Quantification of False Vocal Fold Hyperfunction During Quiet Breathing in Muscle Tension Dysphonia

BACKGROUND/OBJECTIVES

False vocal fold (FVF) hyperfunction during phonation is thought to be a diagnostic sign of primary muscle tension dysphonia (pMTD). However, hyperfunctional patterns with phonation are also observed in typical speakers. This study tested the hypothesis that FVF posturing during quiet breathing, as measured by the curvature of FVF, could differentiate patients with pMTD from typical speakers.

METHODS

Laryngoscopic images were collected prospectively in 30 subjects with pMTD and 33 typical speakers. Images were acquired at the end of expiration and maximal inspiration during quiet breathing, during sustained /i/, and during loud phonation before and after a 30-min vocal loading task. The FVF curvature (degree of concavity/convexity) was quantified using a novel curvature index (CI, >0 for hyperfunctional/convex, <0 for "relaxed"/concave) and compared between the two groups.

RESULTS

At end-expiration, the pMTD group adopted a convex FVF contour, whereas the control group adopted a concave FVF contour (mean CI 0.123 [SEM 0.046] vs. -0.093 [SEM 0.030], p = 0.0002) before vocal loading. At maximal inspiration, the pMTD group had a neutral/straight FVF contour, whereas the control group had a concave FVF contour (mean CI 0.012 [SEM 0.038] vs. -0.155 [SEM 0.018], p = 0.0002). There were no statistically significant differences in FVF curvature between groups in either the sustained voiced or loud conditions. Vocal loading did not change any of these relationships.

CONCLUSIONS

A hyperfunctional posture of the FVFs during quiet breathing especially at end-expiration may be more indicative of a hyperfunctional voice disorder than supraglottic constriction during voicing.

LEVEL OF EVIDENCE

3 Laryngoscope, 133:3449-3454, 2023.

[Subglottic cysts in infants: a report of 3 cases and literature review]

Subglottic cyst is a rare cause of laryngeal tinnitus in infants and young children, and only a few cases have been reported at home and abroad. In this paper, we report the clinical characteristics and treatment experience of three cases of subglottic cysts in Children's Hospital of Nanjing Medical University. All the 3 childrem were prematurechildren, with a history of tracheal intubation, and the main symptoms were coughing and wheezing.Electronic nasopharyngolaryngoscopy revealed spherical neoplasm under the glottis. Neck computed tomography （CT） showed a slightly hypodense shadow with poorly defined borders, and no significant enhancement was observed after enhancement. Under the self-retaining laryngoscope, the new organisms were clamped and nibbled, and the cyst wall was cauterized by low temperature plasma. There was no recurrence in postoperative follow-up.

Value of the Hyomental Distance Measured With Ultrasound in Forecasting Difficult Laryngoscopy in Newborns

PURPOSE

Preoperative evaluations of difficult airways are imperative, especially in newborns. The hyomental distance is a reliable index for predicting difficult airways in adults. However, few studies have evaluated the value of the hyomental distance for predicting difficult airways in newborns. It is unclear whether the hyomental distance forecasts a restricted or difficult view when using direct laryngoscopy. We intended to develop an effective system for predicting difficult tracheal intubation in newborns.

DESIGN

A prospective observational clinical study.

METHODS

Newborns aged 0 to 28 days undergoing oral endotracheal intubation with direct laryngoscopy for elective surgery under general anesthesia were enrolled. The hyomental distance and hyoid level tissue thickness were assessed by ultrasound. Other parameters, such as the mandibular length and sternomental distance, were also evaluated before anesthesia. The glottic structure view under laryngoscopy was graded according to the Cormack-Lehane classification. The patients with Grade 1 and 2 laryngeal views were assigned to Group E. Those with Grade 3 and 4 views were assigned to Group D.

FINDINGS

A total of 123 newborns were recruited for our study. The incidence of poor visualization of the larynx during laryngoscopy in our study was 10.6%. The multifactor logistic regression results showed that the hyomental distance was a powerful predictor of difficult laryngoscopy (OR = 0.16, 95% CI 0.03-0.74, P = .019). The curve with the highest sensitivity and specificity and the maximum area under the curve (AUC) was the hyomental distance. The receiver operating characteristic (ROC) curve for the hyomental distance suggested that the best cut-off value was less than equal to 2.74 cm, with an AUC of 0.80 (95% CI 0.64-0.95).

CONCLUSIONS

It is noninvasive and feasible to accurately measure the hyomental distance with ultrasound in newborns, and the results are reliable. We believe that the hyomental distance measured with ultrasound could be used as a marker for predicting difficult laryngoscopy in newborns.

[Application of peroral endoscopic-assisted laryngeal microsurgery in children with laryngeal neurofibromas]

Objective:To investigate the clinical manifestations and the effect of peroral endoscopic-assisted laryngeal microsurgery for children with laryngeal neurofibroma, and to provide clinical reference for the diagnosis and treatment of this disease. Methods:The clinical data of 4 children with laryngeal tumors admitted to the Department of Otorhinolaryngology, Children's Hospital of Chongqing Medical University from January 2021 to June 2023 were retrospectively analyzed. Laryngeal tumors were removed by peroral endoscopic-assisted laryngeal microsurgery. One case underwent tracheotomy at the same time, and one case was simultaneously performed with laryngeal T tube placement and tracheotomy. Results:Surgical resection is the best treatment for laryngeal neurofibroma, and laryngeal microsurgery should be actively used for patients with surgical indications.This surgical method has the advantages of good efficacy, minimal invasion, aesthetics and preservation of laryngeal function, which not only ensures safety, but also improves the quality of life after surgery, and has the value of development and promotion.

Indirect laryngeal surgery of vocal fold polyps: a dying or evolving art?

Objective

Vocal fold polyps (VFPs) are the most common benign laryngeal lesions that require surgery and are routinely managed by microlaryngoscopy (MLS) under general anaesthesia. Prior to introduction of MLS, VFPs were removed using indirect laryngoscopic surgery (ILS) in local anaesthesia, a procedure that required substantial surgical skill to operate with an unmagnified mirror view of the larynx. With the adoption of wireless endoscopy equipment and personal computers, we tried to simplify this technique so that it can be easily performed in the office. This study aimed to assess the effectiveness of ILS by comparing voice outcomes with MLS.

Materials and methods

ILS and MLS were performed in six patients each. Treatment outcomes were measured using a voice self-assessment and objective acoustic analysis. The total cost of both procedures was calculated.

Results

Both techniques allowed successful removal of VFPs in all patients, without significant intergroup differences in voice outcomes. The cost of ILS was significantly lower.

Conclusions

Despite the pilot nature of the study and the small sample size, our data indicate the potential value of this technique which, considering its simplicity and economic value could be used as an alternative to MLS in carefully selected patients.

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.

Idiopathic subglottic stenosis with an inguinal hernia in children: A case report

RATIONALE

Idiopathic subglottic stenosis is a fibrotic condition of unknown origin that results in blockage of the central airway in the subglottic region. It is widely acknowledged that subglottic stenosis is a relatively uncommon structural anomaly that is difficult to operate on and cure due to its anatomical location. Inguinal hernias are well-established to be prevalent in infants and youngsters. We present a case of subglottic stenosis in a child complicated with an inguinal hernia (IH).

PATIENT CONCERNS

A 7-year-old female was admitted to our hospital with a 1-month history of progressive bulging in the left lower quadrant of the abdomen. She complained of no stomach discomfort, distension, or dyspnea, but her family reports that the patient usually wheezes during moderate exertion and has no family history of asthma or lung illness. However, for unclear reasons, the infant experienced shortness of breath following training. A chest CT scan was unremarkable. Below the glottis, a membranous stenosis was discovered. The stenosis beneath the glottis was discovered using dynamic laryngoscopy.

DIAGNOSES

Idiopathic subglottic stenosis with an IH.

INTERVENTIONS

An otorhinolaryngologist employed a carbon dioxide laser to eliminate the subglottic stenosis. Following successful intubation by the anesthesiologist, pediatric surgeons performed laparoscopic high ligation of the hernial sac.

OUTCOMES

After 1 month, a repeat laryngoscopy revealed significant expansion of the subglottic stenosis, accounting for the improvement in respiratory symptoms.

LESSONS

The present case raises awareness that surgeons should be more vigilant about respiratory complications in patients with an IH. Early diagnosis and treatment of respiratory illnesses are critical for patients undergoing endotracheal intubation.

A Predictor of Difficult Airway: The Tasli Classification in Transnasal Flexible Laryngoscopy

INTRODUCTION

Difficult airway is defined as difficulty or failure in one or more steps in upper airway management. Evaluation of the upper airway with physical examination methods and endoscopic devices is crucial in predicting difficult airway. The aim of this study was to evaluate bedside tests, Cormack Lehane (CL) and Tasli Classification (TC) scores of the patients and it was aimed to reveal the role of TC which will be performed preoperatively as a predictor of difficult tracheal intubation (DTI).

METHODS

The study included a total of 98 patients who underwent surgical treatment under general anesthesia. Demographic data, including age, gender, and body mass index (BMI), and bedside tests consisting Modified Mallampati Classification (MMC), thyromental (TD) and sternomental (SD) distances, neck circumference (NC), interincisor distance (IID), CL and TC were recorded.

RESULTS

Evaluation was made of 64 (65.3%) male and 34 (34.7%) female patients ranging in age from 18 to 84 years (mean age: 50.35 ± 0.47 years). The successfully intubated patients (SIP)  group comprised 68 (69.4%) patients, and the difficult intubation patients (DIP) group, 30 (30.6%). According to CL, the numbers of SIP and DIP constituting grade 1 was 29 (42.6%) and one (3.3%); grade 2a was 29 (42.6%) and one (3.3%); grade 2b was eight (11.8%) and three (10%); grade 3a was one (1.5%) and six (20%); grade 3b was one (1.5%) and 14 (46.7%) respectively. Grade 4 was only detected in the DIP group in 5 (16.7%) patients. According to TC, the numbers of SIP and DIP constituting grade 1 was 20 (29.4%) and 1 (3.3%); grade 2a was 37 (54.4%) and seven (23.3%); grade 2b was 10 (14.7%) and 18 (60%); grade 3 was one (1.5%) and two (6.7%) respectively. Grade 4 was only detected in the DIP group in two (6.7%) patients.

CONCLUSION

The TC, CL, NC and BMI scores were higher in the DIP group and higher TC scores (grade 2b, 3, and 4) can be a predictor of difficult airway. However, it may be more beneficial to use TC as a complementary diagnostic tool with bedside tests such as NC, SM, TM and MMC, rather than used alone.

Tracheal Narrowing and Its Impact on Anesthesia Care in Patients With Morquio A (Mucopolysaccharidosis Type IVA): An Observational Study

BACKGROUND

Recently, tracheal narrowing has been recognized as a significant comorbid condition in patients with Morquio A, also known as mucopolysaccharidosis IVA. We studied a large cohort of patients with Morquio A to describe the extent of their tracheal narrowing and its relationship to airway management during anesthesia care.

METHODS

This is an observational study, collecting data retrospectively, of a cohort of patients with Morquio A. Ninety-two patients with Morquio A syndrome were enrolled, among whom 44 patients had their airway evaluated by computed tomography angiography and had undergone an anesthetic within a year of the evaluation. Our hypothesis was that the tracheal narrowing as evaluated by computed tomography angiography increases with age in patients with Morquio A. The primary aim of the study was to examine the degree of tracheal narrowing in patients with Morquio A and describe the difficulties encountered during airway management, thus increasing awareness of both the tracheal narrowing and airway management difficulties in this patient population. In addition, the degree of tracheal narrowing was evaluated for its association with age or spirometry parameters using Spearman's rank correlation. Analysis of variance followed by the Bonferroni test was used to further examine the age-based differences in tracheal narrowing for the 3 age groups: 1 to 10 years, 11 to 20 years, and >21 years.

RESULTS

Patient age showed a positive correlation with tracheal narrowing ( rs= 0.415; 95% confidence interval [95% CI], 0.138-0.691; P = .005) with older patients having greater narrowing of the trachea. Among spirometry parameters, FEF25%-75% showed an inverse correlation with tracheal narrowing as follows: FEF25%-75% versus tracheal narrowing: ( rs = -0.467; 95% CI, -0.877 to -0.057; P = .007). During anesthetic care, significant airway management difficulties were encountered, including cancelation of surgical procedures, awake intubation using flexible bronchoscope, and failed video laryngoscopy attempts.

CONCLUSIONS

Clinically significant tracheal narrowing was present in patients with Morquio A, and the degree of such narrowing likely contributed to the difficulty with airway management during their anesthetic care. Tracheal narrowing worsens with age, but the progression appears to slow down after 20 years of age. In addition to tracheal narrowing, spirometry values of FEF25%-75% may be helpful in the overall evaluation of the airway in patients with Morquio A.

Effectiveness of ultrasonic measurement for the hyomental distance and distance from skin to epiglottis in predicting difficult laryngoscopy in children

OBJECTIVES

Studies have shown that some ultrasonic indicators can predict difficult airways in adults to an extent. However, whether ultrasonic parameters can be used to predict difficult airways in children is unclear. This study investigated the predictive value of several ultrasonic indices for difficult laryngoscopy (DL) in children.

METHODS

Pediatric patients aged 5 to 12 years who underwent endotracheal intubation under general anesthesia were enrolled. The hyomental distance in the extended position (HMDE), tongue thickness, midsagittal tongue cross-sectional area, tongue width, and distance from skin to epiglottis (DSE) were measured by ultrasound before anesthesia. The study end point was DL. The receiver operating characteristic curve was used to evaluate the predictive value of each parameter.

RESULTS

Three hundred and ten children were included in the final analysis, and fifteen (4.8%) children had DL. The shortened HMDE assessed by ultrasound could help identify children aged 5 to 12 years with DL (5-8 years: area under the curve (AUC) 0.74, sensitivity 0.88, specificity 0.60; 9-12 years: AUC 0.72, sensitivity 0.71, specificity 0.83). An increased DSE could help identify children aged 5 to 8 years with DL (AUC 0.76, sensitivity 0.88, specificity 0.69).

CONCLUSIONS

Ultrasonic measurement of the HMDE can be used to predict DL in children aged 5 to 12 years. The DSE measured by ultrasound can be used to predict DL in children aged 5 to 8 years.

CLINICAL RELEVANCE STATEMENT

The hyomental distance and the distance from skin to epiglottis measured by ultrasound can be used to predict difficult laryngoscopy in children, which can help reduce serious complications caused by unanticipated difficult airways in children during anesthesia.

KEY POINTS

• Ultrasonic measurement of the hyomental distance in the extended position may be an effective predictor of difficult laryngoscopy in children aged 5 to 12 years. • The distance from skin to epiglottis measured by ultrasound can be used to predict difficult laryngoscopy in children aged 5 to 8 years. • Preoperative airway assessment using ultrasound can be effectively applied in children and has a great application prospect.

Simple steps towards improving safety in obstetric airway management: A quality improvement project

BACKGROUND

Guidelines from the Obstetric Anaesthetists' Association and Difficult Airway Society state that 'a videolaryngoscope should be immediately available for all obstetric general anaesthetics'.

OBJECTIVE

To report the incidence of videolaryngoscopy use, and other airway management safety interventions, in an obstetric population before and after various quality improvement interventions.

DESIGN

Prospective data collection was undertaken over 18 months, divided into three separate 6-month periods: June to November 2019; March to August 2021; January to June 2022. These periods relate to evaluation of specific quality improvement interventions.

SETTING

The project was carried out in a large tertiary referral obstetric unit.

PATIENTS

We identified 401 pregnant women (> 20 weeks' gestation) and postnatal women (up to 48 h post delivery) undergoing an obstetric surgical procedure under general anaesthesia.

INTERVENTIONS

To standardise practice, an intubation checklist was introduced in December 2020 and multidisciplinary staff training in August 2021.

MAIN OUTCOME MEASURES

Primary outcome measures were use of a Macintosh-style videolaryngoscope and tracheal intubation success. Secondary outcome measures were use of an intubation checklist; low flow nasal oxygen; and ramped patient positioning.

RESULTS

Data from 334 tracheal intubations (83.3% of cases) were recorded. Videolaryngoscope use increased from 60% in 2019, to 88% in 2021, to 94% in 2022. Tracheal intubation was successful in all patients, with 94% first pass success overall and only 0.9% requiring three attempts. Use of secondary outcome measures also increased: low flow nasal oxygen from 48% in 2019 to 90% in 2022; ramped positioning from 95% in 2021 to 97% in 2022; and checklist use from 63% in 2021 to 92% in 2022.

CONCLUSIONS

We describe the successful adoption of simple safety measures introduced into routine practice. These comprised videolaryngoscopy, ramped positioning and low flow nasal oxygen. Their introduction was supported by the implementation of an intubation checklist and multidisciplinary team training.

Development and validation of a screening method for difficult tracheal intubation based on geometric simulation and computer technology

BACKGROUND

The anatomical characteristics of difficult airways can be analysed geometrically. This study aims to develop and validate a geometry-assisted difficult airway screening method (GADAS method) for difficult tracheal intubation.

METHODS

In the GADAS method, a geometric simulated model was established based on computer graphics. According to the law of deformation of the upper airway on laryngoscopy, the expected visibility of the glottis was calculated to simulate the real visibility on laryngoscopy. Validation of the new method: Approved by the Ethics Committee of Yijishan Hospital of Wannan Medical College. Adult patients who needed tracheal intubation under general anaesthesia for elective surgery were enrolled. The data of patients were input into the computer software to calculate the expected visibility of the glottis. The results of tracheal intubation were recorded by anaesthesiologists. The primary observation outcome was the screening performance of the expected visibility of the glottis for difficult tracheal intubation.

RESULTS

The geometric model and software of the GADAS method were successfully developed and are available for use. We successfully observed 2068 patients, of whom 56 patients had difficult intubation. The area under the receiver operating characteristic curve of low expected glottis visibility for predicting difficult laryngoscopy was 0.96 (95% confidence interval [CI]: 0.95-0.96). The sensitivity and specificity were 89.3% (95% CI: 78.1-96.0%) and 94.3% (95% CI: 93.2%-95.3), respectively.

CONCLUSIONS

It is feasible to screen difficult-airway patients by applying computer techniques to simulate geometric changes in the upper airway.

Real-time detection of laryngopharyngeal cancer using an artificial intelligence-assisted system with multimodal data

BACKGROUND

Laryngopharyngeal cancer (LPC) includes laryngeal and hypopharyngeal cancer, whose early diagnosis can significantly improve the prognosis and quality of life of patients. Pathological biopsy of suspicious cancerous tissue under the guidance of laryngoscopy is the gold standard for diagnosing LPC. However, this subjective examination largely depends on the skills and experience of laryngologists, which increases the possibility of missed diagnoses and repeated unnecessary biopsies. We aimed to develop and validate a deep convolutional neural network-based Laryngopharyngeal Artificial Intelligence Diagnostic System (LPAIDS) for real-time automatically identifying LPC in both laryngoscopy white-light imaging (WLI) and narrow-band imaging (NBI) images to improve the diagnostic accuracy of LPC by reducing diagnostic variation among on-expert laryngologists.

METHODS

All 31,543 laryngoscopic images from 2382 patients were categorised into training, verification, and test sets to develop, validate, and internal test LPAIDS. Another 25,063 images from five other hospitals were used as external tests. Overall, 551 videos were used to evaluate the real-time performance of the system, and 200 randomly selected videos were used to compare the diagnostic performance of the LPAIDS with that of laryngologists. Two deep-learning models using either WLI (model W) or NBI (model N) images were constructed to compare with LPAIDS.

RESULTS

LPAIDS had a higher diagnostic performance than models W and N, with accuracies of 0·956 and 0·949 in the internal image and video tests, respectively. The robustness and stability of LPAIDS were validated in external sets with the area under the receiver operating characteristic curve values of 0·965-0·987. In the laryngologist-machine competition, LPAIDS achieved an accuracy of 0·940, which was comparable to expert laryngologists and outperformed other laryngologists with varying qualifications.

CONCLUSIONS

LPAIDS provided high accuracy and stability in detecting LPC in real-time, which showed great potential for using LPAIDS to improve the diagnostic accuracy of LPC by reducing diagnostic variation among on-expert laryngologists.

A novel technique of handling the blade for videolaryngoscopy intubation in patients with a semi-rigid neck collar: a prospective randomized controlled trial

BACKGROUND

Semi-rigid neck collars to protect the cervical spine can limit the extent of neck movement and mouth opening; this may further complicate orotracheal intubation. We aimed to compare intubation environments obtained with videolaryngoscopy using the technique of gliding a blade under the epiglottis and that obtained using the conventional Macintosh blade technique of blade tip placement on the vallecula.

METHODS

This prospective randomized study included patients aged ≥ 20 years with American Society of Anesthesiologists physical status I-III scheduled for cervical spine surgery between October 2020 and August 2021. Patients were divided into two groups according to the placement of the blade of the McGrathTM videolaryngoscope: the gliding and conventional groups. The percentage of glottic opening (POGO) score was the primary endpoint. We also recorded the time to obtain the optimal laryngoscopic view, intubation duration, and ease and satisfaction of the researcher performing intubation.

RESULTS

Among 176 patients, the POGO scores were significantly higher in the gliding group than in the conventional group (88.9 ± 14.7 vs. 63.8 ± 27.4, P < 0.001). The time to achieve the optimal glottic view for intubation and duration of intubation were also shorter, and ease and satisfaction in performing intubation were better in the gliding group than in the conventional group.

CONCLUSION

Our findings demonstrated a superior glottic view and more favorable intubation environments when the blade tip was placed under the epiglottis than using the conventional Macintosh technique in patients with immobilized cervical spine.

Laryngoscopy and Tracheal Intubation: Does Use of a Video Laryngoscope Facilitate Both Steps of the Procedure?

STUDY OBJECTIVE

To compare the effect of the use of a video laryngoscope versus a direct laryngoscope on each step of emergency intubation: laryngoscopy (step 1) and intubation of the trachea (step 2).

METHODS

In a secondary observational analysis of data from 2 multicenter, randomized trials that enrolled critically ill adults undergoing tracheal intubation but did not control for laryngoscope type (video laryngoscope vs direct laryngoscope), we fit mixed-effects logistic regression models examining the 1) the association between laryngoscope type (video laryngoscope vs direct laryngoscope) and the Cormack-Lehane grade of view and 2) the interaction between grade of view, laryngoscope type (video laryngoscope vs direct laryngoscope), and the incidence of successful intubation on the first attempt.

RESULTS

We analyzed 1,786 patients: 467 (26.2%) in the direct laryngoscope group and 1,319 (73.9%) in the video laryngoscope group. The use of a video laryngoscope was associated with an improved grade of view as compared with a direct laryngoscope (adjusted odds ratio for increasingly favorable grade of view 3.14, 95% confidence interval [CI] 2.47 to 3.99). Successful intubation on the first attempt occurred in 83.2% of patients in the video laryngoscope group and 72.2% of patients in the direct laryngoscope group (absolute difference 11.1%, 95% CI 6.5% to 15.6%). Video laryngoscope use modified the association between grade of view and successful intubation on the first attempt such that intubation on the first attempt was similar between video laryngoscope and direct laryngoscope at a grade 1 view and higher for video laryngoscope than direct laryngoscope at grade 2 to 4 views (P<.001 for interaction term).

CONCLUSIONS

Among critically ill adults undergoing tracheal intubation, the use of a video laryngoscope was associated both with a better view of the vocal cords and with a higher probability of successfully intubating the trachea when the view of the vocal cords was incomplete in this observational analysis. However, a multicenter, randomized trial directly comparing the effect of a video laryngoscope with a direct laryngoscope on the grade of view, success, and complications is needed.

Office-Based Treatment of Vocal Fold Polyps and Reinke's Edema: A Rational Comparison With Suspension Laryngoscopy

OBJECTIVE

Benign laryngeal lesions have traditionally been treated through suspension laryngoscopy under general anesthesia (GA). Recently, the development of operative videoendoscopes coupled with photoangiolytic lasers has allowed clinicians to treat these conditions in the outpatient clinic. We report our experience in the office-based (OB) setting for the treatment of patients affected by vocal fold polyps (VFPs) and Reinke's edema (RE), comparing it to patients treated under GA.

METHODS

A retrospective analysis was conducted on patients affected by VFP or RE. A 445 nm diode blue laser was used through the operative channel of a flexible video-endoscope for OB procedures, while GA surgeries were carried out with cold steel instrumentation. The Voice Handicap Index-10 (VHI-10) represented the primary outcome. Endoscopic outcomes, duration, and morbidity of the procedures were investigated as secondary outcomes.

RESULTS

A total of 153 patients were retrospectively enrolled. 52 were treated in an OB setting, while 91 underwent GA. Regarding patients with RE, both the OB and GA cohorts showed a significant improvement in VHI-10 (from 12.7 to 2.6 and 19.5 to 5.1, respectively; p < 0.001), as did those with VFPs (from 11.8 to 2.3 and 15.9 to 2.9 respectively; p < 0.001). No differences were found when comparing VHI-10 in the OB and GA cohorts. The mean procedural time of OB treatment (4.9 min) was significantly shorter than GA (37.1 min). No adverse events were reported.

CONCLUSION

Our data demonstrate the efficacy and safety of the OB setting. For selected patients, OB treatments offer comparable vocal outcomes, favorable morbidity, and reduced operation times, making them an appealing alternative to the traditional approach.

LEVEL OF EVIDENCE

3 Laryngoscope, 133:2665-2672, 2023.

Single-use versus reusable metallic laryngoscopes for non-emergent intubation: A retrospective review of 72,672 intubations

STUDY OBJECTIVE

Increased regulatory requirements for sterilization in recent years have prompted a widespread transition from reusable to single-use laryngoscopes. The purpose of this study was to determine if the transition from metallic reusable to metallic single-use laryngoscopes impacted the performance of direct laryngoscopy at an academic medical center.

DESIGN

Single-site retrospective cohort study.

SETTING

General anesthetic cases requiring tracheal intubation.

PATIENTS

Adult patients undergoing non-emergent procedures.

INTERVENTIONS

Data were collected two years before and two years after a transition from metallic reusable to metallic single-use laryngoscopes.

MEASUREMENTS

The primary outcome was need for intubation rescue with an alternate device. Secondary outcomes were difficult laryngeal view (modified Cormack-Lehane grade ≥ 2b) and hypoxemia (SpO2 < 90% for >30 s) during direct laryngoscopy intubations. Subgroup analyses for rapid sequence induction, Macintosh blades, Miller blades, and patients with difficult airway risk factors (Obstructive Sleep Apnea, Mallampati ≥3, Body Mass Index >30 kg/m2) were performed.

MAIN RESULTS

In total, 72,672 patients were included: 35,549 (48.9%) in the reusable laryngoscope cohort and 37,123 (51.1%) in the single-use laryngoscope cohort. Compared with reusable laryngoscopes, single-use laryngoscopes were associated with fewer rescue intubations with an alternate device (covariates-adjusted odds ratio [OR] 0.81 95% CI 0.66-0.99). Single-use laryngoscopes were also associated with lower odds of difficult laryngeal view (OR 0.86; 95% CI 0.80-0.93). Single use laryngoscopes were not associated with hypoxemia during the intubation attempt (OR 1.03; 95% CI 0.88-1.20). Similar results were observed for subgroup analyses including rapid sequence induction, Macintosh blades, Miller blades, and patients with difficult airway risk factors.

CONCLUSIONS

Metallic single-use laryngoscopes were associated with less need for rescue intubation with alternate devices and lower incidence of poor laryngeal view compared to reusable metallic laryngoscopes.

[Characteristics performance of laryngopharyngeal reflux in narrow band imaging]

Objective:To study the application value of narrow-band imaging in the diagnosis of laryngopharyngeal reflux. Methods:A total of 275 patients admitted to the inpatient department or laryngoscopy room of the Otolaryngology Head and Neck Surgery Department of the First Affiliated Hospital of Harbin Medical University from September 2022 to April 2023 due to throat discomfort were selected as the research subjects. All of them completed RSI, RFS scoring scales and electronic laryngoscopy（including ordinary white light and NBI）. According to the expert consensus of LPRD in 2022, RSI and RFS scoring scale were used as diagnostic criteria to divide them into LPR group and non-LPR group. Chi-square test was used to analyze the differences of positive rates of characteristic manifestations under NBI among different groups. The consistency of NBI and scale diagnostic methods was analyzed by Kappa, and RSI and RFS scoring were used as diagnostic criteria, The diagnostic efficiency of NBI method was analyzed. Results:There were 190 people in the LPR group, 157 of whom showed characteristic performance under the NBI mode, with a positive rate of 82.6%（157/190）; there were 85 people in the non-LPR group, with a positive rate of 18.8%（16/85）. There was a statistically significant difference in the positive rate between the two groups（χ²=102.47, P<0.05）. The consistency rate between RSI, RFS and NBI was 82.2%（226/275）. Kappa consistency analysis was used, and Kappa=0.605（P<0.05）, indicating good consistency between the two diagnostic methods. Using RSI and RFS as diagnostic criteria for LPR, the sensitivity of NBI diagnostic method was 82.6%（157/190）, specificity 81.2%（69/85）, positive predictive value 90.8%（157/173） and negative predictive value 67.6%（69/102）. Conclusion:Narrow-band imaging, as a new endoscopic imaging technique, can show small changes in mucosal surface micro vessels and play an important role in the diagnosis of laryngopharyngeal reflux.

Paralysis Versus Non-Paralysis Anesthesia for Operative Laryngoscopy: A Randomized Controlled Trial

OBJECTIVE

To compare outcomes between two standard-of-care anesthesia regimens for operative laryngoscopy: general anesthesia with a neuromuscular blocking agent (NMBA) versus remifentanil and propofol (non-NMBA).

METHODS

This was a prospective, single-blinded, randomized controlled trial at a tertiary care center. Patients were randomized to either anesthesia using rocuronium (NMBA) or with remifentanil/propofol infusion alone (non-NMBA). Intraoperative impressions, anesthesia data, and post-operative patient surveys were collected.

RESULTS

Sixty-one patients who underwent suspension laryngoscopy from 2020 to 2022 were included (25 female, 36 male, ranging 20-81 years). Thirty patients were enrolled in the NMBA arm and 31 patients in the non-NMBA arm. Heart rate and mean arterial pressure were higher in the NMBA (p < 0.01). Patients in the non-NMBA group were more likely to require vasopressors (p = 0.04, RR = 3.08 [0.86-11.05]). Surgeons were more frequently satisfied with conditions in the NMBA group (86.7%) compared to the non-NMBA group (58.1%, p < 0.01). Procedures were more likely to be paused due to movement in the non-NMBA group (45.1%) compared to the NMBA group (16.6%, p < 0.03, RR = 2.26 [1.02-4.99]). Patients in the non-NMBA group were more likely to endorse myalgia the week after surgery (44%) compared to the NMBA group (8.3%, p < 0.01) and reported higher average pain levels on a 0-10 pain scale (3.7) compared to the paralysis group (2.0).

CONCLUSIONS

Anesthesia with rocuronium was associated with better intraoperative conditions and postoperative pain compared to anesthesia with remifentanil/propofol. Remifentanil/propofol were associated with lower blood pressure and suppression of laryngoscopy-associated tachycardia.

LEVEL OF EVIDENCE

2 Laryngoscope, 133:2654-2664, 2023.

Videolaryngoscopy in neonatal clinical care

Endotracheal intubation is a life-saving procedure for many newborns. Historically, it has been achieved by obtaining an airway view through the mouth via direct laryngoscopy. It is a skill that takes time and practice to achieve proficiency. Increasing evidence for the benefit of videolaryngoscopy in adults and the new development of technology has allowed videolaryngoscopy to become a reality in neonatal care. Studies have examined its use as both a technique to improve intubation safety and success, and as a training tool for those learning the skill in this vulnerable population. We present the current evidence for videolaryngoscopy in neonates in different settings where intubation may be required, in addition to exploring the challenges and practicalities of implementing this technique into clinical practice.

Comparing Direct and Video Laryngoscopy Skills Between Resident and Attending Emergency Physicians

Introduction Advances in airway technology, in particular video laryngoscopy, are forcing attending emergency medicine physicians to master and maintain innovative airway skills. This study compares intubation times and other airway outcomes between resident and attending physicians using direct and video laryngoscopy in a mannequin model. Methods Fifty emergency medicine resident and attending physicians were asked to intubate a mannequin, using direct laryngoscopy, a C-MAC standard geometry blade, and a GlideScope hyperangulated blade. Intubation times, intubation success and accuracy, Cormack-Lehane grades, and the physician's opinion of the ease of the intubation were recorded for each intubation. Results Second-year residents had significantly quicker intubation times than attending physicians with all 3 intubation modalities. They also outperformed the interns when using the C-MAC standard geometry blade and had faster intubation times compared to third-year residents using direct laryngoscopy. When using the GlideScope hyperangulated blade, all 3 years of residents had lower intubation times compared to attending physicians and they were more accurate with endotracheal tube placement. Unlike the second-year residents, the third-year residents were not faster at direct laryngoscopy compared to the attending physicians. Conclusion Second-year residents outperformed their resident counterparts and the attending physicians with improved intubation times. Nontraditional intubation techniques associated with the GlideScope hyperangulated blade must be learned, practiced, and maintained by attending physicians, which is reflected in their longer intubation times compared to the residents. In addition, DL skills can deteriorate among resident physicians if they are not used on a regular basis.

Out-of-Hospital Pediatric Video Laryngoscopy With an Adult Device: A Case Series Presented With a Contemporary Group Intubated With Direct Laryngoscopy

OBJECTIVES

After introducing an adult video laryngoscope (VL) in our physician-paramedic prehospital and retrieval medical service, our quality assurance process identified this blade being used during pediatric intubations. We present a case series of pediatric intubations using this oversized adult VL alongside a contemporaneous group of direct laryngoscopy (DL) intubations.

METHODS

We performed a retrospective review of intubated patients 15 years or younger in our electronic quality assurance registry from January 1, 2017, to December 31, 2020. Data collected were demographic details, intubation equipment, drug doses, the number of intubation attempts, and complications. Results are presented according to those intubated with C-MAC4 VL (Karl Storz) alongside age-appropriate DL sizes.

RESULTS

Ninety-nine pediatric patients were intubated, 67 (67%) by CMAC4 and 32 (33%) by DL. Video laryngoscopy had a first-attempt success rate of 96% and DL 91%. A Cormach and Lehane view 1 or 2 was found in 66 VL (99%) and 29 DL patients (91%). Desaturation was reported in two VL and 1 DL patient.

CONCLUSIONS

Adult VL became the most common method of intubation in patients older than 1 year during the study period. An adult C-MAC4 VL could be considered for clinicians who prefer VL when a pediatric VL is unavailable or as a second-line device if a pediatric VL is not present when intubating children older than 1 year.

Endobronchial Intubation With the King Vision® and McGrath® Laryngoscopes in Simulated Easy and Difficult Airways by Novices (eKingMath)

Objective. The competency of using video laryngoscopes (VL) for double-lumen tube (DLT) endobronchial intubations can be improved with constant training as assessed by measuring the learning curves. We hypothesized that the time to DLT intubation would be reduced over the intubation attempts. Design. A crossover manikin study. Settings. University-affiliated hospital. Participants. Forty-two novice medical students unfamiliar with DLT intubation. Interventions. Participants were randomly allocated to two sequences, including DLT intubation, using King Vision and McGrath VLs. Each participant completed 100 DLT intubation attempts on both simulated easy and difficult airways on two different mannikins using the study devices (25 attempts for each). Measurements and Main Results. The primary outcome was the time to DLT intubation. The secondary outcomes included the best glottic view, optimizing maneuvers, and intubation first-pass success. The use of King Vision VL was associated with a significantly shorter time to DLT intubation (P < 0.044 and P < 0.05, respectively) and a higher percentage of glottic opening (POGO) compared to the McGrath VL (P < 0.011 and P < 0.002, respectively) in the simulated "easy" and "difficult" over most of the intubation attempts. In the simulated "easy" airway, the first-pass success ratio was higher when using the King Vision VL (median [Minimum-Maximum] 100% [100%-100%] and 100% [88%-100%], P = 0.012). Conclusion. Novice medical students developed skills over intubation attempts, meaning achievement of a faster DLT intubation, better laryngeal exposure, and higher success rate on simulated "easy" and "difficult" airways. A median of 9 DLT intubations was required to achieve a 92% or greater DLT intubation success rate.

Efficacy and adverse events profile of videolaryngoscopy in critically ill patients: subanalysis of the INTUBE study

BACKGROUND

Tracheal intubation is a high-risk procedure in the critically ill, with increased intubation failure rates and a high risk of other adverse events. Videolaryngoscopy might improve intubation outcomes in this population, but evidence remains conflicting, and its impact on adverse event rates is debated.

METHODS

This is a subanalysis of a large international prospective cohort of critically ill patients (INTUBE Study) performed from 1 October 2018 to 31 July 2019 and involving 197 sites from 29 countries across five continents. Our primary aim was to determine the first-pass intubation success rates of videolaryngoscopy. Secondary aims were characterising (a) videolaryngoscopy use in the critically ill patient population and (b) the incidence of severe adverse effects compared with direct laryngoscopy.

RESULTS

Of 2916 patients, videolaryngoscopy was used in 500 patients (17.2%) and direct laryngoscopy in 2416 (82.8%). First-pass intubation success was higher with videolaryngoscopy compared with direct laryngoscopy (84% vs 79%, P=0.02). Patients undergoing videolaryngoscopy had a higher frequency of difficult airway predictors (60% vs 40%, P<0.001). In adjusted analyses, videolaryngoscopy increased the probability of first-pass intubation success, with an OR of 1.40 (95% confidence interval [CI] 1.05-1.87). Videolaryngoscopy was not significantly associated with risk of major adverse events (odds ratio 1.24, 95% CI 0.95-1.62) or cardiovascular events (odds ratio 0.78, 95% CI 0.60-1.02).

CONCLUSIONS

In critically ill patients, videolaryngoscopy was associated with higher first-pass intubation success rates, despite being used in a population at higher risk of difficult airway management. Videolaryngoscopy was not associated with overall risk of major adverse events.

CLINICAL TRIAL REGISTRATION

NCT03616054.