Evaluation of preoperative difficult airway prediction methods for adult patients without obvious airway abnormalities: a systematic review and meta-analysis.

BACKGROUND: This systematic review aims to assist clinical decision-making in selecting appropriate preoperative prediction methods for difficult tracheal intubation by identifying and synthesizing literature on these methods in adult patients undergoing all types of surgery. METHODS: A systematic review and meta-analysis were conducted following PRISMA guidelines. Comprehensive electronic searches across multiple databases were completed on March 28, 2023. Two researchers independently screened, selected studies, and extracted data. A total of 227 articles representing 526 studies were included and evaluated for bias using the QUADAS-2 tool. Meta-Disc software computed pooled sensitivity (SEN), specificity (SPC), positive likelihood ratio (PLR), negative likelihood ratio (NLR), and diagnostic odds ratio (DOR). Heterogeneity was assessed using the Spearman correlation coefficient, Cochran's-Q, and I2 index, with meta-regression exploring sources of heterogeneity. Publication bias was evaluated using Deeks' funnel plot. RESULTS: Out of 2906 articles retrieved, 227 met the inclusion criteria, encompassing a total of 686,089 patients. The review examined 11 methods for predicting difficult tracheal intubation, categorized into physical examination, multivariate scoring system, and imaging test. The modified Mallampati test (MMT) showed a SEN of 0.39 and SPC of 0.86, while the thyromental distance (TMD) had a SEN of 0.38 and SPC of 0.83. The upper lip bite test (ULBT) presented a SEN of 0.52 and SPC of 0.84. Multivariate scoring systems like LEMON and Wilson's risk score demonstrated moderate sensitivity and specificity. Imaging tests, particularly ultrasound-based methods such as the distance from the skin to the epiglottis (US-DSE), exhibited higher sensitivity (0.80) and specificity (0.77). Significant heterogeneity was identified across studies, influenced by factors such as sample size and study design. CONCLUSION: No single preoperative prediction method shows clear superiority for predicting difficult tracheal intubation. The evidence supports a combined approach using multiple methods tailored to specific patient demographics and clinical contexts. Future research should focus on integrating advanced technologies like artificial intelligence and deep learning to improve predictive models. Standardizing testing procedures and establishing clear cut-off values are essential for enhancing prediction reliability and accuracy. Implementing a multi-modal predictive approach may reduce unanticipated difficult intubations, improving patient safety and outcomes.

Preemptive airway management planning: A retrospective evaluation of the pediatric difficult airway consultation service.

BACKGROUND/AIMS: The pediatric Difficult Airway Consultation Service (pDACS) was created in 2017 to identify patients with potentially difficult airways and create airway management plans prior to airway management. METHODS: Consults were either nurse-initiated, physician-initiated, or both nurse-and-physician-initiated and were examined for demographic and clinical factors. If a child had difficult airway risk factors, a consult note with airway management recommendations was completed. RESULTS: We included 419 consults from the 4-year study period for analysis. Sixty-one patients had chronic tracheostomies in place and thus, were analyzed separately. Of the remaining 358 consults, 50% (n = 179) were nurse-initiated, 30.2% (n = 108) physician-initiated, and 19.8% (n = 71) nurse-and-physician-initiated consults. Differences in observed frequency of airway edema (difference, 6.3%; 95%CI 0.1%-12.5%; p = .04), cleft lip/palate (difference, 8.1%; 95%CI 0.07%-16.3%, p = .04), craniofacial abnormalities (difference, 12.3%; 95%CI 1.9%-22.7%, p = .02), and trauma/burn (difference, 6.5%; 95%CI 0.09%-12.8%, p = .04) were calculated. Observed frequencies were higher in physician-initiated compared to nurse-initiated consults. Airway edema was also more prevalent in dual nurse-and-physician-initiated consults (difference, 8.7%; 95%CI 1.6%-15.8%; p = .01). Physician-initiated consults were associated with a greater proportion of high-risk difficult airways than nurse-initiated consults (difference, 26.7%; 95%CI 14.0%-39.4%, p < .001). Approximately 41.9% of patients at high-risk for having a difficult airway were identified by nurse-screening only. Using bag-valve-mask was often the primary ventilation recommendation (89.3%, n = 108) and supraglottic airway placement was the most common tertiary plan (74.2%, n = 83). Direct laryngoscopy (47.1%, n = 65) and videolaryngoscopy (40.6%, n = 56) were the most recommended modes of intubation. Three patients with airway emergencies had previously documented airway management plans and were successfully intubated without complications following the primary intubation technique recommended in their consult note. CONCLUSIONS: In our study, nurse-screening identified patients at high-risk for a difficult airway that would likely not have been identified prior to initiation of a screening protocol. Furthermore, airway management plans outlined prior to an emergent difficult airway event may increase first-attempt success at securing the difficult airway, reducing morbidity and mortality.

Alternative Hybrid Technique of Intubation Using C-MAC and Yankauer Suction Catheter: Case of A Floppy Supraglottic Mass.

Supraglottic masses can be an anaesthesiologist's nightmare due to the difficult airway scenario and bleeding risk during airway manipulation. Awake fibreoptic intubation is the primary method to secure the airway in such cases. However, most practising anaesthesiologists are not experts at handling the fibreoptic scope, especially in cases with a floppy supraglottic mass where it becomes difficult to displace the mask with the thin flexible bronchoscope. A hybrid technique of intubation in supraglottic masses using Bonfils rigid scope and C-MAC is often described but frequently not available. Here we describe a case of an elderly patient in their 80s presenting with a floppy supraglottic mass where an awake fibreoptic bronchoscope failed to secure the airway. Without access to a rigid Bonfils scope, we intuitively used a C-MAC to visualize the larynx and a yankauer suction catheter to displace the mass and perform a bougie-guided endotracheal intubation.

Optimizing Anesthesia for Extensive Extraoral Fungating Lesions: Strategies and Considerations.

A large extraoral fungus, frequently seen in late head and neck cancers, poses serious difficulties for the management of anesthesia and surgery. Essential factors include preoperative optimization, airway assessment, intraoperative monitoring, and postoperative care. Risk mitigation and outcome optimization strategies are discussed, including appropriate airway management and hemodynamic monitoring. Ideal patient outcomes in situations of extensive extraoral fungation can be attained by a complete plan that integrates surgical expertise and anesthetic care. This case discusses the successful anesthetic management of a 55-year-old man undergoing composite resection with segmental mandibulectomy, appropriate neck dissection, free fibular flap, and scalp flap for squamous cell carcinoma of the lower labial mucosa with significant extraoral fungation.

Anesthetic Management of Large Bronchogenic Cyst With Severe Tracheal Compression in Adults: A Case Report.

Bronchogenic cysts (BCs) are a congenital anomaly, forming fluid-filled sacs in the bronchial tree during fetal development, and are relatively rare in adults. Patients with large BCs in the mediastinum presenting with severe tracheal compression pose a significant challenge to anesthesiologists. The confined and narrow space of the mediastinum exacerbates the compression effect on surrounding structures, leading to potential respiratory or cardiovascular collapse during anesthesia and postoperatively. Herein, we report the stepwise anesthetic management of a patient with a BC in the paratracheal region of superior mediastinum, causing near-complete tracheal compression, scheduled for right posterolateral thoracotomy and tumor excision. The patient presented with dyspnea, chest pain, cough, and severe tracheal compression necessitating meticulous airway management. Utilizing awake fiberoptic intubation with a single-lumen endotracheal tube and one-lung ventilation facilitated by an EZ bronchial blocker, we successfully secured the airway, provided ideal surgical conditions through lung deflation, and ensured perioperative safety. This case underscores the crucial role of comprehending the underlying pathophysiology, anticipating complications, and meticulously planning, preparing, and executing strategies for airway management and perioperative care in patients with mediastinal masses leading to significant tracheal compression.

Awake Videolaryngoscopy for Intubation in Patients With Laryngeal Cancer: A Case Series.

Total laryngectomy is the gold standard surgical approach for laryngeal cancer and is generally conducted under general anesthesia. Orotracheal intubation remains a very delicate step in the general anesthesia process. In otolaryngology (ENT) surgery, it remains considered the preferred method of anesthesia for many surgical procedures. A significant challenge in oncological ENT surgery is the difficulty associated with orotracheal intubation, due to a number of reasons that can lead to failure of orotracheal intubation. To mitigate this risk, experts recommend proceeding with orotracheal intubation with the patient awake and breathing spontaneously. In this case series, we report four patients with supraglottic tumors of the larynx who underwent total laryngectomy surgery under general anesthesia, during which they underwent orotracheal intubation while awake and spontaneous breathing, under no sedative drugs of any kind, in order to avoid complications of orotracheal intubation failure and respiratory apnea due to bleeding tumor masses that engaged the supraglottic space.

Structured Routine Use of Styletubation for Oro-Tracheal Intubation in Obese Patients Undergoing Bariatric Surgeries-A Case Series Report.

The aim of this case series report is to provide a new topical view of styletubation (video intubating stylet technique) in obese patients undergoing bariatric surgeries. In contrast to various conventional direct laryngoscopes (DLs), videolaryngoscopes (VLs) have been applied in such obese populations with potentially difficult airway complications. The safety and effectiveness of VLs have been repeatedly studied, and the superiority of VLs has then been observed in and advocated for routine use. In this article, among our vast use experiences with styletubation (more than 54,998 patients since 2016) for first-line routine tracheal intubation, we present the unique experience to apply the styletubation technique in obese patients undergoing bariatric surgery. Consistent with the experiences applied in other patient populations, we found the styletubation technique itself to be swift (the time to intubate from 5 s to 24 s), smooth (first-attempt success rate: 100%), safe (no airway complications), and easy (high subjective satisfaction). The learning curve is steep, but competency can be enhanced if technical pitfalls can be avoided. We, therefore, propose that the styletubation technique can be feasibly and routinely applied as a first-line airway modality in obese patients undergoing bariatric surgery.

Epidural Block in a Patient With Melkersson-Rosenthal Syndrome: A Case Report.

This case report describes the first known application of an epidural block for labor analgesia in a patient with Melkersson-Rosenthal syndrome (MRS), a rare disorder that may present sudden and threatening airway complications. A tailored epidural protocol effectively mitigated symptom exacerbation, facilitating a complication-free vaginal delivery. This report not only enriches the sparse literature on anesthesia in patients with MRS but also provides a crucial review of perioperative considerations for administering either general or regional anesthesia in similar cases.

Corrigendum: Tracheal intubation in patients with Pierre Robin sequence: development, application, and clinical value based on a 3-dimensional printed simulator.

[This corrects the article DOI: 10.3389/fphys.2023.1292523.].

Machine learning models based on ultrasound and physical examination for airway assessment.

PURPOSE: To demonstrate the utility of machine learning models for predicting difficult airways using clinical and ultrasound parameters. METHODS: This is a prospective non-consecutive cohort of patients undergoing elective surgery. We collected as predictor variables age, sex, BMI, OSA, Mallampatti, thyromental distance, bite test, cervical circumference, cervical ultrasound measurements, and Cormack-Lehanne class after laryngoscopy. We univariate analyzed the relationship of the predictor variables with the Cormack-Lehanne class to design machine learning models by applying the random forest technique with each predictor variable separately and in combination. We found each design's AUC-ROC, sensitivity, specificity, and positive and negative predictive values. RESULTS: We recruited 400 patients. Cormack-Lehanne patients≥III had higher age, BMI, cervical circumference, Mallampati class membership≥III, and bite test≥II and their ultrasound measurements were significantly higher. Machine learning models based on physical examination obtained better AUC-ROC values than ultrasound measurements but without reaching statistical significance. The combination of physical variables that we call the "Classic Model" achieved the highest AUC-ROC value among all the models [0.75 (0.67-0.83)], this difference being statistically significant compared to the rest of the ultrasound models. CONCLUSIONS: The use of machine learning models for diagnosing VAD is a real possibility, although it is still in a very preliminary stage of development. CLINICAL REGISTRY: ClinicalTrials.gov: NCT04816435.

The Clinical Usability Evaluation of an Attachable Video Laryngoscope in the Simulated Tracheal Intubation Scenario: A Manikin Study.

The aim of this study was to assess the usefulness of an attachable video laryngoscope (AVL) by attaching a camera and a monitor to a conventional Macintosh laryngoscope (CML). Normal and tongue edema airway scenarios were simulated using a manikin. Twenty physicians performed tracheal intubations using CML, AVL, Pentax Airwayscope® (AWS), and McGrath MAC® (MAC) in each scenario. Ten physicians who had clinical experience in using tracheal intubation were designated as the skilled group, and another ten physicians who were affiliated with other departments and had little clinical experience using tracheal intubation were designated as the unskilled group. The time required for intubation and the success rate were recorded. The degree of difficulty of use and glottic view assessment were scored by participants. All 20 participants successfully completed the study. There was no difference in tracheal intubation success rate and intubation time in the normal airway scenario in both skilled and unskilled groups. In the experienced group, AWS had the highest success rate (100%) in the tongue edema airway scenario, followed by AVL (60%), MAC (60%), and CML (10%) (p = 0.001). The time required to intubate using AWS was significantly shorter than that with AVL (10.2 s vs. 19.2 s) or MAC (10.2 s vs. 20.4 s, p = 0.007). The difficulty of using AVL was significantly lower than that of CML (7.8 vs. 2.8; p < 0.001). For the experienced group, AVL was interpreted as being inferior to AWS but better than MAC. Similarly, in the unskilled group, AVL had a similar success rate and tracheal intubation time as MAC in the tongue edema scenario, but this was not statistically significant. The difficulty of using AVL was significantly lower than that of CML (8.8 vs. 3.3; p < 0.001). AVL may be an alternative for VL.

Anesthetic and Airway Management in a Pediatric Patient with Morquio Syndrome: A Case Report.

Morquio syndrome is a subtype of mucopolysaccharidoses, wherein the accumulation of glycosaminoglycans (GAGs) in various organ systems lead to alteration of anatomy and physiology. Most prominent features are extensive bony abnormalities, which normally require surgical correction. This paper reports the case of a 7-year-old child with Morquio syndrome who successfully underwent correction of genu valgum under general endotracheal anesthesia via asleep induction and videolaryngoscopy, with supplemental peripheral nerve block. The precautions and anesthetic care done to ensure a safe procedure are discussed, especially with anticipation of a possible difficult airway.

Ultrasound predictive parameters of difficult airway in thyroid surgery: a pilot study.

Difficult airway is a major life-threatening complication during induction of general anesthesia. In thyroid surgery, intubation could be complicated by airway distortion because of the enlarged thyroid gland. Recently, ultrasonography has been proposed as a potential modality for airway assessment and management. The aim of the study is to evaluate ultrasound-based measurement of airway parameters in 13 selected patients with compressive goiter and tracheal deviation scheduled for thyroidectomy before induction of general anesthesia. Specifically, we detected the distance between the skin and retro-isthmic trachea (DSRIT) and the distance between the sub isthmic trachea and the carotid artery (DCSIT) at the side of the dominant lobe. We compared ultrasound measures before intubation with Cormack-Lehane laryngoscopes grades recorded during tracheal intubation.

Temporomandibular Joint Ankylosis in a Three-Year-Old Female: Anaesthesia, Airway Management, and Mandibular Distraction Osteogenesis.

Temporomandibular joint (TMJ) ankylosis is generally characterised by a complex aetiology, with several contributing causes, including infections, autoimmune diseases, trauma, and congenital anomalies. This case report describes a three-year-old female suffering from traumatic temporomandibular ankylosis with retrognathia, severe mouth-opening restriction, and obstructive sleep apnea (OSA). The present case highlights the difficulties with TMJ ankylosis, especially when access to healthcare is sought out late and delayed diagnosis is prevalent. Mandibular distraction osteogenesis and awake fiberoptic intubation were used in the surgical and anaesthetic management of this case, with the otorhinolaryngology team on standby to perform a tracheostomy if required, highlighting the necessity of a multidisciplinary approach in such cases. Patients with TMJ ankylosis have significant life-altering changes, including psychological stress, chewing difficulty, speech difficulties, facial distortion, and speech impediment. When OSA progresses, it also presents more health risks. For the purpose of treating TMJ ankylosis, avoiding serious problems, and enhancing patient well-being, prompt diagnosis and therapy are crucial. In order to optimise patient results, this case study highlights the need for knowledge and research in the treatment of TMJ ankylosis as well as the requirement of medical professionals working together in a synergistic way.

Nasopharyngeal Airway in the Trachea: A Case Report.

We report a case of a cannulated nasopharyngeal airway (NPA) in a patient having a neurological deficit, absent gag reflex, and no clinically obvious signs of respiratory distress. The patient had two episodes of vomiting before admission and was admitted with the initial working diagnosis of aspiration pneumonia; however, a preliminary chest X-ray (CXR) revealed an NPA, sitting vertically in the airway. It is our emphasis that thorough clinical history and radiological imaging are of paramount importance in prompt management of such airway complications.

Differential Lung Ventilation Under the Veno-Arterial Extracorporeal Membrane Oxygenation Assistance in a Patient With a Giant Thoracic Tumor: A Case Report.

Airway compression resulting from thoracic tumors requires evaluation of the possibility of fatal ventilation failure when securing the airway. A woman presenting with a thoracic mass on the right side causing airway compression at the level of tracheal bifurcation required tumor removal to alleviate the compression; however, securing the airway proved challenging. Furthermore, differential lung ventilation was necessary for surgical management. We planned to secure the airway and manage breathing with the assistance of veno-arterial extracorporeal membrane oxygenation (V-A ECMO) through an interdisciplinary conference and proceeded according to the plan. The intended tracheal tube could be placed, differential lung ventilation was initiated, and the ECMO was removed. The surgical procedure was carried out. In patients presenting with airway stenosis, the possibility of difficulty in securing the airway and ventilation should be assessed in advance. Creating a detailed treatment plan before surgery is recommended.

A Case of Temporomandibular Joint Ankylosis With Adenoid Hypertrophy and Associated Airway Challenges.

Temporomandibular joint (TMJ) ankylosis is a form of TMJ condition that causes mouth opening limitation, ranging from partial reduction to total immobilization of the jaw. Bony and fibrous ankylosis is most commonly caused by trauma, although it can also happen as a result of surgery, local or systemic infections, or systemic diseases. Childhood TMJ produces facial deformities, which increase with growth and have a major detrimental impact on the patient's psychological development. Each patient with TMJ ankylosis must have a history, physical examination, and radiographic examination in order to determine a definitive diagnosis, severity, involvement of surrounding tissues, and, ultimately, treatment planning. Technical challenges and a high recurrence rate make treating TMJ ankylosis challenging. Intubating a young child with TMJ ankylosis is a difficult job, which is exacerbated by limited mouth opening. This case report describes a five-year-old boy who reported an inability to open his mouth, diagnosed as TMJ ankylosis, and managed in the absence of an appropriately sized tracheostomy tube.

Predicting difficult airway in morbidly obese patients using ultrasound.

Background/aim: Difficult mask ventilation and difficult intubation are more common in obese patients. Ultrasound is a reliable and noninvasive method for evaluating the airway. The aim of this study was to investigate the contribution and availability of anterior neck soft tissue (ANS) thickness at different levels, tongue volume (TV), hyomental distance (HMD), the ratio of preepiglottic distance to distance between the epiglottis and the midpoint of vocal cords (PE/E-VC) measured by ultrasonography in predicting difficult airway in morbidly obese patients. Materials and methods: Between March 2020 and November 2020, patients aged ≥18 years with a body mass index (BMI) of ≥40 kg/m2 who underwent elective surgery under general anesthesia were included in this prospective study at Firat University Hospital. During the preoperative evaluation of patients, ultrasound was used to measure and record TV, ANS thickness at different levels, HMD, and ratio of PE/E-VC. Patients with difficult intubation were identified using the Cormack-Lehane classification system. Patients whohad difficulties with balloon mask ventilation were recorded. Subsequently, the parameters of patients with easy and difficult intubation were compared. In addition, the parameters of patients with easy and difficult mask ventilation were also compared. Results: The preepiglottic ANS thickness at the level of the thyrohyoid membrane and the PE/E-VC value in obese patients with difficult intubation were significantly greater than in obese patients with easy intubation (p < 0.001). In addition, TV (p < 0.001), preepiglottic ANS thickness at the thyrohyoid membrane level (p < 0.001), ANS thickness at the thyroid isthmus level (p = 0.002), ANS-suprasternal notch thickness (p = 0.004), and PE/E-VC (p = 0.005) values were significantly greater in obese patients with difficult mask ventilation. Conclusion: Ultrasound may be a useful tool for predicting difficult airway and difficult mask ventilation. For this purpose, ANS thickness at different levels, PE/E-VC, and TV values measured by ultrasound can be used.