Difficult airway management: comparison of the Bullard laryngoscope with the video-optical intubation stylet

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.

A comparison of two hyperangulated video laryngoscope blades to direct laryngoscopy in a simulated infant airway: a bicentric, comparative, randomized manikin study

Background

In infants, securing the airway is time-critical because of anatomical and physiological differences related to airway management in children less than 1 year old. The aim of this study was to compare the time to ventilation using two different hyperangulated video laryngoscope blades with the time to ventilation via conventional direct laryngoscopy in a normal airway [NA] and in a simulated difficult airway [DA].

Methods

This study was a comparative, bicentric, open-label, randomized controlled evaluation. An infant high-fidelity simulator (SimBaby™; Laerdal® Medical, Stavanger, Norway) was used, and two scenarios were proposed, as follows: NA and DA evoked with tongue edema and cervical collar. After theoretical and practical briefing, each participant compared in the two airway scenarios the novel King Vision™ Pediatric aBlade (KV) (Ambu® A/S, Bad Nauheim, Germany) video laryngoscope and the C-MAC™ D-blade Ped (DB) (Karl Storz® SE & Co. KG, Tuttlingen, Germany) video laryngoscope to conventional laryngoscopy using the Miller Blade (MiB) and the Macintosh Blade (MaB) in a random sequence.

Results

Eighty physicians (65 AN and 15 PCCM staff) were included. In the NA scenario, the median [IQR] time to successful time to ventilation (TTV) was significantly shorter for the KV at 13 s [12–15 s] than for the MaB at 14.5 s [13–16 s], DB at 14.5 s [13–16] and MiB at 16 s [14–19] (p < 0.001). In DA, the KV also shortened TTV to 14 s [13–16], whereas TTV was 23 s with the MaB [20–26], 19 s with the DB [16–21], and 27 s with the MiB [22–31] (p < 0.001). There were no differences in first-pass intubation success rates (FPAs) between hyperangulated blades and direct laryngoscopes in NA. In DA, the hyperangulated blades enabled 92 (DB) to 100% (KV) FPAs compared with 65 (MiB) to 76% (MaB) for conventional laryngoscopy (p < 0.001).

Conclusion

Video laryngoscopes with hyperangulated blades were associated with shorter TTV in normal and difficult infant airway situations. The higher FPAs of hyperangulated blades in DA may avoid desaturations and decrease adverse events in pediatric airway management.

Electronic supplementary material

The online version of this article (10.1186/s12871-018-0580-y) contains supplementary material, which is available to authorized users.

Does glycopyrrolate premedication facilitate tracheal intubation with a rigid video-stylet?: A randomized controlled trial

BACKGROUND

A rigid video-stylet intubation device provides safe and accurate access to the trachea by enabling visualization of the airway structures during tracheal intubation. The primary purpose of this study was to examine the effects of glycopyrrolate premedication on tracheal intubation with a rigid video-stylet.

METHODS

In this prospective, randomized, double-blinded study, 78 patients were randomly assigned to the control group (n = 39; no glycopyrrolate administration) or the glycopyrrolate group (n = 39; 0.005 mg/kg glycopyrrolate, intramuscular injection). A rigid video-stylet was used for tracheal intubation. The degree of oral secretion observed through the video-stylet monitor was assessed using the OptiScope laryngeal view and graded on a 4-point scale (1, excellent; 2, good; 3, poor; and 4, unacceptable). The time to intubation and hemodynamic variables at baseline and 1, 3, and 5 minutes after intubation were recorded.

RESULTS

The OptiScope laryngeal view grades of the glycopyrrolate group (grade 1 = 16 [41.0%], 2 = 17 [43.6%], 3 = 6 [15.4%], and 4 = 0 [0%]) were significantly higher than those of the control group (grade 1 = 9 [23.1%], 2 = 11 [28.2%], 3 = 18 [46.2%], and 4 = 1 [2.6%]; P = .02). The intubation time was shorter in the glycopyrrolate group (18.5 seconds [15.0-22.0]) than the control group (22.0 seconds [17.9-26.4], P = .02). There was no significant difference in the hemodynamic variables between groups.

CONCLUSION

Glycopyrrolate facilitated tracheal intubation with a rigid video-stylet by decreasing oral secretions and providing better visualization and faster intubation with hemodynamic stability.

TRIAL REGISTRY

www.clinicaltrials.gov; Identifier: NCT03050242.

A Manikin Study to Compare Video-Optical Intubation Stylet versus Macintosh Laryngoscope Used by Novice in Normal and Simulated Difficult Airway Intubation

Objective

To compare Macintosh laryngoscope with video-optical intubation stylet on rates and time durations of successful tracheal intubation in normal and simulated difficult airway.

Design

Crossover experimental study.

Setting

Intubation training laboratory.

Methods

A group of novices (58 medical students) attempted intubation on manikin under normal and simulated difficult airway (grade 3 larygnoscopic view) settings using both Macintosh laryngoscope and video-optical intubation stylet. The success rate, duration to intubate and occurrence of complications (oesophageal intubation and incisor breakage) when using the two different devices were measured and compared. The time results were analysed by paired t-test and categorical results by chi square test or Fisher's exact test.

Results

The success rate to intubate difficult airway using video-optical intubation stylet (0.92) was significantly higher than using Macintosh laryngoscope (0.59) (p=0.002). The mean time taken to intubate difficult airway using video-optical intubation stylet was significantly shorter than using Macintosh laryngoscope by 10.90 seconds (p=0.004). Oesophageal intubation rate was significantly higher when using Macintosh laryngoscope to intubate difficult airway compared to video-optical intubation stylet (p=0.002). There was no significant difference on the rate of incisor breakage between the two instruments.

Conclusions

Novice can learn to use both Macintosh laryngoscope and video-optical intubation stylet to intubate successfully after a short training. Video-optical intubation stylet is an effective “Plan B” instrument because it shortens the duration and increases the rate of successful intubation in difficult airway situations.

Video-Assisted Airway Management: Experience in a Hong Kong Emergency Department

Video-assisted airway management is a new concept for monitoring and managing both normal and difficult tracheal intubations, with the aid of video-transmission of the view from the tip of intubating devices such as stylets or intubating laryngoscopes. Its principle, practical application and local experience are illustrated by some sample cases and its future development is discussed.

Using King Vision video laryngoscope with a channeled blade prolongs time for tracheal intubation in different training levels, compared to non-channeled blade

Purpose

It is generally accepted that using a video laryngoscope is associated with an improved visualization of the glottis. However, correctly placing the endotracheal tube might be challenging. Channeled video laryngoscopic blades have an endotracheal tube already pre-loaded, allowing to advance the tube once the glottis is visualized. We hypothesized that use of a channel blade with pre-loaded endotracheal tube results in a faster intubation, compared to a curved Macintosh blade video laryngoscope.

Methods

After ethical approval and informed consent, patients were randomized to receive endotracheal Intubation with either the King Vision^® video laryngoscope with curved blade (control) or channeled blade (channeled). Success rate, evaluation of the glottis view (percentage of glottic opening (POGO), Cormack&Lehane (C&L)) and intubating time were evaluated.

Results

Over a two-month period, a total of 46 patients (control n = 23; channeled n = 23) were examined. The first attempt success rates were comparable between groups (control 100% (23/23) vs. channeled 96% (22/23); p = 0.31). Overall intubation time was significantly shorter with control (median 40 sec; IQR [24–58]), compared to channeled (59 sec [40–74]; p = 0.03). There were no differences in glottis visualization between groups.

Conclusion

Compared with the King Vision channeled blade, time for tracheal intubation was shorter with the control group using a non-channeled blade. First attempt success and visualization of the glottis were comparable. These data do not support the hypothesis that a channeled blade is superior to a curved video laryngoscopic blade without tube guidance.

Trial registration

ClinicalTrials.gov NCT02344030

Evaluation of the McGrath MAC and Macintosh laryngoscope for tracheal intubation in 2000 patients undergoing general anaesthesia: the randomised multicentre EMMA trial study protocol

INTRODUCTION

The direct laryngoscopy technique using a Macintosh blade is the first choice globally for most anaesthetists. In case of an unanticipated difficult airway, the complication rate increases with the number of intubation attempts. Recently, McGrath MAC (McGrath) video laryngoscopy has become a widely accepted method for securing an airway by tracheal intubation because it allows the visualisation of the glottis without a direct line of sight. Several studies and case reports have highlighted the benefit of the video laryngoscope in the visualisation of the glottis and found it to be superior in difficult intubation situations. The aim of this study was to compare the first-pass intubation success rate using the (McGrath) video laryngoscope compared with conventional direct laryngoscopy in surgical patients.

METHODS AND ANALYSIS

The EMMA trial is a multicentre, open-label, patient-blinded, randomised controlled trial. Consecutive patients requiring tracheal intubation are randomly allocated to either the McGrath video laryngoscope or direct laryngoscopy using the Macintosh laryngoscope. The expected rate of successful first-pass intubation is 95% in the McGrath group and 90% in the Macintosh group. Each group must include a total of 1000 patients to achieve 96% power for detecting a difference at the 5% significance level. Successful intubation with the first attempt is the primary endpoint. The secondary endpoints are the time to intubation, attempts for successful intubation, the necessity of alternatives, visualisation of the glottis using the Cormack & Lehane score and percentage of glottic opening score and definite complications.

ETHICS AND DISSEMINATION

The project was approved by the local ethics committee of the Medical Association of the Rhineland Palatine state and Westphalia-Lippe. The results of this study will be made available in the form of manuscripts for publication and presentations at national and international meetings.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov NCT 02611986; pre-results.

A comparison of hemodynamic changes after endotracheal intubation by the Optiscope™ and the conventional laryngoscope

Background

Optiscope™ is a newly developed video stylet device. This study evaluated and compared the hemodynamic changes observed after endotracheal intubation with video stylet and after conventional laryngoscopic endotracheal intubation.

Methods

Fifty-eight adult patients with American Society of Anesthesiologists (ASA) physical status class 1 or 2, undergoing general anesthesia, were randomized into two groups: one group of patients were intubated using video stylet (n = 29) and the other group were intubated using direct laryngoscope (n = 29). Systolic blood pressure (SBP), mean arterial pressure (MAP), diastolic blood pressure (DBP), heart rate (HR), POGO (percentage of glottic opening) score, time for intubation and degree of sore throat were recorded.

Results

There were no significant differences in the SBP, MAP, DBP, HR, and the sore throat incidence between the two groups. Optiscope™ produced better POGO scores, but time for intubation was longer than with conventional laryngoscope.

Conclusions

Optiscope™, when compared with conventional laryngoscope for intubation, does not modify the hemodynamic response, but it provides a better view of the vocal cords.

A comparison of Bonfils intubation fiberscopy and fiberoptic bronchoscopy in difficult airways assisted with direct laryngoscopy

Background

To evaluate the usefulness of Bonfils intubation fiberscope assisted by direct laryngoscopy (BIF-DL) and flexible fiberoptic bronchoscope assisted by direct laryngoscopy (FOB-DL) using video recording in cases of unanticipated difficult intubation with respect to the time required to visualize the vocal cords and place the endotracheal tube. We compared two fiberscopes in patients with authentic difficult airways.

Methods

In this randomized, controlled clinical trial, 40 patients (grade 3 according to grades of difficulty in laryngoscopy), scheduled for surgery under general anesthesia were randomly allocated to BIF-DL group or FOB-DL group. Number of attempts, time required for visualization of the vocal cord (T1) and placement of the endotracheal tube (T2) from insertion of instrument during the last successful attempt, and duration of scope manipulation during all attempts (T_total) were recorded. If intubation failed with one method, the other method was tried; these cases were then excluded. The incidence of sore throat and hoarseness was assessed.

Results

T1, T2, and T_total were significantly shorter in BIF-DL group (T1: 21.9 ± 8.2 sec vs. 80.4 ± 29.9 sec, P < 0.001, T_total: 77.9 ± 41.2 sec vs. 145.5 ± 83.9 sec, P = 0.003). In two cases, it was impossible to intubate with BIF-DL, but the procedure was subsequently successful using fibreoptic bronchoscope.

Conclusions

Intubation of difficult airways can be performed more rapidly with BIF-DL, but sometimes it may not be possible to intubate with the scope.

Retrograde intubation

Airway management in the emergency department is a critical skill that must be mastered by emergency physicians. When rapid-sequence induction with oral-tracheal intubation performed by way of direct laryngoscopy is difficult or impossible due to a variety of circumstances, an alternative method or device must be used for a rescue airway. Retrograde intubation requires little equipment and has few contraindications. This technique is easy to learn and has a high level of skill retention. Familiarity with this technique is a valuable addition to the airway-management armamentarium of emergency physicians caring for ill or injured patients. Variations of the technique have been described, and their use depends on the individual circumstances.

Evaluation of the Airway Scope, a new video laryngoscope, in tracheal intubation by naive operators: a manikin study

BACKGROUND AND AIM

The Airway Scope (AWS) is a new video laryngoscope. The purpose of this study was to compare the AWS and Macintosh laryngoscopes with regard to their usefulness for beginners in tracheal intubation.

METHODS

Thirty-one nurses with no previous experience of tracheal intubation used each device 10 times to intubate the trachea of a manikin (Laerdal Airway Managemant Trainer, Laerdal, Stavanger, Norway). Intubation correctly completed within 30 s was regarded as successful. The intubation time, success rate, number of esophageal intubations and dental clicks, and subjective evaluation of difficulty of intubation [rated from 1 (extremely easy) to 5 (extremely difficult)] were recorded.

RESULTS

The average intubation time was significantly shorter for AWS than for the Macintosh laryngoscope (16.7 +/- 11.0 s vs. 23.2 +/- 24.9 s; mean +/- standard deviation; P = 0.0297), and the success rate with AWS was significantly greater (91.3% vs. 79.4%; P < 0.001). In the total of 310 intubation attempts for each device, the number of esophageal intubations (0/310 with AWS vs. 20/310 with the Macintosh laryngoscope) and dental clicks (0/310 with AWS vs. 40/310 with the Macintosh laryngoscope) differed significantly (P < 0.001). AWS was rated as easier to use than the Macintosh laryngoscope (P < 0.001).

CONCLUSION

AWS is more useful for beginners as it provides quicker and easier tracheal intubation.

Comparison of the Airway Scope®, gum elastic bougie and fibreoptic bronchoscope in simulated difficult tracheal intubation: a manikin study

We compared the Airway Scope with a gum elastic bougie and fibreoptic bronchoscope in a manikin with a simulated Cormack and Lehane Grade 3 laryngoscopic view. Twenty-seven anaesthetists intubated the trachea of the manikin with these devices and the time required for intubation was measured. They were then asked to rate the subjective difficulty of intubation (1 = very easy; 5 = very difficult). Mean (SD) intubation times were 16.6 (11.2) s with the Airway Scope, 29.4 (10.9) s with the gum elastic bougie (p < 0.0001), and 30.6 (20.0) s with the fibreoptic bronchoscope (p < 0.0001). The median (range) difficulty was 2 (1-4) with the Airway Scope, 3 (2-4) with the gum elastic bougie (p < 0.001), and 2 (1-5) with the fibreoptic bronchoscope (p = 0.014). In Cormack and Lehane grade 3 laryngoscopic views, the Airway Scope may enable faster and easier tracheal intubation than does a Macintosh laryngoscope with a gum elastic bougie or a fibreoptic bronchoscope.

A comparison of tracheal intubation using the Airtraq�or the Macintosh laryngoscope in routine airway management: a randomised, controlled clinical trial

The Airtraq laryngoscope is a novel single use tracheal intubation device. We compared the Airtraq with the Macintosh laryngoscope in patients deemed at low risk for difficult intubation in a randomised, controlled clinical trial. Sixty consenting patients presenting for surgery requiring tracheal intubation were randomly allocated to undergo intubation using a Macintosh (n = 30) or Airtraq (n = 30) laryngoscope. All patients were intubated by one of four anaesthetists experienced in the use of both laryngoscopes. No significant differences in demographic or airway variables were observed between the groups. All but one patient, in the Macintosh group, was successfully intubated on the first attempt. There was no difference between groups in the duration of intubation attempts. In comparison to the Macintosh laryngoscope, the Airtraq resulted in modest improvements in the intubation difficulty score, and in ease of use. Tracheal intubation with the Airtraq resulted in less alterations in heart rate. These findings demonstrate the utility of the Airtraq laryngoscope for tracheal intubation in low risk patients.

Bonfils semirigid endoscope for guidance during percutaneous tracheostomy

We report on the use of the Bonfils semirigid scope for endoscopic guidance during percutaneous dilational tracheostomy. Forty patients requiring percutaneous dilational tracheostomy on the General or Neurosurgical Intensive Care Unit were enrolled in this study. We used the '45 degree curved distal tip' scope in the first 15 patients, evaluating its ease of use, optical quality of focus and image resolution as well as light intensity on a 10-point scale. We evaluated straight and curved versions of it in another 15 and 10 patients, respectively. We examined the impact on ventilation and cardiovascular parameters. In all patients (n = 40) visualisation of the procedure was satisfactory. There were no clinically significant changes in ventilatory or cardiovascular parameters. The image quality for most patients received a score of 7-10. The Bonfils scope provides a practical alternative to flexible bronchoscopes in this setting.

Evaluation of intubation using the Airtraq or Macintosh laryngoscope by anaesthetists in easy and simulated difficult laryngoscopy--a manikin study

The Airtraq Laryngoscope is a novel intubation device which allows visualisation of the vocal cords without alignment of the oral, pharyngeal and tracheal axes. We compared the Airtraq with the Macintosh laryngoscope in simulated easy and difficult laryngoscopy. Twenty-five anaesthetists were allowed up to three attempts to intubate the trachea in each of three laryngoscopy scenarios using a Laerdal Intubation Trainer followed by five scenarios using a Laerdal SimMan Manikin. Each anaesthetist then performed tracheal intubation of the normal airway a second time to characterise the learning curve. In the simulated easy laryngoscopy scenarios, there was no difference between the Airtraq and the Macintosh in success of tracheal intubation. The time taken to intubate at the end of the protocol was significantly lower using the Airtraq (9.5 (6.7) vs. 14.2 (7.4) s), demonstrating a rapid acquisition of skills. In the simulated difficult laryngoscopy scenarios, the Airtraq was more successful in achieving tracheal intubation, required less time to intubate successfully, caused less dental trauma, and was considered by the anaesthetists to be easier to use.

Evaluation of the new Viewmax laryngoscope in a simulated difficult airway

BACKGROUND

In this study, we evaluated the learning curve and performance of the Viewmax laryngoscope during simulated difficult laryngoscopy in an intubation manikin (Laerdal Airway Management Trainer).

METHODS

To determine the learning curve, 25 anaesthesiologists without previous experience with the Viewmax laryngoscope performed 10 successive intubations in an intubation manikin with a normal airway. Time to intubation and failed intubation attempts were recorded. Another manikin was modified to enable comparison of the Viewmax laryngoscope with Macintosh and McCoy laryngoscopes. The time to intubation, number of failed intubation attempts, modified Cormack and Lehane (MCL) laryngeal view grading, percentage of glottic opening (POGO score), use of gum elastic bougie and subjective rating of degree of difficulty were recorded.

RESULTS

The learning curve for the Viewmax laryngoscope showed a progressive decrease in time to successful intubation and reached a plateau at the sixth attempt. In simulated difficult laryngoscopy, the Viewmax laryngoscope demonstrated significantly better laryngeal view than the Macintosh and McCoy laryngoscopes in terms of MCL grading (Macintosh, P = 0.01; McCoy, P < 0.01) and POGO score (Macintosh, P < 0.01; McCoy, P < 0.01). The time required for intubation in simulated difficult laryngoscopy for the Viewmax laryngoscope was significantly longer than that for the Macintosh (P = 0.02) and McCoy (P < 0.01) laryngoscopes. There was no significant difference in the degree of difficulty, number of failed intubations and use of gum elastic bougie.

CONCLUSION

When compared with the Macintosh and McCoy laryngoscopes in a manikin, the Viewmax laryngoscope appears to improve the view of the larynx but requires a longer time for tracheal intubation.

A comparison of the Seeing Optical Stylet and the gum elastic bougie in simulated difficult tracheal intubation: a manikin study

Management of the difficult airway is one of the major challenges that anaesthetists face. The flexible fibreoptic scope is widely available but its use requires a level of skill, training and continued practice that is not universally found in all anaesthetists, particularly trainees. The Seeing Optical Stylet is a new, semirigid fibreoptic stylet 'scope. We compared the Seeing Optical Stylet with a gum elastic bougie in a simulated Cormack and Lehane Grade 3 laryngoscopy in a manikin. Forty-four anaesthetists were timed while intubating the manikin's trachea with both devices. The mean (SD) time taken with the Seeing Optical Stylet was 20.8 (9.3) s and with the bougie 30 (19.8) s (p = 0.001). Oesophageal intubation occurred six times with the bougie but did not occur with the Seeing Optical Stylet (p = 0.011). We conclude that the Seeing Optical Stylet may be superior to the bougie in difficult tracheal intubation. We feel that the results of this manikin trial are sufficiently encouraging to proceed to a clinical trial in patients.

Bullard laryngoscopy by naÏve operators in the cervical spine immobilized patient

To determine ease of Bullard laryngoscopy by naïve operators during cervical spine immobilization, 21 residents, naïve to the Bullard laryngoscope, were assigned to perform Bullard laryngoscopy and standard direct laryngoscopy on the Laerdal SimMan Universal Patient Simulator while the rigid cervical spine function was engaged. Sequences were repeated. Success of laryngeal intubation, time to intubation, ease of intubation, and grade of laryngoscopic view were recorded and compared. Pairwise comparisons of consecutive times between standard and Bullard devices showed significant difference in mean times at first attempt, 28.8 (95% confidence interval [CI] 18.1-39.5) seconds in favor of Macintosh laryngoscopy, but no statistical differences between devices at second and third attempts, with differences in mean times of 4.5 (95% CI 2.5-6.5) and 3.8 (95% CI, 0.1-7.7) seconds, respectively. Similarly, ease of use was statistically unchanged over time for Macintosh laryngoscopy, but there was statistically significant improvement in ease of use for the Bullard. The Bullard laryngoscope is an easily mastered airway management device for intubation of the cervical spine immobilized patient.

Video-enhanced visualization of the larynx and intubation with the Bullard laryngoscope--equipment report

PURPOSE

A simple technical solution is presented to provide video transmission from the tip of a Bullard laryngoscope to a bedside video display, while the operator is still able to look through the viewing ocular of the Bullard laryngoscope during tracheal intubation.

EQUIPMENT

This is achieved by insertion of an ultrathin fibreoptic video-endoscopic system into the working channel of the Bullard laryngoscope. Thereby the view from the distal blade tip is transmitted to a bedside monitor, without interfering with the use of the Bullards laryngoscope's original eyepiece. The presented technical solution allows video transmission without considerable additional weight normally associated with attaching video endoscopy cameras, light and camera cables to endoscopic devices. Thus, the Bullard laryngoscope remains lightweight and easy to maneuver. A screw-threaded adapter with a side-port is proposed to prevent displacement of the fibreoptic cable while still allowing application of oxygen.

CONCLUSION

Experience and skills with tracheal intubation using the presented video-enhanced Bullard laryngoscope can be achieved in the originally intended way, while the supervisor or attending viewers can follow the tracheal intubation procedure on the video display.

The Shikani Seeing Stylet for difficult intubation in children: initial experience

The Shikani Seeing Stylet is a recently introduced reusable intubating stylet, produced in adult and paediatric versions. It combines features of a fibreoptic bronchoscope and a lightwand. Inside a malleable stainless steel sheath, the Shikani Seeing Stylet has a fibreoptic cable leading to a distal light source and high-resolution lens. In use, the stylet is placed in the lumen of the selected endotracheal tube and the light source enables the stylet to be used as a lightwand, while the fibreoptic capability enables visualization of the laryngeal inlet. It is portable, relatively inexpensive and easy to maintain. This report describes the use of the stylet on eight occasions in seven children, all of whom were assessed preoperatively as being potentially difficult to intubate. Three had been difficult to intubate previously. All were anaesthetized using inhalational anaesthesia. Once an adequate depth of anaesthesia had been achieved, conventional direct laryngoscopy was performed and identified as Grade 3 in six of the patients and Grade 1 in one. Tracheal intubation was then attempted using the Shikani Seeing Stylet. On six of the eight occasions the attempt was made by different anaesthetists, none of whom had any prior clinical experience with the stylet. There were seven successful intubations and one failure in a patient who could not be intubated by any method. The Shikani Seeing Stylet seems a useful device for use in children with difficult airway problems, suspected cervical spine instability or limited mouth-opening.

Improving styletted oral tracheal intubation: rational use of the OTSU

PURPOSE

To introduce an improved method of styletted oral laryngoscopic tracheal intubation.

DESCRIPTION OF THE TECHNIQUE

The oral tracheal stylet unit (OTSU) is constructed using a commonly available intubating stylet combined with an ordinary endotracheal tube (ETT). The ETT/stylet is created by a series of specific steps to form an OTSU, each with a standard shape and design that allows the tracheal tube to separate freely from the stylet. After construction, every unit is tested to confirm that the frictional resistance created by the tracheal tube, as it slides along the stationary stylet, is at an absolute minimum. Successful tracheal intubation is based on the following concepts: (a) The j-shaped OTSU, when correctly directed through the airway, passes freely from the mouth to the larynx, the laryngoscopic channel; (b) The tip of the ETT must first be placed between the vocal cords with every intubation. The tracheal tube is then launched and advanced into the trachea by sliding along and off a stationary stylette; (c) Only minimal force is required to propel the ETT during intubation; (d) Resistance to placement, launch or advancement means the tip of the OTSU has come into physical contact with the patient's airway; (e) When the epiglottis obscures the larynx, the tip of the OTSU is used to explore the hypopharynx and identify the glottis. The ability to differentiate where the ETT tip is located depends primarily on interpreting the sensations of touch and pressure transmitted from the bevel of the OTSU to the hand. Successful tracheal intubation is accomplished when all criteria for placement, launch, and advancement are met.

CONCLUSION

Styletted oral tracheal intubation is well known. However, we describe an improvement of the technique, based on solid physical principles and years of experience, that should prove useful both for routine intubations and unexpected difficult airways.

Video-intuboscopic assistance is a useful aid to tracheal intubation in pediatric patients

PURPOSE

To evaluate the efficacy of video-intuboscopic assisted tracheal intubation in a difficult intubation setting.

METHODS

In 50 pediatric patients (mean age 12.8 +/- 3.1 yr, range 6-16 yr) a grade 3 direct laryngoscopic view was simulated. Eight certified registered nurse anesthetists without experience in endoscopic intubation performed tracheal intubation on five or more patients using the video-optical intubation stylet. Time from insertion of the tube into the oral cavity until the tip had passed the vocal cords was recorded. Failed intubation was defined as intubation >60 sec, arterial oxygen saturation <92% or esophageal intubation. Subjective degree of difficulty was asked from the operators using a Likert-scale.

RESULTS

Forty-six of the 50 patients were successfully intubated within 60 sec and without arterial oxygen desaturation. In four patients, video-assisted tracheal intubation failed due to prolonged intubation time. Intubation times ranged from 10-40 sec (median 15 sec). Mean intubation time in the first patient (24.5 +/- 17.3 sec) appeared longer than for the fifth patient (20.8 +/- 10.9 sec), but the difference was not statistically significant (P=0.87). Mean estimated degree of difficulty was 3.9 +/- 2.1. Subjective estimates of difficulty increased with intubation times (P=0.001).

CONCLUSION

The video-optical intubation stylet can be considered a valuable aid for tracheal intubation in pediatric patients with a difficult airway.

New equipment and techniques for airway management in trauma

A patent, unobstructed airway is fundamental in the care of the trauma patient, and is most often obtained by placing a cuffed tube in the trachea. The presence of shock, respiratory distress, a full stomach, maxillofacial trauma, neck hematoma, laryngeal disruption, cervical spine instability, and head injury all combine to increase tracheal intubation difficulty in the trauma patient. Complications resulting from intubation difficulties include brain injury, aspiration, trauma to the airway, and death. The use of devices such as the gum-elastic bougie, McCoy laryngoscope, flexible and rigid fiberscopes, intubating laryngeal mask, light wand, and techniques such as rapid-sequence intubation, manual in-line axial stabilization, retrograde intubation, and cricothyroidotomy, enhance the ability to obtain a definitive airway safely. The management of the failed airway includes calling for assistance, optimal two-person bag-mask ventilation, and the use of the laryngeal mask airway, Combitube, or surgical airway. The simulation of airway management using realistic simulator tools (e.g. full-scale simulators, virtual reality airway simulators) is a promising modality for teaching physicians and advanced life support personnel emergency airway management skills.

Video-intuboscopic monitoring of tracheal intubation in pediatric patients

PURPOSE

To evaluate the efficacy of video-intuboscopic monitoring during orotracheal intubation in a pediatric anesthesia teaching unit.

METHODS

In 100 pediatric patients direct laryngoscopy performed by residents or nurse anesthetists was monitored on a video display using a flexible, ultralight video-endoscopic system (O.D. 2.8 mm/length 1.8 m) within the endotracheal tube (ETT). Best direct laryngoscopic view was assessed by the intubator. The instructor observed the intubation procedure on the video display and noted number of intubation attempts, best laryngoscopic monitor view, tube passage through the larynx and final tube position. If required he gave instructions or corrections. After removal of the laryngoscope, tracheal tube position was adjusted using the monitor view. Difficulties attributed to the fibreoptic endoscope during intubation and removal from the ETT were recorded.

RESULTS

The trachea was successfully intubated at the first attempt in all patients. The supervisor detected one esophageal and 12 endobronchial intubations that were immediately corrected before starting ventilation. Final visualized endotracheal tube adjustment above the carina was possible in all patients except in one with copious tracheal secretions. Compared with direct laryngoscopy the video display provided an improved view of the vocal cords during intubation. In six patients direct laryngoscopy was difficult but the tracheas were intubated using the monitor view. No difficulties with the equipment were encountered except that the black coated endoscope compromised recognition of the black ETT depth-markings in small tubes.

CONCLUSIONS

Video-intuboscopic monitoring is a useful monitor of tracheal intubation. "The improved view of the cords may provide assistance during difficult laryngoscopy.