A comparison of the Trachway intubating stylet and the Macintosh laryngoscope in tracheal intubation: a manikin study

Purpose

The Trachway intubating stylet (Trachway^®), when used by experienced anesthesiologists, has been shown to be effective for difficult airway management. We evaluated the efficacy of this intubating stylet for tracheal intubation in a manikin when used by experienced laryngoscopists with little experience using this device.

Methods

Thirty-eight nurse anesthesiologists intubated the trachea of a manikin (Laerdal Airway Management Trainer) with a Trachway intubating stylet or a Macintosh laryngoscope in easy and difficult laryngoscopy scenarios. The duration of the intubation attempts, success rates, dental trauma, and ease of use (0 = very easy; 10 = very difficult) were recorded. The primary endpoint was the duration of the successful tracheal intubation attempt in the difficult laryngoscopy scenario. Data are presented as means (SD).

Results

Both devices resulted in similar tracheal intubation performance in the easy laryngoscopy scenario. However, the Trachway intubating stylet provided shorter intubation times (20.8 ± 5.6 vs. 25.5 ± 7.3 s; p = 0.003) and easier intubations (2.4 ± 1.6 vs. 5.7 ± 1.8; p < 0.001) compared with the Macintosh laryngoscope in the difficult laryngoscopy scenario. All tracheal intubations were successful and no dental trauma was observed when using the Trachway intubating stylet.

Conclusion

We concluded that the Trachway intubating stylet, when used by novices, is effective in both easy and difficult laryngoscopy scenarios. In difficult laryngoscopy scenarios, this device provided faster, easier, and less traumatic intubation than the Macintosh laryngoscope.     

Comparison of a single-use GlideScope® Cobalt videolaryngoscope with a conventional GlideScope® for orotracheal intubation

Background

This study was conceived to compare the single-use GlideScope^® Cobalt videolaryngoscope with the conventional GlideScope^® videolaryngoscope for orotracheal intubation, as judged by time to intubation (TTI) and ease of intubation.

Methods

One hundred patients with normal-appearing airways requiring orotracheal intubation for elective surgery were randomly allocated to have their tracheas intubated by a heterogeneous group of operators with the Cobalt GlideScope® or the conventional GlideScope^®. TTI was assessed by a blinded observer. Operators were blinded until the start of laryngoscopy. A visual analogue scale (VAS) assessed the ease of intubation. The number of intubation attempts, number of failures, glottic grades, and fogging of the video screen were recorded.

Results

There was no difference between the median TTI of the GlideScope^® Cobalt and the conventional GlideScope^® (40.1 sec, interquartile range [IQR] 34.1, 51.3 vs 39 sec, IQR 32.6, 48.1, respectively; P = 0.75). The ease of intubation was similar between the two devices (median Cobalt VAS: 16 mm, IQR 10.8, 27.3, vs median conventional VAS: 12.5 mm, IQR 10, 20.5, respectively; P = 0.12). There were no significant differences between the two devices with respect to glottic exposure, intubation attempts, failures, or video screen fogging.

Conclusions

The GlideScope^® Cobalt has similar performance characteristics compared with the conventional GlideScope^® videolaryngoscope when used for orotracheal intubation. The two devices can likely be used interchangeably. (ClinicalTrials.gov number, NCT00459797.)     

A randomised trial comparing the CEL-100 videolaryngoscope(TM) with the Macintosh laryngoscope blade for insertion of double-lumen tubes

We performed a randomised trial comparing the CEL‐100 videolaryngoscope^TM with the Macintosh laryngoscope blade in 170 patients undergoing double‐lumen tube placement for thoracic surgery. Compared with the Macintosh laryngoscope blade, use of the CEL‐100 resulted in significantly more patients with a Cormack and Lehane Grade‐1 laryngeal view (90.4% vs 61.0%, p < 0.001), a higher rate of successful intubation on the first attempt (92.8% vs 79.3%, p = 0.012), a lower median (IQR [range]) intubation difficulty score (0 (0–0 [0–60]) vs 15 (0–30 [0–80]), p < 0.001), a higher incidence of correct positioning of the tube (90.3% vs 79.2%, p = 0.041) and significantly fewer patients requiring external laryngeal pressure (19.3% vs 32.9%, p = 0.046). Median (IQR [range]) time to successful intubation was 45 (38–55 [22–132]) s with the CEL‐100 compared with 51 (40–61 [30–160] s using the Macintosh laryngoscope blade. We conclude that the CEL‐100 videolaryngoscope is superior to the Macintosh laryngoscope blade for double‐lumen tube insertion.     

Tracheal intubation during chest compressions using Pentax-AWS®, GlideScope®, and Macintosh laryngoscope: a randomized crossover trial using a mannequin

Background

A randomized crossover trial was conducted to compare the performance of two videolaryngoscopes (Pentax-AWS^®, GlideScope^®) with the Macintosh laryngoscope for tracheal intubation during continuous chest compressions on a mannequin.

Methods

Thirty-two inexperienced junior interns performed tracheal intubations on an advanced life support simulator with either a normal or difficult airway scenario. The sequence of intubating devices and airway difficulty were randomized. The following data were measured and recorded: time to complete tracheal intubation (primary end point), overall success rate, time to visualize the vocal cords, percentage of glottic opening, dental compression, and ease of intubation.

Results

With a normal airway, the times (median [interquartile range]) to complete tracheal intubation were shorter with the Pentax-AWS (12.1 [10.1-14.4] sec) and the GlideScope (14.3 [12.4-17.6] sec) than with the Macintosh laryngoscope (16.5 [13.1-22.1] sec) (P < 0.03 for both). The time difference between the two videolaryngoscopes was not statistically significant. With a difficult airway scenario, the times to complete tracheal intubation were 13.9 [10.9-20.4] sec, 19.2 [16.4-32.3] sec, and 30.1 [21.0-56.5] sec, respectively (P < 0.05 for all differences). The videolaryngoscopes were also more effective than the Macintosh laryngoscope with respect to secondary outcomes.

Conclusions

The two videolaryngoscopes were superior to the Macintosh laryngoscope in terms of performing tracheal intubation during continuous chest compressions on a mannequin. In a difficult airway scenario simulating cardiac arrest, the Pentax-AWS performed better than the GlideScope.     

GlideScope videolaryngoscope reduces the incidence of erroneous esophageal intubation by novice laryngoscopists

The purpose of this study was to evaluate the performance of the GlideScope videolaryngoscope for tracheal intubation by novice laryngoscopists compared with that of the Macintosh laryngoscope. Under supervision by staff anesthetists, non-anesthesia residents performed tracheal intubation using either the GlideScope videolaryngoscope (n = 100) or Macintosh laryngoscope (n = 100). The time required for airway instrumentation, the number of attempts required until successful intubation, and erroneous esophageal intubation were investigated. There were no significant differences in the time needed to secure the airway between the GlideScope videolaryngoscope and the Macintosh laryngoscope. Fewer attempts until successful intubation were made with the GlideScope videolaryngoscope than with the Macintosh laryngoscope (p < 0.05). Erroneous esophageal intubation with the GlideScope videolaryngoscope was less frequent than with the Macintosh laryngoscope (p < 0.05). Compared to the Macintosh laryngoscope, the GlideScope videolaryngoscope reduces the incidence of erroneous esophageal intubation by less experienced laryngoscopists.     

Assessing the efficacy of video versus direct laryngoscopy through retrospective comparison of 436 emergency intubation cases

Video laryngoscopy has become a common practice for tracheal intubations. However, information on its efficacy in emergency intubations is minimal. The external video monitor may act as a means for assistance by present staff, heighten teaching ability, and improve intubation outcomes. We conducted a retrospective review consisting of 436 patients requiring emergency intubation outside the operating room to evaluate the application of a C-MAC video laryngoscope for emergency intubation(s). Nine cases were removed, 315 underwent direct laryngoscopy, 73 underwent video laryngoscopy, and 39 underwent both methods. The C-MAC laryngoscope provided a significantly better visualization of the glottis (p = 0.02). The C-MAC also provided successful intubation on the first attempt in 82 % of the 39 direct laryngoscopy cases subsequently intubated with the C-MAC. The presence of the attending anesthesiologist (while the resident intubates) had no effect on complication rates; the number of attempts required and the grade view obtained were nonsignificant (p = 0.91 and p = 0.34, respectively). Overall, use of the C-MAC video laryngoscope provided a better view of the airway structures during an emergency intubation. The success of the C-MAC laryngoscope in intubation after failed direct laryngoscopy suggests the importance of the video laryngoscope as the primary intubation approach during an emergency intubation.     

Efficacy of Coopdech videolaryngoscope: comparisons with a Macintosh laryngoscope and the Airway Scope in a manikin with difficult airways

We studied the efficacy of the Coopdech videolaryngoscope Portable VLP-100, by comparing it with a Macintosh laryngoscope, and another videolaryngoscope, the Airway Scope (AWS), in a manikin with four simulated difficult airways. In a randomized, crossover design, each of 50 residents inserted the three devices, in turn, and graded the view of the glottis at laryngoscopy. Time to see the glottis, time to intubate the trachea, and the success rate of tracheal intubation (within 120 s) were recorded. In all situations, the AWS provided a significantly shorter time to see the glottis. In a manikin with tongue edema, the AWS was associated with a significantly higher success rate of intubation than the VLP-100 and the Macintosh laryngoscope (P < 0.05). In a manikin with cervical spine rigidity or pharyngeal obstruction, the AWS and the VLP-100 provided significantly higher success rates of intubation than the Macintosh laryngoscope (P < 0.05). In a manikin with laryngospasm, no one could intubate the trachea using any device. Our results indicate that, in patients with difficult airways, the videolaryngoscopes (VLP-100 and AWS) would provide higher success rates of tracheal intubation than the Macintosh laryngoscope, but the VLP-100 may be inferior to the AWS.     

Direkte Laryngoskopie oder C-MAC-Videolaryngoskopie?

Background

Previous studies have shown that video laryngoscopy enhances laryngeal view in patients with apparently normal and difficult airways. The utility of the novel, portable, battery-powered C-MAC video laryngoscope is as yet unproven. It was hypothesized that in routine patients undergoing ENT surgery, the rate of glottic views considered unsatisfactory, i.e. Cormack and Lehane grades IIb, III, and IV, could be significantly reduced with the C-MAC video laryngoscope compared to direct laryngoscopy.

Methods

Following ethical approval and sample size estimates 108 consecutive patients undergoing ENT surgery under general anesthesia were studied. First, direct laryngoscopy was performed with the naked eye. The best view obtained was graded by the first anesthesiologist without looking at the video monitor. A second anesthesiologist blinded to the laryngeal view obtained under direct laryngoscopy graded the laryngeal view on the video monitor. Endotracheal intubation using Ring-Adair-Elwyn (RAE) tracheal tubes was then attempted under video-aided visualization. The tubes were not reinforced with a stylet. The C-MAC video laryngoscopy system (Karl Storz, Tuttlingen, Germany) is a novel device that can be used with Macintosh laryngoscope blades in different sizes. A camera and light source are located recessed from the tip of the blade. The camera unit sits in a handle attached to the laryngoscope blade and is connected by a wire to a TFT video monitor. It allows for both direct and indirect laryngoscopy and the low profile of the original British Macintosh blades may prove advantageous in patients with limited mouth opening.

Results

A total of 108 patients were enrolled in the study but for various reasons only 94 completed the study (post hoc power 97%). In 89 patients a size 3 Macintosh laryngoscopewas used while a size 4 blade was used in the remaining 5 patients. With direct laryngoscopy the glottic view was considered unsatisfactory in 40 patients (42%), but this was the case in only 15 patients (16%) when video laryngoscopy was used (p<0.0001). Endotracheal tube placement was successful in all but one patient where the Bonfils intubation fiberscope needed to be employed. No complications related to the C-MAC system were observed.

Conclusions

Compared to direct laryngoscopy with a Macintosh laryngoscope blade in unselected patients undergoing ENT surgery and thus patients more susceptible to an unexpected difficult airway than a general patient population, the mobile C-MAC video laryngoscope significantly enhanced laryngeal view. Using RAE tracheal tubes seems to compensate the unfavorable deviation of optical and anatomical axes when indirect laryngoscopy is performed with the C-MAC system.     

Performance of the C-MAC video laryngoscope in patients after a limited glottic view using Macintosh laryngoscopy

We applied the C-MAC videolaryngoscope in 52 consecutive patients who were found to have an unexpected Cormack and Lehane grade-3 (n = 49) and grade-4 (n = 3) laryngeal view with the Macintosh laryngoscope. The glottic view improved in 49 (94%) patients using the C-MAC. Tracheal intubation was successful in 49 of 52 patients (94%). In one patient, tracheal intubation failed using the C-MAC despite the presence of a Cormack and Lehane grade-2. These results suggest that the C-MAC videolaryngoscope has a role as a rescue device in cases of an initially difficult laryngeal view.     

A randomized comparison of the GlideRite® Rigid Stylet to a malleable stylet for orotracheal intubation by novices using the GlideScope®

Purpose

A stylet is usually necessary when using the GlideScope^® videolaryngoscope for orotracheal intubation. A special stylet, the GlideRite^® Rigid Stylet (GRS), was designed for this purpose. A previous trial involving experienced operators showed that the GRS offered no performance improvement vs a standard malleable stylet (SMS). In our trial, we compared the performance of the GRS with that of the SMS in terms of time to intubation and ease of intubation when used by novice GlideScope^® operators.

Methods

Sixty patients with normal-appearing airways requiring orotracheal intubation for elective surgery were randomly allocated to be intubated by novice operators with the GlideScope^®, using either the GRS or the SMS. Time to intubation was assessed by a blinded observer, and the operators were blinded until just prior to tracheal intubation. Ease of intubation was assessed by a five-point ordinal scale (from 1- easy to 5 -difficult). Intubation attempts/failures, glottic grades, and usage of external laryngeal manipulation were recorded.

Results

There were no significant differences between the GRS and the SMS in terms of the median time to intubation (60 sec, interquartile range [IQR] 48-75 vs 61 sec, IQR 49-75, respectively; P = 0.94) and the ease of intubation (GRS median score: 1.5, IQR 1-2 vs SMS median score: 1, IQR 1-2; P = 0.94). There were no other significant differences between groups.

Conclusion

The GRS and the SMS have similar performance characteristics when used by novice operators for GlideScope^®-assisted orotracheal intubation. (Registered at ClinicalTrials.gov: NCT00884754).     

O papel do videolaringoscópio em programas de treinamento de intubação endotraqueal

Background

Macintosh laryngoscopes are widely used for endotracheal intubation training of medical students and paramedics whereas there are studies in the literature that supports videolaryngoscopes are superior in endotracheal intubation training. Our aim is to compare the endotracheal intubation time and success rates of videolaryngoscopes and Macintosh laryngoscopes during endotracheal intubation training and to determine the endotracheal intubation performance of the students when they have to use an endotracheal intubation device other than they have used during their education.

Comparaison de l’Airtraq, du X-Lite et du laryngoscope standard pour la chirurgie thyroïdienne: une étude clinique randomisée

Purpose

To compare the performance of the Airtraq, X-Lite, and direct laryngoscopes for tracheal intubation for elective thyroid surgery.

Methods

In this randomized prospective study, Patients who were ASA (American Society of Anesthesiologists) I or II physical status I or II and patients undergoing thyroid surgery were included in this randomized prospective study. Patients with attributes for difficult intubation criteria were excluded. After induction of anesthesia with fentanyl, propofol, and cisatracurium, patients were randomized into three groups according to the intubating device used: Airtraq laryngoscope (Airtraq), X-Lite video laryngoscope (X-lLite), and direct laryngoscope with a Macintosh blade (Direct). The primary outcome measurement was the time needed for tracheal intubation. Secondary outcomes included intubation difficulty score (IDS), Cormack-Lehane classification, as well as hemodynamic and respiratory effects.

Results

One hundred and five patients were included. Mean (standard deviation) time for intubation was 28.2 (2.1) sec in the Airtraq group vs 36.6 (3.7) sec in the X-Lite group (P < 0.001), and 41.1 (4.4) sec in the Direct group (P < 0.001). Compared with to the direct laryngoscope, the Airtraq provided better visualization of the glottis (P = 0.003) with fewer attempts (P < 0.001) and lower IDS (P < 0.001). The intubation difficulty score was lower with the Airtraq than with the X-Lite (P = 0.003). Patients in the X-Lite and Direct groups showed more hemodynamic variations than those in the Airtraq group. There was only one failed intubation, in the direct group.

Conclusion

In thyroid surgery, the Airtraq and X-Lite laryngoscopes decrease time to intubation when compared with direct laryngoscopy.     

Comparação entre o videolaringoscópio King Vision e o laringoscópio Macintosh: um ensaio clínico prospectivo randomizado e controlado

Background and objectives

We compared the efficiency of the King Vision video laryngoscope and the Macintosh laryngoscope, when used by experienced anesthesiologists on adult patients with varying intubating conditions, in a prospective randomized controlled clinical trial.

A comparison of the McGrath® Series 5 videolaryngoscope and Macintosh laryngoscope for double‐lumen tracheal tube placement in patients with a good glottic view at direct laryngoscopy

We compared the McGrath^® Series 5 videolaryngoscope with the Macintosh laryngoscope for double‐lumen tracheal tube placement in patients with a predicted good glottic view on assessment of the airway. An initial laryngoscopy was performed using the Macintosh laryngoscope; 96 patients with Cormack and Lehane grade‐1 or ‐2a views were randomly assigned to undergo intubation using either the McGrath or Macintosh device. Compared with the Macintosh laryngoscope, the McGrath videolaryngoscope provided more Cormack and Lehane grade‐1 views (47 (97.9%) vs 29 (60.4%), p < 0.05), a longer mean (SD) intubation time (39.6 (10.0) s vs 24.4 (7.3) s, p < 0.05) and a higher incidence of double‐lumen tube malposition (6 (12.5%) vs 0, p < 0.05). However, in 18 non‐randomised patients with Cormack and Lehane grade ≥ 2b on initial laryngoscopy using the Macintosh, the glottic view was improved on intubation with the McGrath videolaryngoscope, with a total success rate of double‐lumen tube placement of 94.4% and mean (SD) intubation time of 50.0 (18.6) s. We recommend that in patients with a low airway risk index score requiring intubation with a double‐lumen tracheal tube, the Macintosh laryngoscope is used as the first device and the McGrath videolaryngoscope is used only if this provides a poor glottic view.     

The McCoy levering laryngoscope in patients with limited neck extension

Purpose

The McCoy levenng laryngoscope is a modified Macintosh laryngoscope, which has a hinged tip controlled by a lever on the handle. The purpose of this study was to investigate whether the tip elevation of this laryngoscope results in better laryngeal visualization than using the Macintosh laryngoscope when the patient’s neck is fixed in the neutral position.

Methods

Fifty female patients (ASA physical status I–II) undergoing elective surgery during general anaesthesia were investigated. The patient’s neck was manually fixed in the neutral position by an assistant, and laryngeal visualization was attempted first with a size #3 Macintosh laryngoscope (Macintosh trial), and then with a size #3 McCoy levering laryngoscope with blade tip elevation (McCoy trial), and tracheal intubation was attempted. Trials of laryngeal visualization were evaluated with the Cormadc score.

Results

In the Macintosh trial, 36 of 50 (72%) patients were evaluated grade 3, and two grade 4. In most of the patients graded 2 and 3 in the Macintosh trial (70% of the grade 2 and 83% of the grade 3 cases), the laryngeal view was improved by using the McCoy levering laryngoscope. The Cormack grade in the McCoy trial was less than that in the Macintosh tnal (P < 0.01). No complications were observed during the study.

Conclusion

The McCoy levenng laryngoscope improved laryngeal visualization in patients whose neck cannot be extended.     

Distortion of anterior airway anatomy during laryngoscopy with the GlideScope videolaryngoscope

Purpose  

A non-line-of-sight view is expected to cause less movement of the anterior airway anatomy and cervical spine during laryngeal visualization. Reduced distortion of anterior airway anatomy during laryngoscopy with the GlideScope videolaryngoscope (GVL), compared with the Macintosh laryngoscope, could explain the relatively easier nasotracheal intubation with the GVL. The purpose of this radiographic study was to compare the degree of anterior airway distortion and cervical spine movement during laryngoscopy with the GVL and the conventional Macintosh laryngoscope.     

Safety and effectiveness of Thulium VapoEnucleation of the prostate (ThuVEP) in patients on anticoagulant therapy

Introduction

To evaluate the safety and efficacy of Thulium VapoEnucleation of the prostate (ThuVEP) for patients on oral anticoagulants (OA) with symptomatic benign prostatic obstruction (BPO).

Methods

Fifty-six patients, undergoing ThuVEP at two institutions, were evaluated from May 2009 until June 2011. All patients were at high cardiopulmonary risk and presented with a median American Society of Anesthesiology score of 3 [interquartile range (IQR) 2–3]. Thirty-two patients were on aspirin, 8 were on clopidogrel or clopidogrel and aspirin, and 16 on phenprocoumon at the time of surgery. Patient demographic, perioperative, and follow-up data were analyzed.

Results

Median prostate volume was 50 (IQR 34–76) cc, and resected tissue weight was 32 (IQR 20–50) g. The median operative time was 61.5 (IQR 40–100.75) min, and the catheter time 2 (IQR 2–3) days. There were no perioperative thromboembolic events. Five patients (8.9 %) required a second-look operation in the immediate postoperative course (hemorrhage n = 4, residual adenoma n = 1) and four (7.1 %) blood transfusions. Complications within the first 30 days included urinary tract infections (1.7 %), urinary retention (3.6 %), and delayed bleeding (7.1 %). These complications were managed conservatively. At 12-month follow-up, median QoL [5 (IQR 3.75–5) vs. 1 (IQR 1–2)], IPSS [21.5 (IQR 15.5–23.75) vs. 5 (IQR 3–8)], Qmax [7.7 (IQR 6.3–10) vs. 28.3 (IQR 21.25–39.2) ml/s], and postvoiding residual urine [100 (IQR 46–200) vs. 17.5 (IQR 0–36) ml] improved significantly (p < 0.002).

Conclusions

Thulium VapoEnucleation of the prostate seems to be a safe and efficacious procedure for the treatment of symptomatic BPO in patients at high cardiopulmonary risk on OA.     

QT and JT dispersion and cardiac performance in children with neonatal Bartter syndrome: a pilot study

Background

QT dispersion and JT dispersion are simple noninvasive arrhythmogenic markers that can be used to assess the homogeneity of cardiac repolarization. The aim of this study was to assess QT and JT dispersion and their relation with left ventricular systolic and diastolic functions in children with Bartter syndrome (BS).

Methods

Nine neonatal patients with BS (median age 9.7 years) and 20 controls (median age 8 years) were investigated at rest. Both study and control subjects underwent electrocardiography (ECG) in which the interval between two R waves and QT intervals, corrected QT, QT dispersion, corrected QT dispersion, JT, corrected JT, JT dispersion and corrected JT dispersion were measured with 12-lead ECG. Two-dimensional, Doppler echocardiographic examinations were performed.

Results

Patients and controls did not differ for gender and for serum levels of potassium, magnesium, and calcium (p?>?0.05). Both study and control subjects had normal echocardiographic examination and baseline myocardial performance indexes. The QT dispersion and JT dispersion were significantly prolonged in patients with BS compared to those of the controls {37.5 ms [interquartile range (IQR) 32.5–40] vs. 25.5 ms (IQR 20–30), respectively, p?=?0.014 and 37.5 ms (IQR 27.5–40) vs. 22.5 ms (IQR 20–30), respectively, p?=?0.003}.

Conclusions

Elevated QT and JT dispersion during asymptomatic and normokalemic periods may be risk factors for the development of cardiac complications and arrhythmias in children with BS. In these patients the need for systematic cardiac screening and management protocol is extremely important for effective prevention.     

Comparison of intubation performance between the King Vision and Macintosh laryngoscopes in novice personnel: a randomized,crossover manikin study

Purpose

The King Vision laryngoscope is a newly developed video laryngoscope. We conducted a simulation study to evaluate the efficacy of the King Vision in novice personnel.

Methods

Thirty-one registered nurses with no previous experience with tracheal intubation were enrolled. Participants made 6 consecutive attempts at intubation of the manikin’s trachea with a Macintosh laryngoscope (MAC) and the King Vision with channeled blade (KVC) and non-channeled blade (KVNC) in a randomized cross-over fashion. The Grading Scale of Intubation Difficulty (GSID) was rated on a 5-point scale.

Results

Overall median (range) intubation times (sec) were 16.9 (8.0–60.0) with the MAC, 20.5 (7.2–60.0) with the KVC, and 60.0 (11.0–60.0) with the KVNC. The KVNC required significantly longer intubation time compared with the MAC or the KVC (p < 0.001). Success rate with the KVNC was 47.3 %, which was significantly inferior to that with the MAC (91.4 %) or KVC (86.6 %). Median GSID was 2 (range 1–5) with the KVC and 3 (1–4) with the MAC, which were both significantly lower than the 4 (2–5) with the KVNC (p < 0.001). Esophageal intubation with the MAC occurred in 18 of 186 attempts, whereas no incidents of esophageal intubation occurred with the KVC or KVNC.

Conclusion

The KVC facilitated intubation by novice personnel without incidence of esophageal intubation. However, intubation times, success rates, and GSID scores were similar to the values obtained with the MAC. These findings suggest that the KVC, but not the KVNC, could be used as an alternative device for intubation by novice personnel.     

Cricoid pressure with the Truview Evo2TM laryngoscope improves the glottic view

Objective

The Truview Evo2? laryngoscope blade is designed to improve glottic view. This study was designed to evaluate the effect of cricoid pressure (CP) on laryngeal view and the ease of orotracheal intubation with the Truview Evo2 laryngoscope.

Methods

In this randomized controlled trial, 50 patients (American Society of Anesthesiologists physical status I-II, aged 18 to 60 yr) scheduled for elective surgery were enrolled. After induction of anesthesia and muscle paralysis, laryngoscopy was performed using the Truview Evo2^TM laryngoscope with the patient’s head in the neutral position. In Group 1, the percentage of glottic opening (POGO) score was evaluated first without CP, then with CP, and CP was applied for intubation. In Group 2, the POGO score was evaluated first with CP, then without CP, and no CP was applied for intubation. Time to intubation and number of attempts required for intubation were also recorded.

Results

In 50 patients, the mean (standard deviation) POGO view obtained with the application of CP was 93% (10%) compared with 81% (19%) in patients without CP (P < 0.01). Times to intubation were similar in the two groups: 14.2 (6.6) sec vs 14.0 (9.3) sec in Groups 1 and 2, respectively (P = 0.924). Sixteen percent of patients in Group 1 required a second attempt at tracheal intubation, while only 4% of patients in Group 2 required a second attempt (P = 0.162).

Conclusion

When using the Truview Evo2^TM laryngoscope with the patient’s head in the neutral position, application of CP improves the glottic view. This approach is not associated with increased difficulty in intubation.