A review of the literature: direct and video laryngoscopy with simulation as educational intervention

Figures & data

Table 1 Study participants, simulation, features of training procedures, and assessment

Citation	Participants	Simulation intervention	Laryngoscope blade	Training time	Intubation scenarios
Aziz et al^Citation20	• 25 novice paramedic students	• SimMan®	• Macintosh 3 • MVL with Mac3	• No practice	• Mac3/normal neck • Mac3/stiff neck • Mac3 + MVL/normal neck • Mac3 + MVL/stiff neck
Bair et al^Citation18	• 39 emergency medicine residents and attending physicians	• AirMan®	• Macintosh	• Unstructured	• Normal airway with direct laryngoscopy • Difficult airway simulation (maximal cervical spine stiffness and trismus), with direct laryngoscopy • Same difficult airway simulation managed with video laryngoscopy
Butchart et al^Citation21	• 30 paramedics	• Nakhosteen Bronchoscopy model scopin’	• GlideScope® Ranger (GSR) • Venner AP Advance (APA)	• 1 minute per technique	• Direct laryngoscopy • GSR • APA
Donoghue et al^Citation22	• 26 pediatric emergency physicians	• SimNewB® • SimBaby® • AirMan®	• Miller 0 • Miller 1	• No practice	• Three intubations with video display turned on • Three intubations without video display turned on
Fonte et al^Citation23	• 16 pediatric residents	• SimBaby®	• GlideScope	• 10 minutes	• Easy airway (normal airway) • Tongue edema • Tongue edema and oropharyngeal edema • Cervical collar with normal airway
Hodd et al^Citation24	• 90 clinicians	• Laerdal airway Management trainer • SimMan 3G®	• Macintosh 3 • GlideScope Ranger • AP Advance	• Until the participant believed themselves competent with each technique	• Normal airway • Difficult airway
Lim et al^Citation19	• 20 anesthetists	• Human patient simulator	• Macintosh • GlideScope	• Not specified*	• The GlideScope in easy/difficult laryngoscopies • The Macintosh in easy/difficult laryngoscopies
Legrand et al^Citation25	• 60 anesthetists	• SimMan®	• Bullard • Airtraq • Macintosh-type	• 12 minutes	• Scenario A: neck immobilisation using a hard cervical collar and a long spine board • Scenario B: identical baseline conditions as in scenario A with additional tongue oedema
Narang et al^Citation17	• 52 emergency medicine residents and attending physicians	• SimMan®	• Macintosh	• 10 minutes	• Standard – routine, uncomplicated intubations • Difficult – decreased neck mobility • Difficult – tongue edema
Sylvia et al^Citation26	• 69 pediatric and emergency medicine residents	• SimBaby®	• Miller • Macintosh • GlideScope portable GVL	• Until the participant felt comfortable with the techniques	• Direct laryngoscope • Video laryngoscope
Wetsch et al^Citation27	• 25 anesthetists	• Ambu® Airway Man	• GlideScope Ranger • Storz C-MAC® • Ambu-Pentaz AWS • Airtraq • McGrath series 5 video	• 5 minutes	• Video laryngoscope • Macintosh laryngoscope

Note:

* Articles that are unclear or do not supply an explanation of information.

Abbreviations: APA, AP advance; GSR, GlideScope Ranger; MVL, Macintosh Video Laryngoscope.

Table 2 Published reference, context of final assessment, source of assessment, skills assessed post-training, and results from studies

Citation	Contextual settings for assessment	Source of assessment ratings	Skills assessed post training	Results
Aziz et al^Citation20	• Normal neck on stretcher • Stiffened neck on floor	• Endpoint was recorded by student • Recorded observations	1. Intubation time 2. POGO 3. Success rate 4. Number of attempts 5. Satisfaction of MVL	• The MVL significantly improved POGO in all scenarios (P<0.05) • The MVL improved mean POGO 16%±6% in the manikin with a normal neck position on a stretcher and 33%±7% in the manikin with a stiff neck on the floor • The improvement was significantly greater in simulated difficult scenarios • The intubation success rate (94%) was equal in the two groups, and the POGO was significantly worse in the failures
Bair et al^Citation18	Emergency department	• Single investigator recorded grade I/II Cormack–Lehane direct and videos views	1. Ease of intubation 2. Time to intubation 3. Number of attempts	• On difficult laryngoscopy, a Cormack–Lehane grade I or II view was obtained in 20 (51%) direct laryngoscopies versus 38 (97%) of the video-assisted laryngoscopies (P<0.01) • The median VAS score for difficult airways was 50 mm (IQR =28–73 mm) for direct versus 18 mm (IQR =9–50 mm) for video (P<0.01) • The median time to intubation in difficult airways was 25 seconds (IQR =16–44 seconds) for direct versus 20 seconds (IQR =12–35 seconds) for video laryngoscopy (P<0.01) • All intubations were successful without need for an invasive airway
Butchart et al^Citation21	Ambulance stations and emergency departments	• An investigator by direct visualization under chest plate for time • An investigator counting the number of additional discrete forward advances of the ETT • VAS completed by the participant	1. Time to secure tracheal intubation 2. Evaluation of potential trauma 3. Number of attempts	• Time to achieve optimal view between AP Advance (APA) and GlideScope® Ranger (GSR) was not different (20 seconds versus 19 seconds; P=0.19), but tracheal intubation was significantly faster with the APA (25 seconds versus 46 seconds; P<0.0001) • Intubation success was 97% in both groups • Participants judged subjective trauma to be less for the APA than GSR on a visual analog scale (VAS; 1.6 cm versus 3.3 cm; P<0.001) • More than three forward advances were required in 43% of GSR and 0% of APA intubations
Donoghue et al^Citation22	Tertiary care pediatric hospital simulation lab	• Study subject reported POGO score	1. First attempt success 2. POGO score	• In the adult simulator, videolaryngoscopy use showed a first-attempt success in 81% of subjects compared with 39% with direct laryngoscopy (difference 43%; 95% CI 18% to 67%) • There was no difference in first-attempt success rates between videolaryngoscopy and direct laryngoscopy in the newborn or infant simulators • Videolaryngoscopy use led to increased POGO scores in all three simulators, with a difference of 25% (95% CI 2% to 48%) in newborn simulators, 23% (95% CI 2% to 48%) in infant simulators, and 42% (95% CI 18% to 66%) in adult simulators
Fonte et al^Citation23	Not specified*	• Two investigators present during sessions • SimBaby® video recordings • Participants subjective impression	1. Rate of successful placement of endotracheal tube 2. Duration of the tracheal incubation procedure 3. Number of attempts 4. Number of optimization maneuvers required 5. Severity of upper jaw trauma	• Failed intubations were higher with GlideScope in normal airway and tongue edema scenarios (3 versus 0, in both cases) • Mean (SD) time to successful intubation was significantly longer with GlideScope in the normal airway scenario (GlideScope, 38 [SD, 13] versus Miller, 26 [SD, 16] seconds; P=0.043) • The number of maneuvers was significantly higher with GlideScope in the tongue edema and oropharyngeal edema scenario (2.3 [SD, 1.5] versus 1.5 [SD, 1]; P=0.04) • Upper jaw injury index was significantly lower with GlideScope in normal airway (2.0 [SD, 1] versus 2.6 [SD, 0.8]; P=0.008) and cervical collar (2.1 [SD, 1.0] versus 2.8 [SD, 0.5]; P=0.011) scenarios • Participants considered GlideScope technique more difficult than standard Miller in NA (5 [SD, 2.0] versus 3 [SD, 1.3]; P=0.04) and TE (5.9 [SD, 2.5] versus 3.9 [SD, 1.7]; P=0.02) scenarios
Hodd et al^Citation24	Not specified*	• Participant-declared (time to successful intubation, with censoring of failed intubations)	1. Time 2. Intubation failures 3. Potential damage to laryngoscopy structure 4. Device rating	• APA and Macintosh were virtually identical in normal airways (median, 22 versus 23 seconds) • Intubation with the APA was faster than with the GlideScope in difficult airways (hazard ratio =7.6 [5.0, 11.3], P<0.001; median, 20 versus 59 seconds) • All participants intubated the difficult airway mannequin with the APA, whereas 33% and 37% failed with the GlideScope and Macintosh, respectively • In the difficult airway, 99% of participants achieved a Cormack and Lehane grade I to II view with the APA, versus 85% and 33% with the GlideScope and Macintosh, respectively • When asked to choose one device overall, 82% chose the APA
Lim et al^Citation19	Not specified*	• Blinded investigator	1. Successful or failed intubation 2. Time to intubate 3. Ease of intubation 4. Graded (1–3) by the anesthetist 5. Choice of intubating device	• In the easy scenarios, the anesthetists took longer to intubate using the GlideScope than the Macintosh laryngoscope (mean (SD) 19.0 (9.7) seconds versus 12.7 (5.9) seconds, respectively; P=0.006) • There was no difference in the number of successful intubations, ease of intubation, or choice of intubating device • In the difficult scenarios, the anesthetists took less time to intubate using the GlideScope (23.5 (12.7) seconds versus 70.5 (101.2) seconds, respectively; P=0.001) • The slightly higher success rate with the GlideScope was not statistically significant (20/20 versus 18/20, respectively; P=0.5) • The anesthetists found it easier to intubate using the GlideScope (median (interquartile range [range]) 1 (1–2 [1–2]) vs 2 (2–3 [1–3]), respectively; P<0.0001)
Legrand et al^Citation25	Not specified*	• Verification by one of the investigators using the lung inflation monitoring of the SimMan® • Matlab 7.1 for dental stress • Self-report of device usefulness	1. Intubation success rate 2. Time 3. Amount of dental stress 4. Satisfaction with airway device	• In Scenario A (neck immobilization), intubation success rates were 97%–100% with all devices • In Scenario B (neck immobilization with tongue edema), all participants failed to intubate the trachea using the conventional laryngoscope • When using the Bullard laryngoscope, intubation success rates of 87%–97% did not differ significantly (P>0.05) from those during scenario A and between groups (beginners versus experts) • When using the Airtraq laryngoscope, the overall intubation success rate was significantly lower (P<0.05) compared with scenario A and compared with use of the Bullard laryngoscope, and differed between beginners and experts (20 and 50%, respectively) • Intubation times were longer during scenario B • Dental stress was always lower (P<0.05) during use of the Bullard and Airtraq laryngoscopes compared with the conventional laryngoscope, lowest (P<0.05) during use of the Bullard laryngoscope
Narang et al^Citation17	Not specified*	• Co-investigators • CL classification (grades I–IV)	1. Time to view vocal cords 2. Time to intubate for success or failure	• Participants successfully intubated the mannequin faster using the Macintosh blade in both the normal and neck immobility settings (9.4 seconds faster, 95% CI 3.2–15.7, P=0.004, 16.1 seconds faster, 95% CI 3.6–28.7, P=0.01) • In the tongue edema setting, video laryngoscopy provided a better grade view of the cords, a higher success rate of viewing the cords at time of intubation (50% versus 12%), and a higher rate of successful intubations (83% versus 23%) • The GlideScope significantly reduced the time needed to view the cords (89 seconds reduction, 95% CI 54.4–123.7, P<0.0001) and intubate (131.3 seconds reduction, 95% CI 99.1–163.6, P<0.0001) for the tongue edema setting
Sylvia et al^Citation26	Emergency department	• Ventilation volume was recorded by SimBaby® • Investigators reviewed video sessions	1. Time to complete entire scenario 2. Announce need for intubation 3. Achieve intubation	• Seven subjects in the DL group required multiple attempts (21%), compared with 6 subjects in the VL group (17%) (P=0.718) • Median time to intubation was 30 seconds (95% confidence interval [CI], 19Y41 seconds) for DL and 39 seconds (95% CI, 36Y42 seconds) for VL (P=0.111) • Comparison of programs revealed a 77% PED success rate versus 85% EM success rate (P=0.578) and median time to intubation of 38 seconds (95% CI, 31Y45 seconds) for PED compared with 32 seconds (95% CI, 23Y41 seconds) for EM residents (P=0.316) • Subjects successful at first attempt revealed a 13-second median difference (DL, 23 seconds [95% CI, 18Y28 seconds] vs VL, 36 seconds [95% CI, 29Y43 seconds; P=0.01)
Wetsch et al^Citation27	Typical out-of-hospital setting, major trauma scene	• One member of the investigation team • Cormack and Lehane classification by participants	1. Time to achieve view of the glottis 2. Time of tracheal intubation 3. Time to cuff inflation 4. Time of first ventilation 5. Tracheal tube position	• Glottic view, tracheal intubation, cuff inflation and first ventilation were achieved most rapidly with the Macintosh laryngoscope, although the Airtraq and Pentax AWS video laryngoscopes were not significantly slower • Times were significantly longer when the GlideScope Ranger, McGrath series 5 or Storz C-MAC® video laryngoscopes were used (P<0.05), failure to place the endotracheal tube correctly was significantly commoner with the McGrath series 5 than with the Macintosh (P=0.031)

Notes:

* Articles that are unclear or do not supply an explanation of information.

Abbreviations: APA, AP advance; CI, confidence interval; CL, Cormack–Lehane; DL, direct laryngoscopy; EM, emergency department; ETT, emergency trauma technician; GSR, GlideScope Ranger; IQR, interquartile range; MVL, Macintosh Video Laryngoscope; NA, normal airway; PED, pediatrics; POGO, percentage of glottic opening; SD, standard deviation; TE, tongue edema; VAS, visual analog scale; VL, video laryngoscopy.

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