Reliable prediction of difficult airway for tracheal intubation from patient preoperative photographs by machine learning methods

BACKGROUND

Estimating the risk of a difficult tracheal intubation should help clinicians in better anaesthesia planning, to maximize patient safety. Routine bedside screenings suffer from low sensitivity.

OBJECTIVE

To develop and evaluate machine learning (ML) and deep learning (DL) algorithms for the reliable prediction of intubation risk, using information about airway morphology.

METHODS

Observational, prospective cohort study enrolling n=623 patients who underwent tracheal intubation: 53/623 difficult cases (prevalence 8.51%). First, we used our previously validated deep convolutional neural network (DCNN) to extract 2D image coordinates for 27 + 13 relevant anatomical landmarks in two preoperative photos (frontal and lateral views). Here we propose a method to determine the 3D pose of the camera with respect to the patient and to obtain the 3D world coordinates of these landmarks. Then we compute a novel set of dM=59 morphological features (distances, areas, angles and ratios), engineered with our anaesthesiologists to characterize each individual's airway anatomy towards prediction. Subsequently, here we propose four ad hoc ML pipelines for difficult intubation prognosis, each with four stages: feature scaling, imputation, resampling for imbalanced learning, and binary classification (Logistic Regression, Support Vector Machines, Random Forests and eXtreme Gradient Boosting). These compound ML pipelines were fed with the dM=59 morphological features, alongside dD=7 demographic variables. Here we trained them with automatic hyperparameter tuning (Bayesian search) and probability calibration (Platt scaling). In addition, we developed an ad hoc multi-input DCNN to estimate the intubation risk directly from each pair of photographs, i.e. without any intermediate morphological description. Performance was evaluated using optimal Bayesian decision theory. It was compared against experts' judgement and against state-of-the-art methods (three clinical formulae, four ML, four DL models).

RESULTS

Our four ad hoc ML pipelines with engineered morphological features achieved similar discrimination capabilities: median AUCs between 0.746 and 0.766. They significantly outperformed both expert judgement and all state-of-the-art methods (highest AUC at 0.716). Conversely, our multi-input DCNN yielded low performance due to overfitting. This same behaviour occurred for the state-of-the-art DL algorithms. Overall, the best method was our XGB pipeline, with the fewest false negatives at the optimal Bayesian decision threshold.

CONCLUSIONS

We proposed and validated ML models to assist clinicians in anaesthesia planning, providing a reliable calibrated estimate of airway intubation risk, which outperformed expert assessments and state-of-the-art methods. Our novel set of engineered features succeeded in providing informative descriptions for prognosis.

Derivation of the Difficult Airway Physiological Score (DAPS) in adults undergoing endotracheal intubation in the emergency department

BACKGROUND

Prediction of serious outcomes among patients with physiological instability is crucial in airway management. In this study, we aim to develop a score to predict serious outcomes following intubation in critically ill adults with physiological instability by using clinical and laboratory parameters collected prior to intubation.

METHOD

This single-center analytical cross-sectional study was conducted in the Emergency Department from 2016 to 2020. The airway score was derived using the transparent reporting of a multivariable prediction model for individual prognosis or diagnosis (TRIPOD) methodology. To gauge model's performance, the train-test split technique was utilized. The discrete random number generation approach was used to divide the dataset into two groups: development (training) and validation (testing). The validation dataset's instances were used to calculate the final score, and its validity was measured using ROC analysis and area under the curve (AUC). By computing the Youden's J statistic using the metrics sensitivity, specificity, positive predictive value, and negative predictive value, the discriminating factor of the additive score was determined.

RESULTS

The mean age of the 1021 patients who needed endotracheal intubations was 52.2 years (± 17.5), and 632 (62%) of them were male. In the development dataset, there were 527 (64.9%) physiologically difficult airways, 298 (36.7%) post-intubation hypotension, 124 (12%) cardiac arrest, 347 (42.7%) shock index > 0.9, and 456 [56.2%] instances of pH < 7.3. On the contrary, in the validation dataset, there were 143 (68.4%) physiologically difficult airways, 33 (15.8%) post-intubation hypotension, 41 (19.6%) cardiac arrest, 87 (41.6%) shock index > 0.9, and 121 (57.9%) had pH < 7.3, respectively. There were 12 variables in the difficult airway physiological score (DAPS), and a DAPS of 9 had an area under the curve of 0.857. The accuracy of DAPS was 77%, the sensitivity was 74%, the specificity was 83.3%, and the positive predictive value was 91%.

CONCLUSION

DAPS demonstrated strong discriminating ability for anticipating physiologically challenging airways. The proposed model may be helpful in the clinical setting for screening patients who are at high risk of deterioration.

Airway management in the paediatric difficult intubation registry: a propensity score matched analysis of outcomes over time

Background

The Paediatric Difficult Intubation Collaborative identified multiple attempts and persistence with direct laryngoscopy as risk factors for complications in children with difficult tracheal intubations and subsequently engaged in initiatives to reduce repeated attempts and persistence with direct laryngoscopy in children. We hypothesised these efforts would lead to fewer attempts, fewer direct laryngoscopy attempts and decrease complications.

Methods

Paediatric patients less than 18 years of age with difficult direct laryngoscopy were enrolled in the Paediatric Difficult Intubation Registry. We define patients with difficult direct laryngoscopy as those in whom (1) an attending or consultant obtained a Cormack Lehane Grade 3 or 4 view on direct laryngoscopy, (2) limited mouth opening makes direct laryngoscopy impossible, (3) direct laryngoscopy failed in the preceding 6 months, and (4) direct laryngoscopy was deferred due to perceived risk of harm or poor chance of success. We used a 5:1 propensity score match to compare an early cohort from the initial Paediatric Difficult Intubation Registry analysis (August 6, 2012-January 31, 2015, 785 patients, 13 centres) and a current cohort from the Registry (March 4, 2017-March 31, 2023, 3925 patients, 43 centres). The primary outcome was first attempt success rate between cohorts. Success was defined as confirmed endotracheal intubation and assessed by the treating clinician. Secondary outcomes were eventual success rate, number of attempts at intubation, number of attempts with direct laryngoscopy, the incidence of persistence with direct laryngoscopy, use of supplemental oxygen, all complications, and severe complications.

Findings

First-attempt success rate was higher in the current cohort (42% vs 32%, OR 1.5 95% CI 1.3-1.8, p < 0.001). In the current cohort, there were fewer attempts (2.2 current vs 2.7 early, regression coefficient -0.5 95% CI -0.6 to -0.4, p < 0.001), fewer attempts with direct laryngoscopy (0.6 current vs 1.0 early, regression coefficient -0.4 95% CI -0.4 to 0.3, p < 0.001), and reduced persistence with direct laryngoscopy beyond two attempts (7.3% current vs 14.1% early, OR 0.5 95% CI 0.4-0.6, p < 0.001). Overall complication rates were similar between cohorts (19% current vs 20% early). Severe complications decreased to 1.8% in the current cohort from 3.2% in the early cohort (OR 0.55 95% CI 0.35-0.87, p = 0.011). Cardiac arrests decreased to 0.8% in the current cohort from 1.8% in the early cohort. We identified persistence with direct laryngoscopy as a potentially modifiable factor associated with severe complications.

Interpretation

In the current cohort, children with difficult tracheal intubations underwent fewer intubation attempts, fewer attempts with direct laryngoscopy, and had a nearly 50% reduction in severe complications. As persistence with direct laryngoscopy continues to be associated with severe complications, efforts to limit direct laryngoscopy and promote rapid transition to advanced techniques may enhance patient safety.

Funding

None.

Beyond the Norm: Tracheostomy's Vital Role in Unconventional Foreign Body Removal

BACKGROUND

Foreign Body Aspiration (FBA) is one of the paediatric emergencies which require timely diagnosis and management. The inherent tendency of children to explore small objects with their mouths often prove to be fatal as they are difficult to remove once aspirated.

CASE REPORT

We present the case of a 5-year-old boy who presented with dyspnea and vomiting following the aspiration of a pen cap. Chest radiograph and Rigid Bronchoscopy helped to identify the foreign body but it couldn't be removed by Rigid Bronchoscopy alone due it's wedge-shaped nature. Hence, an unconventional method of foreign body removal was performed by making a tracheostoma, pushing the foreign body to the level of tracheostoma and thereby taking it out from the tracheostoma under strict monitoring of anesthesia team.

CONCLUSION

Alternative approaches like this are required for prompt intervention in a difficult case as it helps to reduce complications produced by repeated failed attempts.

Management of the Difficult Airway: An Appraisal of Clinical Practice Guidelines

OBJECTIVE

Management of the difficult airway can be a challenging process, which necessitates actionable recommendations from well-established guidelines. Herein, clinical practice guideline (CPG) quality is evaluated using the Appraisal of Guidelines for Research and Evaluation (AGREE II) instrument.

STUDY DESIGN

A systematic literature search was performed using Scopus, EMBASE, and MEDLINE via PubMed.

SETTING

Literature database.

METHODS

Data were abstracted from relevant guidelines and appraised by 4 expert reviewers in the 6 domains of quality defined by AGREE II. Intraclass correlation coefficients (ICC) were calculated across domains to quantify interrater reliability.

RESULTS

Twelve guidelines met the inclusion criteria. With a mean quality score of 83.1%, the highest quality guideline was authored by the American Society of Anesthesiologists (ASA). Low-quality content was observed in CPGs authored by the Japanese Society of Anesthesiologists (JSA) and the Chinese Collaboration Group for Emergency Airway Management (CCGEAM). Overall, deficits were most pronounced in domains describing the involvement of stakeholders, developmental rigor, and editorial independence. These findings were consistent among the panel of independent reviewers, with high ICC inter-rater reliability scores of 58.0% to 70.0% for the referenced domains.

CONCLUSION

By providing a comprehensive appraisal of guidelines, this report may serve as a reference for clinicians seeking to understand and improve upon the developmental quality of difficult airway management resources. According to AGREE II criteria for the quality of the guideline creation process, the 2022 ASA guideline outperforms its predecessors.

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.

Anesthetic management in a huge hydrocephalus

The pediatric age group with massive hydrocephalus posted for ventriculoperitoneal (VP) shunt presents a lot of confrontation to anesthesiologists due to macrocephalus and associated congenital anomalies. Here, we presented a case report with massive hydrocephalus with aqueduct stenosis, posted for VP shunt placement, and retained a difficult airway.

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.

General anesthesia for cesarean section in a pregnant woman with systemic vascular malformation: a case report

BACKGROUND

Vascular malformations are composed of morphologically abnormal vascular tissue, and when located in the head and neck region, they can make it difficult to secure the airway during general anesthesia.

CASE PRESENTATION

A 28-year-old pregnant woman with vascular malformations in the pharynx was scheduled to undergo a cesarean section, for which spinal anesthesia was initially chosen. However, after magnetic resonance imaging results revealed the presence of multiple vascular malformations in the lumbar multifidus muscles, spinal anesthesia was considered to be of high risk. Thus, the patient was subjected to general anesthesia tracheal intubation under sedation, and the course of the surgery was without complications.

CONCLUSIONS

Because the pathophysiology and clinical sequelae of vascular malformations may be involved in complications, thorough presurgical evaluation of the patient's physical condition and careful anesthesia planning should be done.

Anesthetic challenges of pregnant obesity women

Obesity causes significant morbidity and increases the mortality risk for both mother and fetus. With an increasing projected prevalence, it is vital that the obstetric anesthetist is equipped with the knowledge and tools to manage these women. A multi-disciplinary team approach and early planning is required. Neuraxial analgesia for labor helps to negate the need for general anesthesia, which is associated with increased risk in this subset of women. Catheter techniques for neuraxial anesthesia allow for titration, manipulation, and prolongation of the anesthetic block to reduce the risk of conversion to general anesthesia.

Mean distance from skin to epiglottis in parturients as measured by airway ultrasound

Introduction

There is an increasing interest in using airway ultrasound to predict difficult intubation. Studies to date have excluded pregnant women in reporting airway measurements. We performed this study to compare the mean distance from skin to epiglottis in parturients to that reported in previously published studies. We also assessed the correlation of mean distance from skin to epiglottis with other elements of the airway examination.

Methods

A total of 100 parturients were recruited from a tertiary hospital's labor and delivery floor. Standard physical examination parameters were recorded in addition to the mean distance from skin to epiglottis for all subjects. The ratio of height-to-thyromental distance was used to classify airways as potentially favorable or unfavorable.

Results

The average mean distance from skin to epiglottis in parturients was 19.9 ± 3.3 mm and followed a normal distribution. The mean distance from skin to epiglottis was moderately correlated with height and body mass index. There was no difference in mean distance from skin to epiglottis between subjects with favorable versus unfavorable airways as classified by ratio of height-to-thyromental distance.

Conclusion

The typical mean distance from skin to epiglottis in parturients falls between previously published values in mixed populations. Previously published cut-off values using airway ultrasound to predict difficult intubation are not likely to apply to parturients.

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.

Extraglottic device use is rare during emergency airway management: A National Emergency Airway Registry (NEAR) study

INTRODUCTION

Airway management is a critical component of the management of emergency department (ED) patients. The ED airway literature primarily focuses upon endotracheal intubation; relatively less is known about the ED use of extraglottic devices (EGDs). The goal of this study was to describe the frequency of use, success, and complications for EGDs among ED patients.

METHODS

The National Emergency Airway Registry (NEAR) is a prospective, multi-center, observational registry. It captures data on all ED patients at participating sites requiring airway management. Intubating clinicians entered all data into an online system as soon as practical after each encounter. We conducted a secondary analysis of these data for all ED encounters in which EGD placement occurred. We used descriptive statistics to characterize these encounters.

RESULTS

Of 19,071 patients undergoing intubation attempts, 56 (0.3%) underwent EGD placement. Of 25 participating sites, 13 reported no cases undergoing EGD placement; the median number of EGDs placed per site was 2 (interquartile range 1-2.5, range 1-31). Twenty-nine (54%) patients had either hypotension or hypoxia prior to the start of airway management. Clinicians reported anticipation of a difficult airway in 55% and at least one difficult airway characteristic in 93% of these patients. Forty-one encounters entailed placement of a laryngeal mask airway (LMA®) Fastrach™, 33 of whom underwent subsequent successful intubation through the EGD and 7 of whom underwent intubation by alternative methods. An additional 10 encounters utilized a standard LMA® device. Providers placed 34 (61%) EGDs during the first intubation attempt. Seventeen EGD patients (30%) experienced peri-procedure adverse events, including 14 (25%) experiencing hypoxemia. None of these patients expired due to failed airways.

CONCLUSIONS

EGD use was rare in this multi-center ED registry. EGD occurred predominantly in patients with difficult airway characteristics with favorable airway management outcomes. Clinicians should consider this emergency airway device for patients with a suspected difficult airway.

[Strategies for airway management in neonates : Results of a survey of German perinatal centers levels II and III]

BACKGROUND

Airway management in children, especially in patients with a difficult airway, remains a major challenge for anesthesiologists, pediatricians, and emergency medicine physicians. In recent years new tools have been introduced into the clinical practice.

OBJECTIVE

The aim was to present the current strategies for securing the airway in neonates in perinatal centers levels II and III in Germany, and to collect data on the rare event of coniotomy.

MATERIAL AND METHODS

From 5 April 2021 to 15 June 2021, physicians practicing intensive care in pediatrics and neonatology at perinatal centers levels II and III in Germany were surveyed by means of an anonymized online questionnaire. The questionnaire was designed by the authors and verified by pretesting with the help of five pediatric specialists. Contact was made digitally via the e‑mail addresses provided on the websites of the respective centers. The survey was administered through the fee for service provider LimeSurvey©. The collected data were transferred to the IBM© statistical package for the social scientists (SPSS, version 28, IBM© Corporation, Armonk, NY, USA) and statistically analyzed. Pearson's χ2-test was used to perform significance testing (significance level p = < 0.05). Only completed questionnaires were included in the analysis.

RESULTS

A total of 219 participants completed the questionnaire. Available airway devices: 94.5% (n = 207) nasopharyngeal tubes, 79.9% (n = 175) video laryngoscope/fiber optic, 73.1% (n = 160) laryngeal masks, 64.8% (n = 142) oropharyngeal tube (Guedel). Of the participants 6 (2.7%) performed coniotomy (⌀ 1.6 children). Out of six cases five (83.3%) were resuscitation situations caused by complex anatomical malformations. Training of coniotomy was not provided in 98.6% (n = 216). A Standard Operating Procedure (SOP) for difficult airway in neonates was possessed by 20.1% (n = 44).

CONCLUSION

The comparison with international studies showed that the equipment of German perinatal centers is above average. The trend towards acquisition of a video laryngoscope and its importance in clinical routine could be confirmed by our data; however, the fact that 20% of the respondents did not have access to video laryngoscopy suggests that further acquisitions will have to be made here in the future. Front of neck access (FONA) methods remain a critically questioned component of neonatal difficult airway algorithms due to their rarity and the resulting lack of data. In summary of the recommendations of the British Association of Perinatal Medicine (BAPM) and the collected data on the theoretical and practical education of the FONA methods in Germany, the implementation of the FONA methods by pediatricians and neonatologists cannot be recommended. As most resuscitation situations were caused by complex anatomical malformations, the early detection of such malformations by means of high-resolution ultrasound seems to be of particular importance. With improvement of early detection, neonates with potentially unmanageable airway problems can be left on uteroplacental circulation for a prolonged period in order to perform necessary interventions, such as tracheostomy, bronchoscopy, or extracorporeal membrane oxygenation (ECMO) device known as the ex utero intrapartum treatment (EXIT) procedure.

Comparison of video laryngoscope, video stylet, and flexible videoscope for transoral endotracheal intubation in patients with difficult airways: a randomized, parallel-group study

BACKGROUND

The 2022 ASA guidelines recommend the video laryngoscope, video stylet, and flexible videoscope as airway management tools. This study aims to compare the efficacy of three airway devices in intubating patients with difficult airways.

METHODS

A total of 177 patients were selected and randomized into the following three groups: the video laryngoscope group (Group VL, n = 59), video stylet group (Group VS, n = 59), and flexible videoscope group (Group FV, n = 59). The success rate of the first-pass intubation, time of tracheal intubation, level of glottic exposure, and occurrence of intubation-related adverse events were recorded and analyzed.

RESULTS

All patients were successfully intubated with three devices. The first-pass intubation success rate was significantly higher in Groups VS and FV than in Group VL (96.61% vs. 93.22% vs. 83.05%, P < 0.01), but it was similar in the first-pass intubation success rate between Groups VS and FV(P > 0.05). The number of patients categorized as Wilson-Cormack-Lehane grade I-II was fewer in Group VL than in Groups VS and FV (77.97% vs. 98.30% vs. 100%, P = 0.0281). The time to tracheal intubation was significantly longer in Group FV(95.20 ± 4.01) than in Groups VL(44.56 ± 4.42) and VS(26.88 ± 4.51) (P < 0.01). No significant differences were found among the three groups in terms of adverse intubation reactions (P > 0.05).

CONCLUSIONS

In patients with difficult airways requiring intubation, use of the video stylet has the advantage of a relatively shorter intubation time, and the flexible videoscope and video stylet yield a higher first-pass intubation success rate and clearer glottic exposure than the use of the video laryngoscope.

TRIAL REGISTRATION

Chinese Clinical Trial Registry. No: ChiCTR2200061560, June 29, 2022.

Securing the Airway in a Patient with Massive neck Swelling, Emergency Tracheostomy: A Technical Note

Objective

To describe the technical aspects of emergency tracheostomy in a case of extensive neck swelling with a challenging airway.

Methods

We report a case of difficult tracheostomy in a patient with a huge neck swelling causing obscured anatomical landmarks in significant stridor. A literature review was performed to identify similar cases or techniques.

Results

Emergency tracheostomy was successfully executed with the help of clinical acumen, imaging findings and intra-operative ultrasound usage.

Conclusions

We describe a safe and effective technique of emergency tracheostomy in patients with huge neck swelling and obscured anatomical landmarks. Collaboration of surgeon with the anaesthesia service is of paramount importance in dealing with challenging airways.

Airway management in mucopolysaccharidosis: a retrospective case series review

Airway management can be difficult in surgeries of patients with mucopolysaccharidosis. We performed a retrospective review of 31 surgeries performed between 2015 and 2019. The mean age of the patients was 127.6 months. MPS-IV and MPS-VI were the most frequent subtypes. Orthopedic surgeries were the most common surgery type. Difficult intubation was seen in 10 procedures. All patients with difficult intubation were aged over 36 months. Video laryngoscopy was the most common intubation method. Seventeen patients were followed up in the intensive care unit. Although video laryngoscopy seems to be a safe method in these patients, one should always be prepared for alternative methods.

Angiotensin-Converting Enzyme Inhibitor-Induced Angioedema

Angioedema is a well-recognized and potentially lethal complication of angiotensin-converting enzyme inhibitor (ACEi) therapy. In ACEi-induced angioedema, bradykinin accumulates due to a decrease in its metabolism by ACE, the enzyme that is primarily responsible for this function. The action of bradykinin at bradykinin type 2 receptors leads to increased vascular permeability and the accumulation of fluid in the subcutaneous and submucosal space. Patients with ACEi-induced angioedema are at risk for airway compromise because of the tendency for the face, lips, tongue, and airway structures to be affected. The emergency physician should focus on airway evaluation and management when treating patients with ACEi-induced angioedema.

Remimazolam for Sedation During Fiberoptic Intubation in an Adolescent

In specific clinical scenarios, fiberoptic intubation (FOI) may be the preferred technique for airway management and endotracheal intubation. In addition to topical anesthesia of the airway, sedation is frequently necessary, especially in younger patients, to facilitate the procedure. The goal is to facilitate the procedure by providing sedation, anxiolysis, and analgesia with maintenance of spontaneous ventilation. Remimazolam is a novel benzodiazepine with a short half-life and limited context sensitive half-life that can be titrated by continuous infusion. These novel properties may make it a suitable agent for sedation during FOI of the trachea. We report the novel use of a combination of remimazolam and remifentanil infusions to provide sedation during FOI in an adolescent. The basic pharmacology of remimazolam is presented and previous reports of its use for sedation during FOI are reviewed.

Hereditary Angioedema

Hereditary angioedema (HAE) is a rare autosomal dominant genetic disorder that usual results from a decreased level of functional C1-INH and clinically manifests with intermittent attacks of swelling of the subcutaneous tissue or submucosal layers of the respiratory or gastrointestinal tracts. Laboratory studies and radiographic imaging have limited roles in evaluation of patients with acute attacks of HAE except when the diagnosis is uncertain and other processes must be ruled out. Treatment begins with assessment of the airway to determine the need for immediate intervention. Emergency physicians should understand the pathophysiology of HAE to help guide management decisions.

Anesthetic management of a pediatric patient with Freeman-Sheldon syndrome undergoing atrial septal defect closure: a case report

BACKGROUND

Freeman-Sheldon syndrome (FSS) is a rare disorder characterized by specific deformities of the extremities and face. There have been no reports of open-heart surgery in pediatric patients with FSS.

CASE PRESENTATION

We present the case of an 8-year-old girl with FSS who underwent atrial septal defect closure. Tracheal intubation was uncomplicated, although the patient had microstomia. Inhalational anesthetics and dopamine antagonists were avoided intraoperatively and perioperatively. We chose dexmedetomidine as an adjuvant for postoperative pain management contributing to adequate analgesia and early extubation without causing respiratory depression.

CONCLUSIONS

Anesthetic management of FSS requires consideration for airway management and prevention of malignant hyperthermia and respiratory complications. We successfully managed the case avoiding the use of malignant hyperthermia-triggering drugs.

Efficacy and safety of Cook staged Extubation Set in patients with difficult airway: a systematic review and meta-analysis

BACKGROUND

Cook Stage extubation is a tool developed by Cook Medical for patients with difficult airways. Multiple clinical studies demonstrated the effectiveness and safety of Cook Stage extubation Set (CSES). Currently, no systematic review evidence has been published in this field. Therefore, this study aimed to review the clinical success rate, safety, and tolerability of CSES in patients with difficult airways.

METHOD

The inclusion criteria were based on the population, intervention, comparator, outcomes, and study designs. An electronic search was conducted, and the following databases were used: PubMed, EMBASE, Cochrane Library, and Web of Science. Search keywords included difficult airway and CSES. The primary outcome was the CSES clinical success rate.The Joanna Briggs Institute Critical Appraisal tools for Case Series were used to assess the risk of bias in the included studies. R studio, version 4.2.2. was used to perform the statistical analysis. The Cochrane Q and I2 statistics were used to test the heterogeneity among all studies. Details of the included case reports were summarized in the systematic review part.

RESULTS

Five studies were eligible for meta-analysis, and 7 case reports were included for systematic review. The pooled overall CSES clinical success rate was 93% (95% CI: 85%, 97%). The CSES intolerable and complication incidence rates were 9% (95% CI: 5%, 18%) and 5% (95% CI: 2%, 12%), respectively. CSES clinical success rate was influenced by the study center and study design. The success rate of CSES was higher in multicenter and prospective design studies. Seven case reports have documented the successful operation of CSES intubation in obese, tall, oncologist, and pediatric patients.

DISCUSSION

This meta-analysis suggested that CSES have achieved a high clinical success rate in adult and pediatric patients with different physical conditions and types of surgery. The results of all original studies and meta-analysis confirmed a remarkably high tolerance rate and low overall complication rate. However, regardless of the tools chosen, a personalized, safe intubation strategy and a highly qualified anesthesiologist should be considered as the fundamental guarantee of a high clinical success rate. Future studies should also focus on the success rate of reintubation using CSES in patients with airway difficulties.

TAScope-guided rapid sequence intubation of a case of retrognathia with a history of failed intubation

A 72-year-old female with symptomatic cholelithiasis was posted for laparoscopic cholecystectomy. She had been previously posted for the same surgery at a different center, but the surgery was not performed due to failed intubation. On airway examination, reduced thyromental distance, prominent incisors, and retrognathia were observed. We planned and executed rapid sequence intubation under videolaryngoscope guidance using The Anaesthetist Society Scope, and the surgery proceeded uneventfully. At the end of the surgery, she was extubated over a bougie, observed, and shifted out without complications.

Prevalence of peri-intubation major adverse events among critically ill patients: A systematic review and meta analysis

BACKGROUND

Peri-intubation major adverse events (MAEs) are potentially preventable and associated with poor patient outcomes. Critically ill patients intubated in Emergency Departments, Intensive Care Units or medical wards are at particularly high risk for MAEs. Understanding the prevalence and risk factors for MAEs can help physicians anticipate and prepare for the physiologically difficult airway.

METHODS

We searched PubMed, Scopus, and Embase for prospective and retrospective observational studies and randomized control trials (RCTs) reporting peri-intubation MAEs in intubations occurring outside the operating room (OR) or post-anesthesia care unit (PACU). Our primary outcome was any peri-intubation MAE, defined as any hypoxia, hypotension/cardiovascular collapse, or cardiac arrest. Esophageal intubation and failure to achieve first-pass success were not considered MAEs. Secondary outcomes were prevalence of hypoxia, cardiac arrest, and cardiovascular collapse. We performed random-effects meta-analysis to identify the prevalence of each outcome and moderator analyses and meta-regressions to identify risk factors. We assessed studies' quality using the Cochrane Risk of Bias 2 tool and the Newcastle-Ottawa Scale.

RESULTS

We included 44 articles and 34,357 intubations. Peri-intubation MAEs were identified in 30.5% of intubations (95% CI 25-37%). MAEs were more common in the intensive care unit (ICU; 41%, 95% CI 33-49%) than the Emergency Department (ED; 17%, 95% CI 12-24%). Intubation for hemodynamic instability was associated with higher rates of MAEs, while intubation for airway protection was associated with lower rates of MAEs. Fifteen percent (15%, 95% CI 11.5-19%) of intubations were complicated by hypoxia, 2% (95% CI 1-3.5%) by cardiac arrest, and 18% (95% CI 13-23%) by cardiovascular collapse.

CONCLUSIONS

Almost one in three patients intubated outside the OR and PACU experience a peri-intubation MAE. Patients intubated in the ICU and those with pre-existing hemodynamic compromise are at highest risk. Resuscitation should be considered an integral part of all intubations, particularly in high-risk patients.

Developing a magnetic POCUS-guided bronchoscope for patients with suspected difficult endotracheal intubation in a general tertiary hospital: protocol for a randomised controlled study

INTRODUCTION

Endotracheal intubation (ETI) is a crucial but risky procedure, especially among patients suspected of difficult endotracheal intubation (DTI). Bronchoscope, as an improved technique commonly used in DTI, might encounter visualisation difficulties. The magnetic point-of-care ultrasound (MGPOCUS) provides a novel visualisation from the outside and enables estimation of the relative position and trajectory of the bronchoscope. The purpose of the study was to evaluate the efficiency of MGPOCUS-guided bronchoscopy, including the time required for successful ETI, the first attempt and overall success rate, the number of attempts, complications, and satisfaction with the visualization of the procedures.

METHODS AND ANALYSIS

The study is a randomised, parallel-group, single-blinded, single-centre study. Participants (n=108) will be recruited by the primary anaesthesiologist and randomised to groups of ETI with bronchoscope or MGPOCUS-guided bronchoscope. The primary outcome is the time taken to the first-attempt success ETI. Secondary outcomes include procedure time, the first-attempt and overall success, complications, and satisfaction of visualisation. Cox regression with Bonferroni correction and linear mixed regression will be used to analyse the outcomes.

ETHICS AND DISSEMINATION

The trial protocol was approved by the ethics committees at the Peking Union Medical College Hospital (Institutional Review Board #ZS-3428). Findings will be disseminated through conference presentations and peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NCT05647174.

A case of safe airway management by fiber-optic nasotracheal intubation in general anesthesia in a pediatric patient with Hajdu-Cheney syndrome: a case report

BACKGROUND

Hajdu-Cheney syndrome (HCS) is an extremely rare disorder characterized by progressive acro-osteolysis. A unique facial structure and deformity of the cervical spine are associated with a difficult airway. Although several reports describe general anesthesia with orotracheal intubation for patients with HCS, there have been no reports of nasotracheal intubation with a risk of skull base fracture. We describe nasotracheal intubation for oral surgery in a patient with HCS.

CASE PRESENTATION

A 13-year-old girl with HCS was scheduled for dental surgery. Preoperative computed tomography revealed no abnormalities including fractures in the skull base or cervical spine. After confirming a lack of vocal cord paralysis by bronchofiberscopic inspection from the nose, general anesthesia was induced with sevoflurane, remifentanil, and rocuronium. Fiber-optic nasotracheal intubation was successfully performed without complications such as depletion of oxygen saturation and massive epistaxis, and the surgery was completed uneventfully. She was discharged the day after surgery with no anesthesia-related complications.

CONCLUSIONS

We were able to safely manage the airway of a patient with HCS by nasotracheal intubation under general anesthesia.

A fully-automatic semi-supervised deep learning model for difficult airway assessment

Background

Difficult airway conditions represent a substantial challenge for clinicians. Predicting such conditions is essential for subsequent treatment planning, but the reported diagnostic accuracies are still quite low. To overcome these challenges, we developed a rapid, non-invasive, cost-effective, and highly-accurate deep-learning approach to identify difficult airway conditions through photographic image analysis.

Methods

For each of 1000 patients scheduled for elective surgery under general anesthesia, images were captured from 9 specific and different viewpoints. The collected image set was divided into training and testing subsets in the ratio of 8:2. We used a semi-supervised deep-learning method to train and test an AI model for difficult airway prediction.

Results

We trained our semi-supervised deep-learning model using only 30% of the labeled training samples (with the remaining 70% used without labels). We evaluated the model performance using metrics of accuracy, sensitivity, specificity, F1-score, and the area under the ROC curve (AUC). The numerical values of these four metrics were found to be 90.00%, 89.58%, 90.13%, 81.13%, and 0.9435, respectively. For a fully-supervised learning scheme (with 100% of the labeled training samples used for model training), the corresponding values were 90.50%, 91.67%, 90.13%, 82.25%, and 0.9457, respectively. When three professional anesthesiologists conducted comprehensive evaluation, the corresponding results were 91.00%, 91.67%, 90.79%, 83.26%, and 0.9497, respectively. It can be seen that the semi-supervised deep learning model trained by us with only 30% labeled samples can achieve a comparable effect with the fully supervised learning model, but the sample labeling cost is smaller. Our method can achieve a good balance between performance and cost. At the same time, the results of the semi-supervised model trained with only 30% labeled samples were very close to the performance of human experts.

Conclusions

To the best of our knowledge, our study is the first one to apply a semi-supervised deep-learning method in order to identify the difficulties of both mask ventilation and intubation. Our AI-based image analysis system can be used as an effective tool to identify patients with difficult airway conditions.

Clinical trial registration

ChiCTR2100049879 (URL: http://www.chictr.org.cn).

An interactive and realistic phantom for cricothyroidotomy simulation of a patient with obesity through a reusable design using 3D-printing and Arduino

BACKGROUND AND OBJECTIVES

Proper airway management during emergencies can prevent serious complications. However, cricothyroidotomy is challenging in patients with obesity. Since this technique is not performed frequently but at a critical time, the opportunity for trainees is rare. Simulators for these procedures are also lacking. Therefore, we proposed a realistic and interactive cricothyroidotomy simulator.

METHODS

All anatomical structures were modeled based on computed tomography images of a patient with obesity. To mimic the feeling of incision during cricothyroidotomy, the incision site was modeled to distinguish between the skin and fat. To reinforce the educational purpose, capacitive touch sensors were attached to the artery, vein, and thyroid to generate audio feedback. The tensile strength of the silicone-cast skin was measured to verify the similarity of the mechanical properties between humans and our model. The fabrication and assembly accuracies of the phantom between the Standard Tessellation Language and the fabricated model were evaluated. Audio feedback through sensing the anatomy parts and utilization was evaluated.

RESULTS

The body, skull, clavicle, artery, vein, and thyroid were fabricated using fused deposition modeling (FDM) with polylactic acid. A skin mold was fabricated using FDM with thermoplastic polyurethane. A fat mold was fabricated using stereolithography apparatus (SLA) with a clear resin. The airway and tongue were fabricated using SLA with an elastic resin. The tensile strength of the skin using silicone with and without polyester mesh was 2.63 ± 0.68 and 2.46 ± 0.21 MPa. The measurement errors for fabricating and assembling parts of the phantom between the STL and the fabricated models were -0.08 ± 0.19 mm and 0.13 ± 0.64 mm. The measurement errors internal anatomy embodied surfaces in fat part were 0.41 ± 0.89 mm. Audio feedback was generated 100% in all the areas tested. The realism, understanding of clinical skills, and intention to retrain were 7.1, 8.8, and 8.3 average points.

CONCLUSIONS

Our simulator can provide a realistic simulation experience for trainees through a realistic feeling of incision and audio feedback, which can be used for actual clinical education.

Anesthesia management in a pediatric patient with complicatedly difficult airway: A case report

BACKGROUND

Reports on perioperative anesthesia management in pediatric patients with difficult airways are scarce. In addition to relatively more difficulties in the technique of endotracheal intubation, the time for manipulation is restricted compared to adults. Securing the airways safely and avoiding the occurrence of hypoxemia in these patients are of significance.

CASE SUMMARY

A 9-year-old boy with spastic cerebral palsy, severe malnutrition, thoracic scoliosis, thoracic and airway malformation, laryngomalacia, pneumonia, and epilepsy faced the risk of anesthesia during palliative surgery. After a thorough preoperative evaluation, a detailed scheme for anesthesia and a series of intubation tools were prepared by a team of anesthesiologists. Awake fiberoptic intubation is the widely accepted strategy for patients with anticipated difficult airways. Given the age and medical condition of the patient, we kept him sedated with spontaneous breathing during endotracheal intubation. The endotracheal intubation was completed on the second attempt after the failure of the first effort. Fortunately, the surgery was successful without postoperative complications.

CONCLUSION

Dealing with difficult airways in the pediatric population, proper sedation allows time to intubate without interrupting spontaneous breathing. The appropriate endotracheal intubation method based on the patient’s unique characteristics is the key factor in successful management of these rare cases.

Automated location of orofacial landmarks to characterize airway morphology in anaesthesia via deep convolutional neural networks

BACKGROUND

A reliable anticipation of a difficult airway may notably enhance safety during anaesthesia. In current practice, clinicians use bedside screenings by manual measurements of patients' morphology.

OBJECTIVE

To develop and evaluate algorithms for the automated extraction of orofacial landmarks, which characterize airway morphology.

METHODS

We defined 27 frontal + 13 lateral landmarks. We collected n=317 pairs of pre-surgery photos from patients undergoing general anaesthesia (140 females, 177 males). As ground truth reference for supervised learning, landmarks were independently annotated by two anaesthesiologists. We trained two ad-hoc deep convolutional neural network architectures based on InceptionResNetV2 (IRNet) and MobileNetV2 (MNet), to predict simultaneously: (a) whether each landmark is visible or not (occluded, out of frame), (b) its 2D-coordinates (x,y). We implemented successive stages of transfer learning, combined with data augmentation. We added custom top layers on top of these networks, whose weights were fully tuned for our application. Performance in landmark extraction was evaluated by 10-fold cross-validation (CV) and compared against 5 state-of-the-art deformable models.

RESULTS

With annotators' consensus as the 'gold standard', our IRNet-based network performed comparably to humans in the frontal view: median CV loss L=1.277·10^-3, inter-quartile range (IQR) [1.001, 1.660]; versus median 1.360, IQR [1.172, 1.651], and median 1.352, IQR [1.172, 1.619], for each annotator against consensus, respectively. MNet yielded slightly worse results: median 1.471, IQR [1.139, 1.982]. In the lateral view, both networks attained performances statistically poorer than humans: median CV loss L=2.141·10^-3, IQR [1.676, 2.915], and median 2.611, IQR [1.898, 3.535], respectively; versus median 1.507, IQR [1.188, 1.988], and median 1.442, IQR [1.147, 2.010] for both annotators. However, standardized effect sizes in CV loss were small: 0.0322 and 0.0235 (non-significant) for IRNet, 0.1431 and 0.1518 (p<0.05) for MNet; therefore quantitatively similar to humans. The best performing state-of-the-art model (a deformable regularized Supervised Descent Method, SDM) behaved comparably to our DCNNs in the frontal scenario, but notoriously worse in the lateral view.

CONCLUSIONS

We successfully trained two DCNN models for the recognition of 27 + 13 orofacial landmarks pertaining to the airway. Using transfer learning and data augmentation, they were able to generalize without overfitting, reaching expert-like performances in CV. Our IRNet-based methodology achieved a satisfactory identification and location of landmarks: particularly in the frontal view, at the level of anaesthesiologists. In the lateral view, its performance decayed, although with a non-significant effect size. Independent authors had also reported lower lateral performances; as certain landmarks may not be clear salient points, even for a trained human eye.

Airway ultrasound for patients anticipated to have a difficult airway: Perspective for personalized medicine

Airway ultrasound allows for precise airway evaluation, particularly for assessing the difficult airway and the potential for front of neck access. Many studies have shown that identification of the cricothyroid membrane by airway ultrasound is more accurate than digital palpation. However, no reports to date have provided clinical evidence that ultrasound identification of the cricothyroid membrane increases the success rate of cricothyroidotomy. This is a narrative review which describes patients with difficult airways for whom airway ultrasound may have been useful for clinical decision making. The role of airway ultrasound for the evaluation of difficult airways is summarized and an approach to the use of ultrasound for airway management is proposed. The goal of this review is to present practical applications of airway ultrasound for patients predicted to have a difficult airway and who undergo cricothyroidotomy.

Rapid sequence tandem intubation to navigate a subglottic obstruction

Emergency airway management requires matching the appropriate intubation tools to anticipated obstacles. Video laryngoscopy and flexible endoscopy are often used for difficult airways. Here we describe a case where neither method alone was anticipated to be sufficient. A 53-year-old female with an obstructing lung mass required intubation for a mixed type 1 and 2 respiratory failure. Chest x-ray revealed a tortuous subglottic obstruction. The patient could not be temporized on maximized non-invasive airway support. These factors made tandem intubation, sequentially using video laryngoscopy and flexible endoscopic intubation, an appropriate intubation strategy. In this case report we describe the rationale and technique for a rapid sequence tandem intubation.

Incidence and diagnostic validity of difficult airway in emergency departments in China: a cross-sectional survey

Background

The difficult airway is a topic of concern for any physician performing intubation. Severe adverse events which can happen because of an unexpected difficult airway emphasize the importance of prediction. This study aimed to investigate the incidence of difficult airways in emergency departments in mainland China and ascertain the predictive value of common assessment formulas.

Methods

This study was a multicentral, cross-sectional investigation of patients intubated in emergency departments in mainland China between March 1-30, 2021. Frequencies and percentages were calculated for patient characteristics. Diagnostic values were analyzed by sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, the area under the curve, and corresponding P values.

Results

Nine hundred and eighty-five patients in 41 hospitals were enrolled in the study. Elderly male patients occupied most of the intubated patients. The difficult face mask ventilation rate (8.2%) was higher, but the difficult glottic exposure (6.8%) and intubation (2.1%) rates were low, while there was widespread use of enhanced visualization equipment (80.6%). Four combined emergency applicable evaluation methods showed a certain predictive value for the difficult airway with a sensitivity [0.71; 95% confidence interval (CI): 0.47-0.89], specificity (0.79; 95% CI: 0.76-0.81), and the area under the curve (0.75; 95% CI: 0.64-0.87, P<0.01).

Conclusions

Despite an insufficient predictive ability for current difficult airway evaluation methods, there were relatively low rates of difficult airways during ED intubations in mainland China. Continuing focus on the difficult airway problems and optimizing airway assessment are required.

Difficult airway due to cervical haemorrhage caused by spontaneous rupture of a parathyroid adenoma: A case report

BACKGROUND

Cervical haemorrhage due to spontaneous rupture of a parathyroid adenoma is a rare complication that may cause life-threatening acute airway compromise.

CASE SUMMARY

A 64-year-old woman was admitted to the hospital 1 day after the onset of right neck enlargement, local tenderness, head-turning difficulty, pharyngeal pain, and mild dyspnoea. Repeat routine blood testing showed a rapid decrease in the haemoglobin concentration, indicating active bleeding. Enhanced computed tomography images showed neck haemorrhage and a ruptured right parathyroid adenoma. The plan was to perform emergency neck exploration, haemorrhage removal, and right inferior parathyroidectomy under general anaesthesia. The patient was administered 50 mg of intravenous propofol, and the glottis was successfully visualised on video laryngoscopy. However, after the administration of a muscle relaxant, the glottis was no longer visible and the patient had a difficult airway that prevented mask ventilation and endotracheal intubation. Fortunately, an experienced anaesthesiologist successfully intubated the patient under video laryngoscopy after an emergency laryngeal mask placement. Postoperative pathology showed a parathyroid adenoma with marked bleeding and cystic changes. The patient recovered well without complications.

CONCLUSION

Airway management is very important in patients with cervical haemorrhage. After the administration of muscle relaxants, the loss of oropharyngeal support can cause acute airway obstruction. Therefore, muscle relaxants should be administered with caution. Anaesthesiologists should pay careful attention to airway management and have alternative airway devices and tracheotomy equipment available.

Anaesthetic implications for Pompe disease. A case description

Pompe disease, or type II glycogenosis, is a rare metabolic myopathy inherited in an autosomal recessive pattern, characterized by progressive muscle weakness and multisystem involvement. The disease often results in premature death. Patients with Pompe disease are at high risk for anaesthesia-related complications, particularly cardiac and respiratory problems, although difficult airway management is the greatest complication. It is essential to perform a comprehensive preoperative study in order to reduce the risk of perioperative morbidity and mortality, and to obtain as much information as possible for the surgical procedure. In this article, we report the case of a patient with a history of adult Pompe disease who underwent combined anaesthesia for osteosynthesis of the proximal end of the left humerus.

Successful surgical cricothyroidotomy following an obstetric "can't oxygenate" scenario: a narrative of enabling factors

The airway management of a patient requiring emergency caesarean delivery for fetal distress and pre-eclampsia with severe features is described. A difficult obstetric airway was anticipated prior to induction and managed with the use of decision-support guidelines and cognitive aids. Failed tracheal intubation later progressed to a "can't oxygenate" scenario necessitating front-of-neck-access via surgical cricothyroidotomy. We discuss the factors which facilitated the preparation and implementation of interventions required to successfully execute this high-acuity task.

Videolaryngoscopy: Channelizing through Intensive Care Unit Intubations

How to cite this article: Kothekar AT, Wajekar AS, Joshi AV. Videolaryngoscopy: Channelizing through Intensive Care Unit Intubations. Indian J Crit Care Med 2023;27(2):85-86.

Anaesthetic considerations in Shrinking Man syndrome: two case reports

BACKGROUND

Shrinking Man syndrome (SMS) is a rare but often serious complication of dialysis-dependent end-stage renal disease, characterized by significant loss of height, bone pain, bone deformity, and skin itching. Patients with SMS always have abnormal facial changes and cardiovascular system damage (manifested by hypertension, hypotension, cardiovascular calcification, and valvular heart disease), which pose a great challenge to anaesthesiologists. The purpose of this report is to describe our anaesthetic experience regarding two patients with SMS combined with alterations of the airway and cardiovascular system.

CASE PRESENTATION

We describe two cases of SMS treated at West China Hospital, a tertiary care centre in Chengdu, China. All cases met the diagnostic criteria, which comprised 1) dialysis-dependent end-stage renal disease, 2) loss of height, and 3) bone pain and bone deformity. One patient had an anticipated difficult airway and moderate-to-severe mitral stenosis. The other patient presented with significant hypotension. Anaesthetic considerations included awake fibreoptic bronchoscopy-assisted tracheal intubation, real-time transoesophageal echocardiogram monitoring and individualized blood pressure management strategies.

CONCLUSION

This case series highlights the importance of adequate preoperative assessment and preparation, as well as individualized anaesthetic management, in patients with SMS.

Utility of the Awake Video Laryngoscopy Assisted Fibreoptic Intubation Technique in Maxillofacial Gunshot Injury - A Case Report

Rationale

Maxillofacial gunshot injury leads to significant soft tissue and bone defects, which compromise airway patency, thus posing a challenge for the anaesthesiologist. The utility of the videolaryngoscopy-assisted fibreoptic intubation (VAFI) technique in maxillofacial gunshot injury has not yet been described in the literature.

Patient Concerns

We report the case of a young male presenting with extensive maxillofacial wounds with fractures of the bilateral maxilla, mandible and floor of orbit secondary to self-inflicted gunshot injury.

Diagnosis

Major peri-operative concerns included anticipated difficult airway, control of potential haemorrhage and airway oedema.

Treatment

A flexible fibreoptic bronchoscope used in combination with a video laryngoscope was used to successfully secure the airway.

Outcome

He was extubated on the same day and discharged after two weeks.

Take-Away Lessons

The current case highlights the safe and effective use of the videolaryngoscopy-assisted fibreoptic intubation technique in maxillofacial gunshot injury.

The Use of McGrath MAC Video Laryngoscope Versus McCoy Laryngoscope in Adults with Anticipated Difficult Airway Undergoing Elective Surgery

Background

Difficult airway management remains one of the most challenging clinical situations encountered by anaesthetists.

Aim

The study compared the effectiveness of the McGrath MAC video laryngoscope to the McCoy® laryngoscope in patients with difficult airway.

Materials and Methods

Following the institution's ethical approval, the randomised controlled trial was conducted involving 74 adults with American Society of anaesthesiologists' physical status (ASA) grading of I-III scheduled for elective surgery. The Patients were randomised into either group MVL (McGrath MAC) or group MCC (McCoy) and intubated after preoxygenation with 100% oxygen and administration of IV propofol and suxamethonium. The Intubation Difficulty Score (IDS), success rate of intubation, time to intubation, number of optimising manoeuvres and complications was assessed. Statistical analysis was performed using the statistical Package for Social Sciences (SPSS) version 24.0 computer software (IBM SPSS Statistics, IBM Corp. NY, United States). Numerical and categorical data were compared using the student's t-test and Chi square (χ2) test respectively. A value of P < 0.05 was considered statistically significant.

Results

Lower IDS scores were noted in the McGrath group; 54.1% vs. 5.4% of patients had IDS score of 0 in the McGrath and McCoy groups respectively, (P < 0.001). Overall success rate was higher in the McGrath group (100% vs. 89.1%), P = 0.040.

Conclusion

Lower IDS scores and improved intubation success rate was achieved with the McGrath compared with the McCoy laryngoscope in patients with predicted difficult airway. The McGrath has proved to be useful in managing patients with difficult airway.

Emergent use of tube tip in pharynx technique in “cannot intubate cannot oxygenate” situation: A case report

BACKGROUND

A “cannot intubate, cannot oxygenate (CICO)” situation is a life-threatening condition that requires emergent management to establish a route for oxygenation to prevent oxygen desaturation. In this paper, we describe airway management in a patient with an extended parotid tumor that invaded the airways during CICO using the endotracheal tube tip in the pharynx (TTIP) technique.

CASE SUMMARY

A 43-year-old man was diagnosed with parotid tumor for > 10 years. Computed tomography and nasopharyngeal fiberoptic examination revealed a substantial mass from the right parotid region with a deep extension through the lateral pharyngeal region to the retropharyngeal region and obliteration of the nasopharynx to the oropharynx. Tumor excision was arranged. However, we encountered CICO during anesthesia induction. An endotracheal tube was used as an emergency supraglottic airway device (TTIP) to ventilate the patient in a CICO situation where other tools such as laryngeal mask airway or mask ventilation were not suitable for this complicated and difficult airway. The patient did not experience desaturation despite sudden loss of definite airway. During tracheostomy, the pulse oximetry remained 100% with our technique of ventilating the patient. The arterial blood gas analysis revealed PaCO₂ 35.7 mmHg and PaO₂ 242.5 mmHg upon 50% oxygenation afterward.

CONCLUSION

Using an endotracheal tube as a supraglottic airway device, patients may have increased survival without experiencing life-threatening desaturation.

Endotracheal Intubation with Laryngeal Mirror in Simulated Difficult Direct Laryngoscopy: Comparison of Gum Elastic Bougie Versus Styleted Endotracheal Tube

Laryngeal mirror (LM) is an inexpensive, portable, readily available device which can help visualize the vocal cords in difficult airway (DA) situations. We evaluated its use in improving glottic view prior to placing the airway adjuncts in simulated difficult airway.Eighty patients scheduled to undergo elective surgery under general anaesthesia with endotracheal intubation were allocated- Bougie group (Group B) and Stylet group (Group S). Direct laryngoscopy was performed and CL grade III simulated. The glottic view was obtained using laryngeal mirror and Gum Elastic Bougie (GEB)/ Styleted Endotracheal Tube (ETT) inserted under mirror view. Time taken to obtain glottic view in LM and time for successful intubation were noted.Significant improvement in glottic view with LM was observed, with the view improving to Grade I in 76.25% and grade II in 23.75% of patients. Both groups were comparable with respect to number of attempts and success rate (p = 0.55).The success rate was 90% in group B and 95% in group S. Time taken for intubation was less in Group S (52.44 ± 14.23 s vs. 62.805 ± 20.74 s) [p = 0.01]. Hence, overall stylet proved to be a better adjunct with mirror guided intubation.We recommend stylet assisted rather than GEB assisted ET intubation under LM guidance in emergency scenarios. Also, further controlled trials are recommended to know the exact location of the mirror in relation to bulb of the laryngoscope as well as different angles at which it is placed to improve the view and stabilize the assembly.

Fine Governance of Difficult Tracheostomy in Difficult Airway with Stridor and Respiratory Distress

Difficult airway is a commonly encountered problem in the anesthesia practice, might needing otolaryngologist expert in creation of surgical airway. Supraglottic airways, surgical or needle cricothyrotomy, high frequency jet ventilation, cardiopulmonary bypass (Tunstall in Can J Anaesth 36:611-613, 1989) are initial rescue measures in such scenario. But in otolaryngology practice, patient presenting with stridor having difficult airway and difficult tracheostomy concurrently will definitely pose problems resulting in life-threatening consequences. We report cases in which difficult airway and difficult tracheostomy coexisted. (1) upper tracheal stenosis following strangulation and intubation (2) short neck with obesity (3) blunt trauma to neck with surgical emphysema (4) deep neck space infection (5) Paediatric tracheostomy in faucial diphtheria. Though difficult surgical tracheostomy in difficult airway is challenging, the anticipation of complications and planning can minimise the difficulty in the technique.

What we have learned from a patient with partial tracheal rupture caused by penetrating neck injuries: a case report

BACKGROUND

Airway management of patients with direct airway trauma caused by penetrating neck injuries is always challenging. When a failed airway occurs and surgery access is difficult, it is crucial to find the optimal approach to save the life. We propose the concept "Cannot intubate, Cannot oxygenate, Difficult surgery access" to describe this emergency scenario.

CASE PRESENTATION

We report a case of a 24-year-old woman who presented with partial tracheal rupture and pneumothorax caused by a knife stab injury to the neck. A "double setup" strategy, simultaneous preparation for orotracheal intubation and tracheotomy, was carried out before rapid sequence induction. A tracheotomy under local anesthesia or an awake intubation was not preferred in consideration that the patient had a high risk of being uncooperative owing to existing mental disease and potential smothering sensation during operation. During rapid sequence intubation, distal part of the tube penetrates the tear and creates a false lumen outside the trachea then a failed airway subsequently occurred. Rescue tracheotomy was successfully performed by an otolaryngology surgeon, with the help of limited ventilation using sequential bag-mask and laryngeal mask airway ventilation provided by an anesthesiologist, without severe sequelae.

CONCLUSIONS

The endotracheal tube have a risk of penetrating the tear outside the trachea in patient with partial tracheal rupture during orotracheal intubation, and once it occurs, proceeding directly to an emergency invasive airway access with optimizing oxygenation throughout procedure might increase the chance of success in rescuing the airway.

Difficult intubation and postoperative aspiration pneumonia associated with Moebius syndrome: a case report

Background

Moebius syndrome is a rare congenital disorder characterized by non-progressive palsy of the abducens (VI) and facial (VII) cranial nerves. Its common features include dysfunctions associated with other cranial nerves, orofacial abnormalities, skeletal muscle hypotonia, and other systemic disorders of differing severities. There are several concerns in the perioperative management of patients with Moebius syndrome.

Case presentation

We present a report on the management of general anesthesia of a 14-year-old male patient with Moebius syndrome who was scheduled for mandibular cystectomy. The patient was diagnosed with Moebius syndrome at the age of 7 years based on his clinical manifestations of nerve palsy since birth and cranial nerve palsy of the trigeminal (V), facial (VII), glossopharyngeal (IX), vagus (X), and sublingual nerves (XII). The patient’s oral morphological abnormalities made intubation difficult. He also experienced dysphagia and aspiration pneumonia on a daily basis. Oral secretions were frequently suctioned postoperatively. However, after discharge, the patient developed aspiration pneumonia and was readmitted to the hospital.

Conclusions

The main problem arising when administering general anesthesia to patients with this syndrome is difficult airway management. The oral abnormalities in these patients, such as small jaw and extreme dental stenosis, make mask ventilation and intubation difficult. Furthermore, this syndrome often involves respiratory impairment and dysphagia due to cerebral nerve palsy, so there is a high risk of postoperative respiratory complications. Since multiple organs are affected in patients with Moebius syndrome, appropriate perioperative management strategies must be prepared for these patients.

An Infected Third Branchial Pouch Cyst presenting with Acute Stridor in an Infant

Branchial pouch cysts clinically mimic deep neck space infection and misdiagnosis leads to surgical drainage which can complicate into a persistently draining sinus or fistula. We present a unique case of infected third branchial pouch cyst in an infant who presented with acute stridor and our experience in its management.

Comparison of double lumen tube insertion using the McGrath MAC versus direct laryngoscopy in adult patients with a limited glottis view: A prospective interventional study

Background and Aims

Passage of double-lumen tubes (DLT) can be challenging in patients with limited glottis view. This study aims to determine the usefulness of McGrath® MAC videolaryngoscope (VL) in cases with limited glottis view on direct laryngoscopy with Macintosh blade.

Material and Methods

After study approval and registration of trial, consent was sought from all adult patients planned for elective DLT insertion for lung isolation during the course of general anesthesia. Patients not consenting, less than 18 years, with anticipated difficult mask ventilation or need for rapid sequence induction were excluded. Following routine anesthetic induction, laryngoscopy was attempted by an experienced anesthesiologist using Macintosh scope. If the view obtained was Cormack and Lehane (CL) view IIB and above or the attempt at intubation using DLT failed despite a CL I/IIA view, the patient was included in the trial. The laryngoscope was removed and after ensuring adequate oxygenation and depth of anesthesia, intubation was attempted using McGrath® MAC VL. The percentage of glottis opening (POGO) score was noted for both the scopes.

Results

DLT insertion was attempted in 76 patients in the study period. Eight patients were included in the trial on account of limited glottis view/failure with Macintosh scope. Insertion of DLT with McGrath MAC was tried only in six patients, in two patients, the VL was not available for use. The mean (standard deviation) POGO score with Macintosh scope was 9 (±20), which significantly improved with the use of VL to 71 (±24), P = 0.01.

Conclusion

McGrath MAC is helpful in inserting DLT in patients with limited glottis view with Macintosh scope.

Unexpected difficult airway due to severe upper tracheal distortion: A case report

BACKGROUND

Difficult airway is a significant cause of anesthesia-associated death and disability. Currently, physical examinations of thyromental distance, mouth opening, Mafampaii classification, etc. combined with X-ray, computed tomography (CT), and other imaging technologies are mainly used to evaluate difficult airways. However, in many special cases, i.e., emergency surgery, imaging examinations cannot be completed preoperatively. Such patients' airway can only be evaluated through general physical examination, which inevitably increases the likelihood of an unexpected difficult airway during anesthesia.

CASE SUMMARY

We report a rare case of difficult intubation because of severe upper trachea distortion after induction. Emergency holmium laser lithotripsy was performed under transurethral ureteroscopy because the patient had anuria for 4 d and a creatinine level of 890 μmol/L. Due to the urgency of the condition, chest radiography or chest CT was not examined before surgery and the anesthesiologist did not evaluate the airway adequately, resulting in an unexpected difficult airway.

CONCLUSION

The incidence of tracheal malformation and tracheal stenosis is extremely low, but the risk of hypoxia and even death due to difficult airways is extremely high for such patients. It is recommended to complete preoperative imaging examinations of the airway. For life-threatening emergency patients, a pre-anesthesia reassessment should be performed and surgeons should be prepared to prevent and manage the difficult airway.