A comparison between left molar direct laryngoscopy and the use of a Bonfils intubation fibrescope for tracheal intubation in a simulated difficult airway

Comparison of video-stylet and conventional laryngoscope for endotracheal intubation in adults with cervical spine immobilization: A PRISMA-compliant meta-analysis

BACKGROUND

Although minimization of cervical spine motion by using a neck collar or manual in-line stabilization is recommended for urgent tracheal intubation (TI) in patients with known or suspected cervical spine injury (CSI), it may worsen glottic visualization. The overall performance of video-stylets during TI in patients with neck immobilization remains unclear. The current meta-analysis aimed at comparing the intubation outcomes of different video-stylets with those of conventional laryngoscopes in patients with cervical immobilization.

METHOD

The databases of Embase, Medline, and the Cochrane Central Register of Controlled Trials were searched from inception to June 2021 to identify trials comparing intubation outcomes between video-stylets and conventional laryngoscopes. The primary outcome was first-pass success rate, while secondary outcomes included overall success rate, time to intubation, the risk of intubation-associated sore throat, or tissue damage.

RESULTS

Five randomized controlled trials published between 2007 and 2013 involving 487 participants, all in an operating room setting, were analyzed. The video-stylets investigated included Bonfils intubation fiberscope, Levitan FPS Scope, and Shikani optical stylet. There was no difference in first-pass success rate (risk ratio [RR] =1.08, 95% confidence interval [CI]: 0.89-1.31, P = .46], overall success rate (RR = 1.06, 95% CI: 0.93-1.22, P = .4), intubation time [mean difference = 4.53 seconds, 95% CI: -8.45 to 17.51, P = .49), and risk of tissue damage (RR = 0.46, 95% CI: 0.16-1.3, P = .14) between the 2 groups. The risk of sore throat was lower with video-stylets compared to that with laryngoscopes (RR = 0.45, 95% CI: 0.23-0.9, P = .02).

CONCLUSION

Our results did not support the use of video-stylets as the first choice for patients with neck immobilization. Further studies are required to verify the efficacy of video-stylets in the nonoperating room setting.

Videolaryngoscopic versus direct laryngoscopic paraglossal intubation for cleft lip/palate reconstructive surgeries: A randomised controlled trial

Background and Aims:

In the cleft lip and palate, the laryngoscope blade often tends to lodge inside midline clefts, causing reduced manoeuvrability and tissue trauma. The paraglossal technique avoids the midline and offers better Cormack Lehane (CL) grades. We aimed to assess the first-pass intubation rate in performing the left paraglossal laryngoscopy with a curved-blade videolaryngoscope (VLS) versus direct laryngoscope (DLS) in children with cleft palate and evaluate the time taken for successful endotracheal intubation (TTI) and Intubation Difficulty Score (IDS) with both devices.

Methods:

This randomised controlled trial included 60 patients with cleft palate, between 3 months and 6 years. Patients were randomised into group V (VLS) (n = 30) and group D (DLS) (n = 30). Left paraglossal laryngoscopy was done with VLS or DLS, and the first-pass intubation, TTI, CL grade and IDS were recorded.

Results:

First-pass intubation (primary outcome) was successful in all cases in group V and in 29 (96%) cases in group D (P = 0.923). Amongst the secondary outcomes, the IDS of the majority in both groups was 1–4 (slight difficulty) (P = 0.98) and the mean TTI In group D was 34.6 s (SD = 19.0) (95% CI: 27.5–41.7) versus 39.8 s (SD = 5.2) (95% CI: 37.8–41.7) in group V (P = 0.151).

Conclusions:

There was no significant difference in the use of a VLS over a DLS in performing the left paraglossal laryngoscopy in terms of first-pass intubation rate, CL Grade, IDS and TTI. Further studies with different VLS may be done to improve the ease of this technique.

Effectiveness of intubation devices in patients with cervical spine immobilisation: a systematic review and network meta-analysis

BACKGROUND

Cervical spine immobilisation increases the difficulty of tracheal intubation. Many intubation devices have been evaluated in this setting, but their relative performance remains uncertain.

METHODS

MEDLINE, EMBASE, and the Cochrane Library were searched to identify randomised trials comparing two or more intubation devices in adults with cervical spine immobilisation. After critical appraisal, a random-effects network meta-analysis was used to pool and compare device performance. The primary outcome was the probability of first-attempt intubation success (first-pass success). For relative performance, the Macintosh direct laryngoscopy blade was chosen as the reference device.

RESULTS

We included 80 trials (8039 subjects) comparing 26 devices. Compared with the Macintosh, McGrath™ (odds ratio [OR]=11.5; 95% credible interval [CrI] 3.19-46.20), C-MAC D Blade™ (OR=7.44; 95% CrI, 1.06-52.50), Airtraq™ (OR=5.43; 95% CrI, 2.15-14.2), King Vision™ (OR=4.54; 95% CrI, 1.28-16.30), and C-MAC™ (OR=4.20; 95% CrI=1.28-15.10) had a greater probability of first-pass success. This was also true for the GlideScope™ when a tube guide was used (OR=3.54; 95% CrI, 1.05-12.50). Only the Airway Scope™ had a better probability of first-pass success compared with the Macintosh when manual-in-line stabilisation (MILS) was used as the immobilisation technique (OR=7.98; 95% CrI, 1.06-73.00).

CONCLUSIONS

For intubation performed with cervical immobilisation, seven devices had a better probability of first-pass success compared with the Macintosh. However, more studies using MILS (rather than a cervical collar or other alternative) are needed, which more accurately represent clinical practice.

CLINICAL TRIAL REGISTRATION

PROSPERO 2019 CRD42019158067 (https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=158067).

Learning Curves for Two Fiberscopes in Simulated Difficult Airway Scenario With Cumulative Sum Method

INTRODUCTION

The aims of this randomized prospective mannequin study were to determine the amount of attempts required for successful intubation using different fiberscopes (Bonfils and SensaScope) by inexperienced anesthesiologists in a difficult airway scenario and to build the associated learning curves.

METHODS

Difficult airway simulation was achieved with tongue edema in mannequin. After approval of volunteers, we asked 15 anesthesiology residents without any experience with fiberscopes to intubate with each device in a random order. Intubation success (endotracheal intubation within 120 seconds), the degree of difficulty of intubation, and reality of simulation using a 10-point scale were recorded. Learning curves were generated with cumulative sum method.

RESULTS

With Bonfils, 13 volunteers were able to pass lower decision boundary with a median number of 26 [95% confidence interval (CI) = 21.4-25.9] attempts, whereas in SensaScope, the same outcome was observed in 10 residents with a median number of attempts of 26 (95% CI = 23.5-32.5). Total success rate was found significantly higher with Bonfils compared with SensaScope (550/600 vs 512/600, respectively, P < 0.001). Intubation with Bonfils was considered as less difficult compared with SensaScope [median = 4 (95% CI = 3.32-4.42) and 6 (95% CI = 4.96-6.64), P = 0.01, respectively]. The reality of the simulation was rated as a median of 5 (95% CI = 4.37-5.8).

CONCLUSIONS

Although a similar number of attempts were required to reach predetermined competency for both fiberscopes, only 10 of residents were able to obtain the targeted success using SensaScope as compared with 13 with Bonfils. Inexperienced residents found intubation via Bonfils less difficult than SensaScope. High individual variability in obtaining competency observed in this study with cumulative sum analysis underlines the importance of defining success a priori to simulation, the need for follow-up of individual progress, and the need to offer adequate trials to achieve competency. Therefore, learning opportunities should be adapted accordingly.

Shikani Optical Stylet versus Macintosh Laryngoscope for Intubation in Patients Undergoing Surgery for Cervical Spondylosis: A Randomized Controlled Trial

Background:

Airway management is critical in patients with cervical spondylosis, a population with a high incidence of difficult airway. Intubation with Shikani Optical Stylet (SOS) has become increasingly popular in difficult airway. We compared the effects of intubation with SOS versus Macintosh laryngoscope (MLS) in patients undergoing surgery for cervical spondylosis.

Methods:

A total of 270 patients scheduled for elective surgery for cervical spondylosis of spinal cord and nerve root type from August 2012 to January 2016 were enrolled and randomly allocated to the MLS or SOS group by random numbers. Patients were evaluated for difficult airway preoperatively, and Cormack-Lehane laryngoscopy classification was determined during anesthesia induction. Difficult airway was defined as Cormack-Lehane Grades III–IV. Patients were intubated with the randomly assigned intubation device. The success rate, intubation time, required assistance, immediate complications, and postoperative complaints were recorded. Categorical variables were analyzed by Chi-square test, and continuous variables were analyzed by independent samples t-test or rank sum test.

Results:

The success rate of intubation among normal airways was 100% in both groups. In patients with difficult airway, the success rates in the MLS and SOS groups were 84.2% and 94.1%, respectively (P = 0.605). Intubation with SOS took longer compared with MLS (normal airway: 25.1 ± 5.8 s vs. 24.5 ± 5.7 s, P = 0.426; difficult airway: 38.5 ± 8.5 s vs. 36.1 ± 8.2 s, P = 0.389). Intubation with SOS required less assistance in patients with difficult airway (5.9% vs. 100%, P < 0.001). The frequency of postoperative sore throat was lower in SOS group versus MLS group in patients with normal airway (22.0% vs. 34.5%, P = 0.034).

Conclusions:

SOS is a safe and effective airway management device in patients undergoing surgery for cervical spondylosis. Compared with MLS, SOS appears clinically beneficial for intubation, especially in patients with difficult airway.

Trial Registration:

Chinese Clinical Trial Registry, ChiCTR-IOR-16007821; http://www.chictr.org.cn/showproj.aspx?proj=13203.

Bonfils intubation fibrescope: use in simulation-based intubation training for medical students in comparison to MacIntosh laryngoscope

Background

A variety of instruments are used to perform airway management by tracheal intubation. In this study, we compared the MacIntosh balde (MB) laryngoscope with the Bonfils intubation fibrescope as intubation techniques. The aim of this study was to identify the technique (MB or Bonfils) that would allow students in their last year of medical school to perform tracheal intubation faster and with a higher success probability. Data were collected from 150 participants using an airway simulator [‘Laerdal Airway Management Trainer’ (Laerdal Medical AS, Stavanger, Norway)]. The participants were randomly assigned to a sequence of techniques to use. Four consecutive intubation ‘trials’ were performed with each technique. These trials were evaluated for differences in the following categories: the ‘time to successful ventilation‘, ‘success probability’ within 90 s,’time to visualisation’ of the vocal cords (glottis), and ‘quality of visualisation’ according to the Cormack and Lehane score (C&L, grade 1–4). The primary endpoint was the ‘time to successful ventilation‘in the fourth and final trial.

Results

There was no statistically significant difference in the ‘time to successful ventilation’ between the two techniques in trial 4 (‘time to successful ventilation’: median: MB: 16 s, Bonfils: 14 s, p = 0.244). However, the ‘success probability’ within 90 s was higher when using a Macintosh blade than when using a Bonfils (95 vs. 87 %). The glottis could be better visualised when using a Bonfils (C&L score of 1 (best view): MB: 41 %, Bonfils: 93 %), but visualisation was achieved more rapidly when using a Macintosh blade (median: ‘time to visualisation’: MB: 6 s, Bonfils: 8 s, p = 0.003).

Conclusions

The time to ventilation using the MacIntosh blade and Bonfils mainly did to differ, however success probabilities and time to visualisation primary favoured the MacIntosh blade as intubation technique, although the Bonfils seem to have a steeper learning curve. The Bonfils is still a promising intubation technique and might be easier to learn as the MB, at least in a manikin.

Electronic supplementary material

The online version of this article (doi:10.1186/s13104-016-1937-2) contains supplementary material, which is available to authorized users.