Abnormal Laryngopharyngeal Sensation in Adductor Laryngeal Dystonia Compared to Healthy Controls

BACKGROUND/OBJECTIVES

Laryngeal sensory abnormality has been implicated as a component of adductor laryngeal dystonia (AdLD). The study objective was to assess laryngopharyngeal sensation in AdLD utilizing a calibrated, tactile aesthesiometer to deliver differential stimuli to lateral pyriform sinus (LPS), aryepiglottic fold (AEF), and false vocal fold (FVF).

METHODS

Patients with known Botox-responsive AdLD underwent sensory testing using a previously-validated methodology involving calibrated tactile stimuli (6-0, 5-0, 4.5-0, 4-0 nylon monofilaments). Laryngeal adductor reflex (LAR) and participant-rated perceptual strength of stimulI were evaluated. Responses were compared to normative controls (n = 33). Two-samples, Mann-Whitney and Fisher exact tests compared mean strength ratings and LAR between AdLD and control groups. Mixed-effects logistic regression and linear models assessed association of filament size, stimulus site, age, sex, and LD status on LAR and perceptual strength rating respectively.

RESULTS

Thirteen AdLD patients (nine women, mean age 60+/-15 years) completed testing. Average LAR response rates were higher amongst all filament sizes in AdLD versus controls at LPS (56.3% vs. 35.7%) and AEF (96.1% vs. 70.2%) with comparable rates at FVF (90.2% vs. 91.7%). AdLD had 3.3 times the odds of observed LAR compared to controls (p = 0.005), but differences in subjective detection of stimuli, perceptual strength ratings, and cough/gag rates were insignificant on multivariate modeling (p > 0.05).

CONCLUSIONS

This is the first study to objectively assess laryngopharyngeal sensation in AdLD. Findings demonstrated increased laryngopharyngeal sensation in AdLD compared to controls. The identification of increased laryngeal hypersensitivity in these patients may improve understanding of AdLD pathophysiology and identify future targets for intervention.

LEVEL OF EVIDENCE

2 Laryngoscope, 133:2271-2278, 2023.

Detection of laryngeal carcinoma during endoscopy using artificial intelligence

BACKGROUND

The objective of this study was to assess the performance and application of a self-developed deep learning (DL) algorithm for the real-time localization and classification of both vocal cord carcinoma and benign vocal cord lesions.

METHODS

The algorithm was trained and validated upon a dataset of videos and photos collected from our own department, as well as an open-access dataset named "Laryngoscope8".

RESULTS

The algorithm correctly localizes and classifies vocal cord carcinoma on still images with a sensitivity between 71% and 78% and benign vocal cord lesions with a sensitivity between 70% and 82%. Furthermore, the best algorithm had an average frame per second rate of 63, thus making it suitable to use in an outpatient clinic setting for real-time detection of laryngeal pathology.

CONCLUSION

We have demonstrated that our developed DL algorithm is able to localize and classify benign and malignant laryngeal pathology during endoscopy.

In Vivo Automatic and Quantitative Measurement of Adult Human Larynx and Vocal Fold Images

INTRODUCTION

Qualitative laryngoscopy belongs to a diagnostic routine. Nevertheless, quantitative morphometric measurements of laryngeal structures remain challenging. This study aimed to introduce a special laser projection device that can facilitate computer-assisted digitalized analysis and provide important quantitative information for diagnostics and treatment planning.

MATERIALS AND METHODS

The laryngeal images were captured with our device, which contained two parallel laser beams in order to provide the scaling reference. The maximum length of the vocal fold during respiration and vibration (phonation), vocal width at midpoint, total fold area, maximum cross-sectional area of the glottic space, and maximum vocal fold angle were determined and calculated. These parameters were analyzed and compared on the basis of age, sex, body height, body weight and body mass index.

RESULTS

A total of 87 subjects were enrolled in this study, comprising 39 males and 48 females. The age range for all subjects was 21 to 80 years old. The maximum value of the glottic area and vocal angle showed no significant gender difference. Both the respiration and vibration vocal fold length was significantly longer in males than in females. The vocal width revealed no gender difference, but the fold area during both respiration and phonation was significantly larger in men than in women. As for the respiration-to-vibration ratio of the vocal length, there was a trend, but without statistical significance (P = 0.06), toward a higher length compression ratio in men than in women. Meanwhile, age was found to have a strong relationship with vocal width during phonation. The width of vibration vocal fold decreased with aging significantly.

CONCLUSION

Our innovative module can provide reference parameters, which makes it possible to directly estimate the objective absolute values of relevant laryngeal structures. Our non-invasive approach can be used during routine laryngoscopy and the findings easily documented. In future, we can extend its clinical application to measure subtle laryngeal or hypopharyngeal changes, which are difficult to objectively quantify.

The effect of the auditory signal on videolaryngostroboscopy ratings and interpretation

OBJECTIVE

The primary aim of this study was to examine the effect of the videolaryngostroboscopic auditory signal on videolaryngostroboscopy (VLS) ratings and interpretation in normophonic and dysphonic speakers.

STUDY DESIGN

Prospective repeated measures design METHOD: Eight speech-language pathologists evaluated rigid VLS exams obtained from 12 dysphonic speakers with vocal fold pathology and 4 normophonic speakers with normal VLS exams. VLS exams were evaluated with the auditory signal present and absent with a washout period between rating sessions. VLS measures were obtained using the Voice-vibratory Assessment of Laryngeal Imaging (VALI) and a 100mm visual analog scale (VAS). The effects of the auditory signal and its interaction with voice quality severity on 9 VLS ratings, diagnostic billing codes, and treatment recommendations were examined.

RESULTS

There was no effect of auditory information on VLS measures or overall severity of laryngeal function evaluated using the VAS (ps > 0.05). There was a main effect of auditory information and a significant interaction with voice quality severity for only one VLS measure (non-vibrating portion-left) evaluated using the VALI (P = 0.05). Post-hoc analysis for this rating showed significant increases (t-test adjusted P < 0.05) when voice quality severity was moderate-severe (M = 4.8%; SD = 1.65%) and auditory information was present. Agreement in individual clinician's selection of diagnostic codes (73%) and treatment recommendations (65.6%) when auditory cues were present and absent was moderate to high.

CONCLUSION

The presence of the videolaryngostroboscopic auditory signal had a minimal effect on VLS ratings, treatment recommendations, or diagnostic billing codes.

Pediatric Bilateral Vocal Cord Immobility: New Treatment With Preservation of Voice

OBJECTIVES

Pediatric bilateral vocal cord immobility (BVCI) represents a severe life-threatening condition that often causes severe dyspnea. Endoscopic arytenoid lateral abduction (EALA) is a relatively new, secure, minimal-invasive surgical technique. The present prospective observational study aims to evaluate the effects of EALA in terms of respiratory function, voice quality, and swallowing capabilities.

METHODS

Twenty-one pediatric patients with BVCI underwent EALA. Eleven out of 21 patients had tracheostomy at the time of surgery. Pre and postoperative functional assessments included endoscopic evaluation, maximum phonation time, pediatric Voice Handicap Index (pVHI), GIRBAS Scale criteria, and Montreal Children's Hospital Feeding scale (MCH-Feeding scale). peak tidal inspiratory flow or peak inspiratory flow (PIF) and number of desaturations/hour (ODI/h) were evaluated in patients without tracheostomy.

RESULTS

Postoperative endoscopy showed glottic airway improvement in all patients. Average time for decannulation was 4.6 weeks. One patient has not yet been decannulated. No major complications occurred. In patients without tracheostomy, we observed a significant improvement of ODI/h and PIF after surgery (p < 0.05) as expected. PVHI, MCH-Feeding scale, and GIRBAS score significantly worsened 1 month after surgical intervention (p < 0.05). One year after surgery, however, all values, except for B and A parameters of the GIRBAS score, returned to levels comparable to those preoperative.

CONCLUSIONS

EALA represents a simple, safe and effective solution in pediatric patients with BVCI, avoiding tracheostomy, allowing early decannulation, preserving swallowing function, and maintaining good quality voice.

LEVEL OF EVIDENCE

4 Laryngoscope, 133:2325-2332, 2023.

Video versus Direct Laryngoscopy for Tracheal Intubation of Critically Ill Adults

BACKGROUND

Whether video laryngoscopy as compared with direct laryngoscopy increases the likelihood of successful tracheal intubation on the first attempt among critically ill adults is uncertain.

METHODS

In a multicenter, randomized trial conducted at 17 emergency departments and intensive care units (ICUs), we randomly assigned critically ill adults undergoing tracheal intubation to the video-laryngoscope group or the direct-laryngoscope group. The primary outcome was successful intubation on the first attempt. The secondary outcome was the occurrence of severe complications during intubation; severe complications were defined as severe hypoxemia, severe hypotension, new or increased vasopressor use, cardiac arrest, or death.

RESULTS

The trial was stopped for efficacy at the time of the single preplanned interim analysis. Among 1417 patients who were included in the final analysis (91.5% of whom underwent intubation that was performed by an emergency medicine resident or a critical care fellow), successful intubation on the first attempt occurred in 600 of the 705 patients (85.1%) in the video-laryngoscope group and in 504 of the 712 patients (70.8%) in the direct-laryngoscope group (absolute risk difference, 14.3 percentage points; 95% confidence interval [CI], 9.9 to 18.7; P<0.001). A total of 151 patients (21.4%) in the video-laryngoscope group and 149 patients (20.9%) in the direct-laryngoscope group had a severe complication during intubation (absolute risk difference, 0.5 percentage points; 95% CI, -3.9 to 4.9). Safety outcomes, including esophageal intubation, injury to the teeth, and aspiration, were similar in the two groups.

CONCLUSIONS

Among critically ill adults undergoing tracheal intubation in an emergency department or ICU, the use of a video laryngoscope resulted in a higher incidence of successful intubation on the first attempt than the use of a direct laryngoscope. (Funded by the U.S. Department of Defense; DEVICE ClinicalTrials.gov number, NCT05239195.).

Visual-perceptive assessment of glottic characteristics of vocal nodules by means of high-speed videoendoscopy

OBJECTIVE

Visual-perceptive assessment of glottic characteristics of vocal nodules by means of high-speed videoendoscopy.

METHODS

Descriptive observational research with convenience sampling of five laryngeal videos of women with an average age of 25 years. The diagnosis of vocal nodules was defined by two otolaryngologists, with 100% intra-rater agreement and 53.40% inter-rater agreement and five otolaryngologists as judge assessed the laryngeal videos based on an adapted protocol. The statistical analysis calculated measures of central tendency and dispersion, as well as percentage. The AC1 coefficient was used for agreement analysis.

RESULTS

In high-speed videoendoscopy imaging, vocal nodules are characterized by amplitude of the mucosal wave and muco-undulatory movement with magnitude between 50% and 60%. Non-vibrating segments of vocal folds are scarce, and the glottal cycle does not show a predominant phase, it is symmetric and periodic. Glottal closure is characterized by the presence of a mid-posterior triangular chink (double chink or isolated mid-posterior triangular chink), without movement of supraglottic laryngeal structures, with irregular contour of the free edge of vocal folds, which are vertically on-plane.

CONCLUSION

Vocal nodules present mid-posterior triangular chink and irregular free edge contour. Amplitude and mucosal wave were partially reduced.

LEVEL OF EVIDENCE

Level 4 (Case-series).

Vocal cord dysfunction/inducible laryngeal obstruction-2022 Melbourne Roundtable Report

Vocal cord dysfunction/inducible laryngeal obstruction (VCD/ILO), is a common condition characterized by breathlessness associated with inappropriate laryngeal narrowing. Important questions remain unresolved, and to improve collaboration and harmonization in the field, we convened an international Roundtable conference on VCD/ILO in Melbourne, Australia. The aims were to delineate a consistent approach to VCD/ILO diagnosis, appraise disease pathogenesis, outline current management and model(s) of care and identify key research questions. This report summarizes discussions, frames key questions and details recommendations. Participants discussed clinical, research and conceptual advances in the context of recent evidence. The condition presents in a heterogenous manner, and diagnosis is often delayed. Definitive diagnosis of VCD/ILO conventionally utilizes laryngoscopy demonstrating inspiratory vocal fold narrowing >50%. Computed tomography of the larynx is a new technology with potential for swift diagnosis that requires validation in clinical pathways. Disease pathogenesis and multimorbidity interactions are complex reflecting a multi-factorial, complex condition, with no single overarching disease mechanism. Currently there is no evidence-based standard of care since randomized trials for treatment are non-existent. Recent multidisciplinary models of care need to be clearly articulated and prospectively investigated. Patient impact and healthcare utilization can be formidable but have largely escaped inquiry and patient perspectives have not been explored. Roundtable participants expressed optimism as collective understanding of this complex condition evolves. The Melbourne VCD/ILO Roundtable 2022 identified clear priorities and future directions for this impactful condition.

A pilot, prospective trial of IntuBrite® versus Macintosh direct laryngoscopy for paramedic endotracheal intubation in out of hospital cardiac arrest

BACKGROUND

Intubation in the case of out-of-hospital cardiac arrest (OHCA) is one of the most difficult procedures for Emergency Medical Services (EMS). The use of a laryngoscope with a dual light source is an interesting alternative to classic laryngoscopes. However, there are as yet no prospective data concerning the use of double light direct laryngoscopy (DL) by paramedics in traditional ground ambulance agencies in OHCA.

METHODS

We performed a non-blinded trial in a single EMS in Poland within ambulances crews, comparing time and first pass success (FPS) for endotracheal intubation (ETI) in DL using the IntuBrite® (INT) and Macintosh laryngoscope (MCL) during cardiopulmonary resuscitation (CPR). We collected both patient and provider demographic information along with intubation details. The time and success rates were compared using an intention-to-treat analysis.

RESULTS

Over a period of 40 months, a total of 86 intubations were performed using 42 INT and 44 MCL based on an intention-to-treat analysis. The FPS time of the ETI attempt (13.49 vs. 15.55 s) using an INT which was shorter than MCL was used (p < 0.05). First attempt success (34/42, 80.9% vs. 29/44, 64.4%) was comparable for INT and MCL with no statistical significance.

CONCLUSIONS

We found a statistically significant difference in intubation attempt time when the INT laryngoscope was used. Intubation first attempt success rates with INT and MCL were comparable with no statistical significance during CPR performed by paramedics.

TRIAL REGISTRATION

Trial was registered in Clinical Trials: NCT05607836 (10/28/2022).

Prevalence and impact of exercise-induced laryngeal obstruction in asthma: a study protocol for a cross-sectional and longitudinal study

INTRODUCTION

Exercise-induced laryngeal obstruction (EILO) and exercise-induced asthma can cause troublesome respiratory symptoms that can be difficult to distinguish between. Further, there is now a growing appreciation that the two conditions may coexist, complicating the interpretation of symptoms. The primary aim of this study is to investigate the prevalence of EILO in patients with asthma. Secondary aims include evaluation of EILO treatment effects and investigation of comorbid conditions other than EILO in patients with asthma.

METHODS AND ANALYSIS

The study will be conducted at Haukeland University Hospital and Voss Hospital in Western Norway, and enrol 80-120 patients with asthma and a control group of 40 patients without asthma. Recruitment started in November 2020, and data sampling will continue until March 2024. Laryngeal function will be assessed at baseline and at a 1-year follow-up, using continuous laryngoscopy during high-intensity exercise (CLE). Immediately after the EILO diagnosis is verified, patients will be treated with standardised breathing advice guided by visual biofeedback from the laryngoscope video screen. The primary outcome will be the prevalence of EILO in patients with asthma and control participants. Secondary outcomes include changes in CLE scores, asthma-related quality of life, asthma control and number of the asthma exacerbations, as assessed between baseline and the 1-year follow-up.

ETHICS AND DISSEMINATION

Ethical approval has been obtained from the Regional Committee for Medical and Health Research Ethics, Western Norway, (ID number 97615). All participants will provide signed informed consent before enrolment. The results will be presented in international journals and conferences.

TRIAL REGISTRATION NUMBER

NCT04593394.

The Pediatric Rigid Stylet Improves First-Pass Success Compared With the Standard Malleable Stylet and Tracheal Tube Introducer in a Simulated Pediatric Emergency Intubation

BACKGROUND

Pediatric emergency intubation is a high-acuity, low-occurrence procedure. Despite advances in technology, the success of this procedure remains low and adverse events are very high. Prospective observational studies in children have demonstrated improved success with the use of video laryngoscopy (VL) compared with direct laryngoscopy, although reported first-pass success (FPS) rates are lower than that reported for adults. This may in part be due to difficulty directing the tracheal tube to the laryngeal inlet considering the cephalad position of the larynx in infants. Using airway adjuncts such as the pediatric rigid stylet (PRS) or a tracheal tube introducer (TTI) may aid with intubation to the cephalad positioned airway when performing VL. The objectives of this study were to assess the FPS and time to intubation when intubating an infant manikin with a standard malleable stylet (SMS) compared with a PRS and TTI.

METHODS

This was a randomized cross-over study performed at an academic institution both with emergency medicine (EM) and combined pediatric and EM (EM&PEDS) residency programs. Emergency medicine and EM&PEDS residents were recruited to participate. Each resident performed intubations on a 6-month-old infant simulator using a standard geometry C-MAC Miller 1 video laryngoscope and 3 different intubation adjuncts (SMS, PRS, TTI) in a randomized fashion. All sessions were video recorded for data analysis. The primary outcome was FPS using the 3 different intubation adjuncts. The secondary outcome was the mean time to intubation (in seconds) for each adjunct.

RESULTS

Fifty-one participants performed 227 intubations. First-pass success with the SMS was 73% (37/51), FPS was 94% (48/51) with the PRS, and 29% (15/51) with the TTI. First-pass success was lower with the SMS (-43%; 95% confidence interval [CI], -63% to -23%; P < 0.01) and significantly lower with the TTI compared with PRS (difference -65%; 95% CI, -81% to -49%; P < 0.01). First-pass success while using the PRS was higher than SMS (difference 22%, 7% to 36%; P < 0.01). The mean time to intubation using the SMS was 44 ± 13 seconds, the PRS was 38 ± 11 seconds, and TTI was 59 ± 15 seconds. The mean time to intubation was higher with SMS (difference 15 seconds; 95% CI, 10 to 20 seconds; P < 0.01) and significantly higher with the TTI compared with PRS (difference 21 seconds; 95% CI, 17 to 26 seconds; P < 0.01). Time to intubation with the PRS was lower than SMS (difference -7 seconds; 95% CI, -11 to -2 seconds; P < 0.01). The ease of use was significantly higher for the PRS compared with the TTI when operators rated them on a visual analog scale (91 vs 20 mm).

CONCLUSIONS

Use of the PRS by EM and EM&PEDS residents on an infant simulator was associated with increased FPS and shorter time to intubation. Clinical studies are warranted comparing these intubation aids in children.

Point-of-Care Ultrasound: A Review of Ultrasound Parameters for Predicting Difficult Airways

Airway management remains a crucial part of perioperative care. The conventional approach to assessing potentially difficult airways emphasizes the LEMON method, which looks for and evaluates the Mallampati classification, signs of obstruction, and neck mobility. Clinical findings help predict a higher likelihood of difficult tracheal intubation, but no clinical result reliably excludes difficult intubation. Ultrasound as an adjunct to clinical examination can provide the clinician with a dynamic anatomical airway assessment, which is impossible with clinical examination alone. In the hands of anesthesiologists, ultrasound is becoming more popular in the perioperative period. This method is particularly applicable for identifying proper endotracheal tube positioning in specific patient populations, such as those who are morbidly obese and patients with head and neck cancer or trauma. The focus is on identifying the normal anatomy, correctly positioning the endotracheal tube, and refining the parameters that predict difficult intubation. Several ultrasound measurements are clinical indicators of difficult direct laryngoscopy in the literature. A meta-analysis revealed that the distance from the skin to the epiglottis (DSE) is most associated with a difficult laryngoscopy. An ultrasound of the airway could be applied in routine practice as an adjunct to the clinical examination. A full stomach, rapid sequence intubation, gross visual anatomical abnormalities, and restricted neck flexibility prevent using ultrasound to assess the airway. The airway evaluation is performed with a linear array transducer of 12-4 MHz, with the patient in the supine position, with no pillow, and with the head and neck in a neutral position. The central axis of the neck is where the ultrasound parameters are measured. These image acquisitions guide the standard ultrasound examination of the airway.

Predicting Difficult Intubation by using Modified Mallampati (MMT) with or without Thyromental Height Test (TMHT)

Failed Tracheal Intubation with Subsequent inability to maintain an open airway and adequate oxygenation is the most frequent cause of brain damage or death during anesthesia. Recognizing before anesthesia the potential for difficult intubation allows time for optimal preparation. Proper Selection of equipment and techniques is needed to avoid unwanted situation. To find out difficulties associated with endotracheal intubation using Modified Mallampati Test (MMT) combined with Thyromental Height Test (TMHT) and MMT without TMHT. This prospective observational study was conducted at the Department of Anesthesia in Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh from April 2018 to September 2018. Two hundred two patients with different surgical procedures under general anaesthesia in different operation theaters of BSMMU, Dhaka were selected as study population. After taking written consents from each patient or his/her attendant elaborate history of illness, meticulous clinical examinations were performed and relevant laboratory investigations were done. All information was recorded in a preformed data sheet and statistical analysis was done by SPSS-22.0. Mean age ±SD of the study subjects was 42.49±14.29 years in MMT with TMHT group and 43.40±15.39 years in MMT without TMHT group. Females were enrolled more than males in both the groups. BMI was 28.75±3.59kg/m² in MMT with TMHT group and 29.44±8.64kg/m² in MMT without TMHT group. There were no significant differences in age, gender and BMI between the groups. Sensitivity, specificity, PPV, NPV and accuracy were 100.0%, 96.0%, 96.2%, 100.0% and 98.0% respectively of MMT with TMHT in predicting intubation difficulty. Sensitivity, specificity, PPV, NPV and accuracy were 100.0%, 96.0%, 96.2%, 100.0% and 98.0% respectively of MMT only in predicting intubation difficulty. MMT combined with TMHT is a better predictor of intubation difficulty than MMT alone.

Pro-Con Debate: Videolaryngoscopy Should Be Standard of Care for Tracheal Intubation

In this Pro-Con commentary article, we discuss whether videolaryngoscopy (VL) should be the standard of care for tracheal intubation. Dr Aziz makes the case that VL should be the standard of care, while Dr Berkow follows with a challenge of that assertion. In this debate, we explore not only the various benefits of VL, but also its limitations. There is compelling evidence that VL improves first-pass success rates, reduces the risk of intubation failure and esophageal intubation, and has benefits in the difficult airway patient. But VL is not without complications and does not possess a 100% success rate. In the case of failure, it is important to have back-up plans for airway management. While transition of care from direct laryngoscopy (DL) to VL may result in improved airway management outcomes, the reliance on VL may degrade other important clinical skills when they are needed most. If VL is adapted as the standard of care, airway managers may no longer practice and retain competency in other airway techniques that may be required in the event of VL failure. While cost is a barrier to broad implementation of VL, those costs are normalizing. However, it may still be challenging for institutions to secure purchase of VL for every intubating location, as well as back-up airway devices. As airway management care increasingly transitions from DL to VL, providers should be aware of the benefits and risks to this practice change.

EARLY TEACHING AND ADOPTION OF VIDEOLARYNGOSCOPY IN EMERGENCY MEDICINE TRAINING

The aim of this paper is to gather and evaluate available literature about using videolaryngoscopy as a training tool for novice learners and compare it to direct laryngoscopy. Search of the available literature was performed using the MEDLINE database, through the PubMed searching tool. The inclusion criteria were that papers had to be original research and participants had to be novices in the field of airway management. The studies also had to pertain to the topic of using videolaryngoscopy as a training tool, therefore all papers that evaluated performance of videolaryngoscopy in clinical applications or did not pertain to using videolaryngoscopy as a training tool were excluded from this review. Five studies were identified that fitted the inclusion criteria, all of which showed a statistically significant difference in first attempt success at endotracheal intubation in favor of videolaryngoscopy when compared to direct laryngoscopy. One of the studies also demonstrated a faster skill acquisition rate when using videolaryngoscopy. The use of videolaryngoscopy in teaching airway management to trainees (emergency medicine residents included) is a viable option and should be encouraged and researched further.

Differences in Glottal Closure and Visibility of the Anterior Commissure during Rigid-90°, Rigid-70°, and Flexible Laryngostroboscopy

INTRODUCTION

The conventional rigid-90° and rigid-70° laryngostroboscopy has been so far considered the gold standard in assessing the vibratory behavior of the vocal folds and the glottal closure configuration during phonation. Meanwhile, this rigid laryngostroboscopy is more and more replaced by flexible chip-on-tip systems. The aim of this study was to evaluate the influence of these different endoscopic techniques on glottal closure configuration and on visibility of the complete focal fold length including anterior commissure during phonation.

METHODS

Twenty-one euphonic subjects were enrolled (mean age 34.6 ± 9.5; m = 10, f = 11). They were examined with the three laryngoscopic techniques (conventional rigid-90°, rigid-70°, and flexible chip-on-tip laryngoscopy during low and high voice pitch with soft and loud voice intensity). For evaluating the degree of glottal closure, a modified classification of Södersten et al. was applied and the visibility of the anterior commissure was evaluated. The correlation of the three endoscopic techniques was assessed with Cohen and Fleiss' kappa.

RESULTS

In even low loud phonation, the rigid-90° and rigid-70° endoscopies revealed a complete closure of the glottis in only 47.6% of subjects but with flexible endoscopy in 81%. The complete vocal fold length with anterior commissure was best visible with flexible endoscopy in 90.5% in low-soft and high-soft phonation. The rigid-90° endoscopy showed a slight agreement in comparison with the flexible endoscopy in regard to the types of vocal fold closure with a Cohen's kappa coefficient k = 0.199. The rigid-90° endoscopy showed an almost perfect agreement with k = 0.84 when compared to the rigid-70° endoscopy. The flexible endoscopy compared to the rigid-70° endoscopy showed a fair agreement with k = 0.346.

CONCLUSION

We found mainly corresponding results in both rigid-90° and rigid-70° endoscopic techniques which can be explained by the same transoral approach with the tongue pulled out, whereas the flexible transnasal endoscopy mainly gives a better view on the anterior commissure. The influence of transorally or transnasally guided endoscopic techniques needs to be considered in interpretation of laryngostroboscopic parameters like vocal fold closure and supraglottal hyperactivity.

Transitioning from Direct to Video Laryngoscopy during the COVID-19 Pandemic Was Associated with a Higher Endotracheal Intubation Success Rate

OBJECTIVE

The objective of this study was to determine the effect of transitioning from direct laryngoscopy (DL) to video laryngoscopy (VL) on endotracheal intubation success overall and with enhanced precautions implemented during the COVID-19 pandemic.

METHODS

We examined electronic transport records from Mayo Clinic Ambulance Service, a large advanced life support (ALS) provider serving rural, suburban, and urban areas in Minnesota and Wisconsin, USA. We determined the success of intubation attempts when using DL (March 10, 2018 to December 19, 2019), VL (December 20, 2019 to September 29, 2021), and VL with an enhanced COVID-19 guideline that restricted intubation to one attempt, performed by the most experienced clinician, who wore enhanced personal protective equipment (April 1 to December 18, 2020). Success rates at first attempt and after any attempt were assessed for association with type of laryngoscopy (VL vs DL) after adjusting for patient age group, patient weight, use of enhanced COVID-19 guideline, medical vs trauma patient, and ALS vs critical care clinician. A secondary analysis further adjusted for degree of glottic visualization.

RESULTS

We identified 895 intubation attempts using DL and 893 intubation attempts using VL, which included 382 VL intubation attempts using the enhanced COVID-19 guideline. Success on first intubation attempt was 69.2% for encounters with DL, 82.9% overall with VL, and 83.2% with VL and enhanced COVID-19 protocols (DL vs overall VL: p < 0.001; COVID-19 vs non-COVID VL: p = 0.86). In multivariable analysis, use of VL was associate with higher odds of successful intubation on first attempt (odds ratio, 2.28; 95%CI, 1.73-3.01; p < 0.001) and on any attempt (odds ratio, 2.16; 95%CI, 1.58-2.96; p < 0.001) compared with DL. Inclusion of glottic visualization in the model resulted in a nonsignificant association between laryngoscopy type and successful first intubation (p = 0.41) and a significant association with the degree of glottic visualization (p < 0.001).

CONCLUSIONS

VL is designed to improve glottic visualization. The use of VL by a large, U.S. multistate ALS ambulance service was associated with increased odds of successful first-pass and overall attempted intubation, which was mediated by better visualization of the glottis. COVID-19 protocols were not associated with success rates.

Emergency airway management in a tertiary trauma centre (AIRMAN): a one-year prospective longitudinal study

PURPOSE

Emergency airway management can be associated with a range of complications including long-term neurologic injury and death. We studied the first-pass success rate with emergency airway management in a tertiary care trauma centre. Secondary outcomes were to identify factors associated with first-pass success and factors associated with adverse events peri-intubation.

METHODS

We performed a single-centre, prospective, observational study of patients ≥ 17 yr old who were intubated in the emergency department (ED), surgical intensive care unit (SICU), medical intensive care unit (MICU), and inpatient wards at our institution. Ethics approval was obtained from the local research ethics board.

RESULTS

In a seven-month period, there were 416 emergency intubations and a first-pass success rate of 73.1%. The first-pass success rates were 57.5% on the ward, 66.1% in the intensive care units (ICUs) and 84.3% in the ED. Equipment also varied by location; videolaryngoscopy use was 65.1% in the ED and only 10.6% on wards. A multivariate regression model using the least absolute shrinkage and selection algorithm (LASSO) showed that the odds ratios for factors associated with two or more intubation attempts were location (wards, 1.23; MICU, 1.24; SICU, 1.19; reference group, ED), physiologic instability (1.19), an anatomically difficult airway (1.05), hypoxemia (1.98), lack of neuromuscular blocker use (2.28), and intubator inexperience (1.41).

CONCLUSIONS

First-pass success rates varied widely between locations within the hospital and were less than those published from similar institutions, except for the ED. We are revamping ICU protocols to improve the first-pass success rate.

A Prospective Observational Crossover Study Comparing Intubation by Pediatric Residents Using Video Laryngoscopy and Direct Laryngoscopy on a Pierre Robin Simulation Manikin

INTRODUCTION

Video laryngoscopy (VL) has been proposed to increase the likelihood of successful intubation in patients with predicted difficult airways such as those with Pierre Robin sequence (PRS). Prior studies have focused on the performance of anesthesiologists, who are generally considered airway experts. Our primary aim was to investigate the success rate of intubation using VL compared with direct laryngoscopy (DL) when attempted by pediatric residents on a PRS model.

METHODS

Participants were administered a 5-minute refresher video on 2 VL techniques (CMAC, conventional geometry VL, and McGrath, unconventional geometry VL) and DL. The participants were asked to intubate the AirSim PRS infant manikin. The order of VL and DL use was randomly selected. All intubations were video recorded, and the recordings were analyzed by 3 anesthesiologists blinded to the participant's identity and previous experience.

RESULTS

Seventeen of 23 residents succeeded in intubating the PRS model using DL. Only 9 residents succeeded in intubating the PRS model using VL (conventional or unconventional geometry). Intubation success rate was higher when comparing DL with VL ( P = 0.04) and similar when comparing VL devices ( P = 0.69).

DISCUSSION

Contrary to expectation, the intubation success rate was lower using VL than with DL among pediatric residents. This should be considered when designing residency training and in real-life resuscitation.

Support of deep learning to classify vocal fold images in flexible laryngoscopy

PURPOSE

To collect a dataset with adequate laryngoscopy images and identify the appearance of vocal folds and their lesions in flexible laryngoscopy images by objective deep learning models.

METHODS

We adopted a number of novel deep learning models to train and classify 4549 flexible laryngoscopy images as no vocal fold, normal vocal folds, and abnormal vocal folds. This could help these models recognize vocal folds and their lesions within these images. Ultimately, we made a comparison between the results of the state-of-the-art deep learning models, and another comparison of the results between the computer-aided classification system and ENT doctors.

RESULTS

This study exhibited the performance of the deep learning models by evaluating laryngoscopy images collected from 876 patients. The efficiency of the Xception model was higher and steadier than almost the rest of the models. The accuracy of no vocal fold, normal vocal folds, and vocal fold abnormalities on this model were 98.90 %, 97.36 %, and 96.26 %, respectively. Compared to our ENT doctors, the Xception model produced better results than a junior doctor and was near an expert.

CONCLUSION

Our results show that current deep learning models can classify vocal fold images well and effectively assist physicians in vocal fold identification and classification of normal or abnormal vocal folds.

Airway management during ongoing chest compressions-direct vs. video laryngoscopy. A randomised manikin study

BACKGROUND

Tracheal intubation is used for advanced airway management during cardiac arrest, particularly when basic airway techniques cannot ensure adequate ventilation. However, minimizing interruptions of chest compressions is of high priority. Video laryngoscopy has been shown to improve the first-pass success rate for tracheal intubation in emergency airway management. We aimed to compare first-pass success rate and time to successful intubation during uninterrupted chest compression using video laryngoscopy and direct laryngoscopy.

METHODS

A total of 28 anaesthetists and 28 anaesthesia nurses with varied clinical and anaesthesiological experience were recruited for the study. All participants performed a tracheal intubation on a manikin simulator during ongoing chest compressions by a mechanical resuscitation device. Stratified randomisation (physicians/nurses) was performed, with one group using direct laryngoscopy and the other using video laryngoscopy.

RESULTS

First-pass success rate was 100% (95% CI: 87.9% - 100.0%) in the video laryngoscopy group and 67.8% (95% CI: 49.3% - 82.1%) in the direct laryngoscopy group [difference: 32.2% (95% CI: 17.8% - 50.8%), p<0.001]. The median time for intubation was 27.5 seconds (IQR: 21.8-31.0 seconds) in the video laryngoscopy group and 30.0 seconds (IQR: 26.5-36.5 seconds) in the direct laryngoscopy group (p = 0.019).

CONCLUSION

This manikin study on tracheal intubation during ongoing chest compressions demonstrates that video laryngoscopy had a higher first-pass success rate and shorter time to successful intubation compared to direct laryngoscopy. Experience in airway management and professional group were not significant predictors. A clinical randomized controlled trial appears worthwhile.

Endotracheal Intubation Strategy, Success, and Adverse Events Among Emergency Department Patients During the COVID-19 Pandemic

STUDY OBJECTIVE

To describe endotracheal intubation practices in emergency departments by staff intubating patients early in the coronavirus disease 2019 (COVID-19) pandemic.

METHODS

Multicenter prospective cohort study of endotracheal intubations conducted at 20 US academic emergency departments from May to December 2020, stratified by known or suspected COVID-19 status. We used multivariable regression to measure the association between intubation strategy, COVID-19 known or suspected status, first-pass success, and adverse events.

RESULTS

There were 3,435 unique emergency department endotracheal intubations by 586 participating physicians or advanced practice providers; 565 (18%) patients were known or suspected of having COVID-19 at the time of endotracheal intubation. Compared with patients not known or suspected of COVID-19, endotracheal intubations of patients with known or suspected COVID-19 were more often performed using video laryngoscopy (88% versus 82%, difference 6.3%; 95% confidence interval [CI], 3.0% to 9.6%) and passive nasal oxygenation (44% versus 39%, difference 5.1%; 95% CI, 0.9% to 9.3%). First-pass success was not different between those who were and were not known or suspected of COVID-19 (87% versus 86%, difference 0.6%; 95% CI, -2.4% to 3.6%). Adjusting for patient characteristics and procedure factors in those with low anticipated airway difficulty (n=2,374), adverse events (most commonly hypoxia) occurred more frequently in patients with known or suspected COVID-19 (35% versus 19%, adjusted odds ratio 2.4; 95% CI, 1.7 to 3.3).

CONCLUSION

Compared with patients not known or suspected of COVID-19, endotracheal intubation of those confirmed or suspected to have COVID-19 was associated with a similar first-pass intubation success rate but higher risk-adjusted adverse events.

Connected consciousness after tracheal intubation in young adults: an international multicentre cohort study

BACKGROUND

Connected consciousness, assessed by response to command, occurs in at least 5% of general anaesthetic procedures and perhaps more often in young people. Our primary objective was to establish the incidence of connected consciousness after tracheal intubation in young people aged 18-40 yr. The secondary objectives were to assess the nature of these responses, identify relevant risk factors, and determine their relationship to postoperative outcomes.

METHODS

This was an international, multicentre prospective cohort study using the isolated forearm technique to assess connected consciousness shortly after tracheal intubation.

RESULTS

Of 344 enrolled subjects, 338 completed the study (mean age, 30 [standard deviation, 6.3] yr; 232 [69%] female). Responses after intubation occurred in 37/338 subjects (11%). Females (13%, 31/232) responded more often than males (6%, 6/106). In logistic regression, the risk of responsiveness was increased with female sex (odds ratio [ORadjusted]=2.7; 95% confidence interval [CI], 1.1-7.6; P=0.022) and was decreased with continuous anaesthesia before laryngoscopy (ORadjusted=0.43; 95% CI, 0.20-0.96; P=0.041). Responses were more likely to occur after a command to respond (and not to nonsense, 13 subjects) than after a nonsense statement (and not to command, four subjects, P=0.049).

CONCLUSIONS

Connected consciousness occured after intubation in 11% of young adults, with females at increased risk. Continuous exposure to anaesthesia between induction of anaesthesia and tracheal intubation should be considered to reduce the incidence of connected consciousness. Further research is required to understand sex-related differences in the risk of connected consciousness.

DirEct versus VIdeo LaryngosCopE (DEVICE): protocol and statistical analysis plan for a randomised clinical trial in critically ill adults undergoing emergency tracheal intubation

INTRODUCTION

Among critically ill patients undergoing orotracheal intubation in the emergency department (ED) or intensive care unit (ICU), failure to visualise the vocal cords and intubate the trachea on the first attempt is associated with an increased risk of complications. Two types of laryngoscopes are commonly available: direct laryngoscopes and video laryngoscopes. For critically ill adults undergoing emergency tracheal intubation, it remains uncertain whether the use of a video laryngoscope increases the incidence of successful intubation on the first attempt compared with the use of a direct laryngoscope.

METHODS AND ANALYSIS

The DirEct versus VIdeo LaryngosCopE (DEVICE) trial is a prospective, multicentre, non-blinded, randomised trial being conducted in 7 EDs and 10 ICUs in the USA. The trial plans to enrol up to 2000 critically ill adults undergoing orotracheal intubation with a laryngoscope. Eligible patients are randomised 1:1 to the use of a video laryngoscope or a direct laryngoscope for the first intubation attempt. The primary outcome is successful intubation on the first attempt. The secondary outcome is the incidence of severe complications between induction and 2 min after intubation, defined as the occurrence of one or more of the following: severe hypoxaemia (lowest oxygen saturation <80%); severe hypotension (systolic blood pressure <65 mm Hg or new or increased vasopressor administration); cardiac arrest or death. Enrolment began on 19 March 2022 and is expected to be completed in 2023.

ETHICS AND DISSEMINATION

The trial protocol was approved with waiver of informed consent by the single institutional review board at Vanderbilt University Medical Center and the Human Research Protection Office of the Department of Defense. The results will be presented at scientific conferences and submitted for publication in a peer-reviewed journal.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov Registry (NCT05239195).

[Diagnostic efficiency of transcutaneous ultrasound scanning and Dopplerography in laryngeal pathology]

OBJECTIVE

To assess the efficiency and the place of grey scale ultrasound and color Doppler sonography of the larynx in the diagnosis of laryngeal pathology.

MATERIAL AND METHODS

A prospective blind cohort examination in B-mode laryngeal ultrasound (LUS) and color Doppler imaging (CDI) with linear scanning transducer 7-15 MHz was performed in 120 patients aged from 6 months to 52 years (average age 7.6±5.8 years, Me 6 year) and in 40 patients without laryngeal pathology (average age 7.0±5.0 years). The patients presented with complaints of voice and/or stridor. The diagnosis was verified by followed laryngoscopy.

RESULTS

Laryngeal papillomas, hemangiomas, scarring and vocal fold's nodules were identified as hyperechoic formations. Color Doppler sonography made it possible to visualize them better: small formations were highlighted in color and the space around the large ones was colored. There were paradoxical movements of the hyperechoic arytenoid cartilages during inspiration to the anterior commissure in patients with laryngomalacia. Color Doppler ultrasonography revealed changes during phonation in patients with functional dysphonia. The sensitivity and specificity of LUS were 58% (95% CI 48-66) and 98% (95% CI 87-99) compared with laryngoscopy in the detection of laryngeal pathology, but laryngeal CDI - 81% (95% CI 72-87) and 98% (95% CI 87-99) respectively.

CONCLUSION

Ultrasound of the larynx in B-mode has a diagnostic efficiency of 67.5%, and in CDI mode - 85% for ruling in laryngeal pathologies compared to laryngoscopy. So, this method is a modern affordable, non-invasive and informative diagnostic tool for the detection of laryngeal diseases, especially in those cases, when it is impossible to carry out a laryngoscopy.