Comparison of the Efficacy of Macintosh Laryngoscope Versus Airtraq Videolaryngoscope for Visualization of Laryngeal Structures at the End of Thyroidectomy: A Randomized Control Study

To compare the efficacy of conventional Macintosh laryngoscope with Airtraq videolaryngoscope for visualization of laryngeal structures to rule out recurrent laryngeal nerve injury at the end of thyroidectomy. This randomized double-blind control study was conducted following IEC-Human approval, prospective CTRI registration and written informed consent from participants. Patients of either sex, aged 18-65 years, ASA grade I/II, scheduled for thyroidectomy under GA were included. Group DL underwent direct laryngoscopy using Macintosh blade whereas group VL underwent laryngoscopy using Airtraq® videolaryngoscope. CL(Cormack-Lehane) grade of laryngeal view, time taken to achieve optimal view, haemodynamic parameters, Patient reactivity score(PRS) and complications were noted. Unpaired t-test, chi-square test were used. A total of 73 patients were included for study with 38 in group DL and 35 in group VL. The grade of laryngeal view was found to be significantly better with Airtraq® VL compared to Macintosh laryngoscope without the application of BURP (p < 0.05). In the DL group, 34.2% (n = 13) had a CL grade I, 36.8% (n = 14) had CL grade 2A, 13.2% had CL grade 2B (n = 5) and 15.8% (n = 6) had CL Grade 3 at the end of thyroidectomy. On the contrary, in the VL Group, 71.5% (n = 25) of the participants had a CL Grade I; whereas, 20% (n = 7) had a CL Grade 2A, 5.7% (n = 2) had CL grade 2B and 2.8% (n = 1) of participants had CL grade 3. The mean "time taken to achieve optimal view' was comparable between the two groups (DL = 39.16 ± 105.53 s vs. VL = 38.89 ± 20.69 s) (p = 0.988).The haemodynamic parameters, Patient reactivity score and complications were comparable between the two groups. The performance of Airtraq® videolaryngoscope, a channelled VL is better than conventional Macintosh laryngoscope in terms of the optimal glottic view obtained to rule out recurrent laryngeal nerve palsy at the end of thyroidectomy.

GlideScope versus C-MAC D-blade videolaryngoscope for double-lumen tube intubation in patients with anticipated difficult airways: A multi-center, prospective, randomized, controlled trial

STUDY OBJECTIVE

Videolaryngoscopes are widely used to visualize difficult airways. Our aim was to compare the GlideScope and C-MAC D-blade videolaryngoscopes for double-lumen tube (DLT) intubation in patients with difficult airways.

DESIGN

A multi-center, prospective, randomized controlled trial.

SETTING

Three comprehensive tertiary, high-volume hospitals from 5 December 2020 to 4 November 2021.

PATIENTS

We included 348 adult patients with anticipated difficult airways who underwent elective thoracic surgery.

INTERVENTIONS

Patients were randomized into two groups: GlideScope and C-MAC D-blade. Following anesthesia induction, DLT intubation was performed using different videolaryngoscopes.

MEASUREMENTS

The primary outcome was the first-pass success rate of DLT intubation. All other results were recorded as secondary outcomes.

MAIN RESULTS

No significant differences were observed in the first-pass success rate of DLT intubation between the GlideScope and C-MAC D-blade (86.21% and 89.66%, respectively; P = 0.323). However, compared with the GlideScope, the C-MAC D-blade provided a lower Cormack-Lehane grade (P < 0.001), lower rates of external laryngeal pressure (48 vs. 15, P < 0.001), and postprocedure sore throat (26 vs. 8, P < 0.001). The numerical rating score for difficulty of videolaryngoscope insertion into the oral cavity, delivery to the glottis, and intubation into the main bronchus were significantly lower when using the C-MAC D-blade (P < 0.001). Moreover, the duration of DLT intubation was shorter in the C-MAC D-blade group (81 s [70-97 s] vs. 95 s [78-115 s], P < 0.001). In each group, two patients underwent fiberoptic intubation after three attempts with a videolaryngoscope failed.

CONCLUSIONS

In patients with difficult airways, the GlideScope and C-MAC D-blade provided a similar success rate on the first DLT intubation attempt; however, the C-MAC D-blade offers a better glottic view, easier and faster intubation, and lower incidence of sore throat.

Assessment of stress response due to C-Mac D-blade guided videolaryngoscopic endotracheal intubation and docking of da Vinci surgical robot using perfusion index in patients undergoing transoral robotic oncosurgery

Clinical utility of perfusion index (PI) has entered a new realm as a non-invasive, quantitative index of stress response to endotracheal intubation. Transoral robotic surgery (TORS) involves F-K retractor aided docking of the surgical robot producing haemodynamic and stress responses akin to laryngoscopy. We compared the stress response to videolaryngoscopy with that due to docking of da Vinci surgical robot using PI, heart rate and mean arterial pressure evaluated at specific time points post-laryngoscopy and post-docking. Twenty-six adult patients, scheduled for TORS under general endotracheal anaesthesia were included in this prospective, observational, single-centric cohort study. Statistical analysis included paired samples t-test, dotted box-whisker plots, trendlines and correlograms for comparative analysis of two stressors, laryngoscopy and docking. Baseline PI was 4.14. PI values increased post-midazolam (4.23), 1 min (5.69) and 3 min (6.25) post anaesthetic-induction, plummeted at laryngoscopy (3.24), remained low at 1 min (3.68), 3 min (4.69) thereafter, and were highest at 10 min (6.17) post-laryngoscopy and predocking (6.84). Docking witnessed a fall in PI (4.1), which remained low at 1 min (4.02), 3 min (4.31) and 10 min (4.79) post-docking. PI was significantly higher at laryngoscopy compared with PI at docking (p = 0.0044). At 1 min and 3 min post-laryngoscopy and post-docking, respectively, the differences in PI were statistically insignificant. PI at 10 min post-laryngoscopy was significantly lower than PI at 10 min post-docking (p < 0.0001). As non-invasively quantified by PI, videolaryngoscopic stress response is more intense but shorter-lived versus that due to docking. PI displays a negative correlation with haemodynamic variables. PI at laryngoscopy is a good predictor of PI at docking, enabling pre-emptive measures (fentanyl bolus; deepening of volatile anaesthesia from MAC-maintenance to MAC-intubation) anticipating the docking-induced stress response.Trial registration http://ctri.nic.in ; Identifier: CTRI/2019/11/022091.

Preoxygenation with standard facemask combining apnoeic oxygenation using high flow nasal cannula versuss standard facemask alone in patients with and without obesity: the OPTIMASK international study

BACKGROUND

Combining oxygen facemask with apnoeic oxygenation using high-flow-nasal-oxygen (HFNO) for preoxygenation in the operating room has not been studied against standard oxygen facemask alone. We hypothesized that facemask-alone would be associated with lower levels of lowest end-tidal oxygen (EtO2) within 2 min after intubation in comparison with facemask combined with HFNO.

METHODS

In an international prospective before-after multicentre study, we included adult patients intubated in the operating room from September 2022 to December 2022. In the before period, preoxygenation was performed with facemask-alone, which was removed during laryngoscopy. In the after period, facemask combined with HFNO was used for preoxygenation and HFNO for apnoeic oxygenation during laryngoscopy. HFNO was maintained throughout intubation. The primary outcome was the lowest EtO2 within 2 min after intubation. The secondary outcome was SpO2 ≤ 95% within 2 min after intubation. Subgroup analyses were performed in patients without and with obesity. This study was registered 10 August 2022 with ClinicalTrials.gov, number NCT05495841.

RESULTS

A total of 450 intubations were evaluated, 233 with facemask-alone and 217 with facemask combined with HFNO. In all patients, the lowest EtO2 within 2 min after intubation was significantly lower with facemask-alone than with facemask combined with HFNO, 89 (85-92)% vs 91 (88-93)%, respectively (mean difference - 2.20(- 3.21 to - 1.18), p < 0.001). In patients with obesity, similar results were found [87(82-91)% vs 90(88-92)%, p = 0.004]; as in patients without obesity [90(86-92)% vs 91(89-93)%, p = 0.001)]. SpO2 ≤ 95% was more frequent with facemask-alone (14/232, 6%) than with facemask combined with HFNO (2/215, 1%, p = 0.004). No severe adverse events were recorded.

CONCLUSIONS

Combining facemask with HFNO for preoxygenation and apnoeic oxygenation was associated with increased levels of lowest EtO2 within 2 min after intubation and less desaturation.

Evaluation of the conventional and modified aerosol boxes during tracheal intubation in normal and difficult airways: a randomized, crossover, manikin simulation study

The aim of this study was to evaluate conventional and modified aerosol boxes in terms of intubation time, first-pass intubation success, and mouth-to-mouth distance between the laryngoscopist and patient during tracheal intubation in simulated patients with normal and difficult airways. Sixteen anesthesiologists performed tracheal intubations with direct laryngoscope or three different videolaryngoscopes (McGRATH MAC videolaryngoscope, C-MAC videolaryngoscope, and Pentax-AWS) without an aerosol box or with a conventional or a modified aerosol boxes in simulated manikins with normal and difficult airways. Intubation time, first-pass intubation success, and mouth-to-mouth distance during tracheal intubation were recorded. Compared to no aerosol box, the use of a conventional aerosol box significantly increased intubation time in both normal and difficult airways (Bonferroni-corrected P-value (P_corrected) = 0.005 and P_corrected = 0.003, respectively). Intubation time was significantly shorter with the modified aerosol box than with the conventional one for both normal and difficult airways (P_corrected = 0.003 and P_corrected = 0.011, respectively). However, no significant differences were found in intubation time between no aerosol box and the modified aerosol box for normal and difficult airways (P_corrected = 0.336 and P_corrected = 0.112, respectively). The use of conventional or modified aerosol boxes significantly extended the mouth-to-mouth distances compared to not using an aerosol box during tracheal intubation with each laryngoscope (all P_corrected < 0.05), and the distances were not different between the conventional and modified boxes in normal and difficult airways. The use of modified aerosol box did not increase intubation time and could help maintain a distance from the simulated patients with normal and difficult airways.

How to improve intubation in the intensive care unit. Update on knowledge and devices

Tracheal intubation in the critically ill is associated with serious complications, mainly cardiovascular collapse and severe hypoxemia. In this narrative review, we present an update of interventions aiming to decrease these complications. MACOCHA is a simple score that helps to identify patients at risk of difficult intubation in the intensive care unit (ICU). Preoxygenation combining the use of inspiratory support and positive end-expiratory pressure should remain the standard method for preoxygenation of hypoxemic patients. Apneic oxygenation using high-flow nasal oxygen may be supplemented, to prevent further hypoxemia during tracheal intubation. Face mask ventilation after rapid sequence induction may also be used to prevent hypoxemia, in selected patients without high-risk of aspiration. Hemodynamic optimization and management are essential before, during and after the intubation procedure. All these elements can be integrated in a bundle. An airway management algorithm should be adopted in each ICU and adapted to the needs, situation and expertise of each operator. Videolaryngoscopes should be used by experienced operators.

Predictors of difficult intubation when using a videolaryngoscope with an intermediate-angled blade during the first attempt: a prospective observational study

The curvature of a videolaryngoscope blade has been diversified from the standard macintosh-type to the hyperacute-angle-type, resulting in different performances. We aimed to determine the intubation success rate and identify predictors of difficult intubation when using an intermediate-angled videolaryngoscope in the first attempt of intubation under routine anaesthesia settings. We enrolled 808 patients between 19 and 79 years of age, scheduled for elective surgeries under general anaesthesia with orotracheal intubation from July 2017 to November 2018; patients who were candidates for awake intubation were excluded. We obtained patient demographic data and performed airway evaluation before induction of anaesthesia for elective surgeries. We used the UEScope for tracheal intubation with a hockey stick-shaped malleable stylet. The intubation time was defined as the total duration from the entry of the blade into the oropharynx to the detection of first end-tidal carbon dioxide capnogram; this duration was recorded along with the number of intubation attempts. Difficult intubation was defined as either > 60 s duration for tracheal intubation, or > 1 intubation attempt. The use of the UEScope demonstrated a 99.4% success rate for intubation; however, increased difficulties were observed in patients who were male, obese, had a short thyromental distance, limited mouth opening, and high upper-lip-bite test class. Despite the high intubation success rate using an intermediate-angled videolaryngoscope, we recommend preparing backup plans, considering the increased difficulty in patients with certain preoperative features.Clinical trial number and registry URL: Clinical Trials.gov Identifier: NCT03215823 (Date of registration: 12 July).

Approaching the airway in prehospital emergency is a common and potentially life-saving practice

Management by the environment is complex, which means a much higher percentage of difficult airways than in a regulated environment such as the operating room. Failure or prolonged attempt to tracheal intubation is associated with unfavorable outcomes and serious complications. Acute epiglottitis is a life-threatening disorder, classified as a medical emergency within the diseases of the upper respiratory airway and characterized by its sudden and deadly evolution if rapid intubation is not achieved to allow oxygenation of the patient. We describe a 36-year-old male patient with stridor, dyspnea e hypoxemia due to total obstruction of airway, caused by an acute epiglottitis. We aim to highlight this unusual injury and its management from the prehospital until discharge illustrating the severity of the clinical presentation, current treatment and outcome.

Features of new vision-incorporated third-generation video laryngeal mask airways

Numerous studies have shown that blindly inserted supraglottic airway devices (SADs) are sub-optimally placed in 50 to 80% of all cases. Placement under direct vision has been recommended. We describe the very first two new SADs of the third generation that incorporate a videoscope with flexible tip. Both devices are made up of two interlocking components-the SAD and a videoscope. The 3rd generation, direct vision SADs allow vision-guided insertion, corrective manoeuvres, if needed, and correct placement in the hypopharynx and possess additional features which permit insertion of a gastric tube and endotracheal intubation should the need arise. This article describes the two new devices' physical characteristics, features, rationale for use, advantages and limitations in comparison to existing devices. Each of the two new devices-the Video Laryngeal Mask (VLM^TM, UE Medical®) and the SafeLM® Video Laryngeal Mask System (SafeLM^TM VLMS, Magill Medical Technology®) consist of two parts: (a) a disposable 2nd generation SAD with a silicone cuff and an anatomically curved tube; and (b) a reusable patient-isolated videoscope and monitoring screen, with the flexible scope located into a specially-designed, blind-end channel terminating in the bowl of the SAD, preventing the videoscope from contacting patient body fluids in the SAD bowl. Third generation placement-under-direct-vision supraglottic airway devices possess several theoretical safety and ease of use advantages which now need to be validated in clinical use.

Approaching the airway in prehospital emergency is a common and potentially life-saving practice

Management by the environment is complex, which means a much higher percentage of difficult airways than in a regulated environment such as the operating room. Failure or prolonged attempt to tracheal intubation is associated with unfavorable outcomes and serious complications. Acute epiglottitis is a life-threatening disorder, classified as a medical emergency within the diseases of the upper respiratory airway and characterized by its sudden and deadly evolution if rapid intubation is not achieved to allow oxygenation of the patient. We describe a 36-year-old male patient with stridor, dyspnea e hypoxemia due to total obstruction of airway, caused by an acute epiglottitis. We aim to highlight this unusual injury and its management from the prehospital until discharge illustrating the severity of the clinical presentation, current treatment and outcome.

An in vitro assessment of light intensity provided during direct laryngeal visualization by videolaryngoscopes with Macintosh geometry blades

BACKGROUND

Adequate illumination of the larynx is needed during laryngoscopy to facilitate tracheal intubation. The International Organization for Standardization (ISO) has established a minimum light intensity for direct laryngoscopy (DL) of over 500 lux for at least ten minutes, but no such standard exists for Macintosh geometry videolaryngoscope (Mac-VL) blades, which allow for both direct or indirect (videoscopic) viewing of the larynx. Using in situ bench and in vitro testing in a human cadaver, we determined illumination and luminance values delivered by various Mac-VLs and compared these with published minimum lighting benchmarks as well as a reference direct laryngoscope.

METHODS

We tested six Mac-VLs (i-view™, McGRATH™ MAC, GlideScope® Spectrum™ [single-use] DVM S4, GlideScope® Titanium [reusable] Mac T4, C-MAC® S [single-use] Macintosh #4, C-MAC® [reusable] Macintosh #4) together with one direct laryngoscope (Heine LED). Each laryngoscope was assessed with three measurements, as follows: part 1: illuminance (lux) was measured in situ using a purpose-designed benchtop light intensity measurement apparatus; part 2: luminance (light reflected back to the eye) was measured (in candela m^-2 [cd·m^-2]) during videolaryngoscopy (VL) and DL in a human cadaver using a spot meter pointed at the interarytenoid notch; part 3: illuminance (lux) was measured during VL and DL in a human cadaver using a light meter surgically implanted just proximal to the vocal cords.

RESULTS

Illuminance and luminance varied significantly among the Mac-VLs. Mean (standard devitation) illuminance among the six tested Mac-VLs ranged from 117 (11) to 2,626 (42) lux in the measurement apparatus and from 228 (11) to 2,900 (374) lux by the surgically implanted light meter in the cadaver. All values were less than the reference Heine direct laryngoscope and some fell below the published ISO standard of 500 lux for DL. Luminance testing by spot meter had a similarly wide range, varying from 3.78 (0.60) to 49.1 (10.4) cd·m^-2, with some Mac-VLs delivering less luminance than the reference Heine direct laryngoscope.

CONCLUSIONS

Our results indicate that illuminance and luminance provided by Mac-VLs used for direct laryngeal viewing varies substantially between devices, with some falling below standards previously suggested as the minimum required for DL. While this may have no implications for the quality of image visible on a device's video monitor, the clinician should be aware that when Mac-VLs are used for direct viewing of the larynx, lighting may not be optimal. This might adversely affect ease or success of tracheal intubation.

Comparison of the strength of various disposable videolaryngoscope blades

PURPOSE

Breaking of disposable blades during emergency endotracheal intubation has been reported. Breakage can cause serious injury and foreign body ingestion. We aimed to measure and analyze the strength characteristics of different disposable videolaryngoscope blades with the application of an upward-lifting force.

METHODS

We measured the strength of four disposable videolaryngoscope blades (C-Mac® S Video laryngoscope MAC #3, Glidescope GVL® 3 stat, Pentax AWS® PBlade TL type, and King Vision® aBlade #3) using the fracture test. The strength of 12 samples of each type of disposable videolaryngoscope blade was measured using an Instron 5,966 tensile tester by applying an upward-lifting force.

RESULTS

After the fracture test using C-Mac, Glidescope GVL, Pentax AWS, and King Vision, the number of deformed blades were 0, 12, 3, and 7, respectively, and the number of broken blades were 12, 0, 9, and 5, respectively. The mean (standard deviation) maximum force strengths of Pentax AWS, C-Mac, King Vision, and Glidescope GVL blades were 408.4 (27.4) N, 325.8 (26.5) N, 291.8 (39.3) N, and 262.7 (3.8) N, respectively (P < 0.001).

CONCLUSION

Clinicians should be aware of the varied strength characteristics of the four types of disposable videolaryngoscope blades when they are used in endotracheal intubation.

Comparison of four channelled videolaryngoscopes to Macintosh laryngoscope for simulated intubation of critically ill patients: the randomized MACMAN2 trial

Background

Videolaryngoscopes with an operating channel may improve the intubation success rate in critically ill patients. We aimed to compare four channelled videolaryngoscopes to the Macintosh laryngoscope used for intubation of a high-fidelity simulation mannikin, in a scenario that simulated critical illness due to acute respiratory failure.

Results

Of the 79 residents who participated, 54 were considered inexperienced with orotracheal intubation. Each participant used all five devices in random order. The first-pass success rate was 97.5% [95% CI 91.1–99.7] for Airtraq™, KingVision™, and Pentax AWS200™, 92.4% [95% CI 84.2–97.2] for VividTrac VT-A100™, and 70.9% [95% CI 59.6–80.6] for direct Macintosh laryngoscopy. The first-pass success rate was significantly lower with direct Macintosh laryngoscopy than with the videolaryngoscopes (p  <  0.0001 for Airtraq™, KingVision™, Pentax AWS200™, and VividTrac VT-A100™).

Conclusion

The Airtraq™, KingVision™, and Pentax AWS200™ channelled videolaryngoscopes produced high first-pass success rates with a lower boundary of the 95% CI above 90%. A multicentre, randomised controlled clinical study comparing channelled videolaryngoscopy to direct laryngoscopy should include one of these three videolaryngoscopes.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13613-021-00916-3.

Successful airway management with combined use of a McGRATHTM MAC videolaryngoscope and fiberoptic bronchoscope in a patient with congenital tracheal stenosis diagnosed in adulthood

Background

Most patients with congenital tracheal stenosis (CTS) develop respiratory symptoms early in life. CTS remaining undiagnosed until adulthood is rare.

Case presentation

A 51-year-old female was scheduled for cardiovascular surgery. She had undergone laparoscopic surgery 3 years earlier and was found to have a difficult airway. Postoperatively, she was diagnosed with CTS. For the current cardiovascular surgery, combined use of a McGRATH^TM MAC videolaryngoscope and fiberoptic bronchoscope allowed sufficient visualization of the glottis and trachea, resulting in successful intubation.

Conclusions

CTS patients have a high probability of difficult intubation. Our experience suggests the efficacy of combined use of a videolaryngoscope and fiberoptic bronchoscope for airway management in CTS patients.

Comparison of McGrath, Pentax, and Macintosh laryngoscope in normal and cervical immobilized manikin by novices: a randomized crossover trial

BACKGROUND

The aim of this study was to compare tracheal intubation performance regarding the time to intubation, glottic view, difficulty, and dental click, by novices using McGrath videolaryngoscope (VL), Pentax Airway Scope (AWS) and Macintosh laryngoscope in normal and cervical immobilized manikin models.

METHODS

Thirty-five anesthesia nurses without previous intubation experience were recruited. Participants performed endotracheal intubation in a manikin model at two simulated neck positions (normal and fixed neck via cervical immobilization), using three different devices three times each. Performance parameters included intubation time, success rate of intubation, Cormack Lehane laryngoscope grading, dental click, and subjective difficulty score.

RESULTS

Intubation time and success rate during first attempt were not significantly different between the 3 groups in normal airway manikin. In the cervical immobilized manikin, the intubation time was shorter (p = 0.012), and the success rate with the first attempt was significantly higher (p < 0.001) when using McGrath VL and Pentax AWS compared with Macintosh laryngoscope. Both VLs showed less difficulty score (p < 0.001) and more Cormack Lehane grade I (p < 0.001) in both scenarios. The incidence of dental clicks was higher with Macintosh laryngoscope compared with McGrath VL in cervical immobilized airway (p < 0.001).

CONCLUSIONS

McGrath VL and Pentax AWS did not show clinically significant decrease in intubation time, however, they achieved higher first attempt success rate, easier intubation and better glottis view compared with Macintosh laryngoscope by novices in a cervical immobilized manikin model. McGrath VL may reduce the risk of dental injury compared with Macintosh laryngoscope in cervical immobilized scenario.

TRIAL REGISTRATION

ClinicalTrials.gov (NCT03161730), May 22, 2017 https://clinicaltrials.gov/ct2/hom.

Downfolding of the epiglottis into the laryngeal inlet after tracheal intubation using the McGRATHTM MAC videolaryngoscope: a case report

Background

Downfolding of the epiglottis into the laryngeal inlet is considered to be a rare complication of tracheal intubation. We describe a case of epiglottic downfolding during tracheal intubation using a McGrath videolaryngoscope (McGRATH^TM MAC).

Case presentation

A 44-year-old female was scheduled for breast reconstruction surgery. Intubation was performed using a McGrath videolaryngoscope. After intubation, videolaryngoscopy revealed that the epiglottis was inverted and folded down into the laryngeal inlet. We elevated the larynx anteriorly using the McGrath videolaryngoscope, enabling the downfolded epiglottis to be pulled out from the laryngeal inlet and restored to its original position. After surgery, the patient was extubated without any complications.

Conclusions

When using the McGrath videolaryngoscope, both glottic exposure similar to that achieved with the Macintosh laryngoscope and careful observation of the epiglottis should enable the prevention, detection, and treatment of epiglottic downfolding into the laryngeal inlet.

Comparison of C-MAC D-blade videolaryngoscope and McCoy laryngoscope efficacy for nasotracheal intubation in simulated cervical spinal injury: a prospective randomized comparative study

BACKGROUND

Immobilization with cervical spine worsens endotracheal intubation condition. Though various intubation devices have been demonstrated to perform well in oral endotracheal intubation, limited information is available concerning nasotracheal intubation (NTI) in patients with cervical spine immobilization. The present study compared the performance of the C-MAC D-Blade videolaryngoscope with the McCoy laryngoscope for NTI in patients with simulated cervical spine injuries.

METHODS

This was a prospective, randomized, controlled, study done in a tertiary hospital. Ninety-five patients requiring NTI were included in data analysis: McCoy group (group M, n = 47) or C-MAC D-Blade videolaryngoscope group (group C, n = 48). A Philadelphia neck collar was applied before anesthetic induction to immobilize the cervical spine. Single experienced anesthesiologist performed NTI. The primary outcome was duration of intubation divided by three steps: nose to oropharynx; oropharynx into glottic inlet; and glottic inlet to trachea. Secondary outcomes included glottic view as percentage of glottis opening (POGO) score and Cormack-Lehance (CL) grade, modified nasal intubation-difficulty scale (NIDS) rating, hemodynamic changes before and after intubation, and complications.

RESULTS

Total intubation duration was significantly shorter in group C (39.5 ± 11.4 s) compared to group M (48.1 ± 13.9 s). Group C required significantly less time for glottic visualization and endotracheal tube placement in the trachea. More patients in group C had CL grade I and higher POGO scores (P <  0.001, for both measures). No difficulty in NTI (modified NIDS = 0) was more in group C than group M. Hemodynamic changes and incidence of complications were comparable between groups.

CONCLUSION

The C-MAC D-Blade videolaryngoscope is an effective tool for NTI in a simulated difficult airway, which improves glottic visualization and shortens intubation time relative to those with McCoy laryngoscope.

TRIAL REGISTRATION

Clinical Research Information Service of the Korea National Institute of Health, Identification number: KCT 0004535, Registered December 10, 2019, Retrospectively registered, http://cris.nih.go.kr.

Recent trends in airway management

Clinical airway management continues to advance at a fast pace. To help update busy anesthesiologists, this abbreviated review summarizes notable airway management advances over the past few years. We briefly discuss advances in video laryngoscopy, in flexible intubation scopes, in jet ventilation, and in extracorporeal membrane oxygenation (ECMO). We also discuss noninvasive ventilation in the forms of high-flow nasal cannula apneic oxygenation and ventilation and nasal continuous positive airway pressure (CPAP) masks. Emerging concepts related to airway management, including the physiologically difficult airway and lower airway management, new clinical subspecialties and related professional organizations such as Anesthesia for Bronchoscopy, the Society for Head and Neck Anesthesia, and fellowship training programs related to advanced airway management are also reviewed. Finally, we discuss the use of checklists and guidelines to enhance patient safety and the value of large databases in airway management research.

Videolaryngoscope-assisted coblation of epiglottic cysts

PURPOSE

This study aims to investigate the safety and effectiveness of videolaryngoscope-assisted coblation of epiglottic cysts (VACECs) under general anesthesia.

METHODS

Twenty-eight consecutive patients with epiglottic cysts (ECs), underwent VACECs in this prospective clinical series from January 2015 to March 2019. The pre-operative electronic flexible laryngoscopic or 70° rigid laryngeal endoscopic examination was carried out to assess the location and size of ECs. There was a periodical follow-up survey for all patients.

RESULTS

A total 28 of patients were enrolled, including 12 men and 16 women, with an average age of 55 (range 24-78). The patient's medical history ranged from half a month to 2 years. The size of the cyst arranged from 0.8 to 1.5 cm. All patients were cured without pharyngeal or systemic complications. No tooth loss occurred in five patients (17.9%) with loose anterior teeth. Specimen pathology confirmed the diagnosis in all patients. No recurrence was found after more than half a year's follow-up.

CONCLUSIONS

VACECs brings together the advantages of videolaryngoscope and coblation. It is a simple, safe and feasible procedure for patients with ECs and is worthy of clinical application.

Guiding Flexible-Tipped Bougie Under Videolaryngoscopy: An Alternative to Fiberoptic Nasotracheal Intubation in Maxillofacial Surgeries

Background

Maxillofacial surgeries are known to have difficulty in airway management due to anatomical and functional reasons. Tumors of maxillofacial region and diseases of TM joint limit mouth opening as well as airway space. Various methods have been tried with success for nasotracheal intubation including fiberoptic-aided as well as blind nasal and light-guided intubation. Video laryngoscopy-assisted intubation uses visualization of glottis without the need of alignment of all the three axes of airway.

Purpose

Video laryngoscopy is being considered to increase the success rate in various different setups including critical care, pre-hospital and operating rooms. Flexible-tipped bougie guided by a video laryngoscope was used in patients with limited airway space undergoing maxillofacial surgery.

Methods

In present study, airway of five patients posted for various maxillofacial surgeries was secured by passing flexible-tipped bougie through the nasopharyngeal airway and, once under the view of a McGrath videolaryngoscope, was advanced toward the glottis; the rotation of the bougie with the required flexion of the tip helped a quick redirection of bougie to enter the larynx at an angle.

Results

Our experience of five cases with anticipated difficult intubation normally judged to be manageable with fiberoptic bronchoscopic intubation were managed without awake fiberoptic bronchoscopy using flexible-tipped bougie under vision of videolaryngoscopy. All patients were successfully managed with this technique.

Conclusion

Flexible-tipped bougie could take the direction toward glottis under a videolaryngoscope in an anticipated difficult airway, making a place for airway management in patients with limited mouth opening.

Nationwide survey on training and device utilization during tracheal intubation in French intensive care units

Background

Intubation is a lifesaving procedure that is often performed in intensive care unit (ICU) patients, but leads to serious adverse events in 20–40% of cases. Recent trials aimed to provide guidance about which medications, devices, and modalities maximize patient safety. Videolaryngoscopes are being offered in an increasing range of options and used in broadening indications (from difficult to unremarkable intubation). The objective of this study was to describe intubation practices and device availability in French ICUs.

Materials and methods

We conducted an online nationwide survey by emailing an anonymous 26-item questionnaire to physicians in French ICUs. A single questionnaire was sent to either the head or the intubation expert at each ICU.

Results

Of 257 ICUs, 180 (70%) returned the completed questionnaire. The results showed that 43% of intubators were not fully proficient in intubation; among them, 18.8% had no intubation training or had received only basic training (lectures and observation at the bedside). Among the participating ICUs, 94.4% had a difficult intubation trolley, 74.5% an intubation protocol, 92.2% a capnography device (used routinely to check tube position in 69.3% of ICUs having the device), 91.6% a laryngeal mask, 97.2% front-of-neck access capabilities, and 76.6% a videolaryngoscope. In case of difficult intubation, 85.6% of ICUs used a bougie (154/180) and 7.8% switched to a videolaryngoscope (14/180). Use of a videolaryngoscope was reserved for difficult intubation in 84% of ICUs (154/180). Having a videolaryngoscope was significantly associated with having an intubation protocol (P = 0.043) and using capnography (P = 0.02). Airtraq^® was the most often used videolaryngoscope (39.3%), followed by McGrath^®Mac (36.9%) then by Glidescope^® (14.5%).

Conclusion

Nearly half the intubators in French ICUs are not fully proficient with OTI. Access to modern training methods such as simulation is inadequate. Most ICUs own a videolaryngoscope, but reserve it for difficult intubations.

Tracheal intubation with the McGrath MAC X-blade videolaryngoscope in morbidly obese and nonobese patients

Background/aim

Increased body mass index (BMI) and neck circumference are the two independent predictors of difficult intubation. McGrath MAC X-Blade is a videolaryngoscope specifically designed for difficult intubations.

Materials and methods

Eighty patients with the American Society of Anesthesiologists (ASA) physical status I–III undergoing elective surgery requiring endotracheal intubation were enrolled in the study. Patients were divided into two groups, nonobese (BMI < 30) and morbidly obese (BMI > 35). All patients were intubated with the McGrath MAC X-Blade in both groups. View optimization and tube insertion maneuvers such as reinsertion of the device, slight removal of the device, cricoid pressure, handling force, 90° anticlockwise rotation of the tube, use of stylet, and head flexion maneuvers were recorded. Cormack–Lehane grades, insertion times, intubation, and total intubation times were recorded. The hemodynamic changes and postoperative minor complications were also recorded.

Results

Body mass index, neck circumference, Mallampati scores, and ASA physical status were statistically higher in the morbidly obese group (P < 0.001 and P < 0.05). Sternomental distances were shorter in the morbidly obese (P < 0.05). Cormack–Lehane grades were comparable among the groups. The morbidly obese patients required more reinsertion attempts and cricoid pressure maneuvers during intubation than the nonobese patients (P = 0.019 versus P = 0.012, respectively). Slight removal of the device, handling force, use of the stylet, 90° anticlockwise rotation of the tube, and head flexion maneuvers were also helpful in both groups. Although device insertion times were similar between the groups, intubation and total intubation times were longer in the morbidly obese group (P = 0.009 and P = 0.034, respectively). The groups were comparable in hemodynamic changes and postoperative minor complications.

Conclusion

The McGrath MAC X-Blade videolaryngoscope could safely be used both in nonobese (BMI < 30) and morbidly obese (BMI > 35) patients with the aid of some key maneuvers and with a statistically significant but clinically negligible prolongation of the intubation time.

Role of playback videolaryngoscope footage in improved patient care

Despite the frequency of videolaryngoscope use, to the authors’ knowledge, there are no publications exploring the role of playback video recording in real time to improve patient care. We present a patient with a difficult airway complicated by trauma during GlideScope® (Verathon Inc., Bothell, WA, USA) intubation. The injury was not recognised by any of the anaesthetic staff observing the intubation, and was only identified when playback video footage was viewed. This provided the opportunity for early ear, nose and throat surgical review prior to extubation. Airway trauma can be missed by the anaesthetist. Reviewing video playback footage at an appropriate time during the case may enable more timely recognition of airway injuries and, ultimately, improved patient care.

Hemodynamic responses to tracheal intubation with Bonfils compared to C-MAC videolaryngoscope: a randomized trial

Background

Direct laryngoscopy (DL) produce tachycardia and hypertension that could be fatal in a patient with a brain injury. Bonfils fiberscope and C-MAC videolaryngoscope are associated with little hemodynamic instability compared to DL. Scientific evidence comparing these two alternatives does not exist. We conducted this study to determine the hemodynamic effects of Bonfils compared to C-MAC in patients undergoing elective surgery.

Methods

Fifty (50) patients listed for elective surgery were randomly assigned to endotracheal intubation with Bonfils or C-MAC. After a standardized induction, intubation was done via the retromolar approach (Bonfils group) or via videolaryngoscopy (C-MAC group). A research assistant, who was not blinded to the intervention, recorded heart rate (HR) and arterial blood pressure (systolic, diastolic and mean arterial blood pressure [MAP]) at induction and at every minute during the 5 min post intubation. The primary outcome was the hemodynamic response to intubation, as verified every minute for the first 5 min compared to baseline value.

Results

After randomization, the two groups were comparable except for ASA I/II ratio which was slightly higher in the C-MAC group (p = 0.046). Heart rate (p = 0.40) and MAP (p = 0.30) were comparable between the two groups within 5 min post intubation. Intubation time was shorter with C-MAC than with Bonfils (30 ± 2 s vs 38 ± 2 s; p = 0.02).

Conclusion

Hemodynamic responses to tracheal intubation using the Bonfils fiberscope is comparable to the C-MAC videolaryngoscope among patients scheduled for an elective surgery. In light of these findings, using either technique appears to be a reasonable course of action.

Trial registration

ISRCTN #34923, retrospectively registered, 26/03/2018.

Electronic supplementary material

The online version of this article (10.1186/s12871-018-0592-7) contains supplementary material, which is available to authorized users.

The pressure exerted on the tongue during intubation with simultaneous cervical spine immobilisation: a comparison between four videolaryngoscopes and the Macintosh laryngoscope-a manikin study

Excessive pressures exerted on the tongue during intubation may be associated with serious complications and may make intubation more difficult. The aim of this study was to evaluate five different intubating devices in the hands of experienced anaesthetists during simulated conditions of reduced cervical spine mobility. Forty senior anaesthetists participated in the study (female = 18, male = 22). The mean pressure exerted on the tongue during intubation was recorded with a standard manometer. The overall intubation success rate as well as the difference in exerted pressures between female and male anaesthetists were also assessed. The five studied devices were used by each participant and they were randomly chosen. Each anaesthetists participating in the study had over 15 years of clinical anaesthetic practice. The mean pressure exerted on the tongue during intubation was significantly lower when the videolaryngoscopes (VLs) were used (p < 0.0001 for each of the studied VL). There were failed intubation attempts with all of the studied devices, the highest failure rate was in the Airtraq® group, 10 in 40 (25%). Female anaesthetists exerted lower pressures during intubation with all studied devices (except the Airtraq®). However, the difference was only significant for the Macintosh laryngoscope (p = 0.0083). The blades of VLs exerted lower pressures on the tongue during intubation than the Macintosh laryngoscope blade. Their use may be associated with less complications. Furthermore, male anaesthetists exerted higher pressures on the soft tissues although this was neither statistically nor clinically significant. There was higher failed intubation rate in the male anaesthetist group.

Comparison of VividTrac®, Airtraq®, King Vision®, Macintosh Laryngoscope and a Custom-Made Videolaryngoscope for difficult and normal airways in mannequins by novices

BACKGROUND

Direct laryngoscopy remains the gold standard for endotracheal intubation and is preferred by experienced operators. However, an increasing number of reports currently support videolaryngoscopy, particularly for novice users. The widespread use of videolaryngoscopy may be limited due to financial limitations, especially in low-income countries. Therefore, affordable single-use scopes are now becoming increasingly popular. We sought to compare these new scopes with direct laryngoscopes and the previously tested videolaryngoscopes in mannequins by novices.

METHODS

Fifty medical students were recruited to serve as novice users. Following brief, standardized training, students were asked to execute endotracheal intubation with each of the devices, including the Airtraq®, a custom-made videolaryngoscope, the King Vision®, the Macintosh laryngoscope and the VividTrac®, on an airway trainer (Laerdal Airway Management Trainer®) in normal and difficult airway scenarios. We evaluated the time to and the proportion of successful intubation, the best view of the glottis, esophageal intubation, dental trauma and user satisfaction.

RESULTS

We observed no differences in esophageal intubation. However, intubation-related times, the view of the glottis and operator satisfaction were significantly better throughout the study with the commercial videolaryngoscopes. In comparison, the custom-made videolaryngoscope performance proved to be similar to that of the Macintosh laryngoscope. The VividTrac® performance was similar (P > 0.05) or significantly better than that of the King Vision® in both scenarios.

CONCLUSIONS

Based upon our results, the Airtraq®, King Vision® and VividTrac® were superior to the Macintosh laryngscope in both normal and difficult airway scencarios for novice users. In particular, our study is the first to report that the VividTrac® shows promise for further clinical evaluation.

Evaluation of gum-elastic bougie combined with direct and indirect laryngoscopes in vomitus setting: A randomized simulation trial

PURPOSE

Videolaryngoscopes may not be useful in the presence of vomitus due to blurred images on the monitor. The objective of our study is to compare the utility of gum-elastic bougie (GEB) application for tracheal intubation with the Macintosh laryngoscope (McL), which is a direct laryngoscope, with that of the Pentax-AWS Airwayscope® (AWS) and McGRATH® MAC (McGRATH) in simulated vomitus settings.

METHODS

Sixteen novice doctors performed tracheal intubation on an adult manikin using McL, AWS, and McGRATH with or without GEB under normal and vomitus simulations.

RESULTS

In the normal setting the tracheal intubation was successful with the three laryngoscopes regardless of GEB application. In the vomitus setting, the intubation success rate did not significantly improve using McL, while it did using McGRATH or AWS. In the normal settings, GEB application significantly lengthened the intubation time in all three laryngoscopes. By contrast, in the vomitus settings, GEB application significantly shortened the intubation time in all three laryngoscopes. For the comparison of three laryngoscopes, the intubation time did not differ significantly in normal setting, while it was significantly longer in McG and AWS trials than McL trial.

CONCLUSION

The GEB application facilitates the tracheal intubation in the vomitus setting using McGRATH and AWS in adult simulation.

Use of King Vision® videolaryngoscope in an unanticipated difficult airway in an adult patient with giant vallecular cyst, a case report

Laryngeal cysts are largely asymptomatic and typically described in the context of incidental discovery on routine laryngoscopy. These cysts, in adults are even rarer and can have catastrophic consequences in an anaesthetized patient if airway management is inappropriate. We describe a case of difficult endotracheal intubation and the treatment of an adult patient with an asymptomatic, giant vallecular cyst that was discovered during rapid-sequence induction of general anesthesia in urgent surgery. In conclusion, vallecular cysts can cause extreme problems in securing the airway. It is important to avoid complications associated with repeated attempts at intubation, airway loss, or cyst rupture causing difficulty visualizing vocal cords and aspiration. The use of King Vision^® videolaryngoscope is a good alternative in these cases. Close attention to logistics and the immediate availability of an otolaryngologist is vital.

Assessment of TruviewPCD videolaryngoscope for intubation in children

OBJECTIVE

The aim of this observational prospective study was to evaluate the usefulness of TruviewPCD for tracheal intubation in clinical practice, and to provide data for future studies.

MATERIAL AND METHOD

A study was conducted on 86 consecutive children undergoing ear, nose and throat (ENT) or paediatric procedures under general anaesthesia with tracheal intubation. Children with two or more difficult airway criteria were excluded. A descriptive statistical analysis was performed.

RESULTS

Eighty-three patients were successfully intubated with TruviewPCD. Demographic data: Age 4.9 (2.8) years, weight 19.5 (7.7)kg. Seventy-nine children needed one attempt and four required two attempts at intubation. Time for glottis view and tracheal intubation was 10.8 (5.6) and 30 [27.9-37] seconds, respectively. Eighty-one patients were classified as easy or very easy to intubate, and only two cases were considered difficult. No significant complications were registered.

CONCLUSIONS

TruviewPCD is a good device for paediatric airway management. It would be interesting to have an intermediate blade between size 1 and 2, as the difference between both is too wide.

[Comparing insertion characteristics on nasogastric tube placement by using GlideScope™ visualization vs. MacIntosh laryngoscope assistance in anaesthetized and intubated patients]

BACKGROUND AND OBJECTIVE

This was a prospective, randomized clinical study to compare the success rate of nasogastric tube insertion by using GlideScope™ visualization versus direct MacIntosh laryngoscope assistance in anesthetized and intubated patients.

METHODS

Ninety-six ASA I or II patients, aged 18-70 years were recruited and randomized into two groups using either technique. The time taken from insertion of the nasogastric tube from the nostril until the calculated length of tube had been inserted was recorded. The success rate of nasogastric tube insertion was evaluated in terms of successful insertion in the first attempt. Complications associated with the insertion techniques were recorded.

RESULTS

The results showed success rates of 74.5% in the GlideScope™ Group as compared to 58.3% in the MacIntosh Group (p=0.10). For the failed attempts, the nasogastric tube was successfully inserted in all cases using rescue techniques. The duration taken in the first attempt for both techniques was not statistically significant; Group A was 17.2±9.3s as compared to Group B, with a duration of 18.9±13.0s (p=0.57). A total of 33 patients developed complications during insertion of the nasogastric tube, 39.4% in Group A and 60.6% in Group B (p=0.15). The most common complications, which occurred, were coiling, followed by bleeding and kinking.

CONCLUSION

This study showed that using the GlideScope™ to facilitate nasogastric tube insertion was comparable to the use of the MacIntosh laryngoscope in terms of successful rate of insertion and complications.

[Outdoor performance of different videolaryngoscopes on a glacier: a manikin study]

OBJECTIVES

Little information about the performance of videolaryngoscopes outdoors is available. We aimed to test the hypothesis that a Macintosh direct laryngoscope would perform less well than videolaryngoscopes under difficult environmental conditions (high-altitude glacier, sun-reflecting snow).

MATERIAL AND METHODS

After local research ethics committee approval, this randomized controlled trial enrolled 20 physicians who intubated manikins with limited cervical extension mouth opening under 5 conditions: 1) in hospitals (indoors), 2) indoors at a high altitude, 3) outdoors on a glacier in sunlight without sunglasses, 4) outdoors on a glacier with sunglasses, and 5) outdoors on a glacier with the physician and manikin covered with a blanket. The following devices were compared to the Macintosh laryngoscope, McGrath, Airtraq-SP, GlideScope, KingVision, C-MAC-D-Blade, AP Advance Difficult Airway Blade and Bonfils. The main outcome was first-attempt intubation success; secondary outcomes were intubation time, visibility on the screen, and view of the glottis.

RESULTS

The best intubation success rates were observed indoors asnd on the glacier under a blanket. The Macintosh performed better than the videolaryngoscopes under bright sunlight. We observed significant differences in the performance of devices with built-in screens under varying conditions. Wearing sunglasses improved performance with some but not all devices. Intubation times differed significantly between devices, regardless of the environmental condition (P<0.01). Screen visibility differed significantly between conditions and devices.

CONCLUSION

Successful intubation with videolaryngoscopes is less likely under bright sunlight conditions. The Macintosh laryngoscope performs better than videolaryngoscopes. Covering the heads of both the physician and the patient with a dark blanket sufficiently overcomes the detrimental effects of sunlight during intubation.

Comparing insertion characteristics on nasogastric tube placement by using GlideScope™ visualization vs. MacIntosh laryngoscope assistance in anaesthetized and intubated patients

BACKGROUND AND OBJECTIVE

This was a prospective, randomized clinical study to compare the success rate of nasogastric tube insertion by using GlideScope™ visualization versus direct MacIntosh laryngoscope assistance in anesthetized and intubated patients.

METHODS

Ninety-six ASA I or II patients, aged 18-70 years were recruited and randomized into two groups using either technique. The time taken from insertion of the nasogastric tube from the nostril until the calculated length of tube had been inserted was recorded. The success rate of nasogastric tube insertion was evaluated in terms of successful insertion in the first attempt. Complications associated with the insertion techniques were recorded.

RESULTS

The results showed success rates of 74.5% in the GlideScope™ Group as compared to 58.3% in the MacIntosh Group (p=0.10). For the failed attempts, the nasogastric tube was successfully inserted in all cases using rescue techniques. The duration taken in the first attempt for both techniques was not statistically significant; Group A was 17.2±9.3s as compared to Group B, with a duration of 18.9±13.0s (p=0.57). A total of 33 patients developed complications during insertion of the nasogastric tube, 39.4% in Group A and 60.6% in Group B (p=0.15). The most common complications, which occurred, were coiling, followed by bleeding and kinking.

CONCLUSION

This study showed that using the GlideScope™ to facilitate nasogastric tube insertion was comparable to the use of the MacIntosh laryngoscope in terms of successful rate of insertion and complications.

[Effectiveness of the GlideScope video laryngoscope in a case of unexpected difficult airway due to lingual tonsil hypertrophy]

Lingual tonsil hypertrophy can cause varying degrees of airway obstruction and is considered a risk factor for difficult mask ventilation and tracheal intubation. We report a case of unexpected difficult airway in a patient with unknown lingual tonsil hypertrophy that was solved with the use of the GlideScope video laryngoscope.

Fiberscope Assisted Videolaryngoscope Intubation in the Surgical Treatment of TMJ Ankylosis

Temporomandibular ankylosis is characterized by the formation of a bony mass which replaces normal temporomandibular joint (TMJ) articulation. Anaesthetic management in these patients requires expertise and dependable intubation technique that allows successful intubation due to anticipated difficulty in accessing the airway. A novel technique of endotracheal intubation is used for the successful airway management during the surgical treatment in patients with TMJ ankylosis with the assistance of fiberscope and GlideScope(®) videolaryngoscope. GlideScope(®) videolaryngoscope is a recently introduced system for tracheal intubation that has a dedicated video camera encased into a laryngoscope blade and provides better panoramic view than the conventional laryngoscopes. This technique avoids complications such as trauma to soft tissue structures surrounding the glottis during the passage of the tube over the fiberscope. It gives a clear view of the tube and its cuff position during intubation. It also abbreviates the time required for intubation which is a crucial determinant in this subset of patients owing to the difficult airway associated with paediatric age group.

Using image processing technology and mathematical algorithm in the automatic selection of vocal cord opening and closing images from the larynx endoscopy video

The human larynx is an important organ for voice production and respiratory mechanisms. The vocal cord is approximated for voice production and open for breathing. The videolaryngoscope is widely used for vocal cord examination. At present, physicians usually diagnose vocal cord diseases by manually selecting the image of the vocal cord opening to the largest extent (abduction), thus maximally exposing the vocal cord lesion. On the other hand, the severity of diseases such as vocal palsy, atrophic vocal cord is largely dependent on the vocal cord closing to the smallest extent (adduction). Therefore, diseases can be assessed by the image of the vocal cord opening to the largest extent, and the seriousness of breathy voice is closely correlated to the gap between vocal cords when closing to the smallest extent. The aim of the study was to design an automatic vocal cord image selection system to improve the conventional selection process by physicians and enhance diagnosis efficiency. Also, due to the unwanted fuzzy images resulting from examination process caused by human factors as well as the non-vocal cord images, texture analysis is added in this study to measure image entropy to establish a screening and elimination system to effectively enhance the accuracy of selecting the image of the vocal cord closing to the smallest extent.

[Glottiscopes and videolaryngoscopes: a rational choice?]

Different airway devices can be used by paediatrician anaesthesiologists for difficult airway management in infant younger than 2 years. The four devices analyzed (Airtraq® [Prodol Meditec]; Glidescope® Cobalt [Verathon]; Vidéolaryngoscope [Storz]; laryngoscope Truview® [Truphatek]) increase the Cormack and Lehane grade against direct laryngoscopy and optimized external larynx movements. They need training, on manikin then in vivo, for an optimal use. The needed number of in vivo successful intubations is not determined. It is probably between 10 and 20. The choice between these devices, in accordance with the published studies, which compared the devices, is difficult. The manikin studies allow to standardize airway, but the results are not transposable in vivo. Concerning the airway devices with disposable blade, the Glidescope®, for oral intubation, seems to be better than Airtraq® if we take into account the oropharyngeal volume needed.