Correlation of narrow-band imaging findings using the Ni and European Laryngeal Society classification systems during in-office flexible laryngoscopy with histopathology

OBJECTIVE

This study used the European Laryngeal Society (2016) and Ni (2011 and 2019) classifications for narrow-band imaging and correlated the findings with histopathology.

METHODS

Retrospective analysis was conducted by retrieving data of patients who underwent micro-laryngoscopy for suspicious glottic lesions. The narrow-band imaging findings were classified using both classification systems. Retrieved histopathology report findings were correlated with narrow-band imaging data.

RESULTS

Using the European Laryngeal Society and Ni classifications, 37 (69.8 per cent) and 35 (66 per cent) patients, respectively, were suspected to have malignant lesions. Upon histopathology, 37 (69.8 per cent) lesions were malignant. Sensitivity, specificity, positive predictive value, negative predictive value and accuracy using the European Laryngeal Society classification were 91.9 per cent, 81.3 per cent, 91.9 per cent, 81.3 per cent and 88.7 per cent, and using the Ni classification were 91.9 per cent, 93.8 per cent, 97.1 per cent, 83.3 per cent and 92.5 per cent, respectively.

CONCLUSION

The Ni classification had better specificity and accuracy. The European Laryngeal Society classification is simple to use and may serve as a useful screening tool. For optimum results, both European Laryngeal Society and Ni classifications may be used together, in that order.

A Novel Intubation Technique: Bougie Introduction Via Ducanto Suction Catheter

BACKGROUND

Airway management is a defining skill that demands mastery by emergency physicians. Airway emergencies pose considerable morbidity and mortality risks. Familiarity with, and mastery of, a variety of airway management approaches and equipment can prove invaluable for management of anatomically and physiologically difficult airways.

CASE REPORT

A 67-year-old woman presented to a level II trauma after a motor vehicle collision. Emergency medical services reported left-sided injuries, including diminished breath sounds. She arrived in extremis with dyspnea and hypoxia refractory to supplemental oxygen. A portable chest x-ray study showed a considerable traumatic diaphragmatic hernia. Initial attempts at intubation via video laryngoscopy were unsuccessful. Difficulties were attributed to anatomic variation, possibly due to the traumatic diaphragmatic hernia, and hematemesis. The airway was repositioned after removal of a cervical collar and suction-assisted laryngoscopy airway decontamination was performed under video guidance. During airway decontamination, the tip of a DuCanto suction catheter (SSCOR) became located at the level of the vocal cords, prompting the decision to control the airway via utilization of the DuCanto suction catheter and a bougie. The suction tubing was disconnected, a bougie was inserted through the catheter, and the DuCanto was subsequently removed and replaced with a cuffed endotracheal tube. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Airway emergencies are imminent life threats. Familiarity with a variety of tools and techniques allows for definitive airway management via primary, back-up, and contingency plans to secure anatomically or physiologically difficult airway.

Indirect laryngoscopy is more effective than direct laryngoscopy when tracheal intubation is performed by novice operators: a systematic review, meta-analysis, and trial sequential analysis

PURPOSE

We sought to perform a systematic review and meta-analysis to determine whether indirect laryngoscopy has an advantage over direct laryngoscopy in terms of the tracheal intubation rate, glottic visualization, and intubation time when used by novice operators.

METHODS

We extracted adult prospective randomized trials comparing tracheal intubation with indirect vs direct laryngoscopy in novice operators from electronic databases. We extracted the following data from the identified studies: success rate, glottic visualization, and intubation time. Data from each trial were combined via a random-effects model to calculate the pooled relative risk (RR) or weighted mean difference (WMD) with a 95% confidence interval (CI). We also performed a trial sequential analysis.

RESULTS

We included 15 articles (17 trials) comprising 2,290 patients in the systematic review. Compared with the direct laryngoscopy, indirect laryngoscopy improved success rate (RR, 1.15; 95% CI, 1.07 to 1.24; P = 0.0002; I2 = 88%), glottic visualization (RR, 1.76; 95% CI, 1.36 to 2.28; P < 0.001; I2 = 85%), and intubation time (WMD, -9.06 sec; 95% CI, -16.4 to -1.76; P = 0.01; I2 = 98%) in tracheal intubation. Trial sequential analysis showed that the total sample size was sufficient to analyze the success rate and intubation time.

CONCLUSION

In this systematic review, we found that the tracheal intubation success rate, glottic visualization, and intubation time were improved when novice operators used indirect laryngoscopy rather than direct laryngoscopy. Trial sequential analysis results indicated that the sample size was sufficient for examining the success rate and intubation time.

STUDY REGISTRATION

PROSPERO (CRD42022309045); first registered 4 September 2022.

Factors associated with 30- and 90-day mortality in intubations among critically ill patients

BACKGROUND

Emergency intubations are commonly associated with adverse events when performed in critically ill patients. A detailed look at intubation factors and their association with procedural success and mortality has yet to be fully conducted.

METHODS

A total of 299 successive intubations at a tertiary Veteran Affair hospital were analyzed. Situational factors, personnel involved, intubation indications, induction agents, and airway management techniques were prospectively collected and entered into univariable and multivariable analyses to identify factors associated with procedural difficulty and mortality.

RESULTS

The use of paralytics was associated with easier intubations (OR: 0.31, 95% CI: 0.11-0.87, p = .03). The use of direct laryngoscopy or video laryngoscopy had no significant association with difficult intubation. Factors associated with increased 30-day mortality were cardiac arrest (OR: 7.90, 95% CI: 2.77-22.50, p < .001), hypoxia as indication for intubation (OR: 2.31, 95% CI: 1.23-4.35, p = .009), and nadir SpO2  < 90% (OR: 2.70, 95% CI: 1.01-7.21, p = .048). Presence of an attending anesthesiologist during intubation was associated with a lower 30-day mortality (OR: 0.11, 95% CI: 0.04-0.29, p < .001). Factors associated with increased 90-day mortality were cardiac arrest (OR: 6.57, 95% CI: 2.23-19.34, p = .001), hypoxia as indication for intubation (OR: 1.97, 95% CI: 1.10-3.55, p = .023), and older age (OR: 1.38, 95% CI: 1.07-1.78, p = .013). Similarly, presence of an attending anesthesiologist was found to be associated with a lower 90-day mortality (OR: 0.19, 95% CI: 0.07-0.50, p = .001).

CONCLUSION

Cardiovascular and respiratory instability were associated with increased 30- and 90-day mortality. Presence of an attending anesthesiologist was associated with a better survival following intubation outside operating room.

Endoscopic assisted microscopic posterior cordotomy for bilateral abductor vocal fold paralysis using radiofrequency versus coblation

PURPOSE

To assess the outcomes of endoscopic assisted microscopic posterior cordotomy for bilateral abductor vocal fold paralysis (BAVFP) using radiofrequency versus coblation.

METHODS

This was a randomized prospective cohort study that carried out on 40 patients with BAVFP who were subjected to endoscopic/assisted microscopic posterior cordotomy. The patients were randomly allocated into two groups: group (A) patients were operated with radiofrequency, and group (B) patients were operated with coblation. Glottic chink, grade of dyspnea, voice handicap index 10 (VHI10), and aspiration were evaluated pre-operatively and 2 weeks and 3 months post-operatively.

RESULTS

There was a significant improvement in the glottic chink and VHI10 scores postoperatively with a non-significant difference between both groups regarding the degree of improvement. In addition, there was a significant improvement of the grade of dyspnea with a non-significant impact on the degree of aspiration in both groups post operatively. There was a lower incidence of oedema and granulation formation in the coblation group but without a statistical significance.

CONCLUSION

Both techniques are effective alternatives for performing posterior transverse cordotomy in cases of BAVFP.

Topical Anaesthesia Using a Soft Mist Spray Device Allows Comfortable Awake Visualisation of the Airway via Self-Videolaryngoscopy in Volunteers

Background: During endotracheal intubation, there is a 10% incidence of difficult laryngoscopy, which may result in serious complications. It is important to obtain as much information about the visibility of laryngeal structures before the patient is anaesthetised. Performing awake (video-) laryngoscopy on a patient is uncomfortable and can trigger gagging and coughing reflexes, making visualisation nearly impossible. The objective of this study is to evaluate the effectiveness of a soft mist spray device for airway anaesthesia during awake (video-) laryngoscopy. Methods: Twenty healthy volunteers inhaled through the Trachospray device, which was placed in their mouths. Two 2 mL syringes containing lidocaine at 4% were sprayed into the airway during inspiration. After several minutes, the subjects were asked to perform a videolaryngoscopy on themselves until the glottic structures and the vocal cords were visible. Upon completion of the procedure, all participants were asked to fill out a feedback form. Results: The duration of the videolaryngoscopy to visualisation of the vocal cords averaged 17 ± 13 s. After analysing the data, three distinct groups emerged as follows: Group 1 (70% of participants) showed no response, allowing for easy insertion of the videolaryngoscope. Group 2 (25% of participants) exhibited a light response but still permitted easy insertion and visualisation. One patient demonstrated a clear response with noticeable laryngeal contraction, requiring slightly more effort and discomfort for insertion. In 80% of the participants, the laryngeal structures were visualised according to Cormack-Lehane grade 1. All participants reported a high level of comfort, with an average rating of NRS 8. The anaesthesiologist assessed the level of anaesthesia as good to very good. No adverse events were observed. Conclusions: The Trachospray provided good, reliable, comfortable, and safe topical anaesthesia for awake videolaryngoscopy. This enables a direct visual assessment of the airway and may assist in making decisions regarding airway management for tracheal intubation.

An analysis of a new rapid difficult airway response team in a vertically built children's hospital

BACKGROUND

Intrahospital transport is associated with adverse events. This challenge is amplified during airway management. Although difficult airway response teams have been described, little attention has been paid to patient transport during difficult airway management versus the alternative of managing patient airways without moving the patient. This is especially needed in a 22-floor vertical hospital.

HYPOTHESIS

Development of a rapid difficult airway response team and an associated difficult airway cart will allow for the ability to manage difficult airways in the patient's primary location.

METHODS

A retrospective chart review of all rapid difficult airway response activations from December 18, 2019 to December 31, 2021 was performed to determine the number of airways secured in the patient's primary location (primary outcome). Secondary outcomes included length of time until airway securement, airway device used, number of attempts, complications, use of front of neck access, and mortality.

RESULTS

There were 96 rapid difficult airway response activations in a 2-year period, with 18 activations deemed inappropriate. Of the 78 indicated rapid difficult airway response deployments, all activations resulted in a secure airway, and 76 (97.4%) of cases had an airway secured in the patient's primary location. The mean time to airway securement was 17.1 min (standard deviation 18.8 min). The most common methods of airway securement were direct laryngoscopy (42.3%, 33/78) and video laryngoscopy (29.5%, 23/78). The mean number of attempts by the rapid difficult airway response team was 1.4. There were no documented cases requiring front of neck access. The Cormack-Lehane airway grade at time of intubation was I-II in 83.3% (65/78) of activations. Rapid difficult airway response activation resulted in 16 cases of cardiac arrest and 4 patient deaths within 48 h.

CONCLUSIONS

A rapid difficult airway response team allows a large majority of patients' airways to be managed and secured in the patient's primary hospital location. Future directions include reducing time to airway securement and identifying factors associated with cardiac arrest.

Subtotal Submucosal Arytenoidectomy with Lateralization Sutures (SMALS) Covered by a Mucosal Flap

OBJECTIVE

Glottic airway stenosis (GAWS) may result from bilateral paralysis (BVFP) or posterior glottic stenosis (PGS). Since the glottis is the principal airway sphincter, surgeons shift on the balance between airway, aspirations, and voice. We aim to describe our surgical technique and outcome of the SMALS procedure for GAWS correction.

METHODS

A retrospective cohort of patients who underwent SMALS for PGS between 2018 and 2021. SMALS involves: endoscopic submucosal subtotal arytenoidectmy (preserving medial mucosal flap) and lateralization sutures. The sutures lateralize the mucosal flap to cover the arytenoidectomy bed without lateralization of the membranous vocal fold; expanding the posterior glottis, while preserving a relatively good voice. Covering the arytenoidectomy bed enhances healing. Medical and surgical data, airway, voice, and swallowing symptoms were collected. Relative glottic opening area (RGOA) and relative glottic insufficiency area (RGIA) were calculated.

RESULTS

Eleven PGS patients who underwent 15 SMALS were included (4 bilateral), all patients had post-intubation PGS, 1 patient also had prior radiation to the larynx. All patients were tracheostomy-dependent. There were no major complications. No granulation or retracting scar was observed at follow-up. None had a persistent voice or swallowing disability. Successful outcome (decannulation) was achieved in 8 (73%); RGOA increased in all (Δ = 0.37; p = 0.003), while RGIA remained relatively stable (Δ = 0.02; p = 0.055).

CONCLUSIONS

SMALS is a safe and effective, novel modification of the classic arytenoidectomy, for GAWS correction that can be easily applied and may expand the airway without significant glottic insufficiency symptoms.

LEVEL OF EVIDENCE

4 Laryngoscope, 134:353-360, 2024.

[Laryngeal carcinosarcoma]

A clinical case of a rare malignant tumor of the larynx, carcinosarcoma, is described. The features of the clinical picture, diagnostic methods: instrumental and morphological are presented.

Recommendations from the Brazilian Society of Anesthesiology (SBA) for difficult airway management in pediatric care

Difficult airway management in pediatrics during anesthesia represents a major challenge, requiring a careful approach, advanced technical expertise, and accurate protocols. The task force of the Brazilian Society of Anesthesiology (SBA) presents a report containing updated recommendations for the management of difficult airways in children and neonates. These recommendations have been developed based on the consensus of a panel of experts, with the objective of offering strategies to overcome challenges during airway management in pediatric patients. Grounded in evidence published in international guidelines and expert opinions, the report highlights crucial steps for the appropriate management of difficult airways in pediatrics, encompassing assessment, preparation, positioning, pre-oxygenation, minimizing trauma, and, paramountly, the maintenance of arterial oxygenation. The report also delves into additional strategies involving the use of advanced tools, such as video laryngoscopy, flexible intubating bronchoscopy, and supraglottic devices. Emphasis is placed on the simplicity of implementing the outlined recommendations, with a focus on the significance of continuous education, training through realistic simulations, and familiarity with the latest available technologies. These practices are deemed essential to ensure procedural safety and contribute to the enhancement of anesthesia outcomes in pediatrics.

Complications and degree of difficulty of orotracheal intubation in the Intensive Care Unit before and after the establishment of an intubation protocol for critically ill patients: a prospective, observational study

OBJECTIVE

The objective of our study was to compare the degree of difficulty and complications related to tracheal intubation in an Intensive Care Unit (ICU) before and after the introduction of an intubation protocol based on the Difficult Airway Society guidelines for the management of tracheal intubation in critically ill adults, published in 2018.

METHODS

Prospective, observational study comparing all intubations performed in our ICU over 2 periods: pre-protocol (January 2015-January 2019) and post-protocol (February 2019-July 2022). The material used for intubation, the degree of difficulty, and intubation-related complications were recorded.

RESULTS

During the study period, 661 patients were intubated - 437 in the pre-protocol period (96% by direct laryngoscopy) and 224 in the post-protocol period (53% with direct laryngoscopy, 46% with video laryngoscopy). We observed an improvement in laryngeal view in the post-protocol period compared to the pre-protocol period (Cormack-Lehane ≥ 2b in 7.6% vs. 29.8%, p < 0.001), and a decrease in the number of moderate-to-severely difficult intubations (6.7% vs. 17.4%, p < 0.001). The first-pass success rate was 92.8% in the post-protocol period compared to 90.2% pre-protocol (p = 0.508). We did not find significant differences in complications between the periods studied.

CONCLUSIONS

Intubations performed in the post-protocol period were associated with improved laryngeal view and fewer cases of difficult intubation compared with the pre-protocol period.

Curious Case of Pediatric One-Lung Ventilation with Two Endotracheal Tubes: A Case Report

ABSTRACT

One-lung ventilation is indicated during thoracic surgery for visualization and exposure of surgical site. It is achieved with bronchial blockers, double-lumen endobronchial tube, single-lumen endotracheal tubes and Univent tube for infants and children. Fibreoptic bronchoscope is required for placing and confirming the correct position of these tubes. We report a perioperative management of safe conduct of one lung ventilation for a 6-year child undergoing left lower lobe lobectomy through C-MAC video laryngoscope guided two single lumen tubes in limited resource settings where paediatric-sized fibreoptic bronchoscope is unavailable.

Recommendations from the Brazilian Society of Anesthesiology (SBA) for difficult airway management in adults

Difficult airway management represents a major challenge, requiring a careful approach, advanced technical expertise, and accurate protocols. The task force of the Brazilian Society of Anesthesiology (SBA) presents a report with updated recommendations for the management of difficult airway in adults. These recommendations were developed based on the consensus of a group of expert anesthesiologists, aiming to provide strategies for managing difficulties during tracheal intubation. They are based on evidence published in international guidelines and opinions of experts. The report underlines the essential steps for proper difficult airway management, encompassing assessment, preparation, positioning, pre-oxygenation, minimizing trauma, and maintaining arterial oxygenation. Additional strategies for using advanced tools, such as video laryngoscopy, flexible bronchoscopy, and supraglottic devices, are discussed. The report considers recent advances in understanding crisis management, and the implementation seeks to further patient safety and improve clinical outcomes. The recommendations are outlined to be uncomplicated and easy to implement. The report underscores the importance of ongoing education, training in realistic simulations, and familiarity with the latest technologies available.

Comparison of three different image enhancement systems for detection of laryngeal lesions

OBJECTIVE

Image enhancement systems are important diagnostic tools in the detection of laryngeal pathologies. This study aimed to compare three different image enhancement systems: professional image enhancement technology, Image1 S and narrow-band imaging.

METHOD

Using the three systems, 100 patients with laryngeal lesions were investigated using a flexible and a 30° rigid endoscope. The lesions were diagnosed by three experts and classified using the Ni classification. The findings were compared.

RESULTS

Lesions classified as 'benign' were histopathologically confirmed in 50 per cent of patients, malignant lesions were confirmed in 41 per cent and recurrent respiratory papillomatosis were confirmed in 9 per cent. There was no significant difference between the experts' assessments of each image enhancement system.

CONCLUSION

The three systems give comparable results in the detection of laryngeal lesions. With two additional systems, more users can perform image-enhanced endoscopy, resulting in a broadly available tool that can help to improve oncological assessment.

Airway management of lingual tonsillar hypertrophy: A narrative review

Lingual tonsillar hypertrophy is rarely identified on routine airway assessment but may cause difficulties in airway management. We conducted a narrative review of case reports of lingual tonsillar hypertrophy to examine associated patient factors, success rates of airway management techniques and complications. We searched the literature for anaesthetic management of cases with lingual tonsillar hypertrophy. We found 89 patients in various case reports, from which we derived 92 cases to analyse. 64% of cases were assessed as having a normal airway. Difficult and impossible face mask ventilation occurred in 29.6% and 1.4% of cases, respectively. Difficult intubation and failed intubation occurred in 89.1% and 21.7% of cases, respectively. Multiple attempts (up to six) at intubation were performed, with no successful intubation after the third attempt with direct laryngoscopy. Some 16.5% of patients were woken up and 4.3% required emergency front of neck access. Complications included oesophageal intubation (10.9%), bleeding (9.8%) and severe hypoxia (3.2%). Our findings show that severe cases of lingual hypertrophy may cause an unanticipated difficult airway and serious complications, including hypoxic brain damage and death. A robust airway strategy is required which includes limiting the number of attempts at laryngoscopy, and early priming and performance of emergency front of neck access if required. In patients with known severe lingual tonsillar hypertrophy, awake intubation should be considered.

Difficult Tracheal Intubation and Airway Outcomes after Radiation for Nasopharyngeal Carcinoma

OBJECTIVE

The aim of the study was to characterize the incidence and management of difficult tracheal intubations (DTIs) in nasopharyngeal carcinoma (NPC) after primary radiation therapy (RT).

METHODS

The study was a retrospective review of airway assessment and outcomes in post-RT NPC patients. Primary analysis was performed on patients who underwent post-RT procedures, who were split into non-DTI and DTI groups. Patients were classified as DTI if they (i) required >1 attempt to intubate, (ii) failed to be intubated, or (iii) experienced complications attributed to airway management. Secondary analysis was performed between patients who underwent post-RT procedures (procedure group) and those who did not (control group).

RESULTS

One-hundred and fifty patients were included, and 71.3% underwent post-RT procedures, with no differences in characteristics between the procedure and control groups. One-hundred and fifty procedures were identified, and 28.0% were categorized as DTI. There was no difference in patient characteristics or airway assessment measures between DTI and non-DTI groups. Regression analysis revealed concurrent cervical mobility restriction, and trismus increased DTI incidence by 7.1-fold (p = 0.011). Being non-White was an independent predictor of DTI. The incidence of high-grade intraoperative laryngoscopic view was lower in the non-DTI compared to the DTI group (20.4% vs. 64.3%, p < 0.0001). Failure to intubate occurred in 2.0% of cases, and 6.0% cases had perioperative complications. Based on preoperative assessment, sensitivity of predicting DTI was 54.8% and specificity was 63.9%.

CONCLUSION

NPC patients frequently undergo post-RT procedures requiring complex airway management. Rates of DTI and failed intubation are significantly higher than those in the general surgical population, and the ability to predict DTI with standard preoperative airway measures is poor.

LEVEL OF EVIDENCE

4 Laryngoscope, 134:120-126, 2024.

[A clinical case of successful treatment of an air cyst of the larynx]

Laryngeal air cyst (laryngocele) is a rare disease that is an abnormal cystic expansion of the deep structures of the laryngeal ventricle. They can be accompanied by serious complaints, such as shortness of breath, difficulty breathing during exercise, as well as at rest with large cysts. Computed tomography is the most effective method for determining the type, localization and degree of laryngocele. Although surgical treatment is considered the method of choice in cases of laryngeal air cyst, the approach significantly depends on the size of the lesion.

Development and validation of an artificial intelligence algorithm for detecting vocal cords in video laryngoscopy

Airway procedures in life-threatening situations are vital for saving lives. Video laryngoscopy (VL) is commonly performed during endotracheal intubation (ETI) in the emergency department. Artificial intelligence (AI) is widely used in the medical field, particularly to detect anatomical structures. This study aimed to develop an AI algorithm that detects vocal cords from VL images acquired during emergent situations. This retrospective study used VL images acquired in the emergency department to facilitate the ETI. The vocal cord image was labeled with a ground-truth bounding box. The dataset was divided into training and validation datasets. The algorithm was developed from a training dataset using the YOLOv4 model. The performance of the algorithm was evaluated using a test set. The test set was further divided into specific environments during the ETI for clinical subgroup analysis. In total, 20,161 images from 84 patients were used in this study. A total of 10,287, 5766, and 4108 images were used for the model training, validation, and test sets, respectively. The developed algorithm achieved F1 score 0.906, sensitivity 0.963, and specificity 0.842 in the validation set. The performance in the test set was F1 score 0.808, sensitivity 0.823, and specificity 0.804. We developed and validated an AI algorithm to detect vocal cords in VL. This algorithm demonstrated a high performance. The algorithm can be used to determine the vocal cord to ensure safe ETI.

Can chin-nape circumference and the ratio of neck circumference to chin-nape circumference predict difficult mask ventilation or difficult intubation in obese patients?

We aimed to evaluate the success of the ratio of chin-nape circumference (CNC) and neck circumference (NC) to CNC in predicting difficult mask ventilation (DMV) or difficult intubation (DI). Eighty-seven obese patients (body mass index ≥ 30) were evaluated between September 15, 2019 and September 15, 2020. Mallampati score, mouth opening, upper lip bite test, distance between incisors, thyromental distance (TMD), sternomental distance (SMD), and thyromental height were recorded. NC and CNC were measured in a neutral position. The ratio of NC to TMD and the ratio of NC to CNC were calculated. Mask ventilation was graded according to the method described by Han et al (Grade 3 or 4 equals DMV). DI assessment was performed using the intubation difficulty scale (IDS, IDS < 5 equals easy intubation, IDS ≥ 5 equals DI). Logistic regression analysis was performed to identify the variables thought to be effective in DMV and DI. Receiver operating characteristic curves were generated for each parameter considered effective. DMV was found in 17.2% (n = 15) of the patients included in the study, and DI was found in 16.1% (n = 14). The relationship between DMV and age, male gender, obstructive sleep apnea syndrome, NC, ratio of NC to TMD, ratio of NC to SMD, ratio of NC to CNC, and CNC was significant. Male gender and NC >45.5 cm were independent risk factors for DMV. The relationship between DI and distance between incisors, NC, ratio of NC to TMD, ratio of NC to SMD, and CNC was significant. A distance between the incisors < 4.85 cm and a NC > 41.5 cm were found to be independent risk factors for DI. CNC may predict DMV and DI in obese patients. The ratio of NC to CNC may predict DMV in obese patients.

Observation of the validity of the upper lip bite test in predicting difficult intubation

The upper lip bite test (ULBT) is considered an effective method for predicting difficult airways, but data on the ULBT for predicting difficult tracheal intubation are lacking. This study aimed to examine the clinical utility of the ULBT in predicting difficult endotracheal intubation. We conducted an observational case-cohort study of adult patients undergoing elective surgery and requiring endotracheal intubation for general anesthesia. Difficult airway assessment was performed on the recruited patients before the operation, including the ULBT, mouth opening, thyromental distance, modified Mallampati test, and body mass index. The primary outcome was the incidence of difficult tracheal intubation. The receiver operating characteristic curve analysis was used to compare the performance of variables in predicting difficult tracheal intubation. We successfully recruited 2522 patients for analysis and observed 64 patients with difficult tracheal intubation. When predicting difficult tracheal intubation, grade 2 ULBT had a sensitivity of 0.75 and a specificity of 0.54, and grade 3 had a sensitivity of 0.28 and a specificity of 0.75. Compared with mouth opening, the area under the receiver operating characteristic curve of the ULBT was lower in predicting difficult tracheal intubation (0.69 [95% confidence interval: 0.67-0.71] vs. 0.84 [95% confidence interval: 0.82-0.87], P < 0.05).Clinical Trials Registry: ChiCTR-ROC-16009050, principal investigator: Weidong Yao.

[Application of endoscopic surgical repair through bracing laryngoscope in children with type Ⅲ laryngeal clefts]

Objective:To analyze the efficacy of endoscopic surgical repair in the treatment of type Ⅲ laryngeal clefts and to explore the feasibility of the treatment for type Ⅲ laryngeal clefts. Methods:The clinical data of 6 children with type Ⅲ laryngeal clefts who underwent endoscopic surgical repair in our department from June 2018 to January 2023 were analyzed retrospectively. The operation was performed under combined intravenous and general anesthesia,preserving the spontaneous breathing of the children. With the assistance of 4 mm/0° endoscope, radiofrequency knife or laryngeal scissors were used to make fresh wounds along the edge of laryngeal clefts,and cotton pads infiltrated with adrenaline （1:10 000） were used to compress the wound. 6-0 PDP suture was used to suture 3-6 stitches according to the extent of laryngeal clefts. Modified barium swallowing test （MBS） was performed 3 months after operation. Results:All the children were successfully treated with endoscopic surgical repair. After surgery, 2 cases were transferred to pediatric intensive care unit （ICU） for 7 days of monitoring, and the rest were transferred back to the general ward. There were no postoperative complications. The symptoms of dysphagia, laryngitis and recurrent pneumonia were improved in all children. According to the follow-up results of postoperative MBS,no aspiration was found in all children, and 2 children had intermittent cough when drinking large amounts of water. During the follow-up, there were 2 cases of recurrence, and the cracks were completely repaired after the second endoscopic surgical repair treatment,and no recurrence has been observed so far. Conclusion:Endoscopic surgical repair can be applied to some children with type Ⅲ laryngeal clefts with less intraoperative bleeding and fewer operative complications. It can significantly improve the symptoms such as swallowing dysfunction and recurrent pneumonia. It is a safe and effective surgical treatment.

[Present situation and progress of surgical treatment for laryngeal clefts]

At present, there is no unified gold standard for the treatment of laryngeal clefts. Type Ⅰ laryngeal clefts with mild symptoms can be treated conservatively, such as thick diet feeding and using proton pump inhibitor to control reflux, while Ⅱ-Ⅳ laryngeal clefts mostly requires surgical intervention.There are many different surgical methods for the treatment of laryngeal clefts, including injection laryngoplasty, endoscopic surgical repair of laryngeal clefts and open laryngoplasty through anterior cervical approach. How to choose a more suitable surgical plan for children is a problem worth discussing. This article will review the literature on the surgical treatment of laryngeal clefts both domestically and internationally, and summarize the current situation and challenges of surgical treatment of laryngeal clefts.

Endoscopic posterior ventricular cordectomy with contact diode laser: how I do it

BACKGROUND

The treatment of bilateral vocal fold paralysis is mainly surgical and several procedures can be used to guarantee adequate breathing. Furthermore, other causes of the narrowing of the natural airways could coexist and the treatment should consider all of them.

METHODS

A supraglottic extension of posterior cordectomy to the false homolateral chord is described, which provides a further widening of the airway while maintaining acceptable voice quality.

CONCLUSION

Endoscopic posterior ventricular cordectomy performed by contact diode laser may be a viable and safe option, especially in those patients who present bilateral vocal fold paralysis associated with various degrees of laryngospasm.

Interpretable Computer Vision to Detect and Classify Structural Laryngeal Lesions in Digital Flexible Laryngoscopic Images

OBJECTIVE

To localize structural laryngeal lesions within digital flexible laryngoscopic images and to classify them as benign or suspicious for malignancy using state-of-the-art computer vision detection models.

STUDY DESIGN

Cross-sectional diagnostic study SETTING: Tertiary care voice clinic METHODS: Digital stroboscopic videos, demographic and clinical data were collected from patients evaluated for a structural laryngeal lesion. Laryngoscopic images were extracted from videos and manually labeled with bounding boxes encompassing the lesion. Four detection models were employed to simultaneously localize and classify structural laryngeal lesions in laryngoscopic images. Classification accuracy, intersection over union (IoU) and mean average precision (mAP) were evaluated as measures of classification, localization, and overall performance, respectively.

RESULTS

In total, 8,172 images from 147 patients were included in the laryngeal image dataset. Classification accuracy was 88.5 for individual laryngeal images and increased to 92.0 when all images belonging to the same sequence (video) were considered. Mean average precision across all four detection models was 50.1 using an IoU threshold of 0.5 to determine successful localization.

CONCLUSION

Results of this study showed that deep neural network-based detection models trained using a labeled dataset of digital laryngeal images have the potential to classify structural laryngeal lesions as benign or suspicious for malignancy and to localize them within an image. This approach provides valuable insight into which part of the image was used by the model to determine a diagnosis, allowing clinicians to independently evaluate models' predictions.