The results of this study suggest that assisted head extension during tracheal intubation may reduce the possibility of unexpected dental injury.

Background: Myocardial injury is associated with an adverse outcome after off-pump coronary artery bypass graft surgery (OPCAB). The authors conducted a randomized controlled trial to evaluate whether remote ischemic preconditioning (RIPC) with remote ischemic postconditioning (RIPostC) reduces myocardial injury in patients undergoing OPCAB. Methods and Results: Seventy patients scheduled for OPCAB were randomly assigned to an RIPC+RIPostC group (n=35) or a control group (n=35). In the RIPC+RIPostC group, 4 cycles of 5-min ischemia and 5-min reperfusion were done on a lower limb before anastomoses (RIPC) and after anastomoses (RIPostC). RIPC+RIPostC significantly reduced postoperative serum troponin I levels (P=0.001). The area under the curve for postoperative troponin I was 48.7% lower in the RIPC+RIPostC group (median [interquartile range], 21.3h·ng-1·ml-1, 16.5-53.1h·ng-1·ml-1 vs. 41.5h·ng-1·ml-1, 24.6-90.2h·ng-1·ml-1, P=0.020). There was no significant difference in creatinine levels and PaO2/FiO2 ratios between the 2 groups. Conclusions: RIPC+RIPostC by lower limb ischemia decreased postoperative myocardial enzyme elevation by almost half postoperatively in patients undergoing OPCAB. (Circ J 2012; 76: 884-890)

Previous studies have failed to demonstrate that the head-down tilt position confers benefits in hypovolaemic hypotensive patients. The aim of this study was to evaluate the haemodynamic effect and vasopressor use by this position in hypotensive patients after the induction of general anaesthesia.This prospective randomised study involved 98 patients scheduled for elective cardiac surgery and 40 patients (40.1%) developed hypotension after anaesthesia induction. Upon occurrence of hypotension, patients were randomly allocated to the supine (n = 19) or head-down tilt (n = 21) groups (15° head-down tilt position). Blood pressure, heart rate, cardiac index and stroke volume index were recorded at 1-min interval for 10 min from the occurrence of hypotension. Vasopressors were administered to treat hypotension in both groups.No haemodynamic difference was observed between the supine and head-down tilt groups except for SBP changes from baseline at 1 min (-3.98 ± 6.31 vs. 1.84 ± 8.25%, P = 0.004) and 2 min (1.51 ± 14.34 vs. 9.37 ± 10.57%, P = 0.032). The number of vasopressor administrations and percentage of the patients requiring vasopressors in the supine group were greater than that in the head-down tilt group [median 1 (range 1-5) vs. median 0 (range 0-2), P = 0.002, 19/19 (100%) vs. 10/21 (47.6%), P0.001].The head-down tilt position in hypotensive patients following anaesthesia induction reduced vasopressor requirement by almost one third. Minimal haemodynamic effect may be caused by different vasopressor administrations. This result suggests that the head-down tilt position may enable more stable anaesthesia induction in patients undergoing elective coronary artery bypass graft or valvular heart surgeries.

We performed a prospective cohort trial on 220 patients undergoing elective off-pump coronary artery bypass surgery and taking aspirin to evaluate the effect of aspirin resistance on myocardial injury. The patients were divided into aspirin responders and aspirin non-responders by the value of the aspirin reaction units obtained preoperatively using the VerifyNow™ Aspirin Assay. The serum levels of troponin I were measured before surgery and 1, 6, 24, 48 and 72 hr after surgery. In-hospital major adverse cardiac and cerebrovascular events, graft occlusion, the postoperative blood loss and reexploration for bleeding were recorded. Of the 220 patients, 181 aspirin responders (82.3%) and 39 aspirin non-responders (17.7%) were defined. There were no significant differences in troponin I levels (ng/mL) between aspirin responders and aspirin non-responders: preoperative (0.04 ± 0.08 vs 0.03 ± 0.06; P = 0.56), postoperative 1 hr (0.72 ± 0.87 vs 0.86 ± 1.10; P = 0.54), 6 hr (2.92 ± 8.76 vs 1.50 ± 2.40; P = 0.94), 24 hr (4.16 ± 13.44 vs 1.25 ± 1.95; P = 0.52), 48 hr (2.15 ± 7.06 vs 0.65 ± 0.95; P = 0.64) and 72 hr (1.20 ± 4.63 vs 0.38 ± 0.56; P = 0.47). Moreover, no significant differences were observed with regard to in-hospital outcomes. In conclusion, preoperative aspirin resistance does not increase myocardial injury in patients undergoing off-pump coronary artery bypass surgery. Postoperative dual antiplatelet therapy might have protected aspirin resistant patients.