Comparative Analysis of Hemodynamic Responses and Oropharyngeal Complications in Tracheal Intubation: Evaluating Conventional, Video, and Rigid Video Laryngoscopes Under General Anesthesia.

BACKGROUND This study aimed to compare the hemodynamic changes and the occurrence of oropharyngeal complications among patients undergoing tracheal intubation with an ordinary laryngoscope, video laryngoscope, and rigid video laryngoscope under general anesthesia. MATERIAL AND METHODS Patients undergoing elective tracheal intubation under general anesthesia were prospectively enrolled as study subjects. Hemodynamic indicators such as diastolic blood pressure (DBP), systolic blood pressure (SBP), mean arterial pressure (MAP), and heart rate (HR), as well as the incidences of oropharyngeal complications, including dental injury, oral mucosal injury, hoarseness, sore throat, and dysphagia, were observed in the patients of 3 groups (group A: ordinary laryngoscope, group B: video laryngoscope, group C: rigid video laryngoscope). Observations were made after anesthesia induction (T0), immediately after tracheal intubation (T1), and at 5 min after intubation (T2). RESULTS The HR at T1 in group A was significantly higher than in groups B and C (P<0.05). However, the difference in the number of tracheal intubations was statistically significant among the 3 groups (P<0.05); group C exhibited the highest first-time success rate of tracheal intubation (95%), whereas group A had the highest failure rate (5%). Significant differences were also noted in the incidences of oral mucosal injury and sore throat among the groups (P<0.05), with the highest incidence in group A and the lowest in group C. CONCLUSIONS Compared with the ordinary laryngoscope, tracheal intubation using a video or rigid video laryngoscope results in milder hemodynamic impacts and fewer intubation-related complications. The rigid video laryngoscope may be safer and more effective.

Channelled versus nonchannelled Macintosh videolaryngoscope blades in patients with a cervical collar: a randomized controlled noninferiority trial.

PURPOSE: Channelled blades have the advantage of avoiding stylet use and potential airway injury during videolaryngoscopic intubation. Nevertheless, the effectiveness of channelled Macintosh-type blades has not yet been fully established. We sought to assess the utility of channelled Macintosh-type blades for videolaryngoscopic intubation under cervical spine immobilization. METHODS: We conducted a randomized controlled noninferiority trial in neurosurgical patients with a difficult airway simulated by a cervical collar. Videolaryngoscopic intubation with a reinforced tracheal tube was performed using a channelled Macintosh-type blade without a stylet (channelled group, n = 130) or a nonchannelled Macintosh-type blade with a stylet (nonchannelled group, n = 131). The primary outcome was intubation success rate. Secondary outcomes included time to intubation and incidence or severity of intubation-related complications (subglottic, lingual, and dental injuries; bleeding; sore throat; and hoarseness). RESULTS: The initial intubation success rate was 98% and 99% in the channelled and nonchannelled groups, respectively, showing the noninferiority of the channelled group (difference in proportions -0.8%; 95% confidence interval [CI], -4.8% to 2.9%; predefined noninferiority margin, -5%; P = 0.62). Fewer participants in the channelled group had subglottic injuries than in the nonchannelled group (32% [32/100] vs 57% [54/95]; difference in proportions, -25%; 95% CI, -39% to -11%; P < 0.001). There were no significant differences between the two groups in the overall intubation success rate, time to intubation, and incidence or severity of other intubation-related complications. CONCLUSIONS: For videolaryngoscopic intubation in patients with a cervical collar, channelled Macintosh-type blades are an alternative to nonchannelled Macintosh-type blades, with a noninferior initial intubation success rate and a lower incidence of subglottic injury. STUDY REGISTRATION: CRIS.nih.go.kr ( KCT0005186 ); first submitted 29 June 2020.

RéSUMé: OBJECTIF: Les lames avec canal ont l'avantage de ne pas nécessiter l'utilisation d'un stylet et d'ainsi éviter les lésions potentielles des voies aériennes lors de l'intubation vidéolaryngoscopique. Néanmoins, l'efficacité des lames avec canal de type Macintosh n'a pas encore été pleinement établie. Nous avons cherché à évaluer l'utilité des lames avec canal de type Macintosh pour l'intubation vidéolaryngoscopique lorsque le rachis cervical était immobilisé. MéTHODE: Nous avons mené une étude randomisée contrôlée de non-infériorité chez des patient·es de neurochirurgie présentant des voies aériennes difficiles simulées par le port d'un collier cervical. L'intubation vidéolaryngoscopique avec une sonde trachéale renforcée a été réalisée à l'aide d'une lame Macintosh avec canal sans stylet (groupe avec canal, n = 130) ou d'une lame Macintosh sans canal avec stylet (groupe sans canal, n = 131). Le critère d'évaluation principal était le taux de réussite de l'intubation. Les critères d'évaluation secondaires comprenaient le temps d'intubation et l'incidence ou la gravité des complications liées à l'intubation (lésions sous-glottiques, linguales et dentaires, saignements, maux de gorge et enrouement). RéSULTATS: Le taux de réussite initial de l'intubation était de 98 % et 99 % dans les groupes avec et sans canal, respectivement, montrant la non-infériorité du groupe lame avec canal (différence de proportions −0,8 %; intervalle de confiance [IC] à 95 %, −4,8 % à 2,9 %; marge de non-infériorité prédéfinie, −5 %; P = 0,62). Les lésions sous-glottiques ont été moins nombreuses dans le groupe avec canal que dans le groupe sans canal (32 % [32/100] vs 57 % [54/95]; différence de proportions, −25 %; IC 95 %, −39 % à −11 %; P < 0,001). Il n'y avait pas de différences significatives entre les deux groupes en matière de taux global de réussite de l'intubation, de temps d'intubation et d'incidence ou de gravité des autres complications liées à l'intubation. CONCLUSION: Pour l'intubation vidéolaryngoscopique des patient·es portant un collier cervical, les lames avec canal de type Macintosh constituent une alternative aux lames sans canal de type Macintosh, avec un taux de réussite d'intubation initial non inférieur et une incidence plus faible de lésions sous-glottiques. ENREGISTREMENT DE L'éTUDE: CRIS.nih.go.kr ( KCT0005186 ); première soumission le 29 juin 2020.

A multicentre randomised controlled trial of the McGrath™ Mac videolaryngoscope versus conventional laryngoscopy.

Before completion of this study, there was insufficient evidence demonstrating the superiority of videolaryngoscopy compared with direct laryngoscopy for elective tracheal intubation. We hypothesised that using videolaryngoscopy for routine tracheal intubation would result in higher first-pass tracheal intubation success compared with direct laryngoscopy. In this multicentre randomised trial, 2092 adult patients without predicted difficult airway requiring tracheal intubation for elective surgery were allocated randomly to either videolaryngoscopy with a Macintosh blade (McGrath™) or direct laryngoscopy. First-pass tracheal intubation success was higher with the McGrath (987/1053, 94%), compared with direct laryngoscopy (848/1039, 82%); absolute risk reduction (95%CI) was 12.1% (10.9-13.6%). This resulted in a relative risk (95%CI) of unsuccessful tracheal intubation at first attempt of 0.34 (0.26-0.45; p < 0.001) for McGrath compared with direct laryngoscopy. Cormack and Lehane grade ≥ 3 was observed more frequently with direct laryngoscopy (84/1039, 8%) compared with McGrath (8/1053, 0.7%; p < 0.001) No significant difference in tracheal intubation-associated adverse events was observed between groups. This study demonstrates that using McGrath videolaryngoscopy compared with direct laryngoscopy improves first-pass tracheal intubation success in patients having elective surgery. Practitioners may consider using this device as first choice for tracheal intubation.

Use of a Video Laryngoscope to Reduce Complications of Transesophageal Echocardiography Probe Insertion: A Multicenter Randomized Study.

OBJECTIVE: The objective of this multicenter study was to test the hypothesis of whether the use of a video laryngoscope (VL) reduces complications related to transesophageal echocardiography (TEE) probe insertion. DESIGN: A multicenter randomized control study. SETTING: At 5 tertiary care level hospitals. PARTICIPANTS: Three hundred sixty-three adult patients undergoing elective cardiac surgery. INTERVENTIONS: The patients were randomized into 2 groups-the conventional group (C group; n = 177) and the VL group (n = 186) for TEE probe insertion. MEASUREMENTS AND MAIN RESULTS: The primary endpoint of the study was the incidence of oropharyngeal injury, which was defined as blood at the tip of the TEE probe at the end of surgery and/or evidence of injury on VL examination at the end of surgery. The secondary endpoints of the study were the number of attempts required for successful TEE probe insertion and the relation between the esophageal inlet and the larynx. There was a higher incidence of injuries in the C group (n = 26; 14.7%) compared to the VL group (n = 14; 7.5%; p = 0.029). The number of attempts for probe insertion was significantly lower in the VL group (p = 0.0023). The most common relation between the esophageal inlet and the larynx was posterolateral (n = 88; 47%), followed by posterior (n = 77; 41%) and lateral (n = 21;12%). CONCLUSION: The use of VL was associated with a lesser incidence of injury compared to the conventional technique, and its use for this purpose is recommended. The use of VL for probe insertion resulted in fewer attempts compared with the conventional technique. Significant variations do exist in the relation between the esophageal inlet and the larynx, and direct visualization with VL may contribute to better safety.

Comparison of the success with two bending angles for lighted stylet intubation in children: A prospective randomised study.

BACKGROUND AND AIM: The bend angle of a lighted stylet is an important factor for successful orotracheal intubation. The aim of this study was to test the differences in the success of endotracheal intubation using lighted stylet with 70° versus 90° bend angles in children aged 4-6 years with normal airways. METHODS: A total of 136 children with normal airways required orotracheal intubation were enrolled and were randomly allocated to the 90° or 70° bend angle groups. The first-attempt success rate was assessed as the primary outcome. The intubation time, lighted stylet search time, lighted stylet withdrawal time, hemodynamic responses, and perioperative complications were recorded as secondary outcomes. RESULTS: All intubations were completed within three attempts (the 90° group, 63/5/0; the 70° group, 55/11/2). The first-attempt success rate was higher in the 90° group than that in the 70° group (92.6% [63/68 patients] versus 80.9% [55/68 patients], respectively; risk ratio, 1.15; 95% CI, 1.01-1.31; p = .04). Esophageal entry occurred in nine of 83 intubation attempts in the 70° group and two of 73 intubation attempts in the 90° group (risk ratio, 1.09; 95% CI, 1.01-1.19; p = .04). The intubation time and the lighted stylet search time were significantly shorter in the 90° group than that in the 70° group (intubation time: 12.2 ± 2.0 s versus 14.9 ± 2.6 s, respectively; mean difference, 2.65; 95% CI, 1.87-3.43; p < .01; effect size, 1.16; lighted stylet search time: 5.4 ± 1.0 s versus 8.0 ± 1.6 s, respectively; mean difference, 2.66; 95% CI, 2.21-3.12; p < .01; effect size, 1.95). CONCLUSIONS: Lighted stylet intubation with a 90° bend angle improved the first-attempt success rate and reduced esophageal intubation in children aged 4-6 years with normal airways.

An optimal tracheal tube preshaping strategy for endotracheal intubation using video laryngoscopy: a randomized controlled trial.

Although video laryngoscopy solves the problem of glottis exposure, it is difficult to deliver the tube to the glottic opening when the tracheal tube is unevenly shaped. This study aimed to compare the effects of different tube shapes on the first-pass success (FPS) rate in patients undergoing video laryngoscopy-assisted tracheal intubation. Three hundred patients above 18 years of age who underwent general anaesthesia and required endotracheal intubation were included in the study. The participants were randomly allocated to three groups with 100 participants in each group as follows: Group A, video laryngoscopes with a self-equipped stylet are used for tube preshaping; Group B: curvature of the video laryngoscope blade is modelled for tube preshaping; Group C: tube preshaping angle is consistent with the video laryngoscope blade, and the bending point is set 1 cm above the tracheal tube cuff. The primary outcome was FPS rates. The secondary outcomes included time to tracheal intubation, haemodynamic responses and adverse events. No significant differences in patient characteristics or airway assessments were noted (P > 0.05). Compared with Groups A, Group B and Group C exhibited a higher FPS rate (68% vs. 86% vs. 92%; P < 0.001). However, there is no significant difference in FPS rate between Group B and Group C (P > 0.05). And the time to tracheal intubation in Group C was significantly less than that in Group A and Group B (22.21 ± 4.01 vs. 19.92 ± 4.11 vs. 17.71 ± 3.47; P < 0.001). The straight-to-cuff stylet preshape angulation of curvature of the blade could provide a higher FPS rate and shorter time to tracheal intubation during video laryngoscopy-assisted endotracheal intubation. Trial registration: Chinese Clinical Trial Registry, ChiCTR1900026019.

Laryngoscope burn risk in neonatal intubation.

LARYNGOSCOPE BURNS IN NEONATAL INTUBATION: Following burns during neonatal intubation, we mounted an in vitro study of laryngoscopes to determine the temperatures reached during clinical use. The temperature of 10 different bulb laryngoscopes heads and two fibre optic heads were measured with a thermocouple, once opened, and upon closing. Within 60 s, all ten laryngoscopes, with light-bulb sources, had gained significant heat to cause thermal injury to neonatal skin. Laryngoscopes with LED light source and fibre optic heads did not. CONCLUSION: We recommend that the bulb laryngoscope blade, if used, is not left open prior to intubation and that it is closed between intubation attempts. What is Known: • The preterm epidermis is particularly vulnerable to injury. What is New: • Bulb laryngoscope light bulbs consistently reach temperatures sufficient to burn neonatal skin in less than 100 s in an in vitro study. • Bulb light safety advice should be incorporated into intubation guidelines.

A randomized controlled comparison of non-channeled king vision, McGrath MAC video laryngoscope and Macintosh direct laryngoscope for nasotracheal intubation in patients with predicted difficult intubations.

BACKGROUND: King Vision and McGrath MAC video laryngoscopes (VLs) are increasingly used. The purpose of this study was to evaluate the performance of nasotracheal intubation in patients with predicted difficult intubations using non-channeled King Vision VL, McGrath MAC VL or Macintosh laryngoscope by experienced intubators. METHODS: Ninety nine ASA I or II adult patients, scheduled for oral maxillofacial surgeries with El-Ganzouri risk index 1-7 were enrolled. Patients were randomly allocated to intubate with one of three laryngoscopes (non-channeled King Vision, McGrath MAC and Macintosh). The intubators were experienced with more than 100 successful nasotracheal intubations using each device. The primary outcome was intubation time. The secondary outcomes included first success rate, time required for viewing the glottis, Cormack-Lehane grade of glottis view, the number of assist maneuvers, hemodynamic responses, the subjective evaluating of sensations of performances and associated complications. RESULTS: The intubation time of King Vision and McGrath group was comparable (37.6 ± 7.3 s vs. 35.4 ± 8.8 s) and both were shorter than Macintosh group (46.8 ± 10.4 s, p < 0.001). Both King Vision and McGrath groups had a 100% first attempt success rate, significantly higher than Macintosh group (85%, p < 0.05). The laryngoscopy time was comparable between King Vision and McGrath group (16.7 ± 5.5 s vs. 15.6 ± 6.3 s) and was shorter than Macintosh group (22.8 ± 7.2 s, p < 0.05) also. Compared with Macintosh laryngoscope, Glottis view was obviously improved when exposed with either non-channeled King Vision or McGrath MAC VL (p < 0.001), and assist maneuvers required were reduced (p < 0.001). The maximum fluctuations of MAP were significantly attenuated in VL groups (47.7 ± 12.5 mmHg and 45.1 ± 10.3 mmHg vs. 54.9 ± 10.2 mmHg, p < 0.05 and p < 0.01). Most device insertions were graded as excellent in McGrath group, followed by Macintosh and King Vision group (p = 0.0014). The tube advancements were easier in VLs compared with the Macintosh laryngoscope (p < 0.001). Sore throat was found more frequent in Macintosh group compared with King Vision group (p < 0.05). CONCLUSIONS: Non-channeled King Vision and McGrath MAC VLs were comparable and both devices facilitated nasotracheal intubation in managing predicted difficult intubations compared with Macintosh laryngoscope. TRIAL REGISTRATION: ClinicalTrials registration number NCT03126344 . Registered on April 24, 2017.

Process conformance is associated with successful first intubation attempt and lower odds of adverse events in a paediatric emergency setting.

BACKGROUND: Intubation is an essential, life-saving skill but associated with a high risk for adverse outcomes. Intubation protocols have been implemented to increase success and reduce complications, but the impact of protocol conformance is not known. Our study aimed to determine association between conformance with an intubation process model and outcomes. METHODS: An interdisciplinary expert panel developed a process model of tasks and sequencing deemed necessary for successful intubation. The model was then retrospectively used to review videos of intubations from 1 February, 2014, to 31 January, 2016, in a paediatric emergency department at a time when no process model or protocol was in existence. RESULTS: We evaluated 113 patients, 77 (68%) were successfully intubated on first attempt. Model conformance was associated with a higher likelihood of first attempt success when using direct laryngoscopy (OR 1.09, 95% CI 1.01 to 1.18). The use of video laryngoscopy was associated with an overall higher likelihood of success on first attempt (OR 2.54, 95% CI 1.10 to 5.88). Thirty-seven patients (33%) experienced adverse events. Model conformance was the only factor associated with a lower odds of adverse events (OR 0.94, 95% CI 0.88 to 0.99). CONCLUSIONS: Conformance with a task-based expert-derived process model for emergency intubation was associated with a higher rate of success on first intubation attempt when using direct laryngoscopy and a lower odds of associated adverse events. Further evaluation of the impact of human factors, such as teamwork and decision-making, on intubation process conformance and success and outcomes is needed.

C-MAC Video Laryngoscope versus Conventional Direct Laryngoscopy for Endotracheal Intubation During Cardiopulmonary Resuscitation.

Background and objectives: To compare the first pass success (FPS) rate of the C-MAC video laryngoscope (C-MAC) and conventional Macintosh-type direct laryngoscopy (DL) during cardiopulmonary resuscitation (CPR) in the emergency department (ED). Materials and Methods: This study was a single-center, retrospective study conducted from April 2014 to July 2018. Patients were categorized into either the C-MAC or DL group, according to the device used on the first endotracheal intubation (ETI) attempt. The primary outcome was the FPS rate. A multiple logistic regression model was developed to identify factors related to the FPS. Results: A total of 573 ETIs were performed. Of the eligible cases, 263 and 310 patients were assigned to the C-MAC and DL group, respectively. The overall FPS rate was 75% (n = 431/573). The FPS rate was higher in the C-MAC group than in the DL group, but there was no statistically significant difference (total n = 431, 79% compared to 72%, p = 0.075). In the multiple logistic regression analysis, the C-MAC use had higher FPS rate (adjusted odds ratio: 1.80; 95% CI, 1.17-2.77; p = 0.007) than that of the DL use. Conclusions: The C-MAC use on the first ETI attempt during cardiopulmonary resuscitation in the emergency department had a higher FPS rate than that of the DL use.

Radiographic comparison of cervical spine motion using LMA Fastrach, LMA CTrach, and the Macintosh laryngoscope

Background/aim/AIM: The optimal technique for airway management in patients with cervical pathology remains unclear. Intubating laryngeal mask airway devices such as LMA CTrach and LMA Fastrach have not been compared for cervical spine (C-spine) movements in the context of cervical pathology. The present study aimed to determine upper C-spine movements by radiography during intubation with different devices as well as comparing the duration and success of intubation in cervical surgery. Materials and methods: Sixty patients scheduled for elective cervical surgery were registered in this prospective, randomized study. Patients with cervical trauma/injury, previous neck surgery, and body mass index (BMI) of >35 kg/m2 were excluded. Participants were randomized to one of the 3 groups: LMA CTrach, LMA Fastrach, or the Macintosh laryngoscope. C-spine motion was evaluated by measuring angles created by bordering vertebrae at cervical 1/2 and 2/3 (C1/2, C2/3) segments on 2 lateral cervical radiographs for each patient. Intubation time, ease of intubation, number of attempts, and success rate were also documented. Results: Demographic data were similar in all the groups. The cervical movement with LMA CTrach and LMA Fastrach compared to the Macintosh laryngoscope were similar at C1/2. However, LMA CTrach significantly reduced extension compared to LMA Fastrach and Macintosh laryngoscopes at C2/3. Duration of intubation was significantly shorter with the Macintosh laryngoscope. The rate of successful intubation was 80% with LMA Fastrach and 100% with both LMA CTrach and the Macintosh laryngoscopes. Conclusion: The LMA CTrach laryngoscopy involves less upper C-spine movement than the LMA Fastrach and does not increase the duration of the intubation period.

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.

Difficult tracheal tube passage and subglottic airway injury during intubation with the GlideScope® videolaryngoscope: a randomised, controlled comparison of three tracheal tubes.

Difficulty during placement of the tracheal tube is a known problem when intubating with the GlideScope® , which may lead to subglottic airway injury. This randomised, controlled clinical trial was designed to compare the resistance to passage of PVC (polyvinyl chloride), reinforced or BlockBuster tracheal tubes during intubation with the GlideScope. Secondary outcomes included the time taken to intubate and assessment of subglottic airway injury. One-hundred and seventy-seven patients were included in the data analysis. There was difficult tracheal tube passage (moderate or severe resistance) in 15 (21.4%) patients using the PVC tube compared with 4 (7.4%) and 1 (1.9%) using the reinforced and BlockBuster tubes, respectively (p = 0.003 for PVC vs. BlockBuster). The median (IQR [range]) time taken to intubate was 35 (27-45 [15-115]) s, 25 (20-27 [15-110]) s and 25 (22-30 [16-90]) s, respectively, (p < 0.001 for PVC vs. reinforced as well as PVC vs. BlockBuster). Subglottic airway injury, assessed using a fibreoptic bronchoscope after extubation, was higher with the PVC tube (p < 0.001) and the reinforced tube (p = 0.012) compared with the BlockBuster tube. We conclude that the BlockBuster tracheal tube is a better choice for orotracheal intubation with the GlideScope than PVC or reinforced tubes.

Evaluation of three unchannelled videolaryngoscopes and the Macintosh laryngoscope in patients with a simulated difficult airway: a randomised, controlled trial.

This prospective randomised, controlled trial compares the performance of three unchannelled videolaryngoscopes (KingVision™ , Airtraq™ , A.P. Advance™ MAC) and the standard Macintosh laryngoscope. With ethics committee approval and written informed consent, 480 patients were included. A difficult airway was created with a cervical collar, limiting mouth opening and neck movement. Primary outcome was first-attempt orotracheal intubation success. Overall success, laryngeal view, intubation difficulty scale, handling, intubation times and side-effects were secondary outcomes. First-attempt success rates were: KingVision 90% (95% CI 83-94%), Airtraq 82% (74-88%), A.P. Advance MAC 49% (40-58%), Macintosh 44% (35-53%; p < 0.001). The 95% confidence interval of first-attempt success rate was thus below 90% for all devices, but the KingVision and the Airtraq performed better than the A.P. Advance MAC and the Macintosh laryngoscope. Also, performance was better with the KingVision and the Airtraq in terms of overall success, laryngeal view, intubation difficulty scale and quality of view. Problems with tube advancement were a frequent cause of intubation failure. In summary, the KingVision and the Airtraq performed better than the A.P. Advance MAC and the Macintosh laryngoscope. Success rates of the unchannelled KingVision and Airtraq were similar to those of their channelled versions reported previously, indicating that performance largely depends on blade design rather than the presence of a channel for tube advancement.

Incidence and severity of postoperative sore throat: a randomized comparison of Glidescope with Macintosh laryngoscope.

BACKGROUND: Postoperative sore throat (POST) is a common problem following endotracheal (ET) intubation during general anesthesia. The objective was to compare the incidence and severity of POST during routine intubation with Glidescope (GL) and Macintosh laryngoscope (MCL). METHODS: One hundred forty adult patients ASA I and II with normal airway, scheduled to undergo elective surgery under GA requiring ET intubation were enrolled in this prospective randomized study and were randomly divided in two groups, GL and MCL. Incidence and severity of POST was evaluated at 0, 6, 12 and 24 h after surgery. RESULTS: At 0 h, the incidence of POST was more in MCL than GL (n = 41 v.s n = 22, P = 0.001), and also at 6 h after surgery (n = 37 v.s n = 23, P = 0.017). Severity of POST was more at 0, 6 and 12 h after surgery in MCL (P < 0.001, P = 0.001, P = 0.004 respectively). CONCLUSIONS: Routine use of GL for ET tube placement results in reduction in the incidence and severity of POST compared to MCL. TRIAL REGISRATION: ClinicalTrials.gov NCT02848365 . Retrospectively Registered (Date of registration: July, 2016).

Use of McGrath MAC Videolaryngoscope to Assist Transesophageal Echocardiography Probe Insertion in Intubated Patients.

OBJECTIVES: Transesophageal echocardiography (TEE) probe insertion with the conventional blind insertion technique may be difficult in anesthetized and intubated patients. The use of a videolaryngoscope may facilitate the insertion of the TEE probe. The aim of this study was to compare the conventional technique with the use of the McGrath MAC videolaryngoscope for TEE probe insertion in terms of success rate, duration of insertion, and complications in patients undergoing cardiovascular surgery. DESIGN: A prospective, randomized study. SETTING: Training and research hospital. PARTICIPANTS: Eighty-six adult patients undergoing cardiovascular surgery were included. INTERVENTIONS: Eighty-six adult patients were randomized into 2 groups: conventional group (n = 43) and McGrath videolaryngoscope group (n = 43). Success rates, duration of insertion, complications, and hemodynamic changes during insertion were recorded. MEASUREMENTS AND MAIN RESULTS: The success rate of TEE probe insertion at the first attempt was higher in the McGrath videolaryngoscope group (90.5%) than in the conventional group (43.9%) (p = 0.012). The mean duration for successful insertion of the TEE probe at the first attempt was longer in the McGrath videolaryngoscope group (24 s v 11 s) (p = 0.016). The total time for successful insertion of the TEE probe was similar in both groups. Pharyngeal injuries were observed more frequently in the conventional group (17.1% v 2.4%) (p = 0.037). The rate of blood presence on the probe tip in the conventional group was higher than in the McGrath group (21.9% v 4.8%). There were no statistical differences between the 2 groups in systolic blood pressure, mean arterial pressure, diastolic blood pressure, and heart rate before and after TEE insertion. CONCLUSIONS: The use of the McGrath MAC videolaryngoscope for TEE insertion in cardiovascular surgery patients increases the success rate and reduces pharyngeal injuries compared to the conventional technique. The use of the McGrath MAC videolaryngoscope for TEE insertion causes similar hemodynamic changes as in the conventional blind insertion technique.

Evaluation of six videolaryngoscopes in 720 patients with a simulated difficult airway: a multicentre randomized controlled trial.

BACKGROUND: Videolaryngoscopes are aggressively marketed, but independent evaluation in difficult airways is scarce. This multicentre, prospective randomized controlled trial evaluates six videolaryngoscopes in patients with a simulated difficult airway. METHODS: With ethics committee approval and written informed consent, 12 senior anaesthetists intubated the trachea of 720 patients. A cervical collar limited mouth opening and neck movement, making intubation difficult. We evaluated three unchannelled (C-MAC™ D-blade, GlideScope™, and McGrath™) and three channelled videolaryngoscopes (Airtraq™, A.P. Advance™ difficult airway blade, and KingVision™). The primary outcome was first-attempt intubation success rate. Secondary outcomes included overall success rate, laryngeal view, intubation times, and side-effects. The primary hypothesis for every videolaryngoscope was that the 95% confidence interval of first-attempt success rate is ≥90%. RESULTS: Mouth opening was decreased from 46 (sd 7) to 23 (3) mm with the cervical collar. First-attempt success rates were 98% (McGrath™), 95% (C-MAC™ D-blade), 87% (KingVision™), 85% (GlideScope™ and Airtraq™), and 37% (A.P. Advance™, P<0.01). The 95% confidence interval of first-attempt success rate was >90% only for the McGrath™. Overall success, laryngeal view, and intubation times differed significantly between videolaryngoscopes (all P<0.01). Side-effects were minor. CONCLUSIONS: This trial revealed differences in the performance of six videolaryngoscopes in 720 patients with restricted neck movement and limited mouth opening. In this setting, first-attempt success rates were 85-98%, except for the A.P. Advance™ difficult airway blade. Highest success and lowest tissue trauma rates were achieved by the McGrath™ and C-MAC™ D-blade, highlighting the importance of the videolaryngoscope blade design. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov: identifier NCT01692535.

The performance of rigid scopes for tracheal intubation: a randomised, controlled trial in patients with a simulated difficult airway.

We compared the Bonfils™ and SensaScope™ rigid fibreoptic scopes in 200 patients with a simulated difficult airway randomised to one of the two devices. A cervical collar inhibited neck movement and reduced mouth opening to a mean (SD) of 23 (3) mm. The primary outcome parameter was overall success of tracheal intubation; secondary outcomes included first-attempt success, intubation times, difficulty of intubation, fibreoptic view and side-effects. The mean (95% CI) overall success rate was 88 (80-94)% for the Bonfils and 89 (81-94)% for the SensaScope (p = 0.83). First-attempt intubation success rates were 63 (53-72)% for the Bonfils and 72 (62-81)% for the SensaScope (p = 0.17). Median (IQR [range]) intubation time was significantly shorter with the SensaScope (34 (20-84 [5-240]) s vs. 45 (25-134 [12-230]) s), and fibreoptic view was significantly better with the SensaScope (full view of the glottis in 79% with the SensaScope vs. 61% with the Bonfils). This might be explained by its steerable tip and the S-formed shape, contributing to better manoeuvrability. There were no differences in the difficulty of intubation or side-effects.