Unanticipated Difficult Airway Research Articles

Comparative study of sonographic measurement of PRE-E/E-VC ratio versus Hyomental distance ratio to correlate Cormack–Lehane grading for airway assessment

Background: Predicting a difficult airway preoperatively overcomes the hurdles of unanticipated difficult airway management. Cormack–Lehane grading (CL Grading) best describes the view of larynx. However, direct laryngoscopy cannot be used to predict difficult airway for patients undergoing intubation for the 1st time. On the other hand, ultrasound is a safe and painless procedure. This study was done to correlate airway ultrasound findings with CL Grading by direct laryngoscopy. The patients selected were undergoing elective surgeries under general anesthesia. Aims and Objectives: The aims of the present study were to correlate the ultrasound view of the airway with the Cormack–Lehane classification by direct laryngoscopy. Materials and Methods: A group of 94 patients, aged 18–60 years, ASA I/II were selected who underwent elective surgical procedures under general anesthesia requiring intubation by direct laryngoscopy. Pre-epiglottic (PRE-E) depth and epiglottic vocal distance (E-VC) were measured along with hyomental distance ratio (HMDR) by ultrasound. The ultrasound parameters were then compared with CL Grading during laryngoscopy. Results: The PRE-E depth/epiglottic vocal cord distance correlated better than hyomental distance ratio in predicting CL Grading (P=0.000). Conclusion: The PRE-E/E-VC ratio was a better predictor of CL Grading than the HMDR.

Analysis of a national difficult airway database.

Difficult airway management continues to adversely affect patient care and clinical outcomes and is poorly predicted. Previous difficult airway management is the most accurate predictor of future difficulty. The Difficult Airway Society initiated a national airway database to allow clinicians to access details of previous difficult airway episodes in patients issued with a difficult airway alert card. We aimed to analyse this database, reporting patient characteristics, airway management and patient outcomes. We included all living adult patients reported in the first 5 years of the database (n = 675). Clinical airway assessment was reported in 634 (94%) patients, with three or more parameters assessed in 488 (72%). A history of difficult airway was known in 136 (20%) patients and difficult airway management was anticipated in 391 (58%). In all, 75 (11%) patients had an airway-related critical incident, with 1 in 29 being awoken from anaesthesia, 1 in 34 requiring unplanned or prolonged stay in the intensive care unit and 1 in 225 needing an emergency front-of-neck airway or had a cardiac arrest/peri-arrest episode. Airway-related critical incidents were associated with out-of-hours airway management, but no other associations were apparent. Our data report the first analysis of a national difficult airway database, finding that unanticipated difficult airway management continues to occur despite airway assessment, and the rate of critical incidents in this cohort of patients is high. This database has the potential to improve airway management for patients in the future.

Morphometric and ultrasonographic determinants of difficult laryngoscopy in obese patients: A prospective observational study.

Obese people have a higher risk of difficult laryngoscopy due to their thick neck, large tongue, and redundant pharyngeal soft tissue. However, there is still no established predictive factor for difficult laryngoscopy in obese population. We conducted a prospective assessor-blind observational study to enroll adult patients with a body mass index of 30 kg·m-2 or higher undergoing laparoscopic sleeve gastrectomy at a medical center between May 2020 and August 2021. Conventional morphometric characteristics along with ultrasonographic airway parameters were evaluated before surgery. The primary outcome was difficult laryngoscopy, defined as a Cormack and Lehane's grade III or IV during direct laryngoscopy. Logistic regression analyses were performed to evaluate the association between included factors and difficult laryngoscopy. Discrimination performance of predictive factors was assessed using area under the receiver operating characteristic curve (AUC). A total of 80 patients were evaluated, and 17 (21.3%) developed an event of difficult laryngoscopy. Univariate analyses identified five factors associated with difficult laryngoscopy, including age, sex, hypertension, neck circumference, and cross-sectional area of tongue base. After adjusting for these variables, neck circumference was the only independent influential factor, adjusted odds ratio: 1.227 (95% confidence interval, 1.009-1.491). Based on Youden's index, the optimal cutoff of neck circumference was 49.1 cm with AUC: 0.739 (sensitivity: 0.588, specificity: 0.889; absolute risk difference: 0.477, and number needed to treat: 3). Greater neck circumference was an independent risk factor for difficult laryngoscopy in obese patients. This finding provides a way of reducing unanticipated difficult airway in this high-risk population.

Anaesthesia management in a dwarf patient with failed spinal anaesthesia and unanticipated difficult airway posted for emergency cesarean section: A case report

Background: Pregnancy in dwarfism generally present with contracted pelvis and cephalopelvic disproportion. Cesarean section is generally indicated for deliver. However, Anaesthesia management in dwarf pregnant patient is difficult and challenging as they are other concurrent conditions like atlanto-axial instability, spine deformities like kyphoscoliosis and narrowed pharynx leading to higher risk for both general as well as regional anaesthesia. Here, we are presenting a successful case of anaesthesia management in dwarf patient with failed spinal anaesthesia and unanticipated difficult airway for emergency cesarean section.

A Review of Current Literature of Interest to the Office-Based Anesthesiologist.

A Review of Current Literature of Interest to the Office-Based Anesthesiologist.

'Locked jaw' - An unusual unanticipated difficult airway.

'Locked jaw' - An unusual unanticipated difficult airway.

Trivia of an unnoticed miscreant at the glottis resulting in an unanticipated difficult airway

Trivia of an unnoticed miscreant at the glottis resulting in an unanticipated difficult airway

Difficult Airway ManagementA Challenge to Anaesthesiologists

Anticipated and unanticipated difficult airway remains an everlasting challenge for anesthesiologist. Most airway problems can be solved with enough resources available but clinical judgment borne of experience, and expertise is crucial in implementing the skills in any difficult airway scenario. Detailed patient history, best utilisation patient protocols, with good clinical assessment may reduce the difficult airway complications. The present series reports six patients with anticipated difficult airway-burn contracture, fractured mandible with restricted mouth opening: meningo myelocoele (in a neonate, and there was difficulty in positioning for intubation), anterior mediastinal mass (with difficulty in maintenance of anesthesia), cervical spine injury and one patient with left mandible fracture with history of road traffic accident. Different methods were successfully adopted for managing all of these difficult airway cases. Hence planning, preparation, and execution is very important in successful management of difficult airway.

202 High-Fidelity Simulated Bronchoscopy: Incorporating Simulator into A Mannequin

Fiberoptic intubation (FOI) is a technique used to establish airway access in patients with anticipated and unanticipated difficult airways. Fiberoptic bronchoscopes are currently used to facilitate endotracheal intubation via either the nasal or oral route, in the positioning of endotracheal and endobronchial tubes and bronchial blocking devices, and in airway examination or evaluation. FOI is used in the management of awake spontaneously breathing patients with an anticipated difficult airway The aim of this project was to incorporate the ORSIM® simulator into a manikin for use in high-fidelity simulation. A basic resuscitation training manikin was used (A basic resuscitation training manikin is used. The silicone/rubber skin is removed.The ORSIM® black sensor box is placed over the head with an exit point towards the thorax.Place polystyrene to support head and cheek region. This could be substituted with other materials such as foam/wax.Optional: the use of inexpensive props such as wigs/hats/shirts.Position patient and monitor for high-fidelity simulation.We found that the ORSIM® simulator was a useful tool for training. The virtual video guidance can be used to familiarize clinicians with different pathology and improve technical skills. By incorporating the simulator into a manikin, a more realistic model can be created. Here we have used very inexpensive and often readily available equipment within a healthcare setting to achieve this. This model can be used as part of a high-fidelity simulated scenario to improve the learning experience.

Study on airway assessment practices for elective procedures during pre-anesthetic evaluation in COVID-19 pandemic- A national online survey (SAFE PAC Survey).

Background and Aims:A pilot study among anesthesiologists, revealed a wide variation among individual practices including skipping pre-anesthetic airway assessment during COVID-19 pandemic because of the fear of getting infected. Risk of infection during pre-anesthetic airway assessment has not been studied. The primary objective of the survey was to evaluate the practices of airway examination by anesthesiologists during this pandemic period. Secondary objectives were to study the effects of institutional factors and other individual practices on risk modification and the incidence of COVID-19 infection among anesthesiologists.Material and Methods:A survey was conducted using a pre-validated questionnaire comprising of 35 questions. The questionnaire was circulated among 4676 members of the Indian Society of Anaesthesiologists (ISA) through Google Forms by email.Results:Of the 4676 members contacted via email, 470 were returned undelivered. From the remaining 4206 questionnaire recipients, 456 completed responses were obtained giving a response rate of 10.8%. Percentage, mean and standard deviation were calculated using EZR software. The conduct of pre-anesthetic airway assessment has decreased by 31.7% during the pandemic, leading to 5.2% of participants encountering unanticipated difficult airway. Among the respondents, eight percent were infected.Conclusion:Avoidance of preoperative airway assessment by anesthesiologists during the COVID-19 pandemic has led to rising unanticipated difficult airway undermining the patient safety. Adherence to recommended practices ensures safety from risk of COVID-19 infection.

Evaluation of Ultrasound Guided Measurement of Anterior Neck Soft Tissue Thickness in Predicting Difficult Laryngoscopy in Obese Patients

Background: The incidence of unanticipated difficult airway is 14.3-17.5% in obese. Preoperative difficult airway prediction is important to avoid postoperative morbidity and mortality. USG guided measurement of anterior neck soft tissue thickness can be used to predict difficult laryngoscopy in obese patients and we thus undertook this study to determine the role of USG guided measurement of anterior neck thickness at the level of vocal cords in difficult laryngoscopy prediction. Methods: Sixty obese patients (BMI≥30kg/m2), 18-70 years of age of either sex, were included. Anterior neck soft tissue thickness was measured by ultrasound as the distance from the skin to the anterior commissure of vocal cord. Neck circumference was measured at mid neck just below the laryngeal prominence with the subjects standing upright and facing forward with shoulders relaxed. Thyromental distance, sternomental distance, Mallampatti score and neck circumference were also recorded. Results: The cut off values of BMI (46.94 kg/m2), neck circumference (41.5 cm) and anterior neck soft tissue thickness (22.1mm). Four patients in the morbidly obese and 80% of the superobese patients had a difficult laryngoscopy. Sixteen (26.67%) patients had an anterior neck soft tissue thickness of >22.1mm. Of these, 11 (91.67%) patients had difficult laryngoscopy while one (8.33%) patient with anterior neck soft tissue thickness ≤ 22.1mm had difficult laryngoscopy (P<0.05). There was also significant association between neck circumference and BMI. Conclusion: The USG guided measurement of anterior neck soft tissue thickness, BMI and neck circumference can reliably predict difficult laryngoscopy in obese patients.

Management of the Unexpected Difficult Airway in Neonatal Resuscitation.

A “difficult airway situation” arises whenever face mask ventilation, laryngoscopy, endotracheal intubation, or use of supraglottic device fail to secure ventilation. As bradycardia and cardiac arrest in the neonate are usually of respiratory origin, neonatal airway management remains a critical factor. Despite this, a well-defined in-house approach to the neonatal difficult airway is often lacking. While a recent guideline from the British Pediatric Society exists, and the Scottish NHS and Advanced Resuscitation of the Newborn Infant (ARNI) airway management algorithm was recently revised, there is no Norwegian national guideline for managing the unanticipated difficult airway in the delivery room (DR) and neonatal intensive care unit (NICU). Experience from anesthesiology is that a “difficult airway algorithm,” advance planning and routine practicing, prepares the resuscitation team to respond adequately to the technical and non-technical stress of a difficult airway situation. We learned from observing current approaches to advanced airway management in DR resuscitations in a university hospital and make recommendations on how the neonatal difficult airway may be managed through technical and non-technical approaches. Our recommendations mainly pertain to DR resuscitations but may be transferred to the NICU environment.

Managing the difficult airway: A survey of doctors with different seniority in China.

Although equipment and human resources are vital elements of difficult airway management (DAM). But the approach and practice of DAM are more important. So, we conducted the present survey to address anesthesiologists of different working years in this knowledge gap.This nationwide cross-sectional study was conducted from October 27, 2016 to November 27, 2016. The survey was completed online in New Youth Anesthesia Forum including DAM assessment, anticipated and unanticipated DAM, difficult airway algorithm, use of the front of neck access (FONA) technique and training, DAM outside the operation room, and difficult extubation management.We received 1935 replies (44%). Mouth opening and Mallampati classification were the most common methods to evaluate difficult airways. When suffering from unanticipated difficult airway 63% less than 10 years anesthesiologists (LA) and 65% more than 10 years anesthesiologists (MA) would ask for help after trying 1 to 2 times (P = .000). More than 70% of LA and MA respondents reported preferring cannula cricothyrotomy to deal with emergency airway, 507 (41.6%) MA respondents reported that they used FONA techniques to save patients’ lives (P = .000). Nearly 70% respondents worried full stomach when intubated outside operation room and more than 80% respondents selected auscultation to identify the placement. More than 80% respondents had not used Bougie to assist extubation. A 73.2% respondents know ABS algorithm and 96.4% know Chinese airway expert consensus among MA respondents, this was significant to LA respondents (P = .000).The respondents in the LA and MA have a training gap in their evaluation of difficult airways, trained and used FONA emergency skills, facilitated of the airway guidelines at home and abroad. Also, we should provide more airway theory and skill training to our young doctors to advanced airway skills.

Unanticipated Difficult Airway Management in a Trauma Partient with Severe Ankylosing Spondylitis

Ankylosing Spondylitis is a debilitating chronic arthropathy that affects multiple joints. Anaesthesiologists face significant challenges when dealing with the airway implications of this disease, especially when it is unanticipated that a difficult airway may be encountered. This case describes a 42-year-old trauma victim who required an emergency denitive trachea at his ward. Ankylosing Spondylitis and complex airway anatomy led to his intubation failure. He was eventually given an emergency surgical tracheostomy. The successful management of a difficult airway was possible thanks to the appropriate use of modern airway adjuncts as well as workplace soft skills.

Seven years on from the Canadian Airway Focus Group Difficult Airway Guidelines: an observational survey.

PurposeNumerous clinical guidelines are available for management of the unanticipated difficult airway. It is unclear if practice recommendations are endorsed on regional, local, or individual levels. The objective of this observational study was to examine local and regional use of airway guidelines by anesthesiologists within a hospital partnership in Southwestern Ontario.MethodsUsing a paper survey, distributed locally to consultant and trainee anesthesiologists in a tertiary hospital, we examined individual clinical and educational practices regarding guideline use in airway management. Respondents were asked to report which published guideline they used for unanticipated airway difficulty. The effectiveness of dissemination of the national Canadian airway guidelines—the Canadian Airway Focus Group (CAFG) Difficult Airway Guidelines—was examined. We invited anesthesia department heads within the regional hospital partnership to complete an electronic survey investigating departmental adoption of guidelines.ResultsThe response rate was 70% locally (79/112 anesthesiologists) and 52% regionally (11/21 department heads). Approximately 80% (64/79) of respondents reported using a formal clinical guideline if unanticipated difficulty with airway management was encountered. Seventy-two per cent of respondents (57/79) were aware of the published CAFG guidelines. Approximately 30% (16/51) of consultant anesthesiologists reported using the CAFG guidelines in clinical practice. Within the hospital partnership, 36% (4/11) of departments formally endorsed use of a specific airway management guideline.ConclusionsDespite widespread awareness of the national CAFG Difficult Airway Guidelines, they are not widely adopted in clinical practice. Further research is warranted to explore barriers to adoption of airway management guidelines for both individual anesthesiologists and anesthesia departments.Supplementary InformationThe online version contains supplementary material available at 10.1007/s12630-021-02056-5.

Translation and application of guidelines into clinical practice: A colour-coded difficult airway trolley

An unanticipated difficult airway needs immediate and well-coordinated management to maintain oxygenation and avoid a poor patient outcome. In addition to medical knowledge, technical skills, competencies and performance, human factors contribute substantially to success during unanticipated difficult airway management. Human factors can be influenced by cognitive aids like algorithms. These algorithms can be further enhanced by using a strong visual stimulus like colour coding to provide easy and fast orientation. Colour coding as cognitive aid is recommended in some difficult airway guidelines but the translation into clinical practice is underreported. This article describes the application of colour coding for cognitive aids to facilitate the management of an unanticipated difficult airway and its further local implementation in the form of a colour-coded difficult airway trolley.

Emerging Perspectives of Endotracheal Intubation in Patients with Severe COVID- 19 Pneumonia: A Narrative Review

The coronavirus disease 2019 (COVID -19) pandemic that has engulfed the world has put an immense strain on the existing healthcare systems. The rapid, insidious and often dramatic deterioration of the respiratory function of an infected patient, has led to an increased need for effective and rapid airway control. However, such airway control techniques put the healthcare workers to an increased risk of exposure to the virus. Therefore, interventions aimed at minimising such risks, while preventing the complications inherent to securing an airway are imperative to the management of a COVID-19 patient in acute respiratory failure (ARF). Personal protective equipment (PPE) is sine qua non to keep the intubator safe, however some barrier equipment’s have been employed with limited success. There are varied schools of thought on whether to intubate early or late, and the use of non-invasive methods for management of respiratory failure, however, most consensus statements reinforce the need for rapid sequence induction (RSI), which provides ideal intubating environment for an experienced intubator. Techniques, which decrease the number of required personnel as well as time, to secure the airway and increase the distance of the intubating physician from the patient, are recommended. Routine use of, videolaryngoscope, if available, is recommended. While intubation with an endotracheal tube is the gold standard airway technique, second generation supraglottic airway devices (SAD) are increasingly being recommended, particularly in cases of failure to intubate or in an unanticipated difficult airway. Awake intubation techniques are contraindicated due to increased risk of cough and subsequent aerosolization; however, few modifications were innovated when if it all required. In this review, we summarise the existing data with respect to the modifications and guidelines in severe COVID-19 patients who requires endotracheal intubation for invasive mechanical ventilatory support.

Anaesthetic Management of a Child with Congenital Rubella Syndrome Posted for Cochlear Implant - A Case Report

Congenital Rubella Syndrome (CRS) is a constellation of multi-system abnormalities and each problem has significant anaesthetic implications. These patients pose various challenge to anesthesiologists like unanticipated difficult airway, uncorrected cardiac lesions, etc. Anesthetic for cochlear implant in child with CRS has not been reported. Anaesthetic management in an infant with PS should be based on decrease in pulmonary vascular resistance (PVR), avoidance of tachycardia with sinus rhythm, myocardial depression, systemic hypotension and adequate intra vascular volume. Here we report the anaesthetic management of a 5 year aged child with congenital rubella syndrome - post device closure of Patent ductus arteriosus, bilateral cataract surgery with moderate branch pulmonary artery stenosis and mental retardation posted for cochlear implant. Keywords: Congenital rubella syndrome, pulmonary artery stenosis, difficult airway, cochlear implant, patent ductus arteriosus.

Modified Infant Feeding Tube as an Indigenous Endotracheal Tube in Unanticipated Congenital Subglottic Stenosis

Introduction: In neonates with an unanticipated difficult airway, there is an increased probability of failed intubation even with highly trained hands while performing direct laryngoscopy. Aims: We describe our experience of using a modified infant feeding tube (IFT) as an indigenous endotracheal tube (ETT) in a series of paediatric surgical patients with congenital subglottic stenosis (SGS). Material and Methods: A retrospective study was performed in our institute from January 2018 to December 2019. ETT with modified 6 and 8 French (Fr) sized IFT’s were used. A stylet obtained from the VP shunt system was used to aid in intubation. Results: Out of 12,500 admissions in our department, there were 5 pediatric cases with SGS which were managed using modified IFT. Four were neonates and 1 infant (M:F = 2:3). Modified IFT(s) were used after failed intubation with ETT of size 2.5 mm in 4 patients (non-availability of ETT of size 2 mm), while in one neonate, even 2 mm ETT could not be negotiated due to SGS. In all the 5 children, successful intubation was finally performed with modified 8 French (Fr) IFT in 3, and with modified 6 Fr IFT in two cases. The surgical procedure was completed in 4 neonates out of 5 cases, while in one infant it was deferred due to the clinical condition of the patient and significant SGS. Conclusion: All 5 patients with SGS were managed without performing a tracheostomy. Modified IFT(s) is an effective alternative if smaller sized ETT(s) cannot be negotiated or unavailable in difficult neonatal and paediatric airway. This modified IFT as ETT has to be an important part of the emergency airway tray. It should not be considered as a replacement for routine use of standard ETT.

Ease of intubation and incidence of dental injury during direct laryngoscopy: A randomized controlled trial comparing five different laryngoscope blades (Macintosh, Miller, Reduce flange, Blechman and Flangeless)

BackgroundDirect laryngoscopy remains an invaluable and readily available option despite the increasing use of video laryngoscope for securing the airway in different situations, particularly in limited resource and unanticipated difficult airway scenarios. Several variations of the laryngoscope blades are available for various purposes. However, knowledge of the functioning of different blades in a similar controlled environment is required because of the unavailability of all blades in a given setting. AimThis study assessed the ease of intubation and the degree of dental injury with five types of laryngoscope blades (Macintosh, Miller, Reduced flange, Blechman, and Flangeless blade). MethodsThis prospective randomized controlled study was conducted in patients undergoing tracheal intubation with direct laryngoscopy using five different blades posted for elective surgery under general anesthesia in a single center.The primary outcome parameters were Cormack–Lehane grade and intubation difficulty score, whereas secondary outcome measures were the proportion and grades of dental injury. ResultsA Cormack–Lehane grade 3 view was observed more often with flangeless blades 7 (22.5%) than others, with the lowest incidence for the Macintosh blade 1 (3%) (p = 0.228). The first pass success rate was highest in Macintosh (94%), similar in reduced flange Macintosh and Blechman blades (90% each) and least in the flangeless blade (77%). The force required for laryngoscopy varied significantly between the blades (p < 0.001). The median interquartile range intubation difficulty score was the highest with flangeless blades [2 (2–3)] among all the groups (p = 0.048). The dental contact during laryngoscopy varied significantly between the groups (p < 0.001). The incidence of dental injury was the highest in flangeless (13%) among all the blades (p = 0.526). ConclusionsReduced flange Macintosh and Blechman blade had ease of intubation similar to standard Macintosh blade, where as flangeless blade is associated with more difficult intubations. Reduced flange Macintosh, and Blechman blades were associated with a lower incidence of dental contact and injury than other three study blades.