Unanticipated Difficult Airway Research Articles

The Prevalence of Difficult Airway and Associated Risk Factors in Pediatric Patients: A Cross-sessional Observational Study.

Difficult airway remains a great challenge in pediatric anesthesia practice. Previously published data show the prevalence of difficult airways in pediatric population varies in a wide range. However, there is a lack of studies in the Asian region. This cross-sectional single-center study was conducted in a tertiary pediatric hospital in China from October 2022 to October 2023. The patients who underwent elective surgery under general anesthesia with tracheal intubation were recruited consecutively. Data on patient characteristics, airway assessment, and airway management information were collected. Multivariable logistic regression analysis was performed to detect the independent variables of difficult airway in pediatric patients. A total of 18,491 pediatric patients were included in this study. The overall incidence of difficult airways was 0.22%, 39% of whom were unanticipated. Very few previous airway management information was available in the patients presented with a known difficult airway. Patients with younger age, higher American Society of Anesthesiologists (ASA) physical status classification grade, and presented for craniofacial and thoracic surgery were associated with higher incidence of difficult airway. Further multivariable logistic regression analysis revealed that age ≤28 days (OR=50.48), age between 28days and 1 year (OR=6.053), craniofacial surgery (OR=1.81), and thoracic surgery (OR=0.2465) were independent risk factors of increased incidence of difficult airway. Our study showed the prevalence of difficult airways in pediatric surgical patients. Patient characteristics, age, and type of surgery were identified as the independent factors associated with increased occurrence of difficult airways. Unanticipated difficult airway was not unusual in our study population, even for the patients with previous surgical history.

Trans-nasal Humidified Rapid Insufflation Ventilatory Exchange (THRIVE) and its Utility in Otolaryngology, Head and Neck Surgery: A Literature Review.

High-flow nasal oxygen (HFNO) therapy is extensively used in critical care units for spontaneously breathing patients. Trans-nasal humidified rapid insufflation ventilatory exchange (THRIVE) is a method of apnoeic oxygenation with continuous nasal delivery of warmed, humidified oxygen at high-flow rates up to 70L/min. THRIVE extends the apnoeic window before desaturation occurs so that tubeless anaesthesia is possible. The advent of THRIVE has had a monumental impact on anaesthetic practice, with a diverse range of clinical applications and it has been incorporated into difficult airway guidelines. THRIVE has many applications in otolaryngology and head and neck surgery. It is used as a pre-oxygenation tool during induction in both anticipated and unanticipated difficult airway scenarios and as a method of oxygenation for tubeless anaesthesia in elective laryngotracheal and hypopharyngeal surgeries and during emergence from anaesthesia. In this scoping review of the literature, we aim to provide an overview on the utility of THRIVE in otolaryngology, including the underlying physiologic principles, current indications and limitations, and its feasibility and safety in different surgical contexts and specific population groups.

Video Laryngoscope-Guided Fiberoptic Intubation in Patients with Unanticipated Difficult Airway: Two Case Reports

Fiberoptic intubation plays a crucial role in airway management. In particular, it is considered a basic method in difficult airway management. To enhance the success rate and feasibility of fiberoptic intubation, various adjunctive methods are often used concurrently. Video laryngoscope can be a valuable adjunct during fiberoptic intubation by ensuring visualization of laryngeal space and facilitating real-time monitoring of fiberoptic bronchoscope movements. In this report, we present our experiences with video laryngoscopy-guided fiberoptic intubation in patients with unanticipated difficult airway.

"Can't Intubate Can't Oxygenate" Situation in an Elective Patient in Suspected Sarcoidosis: A Case Report.

The CICO protocol was effective to manage an unanticipated difficult airway. The patient was resuscitated with the use of a microlaryngeal endotracheal tube of the 3rd generation laryngeal mask, placed on the fibrescope.The patient's previous and current medical condition is of vital importance for the pre-operative anaesthetic assessment.Specific questioning during the pre-operative anaesthetic interview could detect events that seem to be insignificant to the patient but are significant for a diagnostic intervention in a new situation.

A Randomized Double-Blind Comparative Study of the Intubating Conditions and Hemodynamic Effects of Rocuronium and Succinylcholine in Pediatric Patients.

The incidence of unanticipated difficult airways is higher in pediatric age groups than in adults due to the different airway anatomy, difficulty in airway examination, and congenital malformations. Rocuronium bromide has a comparable onset time to succinylcholine at its proportionate dose. Hence, we compared rocuronium bromide with succinylcholine to assess intubating conditions and their side effects, if any. A total of 200 pediatric patients ofAmerican Society of Anesthesiologists (ASA) grades I and II between one and 14 years of age of either sex posted for elective surgery were included in the study. After randomization, group R (n = 100) received 1.2 mg/kg rocuronium, and group S (n = 100) received 2 mg/kg succinylcholine intravenously. After confirming the mask ventilation, the study drugs were administered, and intubating conditions were assessed as excellent, good, poor, or impossible. Hemodynamic changes post-intubation were recorded as our secondary outcome. Intubating conditions were excellent( 65%), good( 25%) and fair (10%) in patients of group R, while results in group S were excellent( 60%), good( 20%), fair (15%), and poor (5%) (p = 0.010). The heart rate was significantly increased post-intubation in group S, while there was no significant increase in systolic or diastolic blood pressure in either group. At a dose of 1.2 mg/kg body weight, rocuronium was a better alternative to succinylcholine for providing rapid intubating conditions and stable hemodynamics without associated adverse effects.

Development and validation of a nomogram for difficult laryngoscopy at visual laryngoscopy: a prospective nested case-control study.

Unsuccessful airway management is associated with increased perioperative morbidity and mortality. Difficult laryngoscopy is a leading cause of unanticipated difficult airways and presents a challenge for anesthesiologists. Airway ultrasound assessment can be used as a priority diagnostic strategy for difficult laryngoscopy because of its diagnostic performance in difficult airways. This study was designed to develop a comprehensive model based on multivariate statistical analysis (including bedside examination tests and ultrasonography) for difficult laryngoscopy. This study was conducted from December 27, 2021, to September 16, 2022. All patients underwent an airway ultrasonographic measurement with a standard operating procedure. The baseline characteristics and bedside examination tests were also recorded. Laryngoscopy with a Cormack-Lehane (CL) grade of 1-2 was defined as "easy laryngoscopy", whereas "difficult laryngoscopy" was based on a CL grade of 3-4. The prediction model was built by using baseline characteristics, bedside examination tests, and ultrasonographic measurements as independent variables and easy/difficult laryngoscopy as the dependent variable. A total of 516 patients were eligible, and 456 patients were finally enrolled in the study. A 4-variable analysis, including inter-incisor gap (IIG), thyromental distance (TMD), the distance from the skin to the tongue root, and airway-related diseases, was performed to construct the optimum prediction model. The area under curve (AUC) value of the prediction model was 0.933 [95% confidence interval (CI): 0.770 to 0.935] in the training set and 0.956 (95% CI: 0.915 to 0.997) in the validation set. The comprehensive model and nomogram, especially the integration of tongue root thickness, can predict the risk of difficult laryngoscopy more accurately and reliably than any other screening method alone, allowing for reasonable individualized regimen decision-making.

A Feasibility Study on a Telemedicine Hybrid Protocol for Preoperative Anesthetic Assessment.

Background Over the past decade, telemedicine has experienced significant growth due to technological advancement, and the coronavirus disease 2019 (COVID-19) pandemic further accelerated its adoption. However, the field of anesthesiology has been slow in integrating and embracing telemedicine compared to other medical specialties. Methods We conducted an observational pilot feasibility study at a tertiary hospital in Singapore to assess the viability of a telemedicine hybrid protocol for preoperative anesthetic assessment. The study included patients aged 21 to 65 years, classified as American Society of Anesthesiology (ASA) physical status class 1 or 2, with a body mass index (BMI) below 35 kg/m2, who were capable of managing video conferencing. The patients selected were scheduled for low-risk surgeries. The primary objective was to evaluate the medical and technical feasibility of our telemedicine hybrid protocol, while the secondary objectives included assessing patient satisfaction and obtaining feedback from relevant stakeholders. Results From November 2021 to April 2022, a total of 116 patients were recruited, with 96 patients completing the study. No technical difficulties, surgical case cancellations, or incidents of unanticipated difficult airways were reported. The majority of survey respondents (88%) expressed satisfaction with the video consultation and indicated a preference for it over physical consultations for future preoperative anesthesia evaluations. Conclusion Based on our findings, a telemedicine hybrid protocol for preoperative anesthetic assessment demonstrated both technical and medical feasibility while yielding high patient satisfaction. Future research could focus on expanding the protocol to encompass more complex surgeries and include patients with higher ASA status.

Randomized controlled trial assessing intubation time with and without an aerosol biocontainment device

Introduction: The emergence of the coronavirus disease 2019 (COVID-19) pandemic renewed interest in infectious aerosols and methods to reduce risk of airborne respiratory pathogen transmission. This has led to the development of novel aerosol protective devices for which clinical and aerosol protective features have not been fully characterized. The relative efficacy of these devices for use during airway procedures has not been assessed in randomized controlled trials. Materials and Methods: We recruited anesthesiology attendings, residents, and certified registered nurse anesthetists to perform intubations with an aerosol biocontainment device (ABCD). Thirty-seven patients undergoing procedures requiring intubation in the operating room were recruited and randomized (2:1) to intubation with (25) or without (12) the ABCD. Primary endpoints were time to secure the airway and adverse events. Secondary endpoints were a number of intubation attempts, access to the patient and airway equipment through the device ports, user assessment of ABCD function and technical burden, and patient experience in the ABCD. Results: Intubation time with the ABCD (46 s) was not significantly different compared to intubation without the ABCD (37 s; P=0.06). There were 3 adverse events with the ABCD (1 claustrophobia, 2 unanticipated difficult airways) that required device removal for intubation. In general, patients tolerated the device well and ABCD users felt the device functioned as intended but increased the technical burden associated with intubation. Discussion: It is feasible to use an aerosol protective device for intubation. The introduction of novel devices into high acuity airway procedures should be approached with caution and should account for the risk mitigation gained from the device balanced against the increased procedural complexity and potential safety risks associated with restricted access to the airway.

Effectiveness of ultrasonic measurement for the hyomental distance and distance from skin to epiglottis in predicting difficult laryngoscopy in children

ObjectivesStudies have shown that some ultrasonic indicators can predict difficult airways in adults to an extent. However, whether ultrasonic parameters can be used to predict difficult airways in children is unclear. This study investigated the predictive value of several ultrasonic indices for difficult laryngoscopy (DL) in children.MethodsPediatric patients aged 5 to 12 years who underwent endotracheal intubation under general anesthesia were enrolled. The hyomental distance in the extended position (HMDE), tongue thickness, midsagittal tongue cross-sectional area, tongue width, and distance from skin to epiglottis (DSE) were measured by ultrasound before anesthesia. The study end point was DL. The receiver operating characteristic curve was used to evaluate the predictive value of each parameter.ResultsThree hundred and ten children were included in the final analysis, and fifteen (4.8%) children had DL. The shortened HMDE assessed by ultrasound could help identify children aged 5 to 12 years with DL (5–8 years: area under the curve (AUC) 0.74, sensitivity 0.88, specificity 0.60; 9–12 years: AUC 0.72, sensitivity 0.71, specificity 0.83). An increased DSE could help identify children aged 5 to 8 years with DL (AUC 0.76, sensitivity 0.88, specificity 0.69).ConclusionsUltrasonic measurement of the HMDE can be used to predict DL in children aged 5 to 12 years. The DSE measured by ultrasound can be used to predict DL in children aged 5 to 8 years.Clinical relevance statementThe hyomental distance and the distance from skin to epiglottis measured by ultrasound can be used to predict difficult laryngoscopy in children, which can help reduce serious complications caused by unanticipated difficult airways in children during anesthesia.Key Points• Ultrasonic measurement of the hyomental distance in the extended position may be an effective predictor of difficult laryngoscopy in children aged 5 to 12 years.• The distance from skin to epiglottis measured by ultrasound can be used to predict difficult laryngoscopy in children aged 5 to 8 years.• Preoperative airway assessment using ultrasound can be effectively applied in children and has a great application prospect.

No: 5006 Large tube or narrow airway? Unanticipated difficult airway in an adult

No: 5006 Large tube or narrow airway? Unanticipated difficult airway in an adult

Nove preporuke Američkog udruženja anesteziologa (2022) za zbrinjavanje otežanog disajnog puta

Difficulty establishing an airway and lung ventilation is one of the most urgent conditions in medicine, which can lead to severe complications, including permanent neurological damage and death. To facilitate handling this difficult clinical situation, various guides and recommendations were created to increase patient safety, help doctors, and protect them from criminal liability. The American Society of Anesthesiologists (ASA) issued new recommendations in 2022, which cover all segments of this problem, starting with the clear definition of different clinical situations (difficult laryngoscopy, difficult tracheal intubation, difficult face mask ventilation, difficult placement supra, and infraglottic means), through recommendations for the preparation of care for difficult airway, to algorithms and strategies for solving anticipated and unanticipated difficult airway. The paper presents the most important aspects of the mentioned segments of the new ASA recommendations, as well as their comparison with previous ASA recommendations and recommendations of other associations.

Tube-within-Tube Technique during Emergency Intubation for the Unanticipated Difficult Airway in Low-Resource Settings: A Case Report

Emergency intubation can pose numerous difficulties for an anaesthesiologist, especially in unpredictable situations. A crucial aspect in trauma cases with a low Glascow Coma Scale (GCS) is to promptly and safely secure the airway. Patient and environmental factors further complicate the intubation process. The survival rate of patients is closely linked to successfully establishing a patent airway. Factors that hinder intubation include limited ability to assess the airway, inadequate equipment and positioning, lack of backup, challenging or insufficient preoxygenation, presence of other life-threatening conditions, and the risk of aspiration. Familiarity with alternative techniques and utilization of all available aids can significantly reduce morbidity and mortality in settings with limited resources. The author presents a case report of a 26-year-old male patient with polytrauma and a head injury, presenting with a low GCS score, who required emergency intubation. This situation occurred unexpectedly in the triage area of the hospital. The ‘tube within tube’ intubation technique was effectively employed to achieve early and successful airway control in this resource-limited setting.

A Survey of Current Practices and Adherence to Coronavirus Disease Airway Management Guidelines Among Frontline Healthcare Professionals in a Resource-Limited Country.

The coronavirus disease 2019 (COVID-19) has brought anaesthesiologists, intensive care and emergency physicians to the forefront due to their airway management skills. The aim of survey was to determine current practice trends in COVID-19 airway management among frontline healthcare professionals of Pakistan and their adherence to standard principles proposed by most consensus guidelines. An online questionnaire was designed based on consensus guidelines from international societies. We contacted consultants and trainees nationwide working in anaesthesia, intensive care, and emergency departments through emails, phone calls, and social media platforms. A total of 285 individuals participated in this cross-sectional descriptive study. Intubations were largely performed by anaesthetists followed by emergency physicians. Deteriorating respiratory failure (89%) was the most frequent indication. Availability of trained staff, use of intubation checklist, limited staff presence during intubation, and use of appropriate personal protective equipment were positive findings. One-third reported that their workplace did not have negative pressure rooms for aerosol-generating procedures, and 63.3% responders do not perform airway assessment before intubation. The device of choice for the first attempt at laryngoscopy was Macintosh laryngoscope (51.6%) followed by videolaryngoscopes with disposable blades (24.2%). Availability of rescue devices in case of unanticipated difficult airway is variable; laryngeal mask airway (70.1%), bougie (82.2%), and stylet (68.7%) were present at majority places. Frequency of airway-related adverse events including hypoxemia (69.8%) and failed first attempt intubation (35.2%) was significant. This survey found satisfactory knowledge, comparable practices, and offers some important insights about airway management in COVID-19 patients by healthcare professionals of Pakistan.

INSTITUTIONAL EXPERIENCE OF ENDOTRACHEAL INTUBATION IN SEVERE COVID-19 PATIENTS AT PKLI&RC

Millions of people worldwide have been affected by the Coronavirus disease (SARS-CoV-2 or COVID-19) pandemic. Intensive care unit admissions are frequent and some patients with hypoxic respiratory failure need invasive mechanical ventilation. We retrospectively reviewed the medical records of 22 critically ill patients with SARS-CoV-2 pneumonia who required endotracheal intubation from March 2020 till August 2020 at our institute, a tertiary care government designated center for treating moderate and severely ill COVID patients. Patient’s demographics, clinical features, use of personal protective equipment (PPE) for intubation, intubation process, adverse events and anesthesiologist infection rate was determined. Patients intubated were elderly and comorbidities were common. We successfully intubated all patient using level-3 PPE. Hypoxia, hypotension, arrhythmias and unanticipated difficult airway were common events in peri-intubation period.

A Simulation-Based Training Program in Rapid Sequence Induction for Novice Anesthesiology Trainees Using a Novel Checklist.

The novice anesthesiology trainee is required to assimilate the technical and nontechnical skills required to safely perform a rapid sequence induction (RSI). Acquisition of this core competency is traditionally achieved using operating room-based experiential learning, which may be associated with significant gaps in early trainee preparation. We conducted a study to explore the role of a new, customized, high-fidelity simulation-based training program designed to address this gap in RSI training. We then assessed mean performance scores of participants in the simulator and 4 weeks later. This observational study assessed participants' performance in the simulator on the day of training and in the workplace 4 weeks later. There is no universally agreed checklist or cognitive aid incorporating nontechnical skills and planning for unanticipated difficult airway management in RSI, so we applied a new scoring checklist developed by 6 experts using the modified Delphi technique. Our task scoring checklist included nontechnical skills and consisted of 37 weighted parameters with a maximum performance score of 171. On the day of training, mean performance score was 105 (SD of 16). At the workplace evaluation 4 weeks after simulation training, the mean performance score of participants had increased to 140 (SD of 14.5; P = .001). The 95% confidence intervals for the simulator and workplace participant scores were 92 to 118 and 128 to 152, respectively. The results suggest that this simulation-based training in RSI was associated with an improvement in RSI performance in novice trainees and may complement the current system of workplace-based training.

Case report of prune belly syndrome: An airway challenge too?

Prune belly syndrome (PBS) is a rare congenital disease presenting a characteristic triad of abdominal muscle deficiency, urinary tract abnormality, and cryptorchidism with associated anomalies of various systems. We report the anesthetic management of an infant with PBS with no obvious facial deformity in whom we encountered an unanticipated difficult airway. Multiple attempts to secure the airway with different supraglottic airway devices were unsuccessful and the trachea could be intubated only on the second attempt. The patient had deficient abdominal muscle and thus a prolonged duration of action of non-depolarizing muscle relaxant.

Comparison of acromio axillary sternal notch index, thyromental height test, and modified mallampati test in preanesthetic prediction of difficult laryngoscopy

IntroductionThe unanticipated difficult airway is a challenge to anaesthesiologists owing to the undesirable respiratory and cardiac outcomes and other related complications. Three different predictors have been used, which include a Modified Mallampati Test, Thyromental Height Test, and the newly proposed Acromio Axillary Sternal Notch Index. In this study, we aim to compare the validity of the Acromio Axillary Sternal Notch Index, Thyromental Height Test and the Modified Mallampati Test as preanesthetic predictors of difficult laryngoscopy. MethodologyPatient's demographics were assessed and physical examination were carried out based on the predictive tools Modified Mallampati Test, Thyromental Height Test, Acromio Axillary Sternal Notch Index. ResultsThe majority of the patients in this study were <60yrs of age. Out of 358 participants, 57.5% were females and 42.5% were males. Our study shows an incidence of 24.6% for difficult laryngoscopy. The study reveals that the Thyromental Height Test examination had high specificity compared to the Modified Mallampati Test examination, but the ability to predict true difficult laryngoscopy was less when compared to Modified Mallampati Test. The new predictor, Acromio Axillary Sternal Notch Index, had high sensitivity and high positive predictive compared to the other two predictors, Modified Mallampati Test and Thyromental Height Test. ConclusionThe study concludes that the Acromio Axillary Sternal Notch Index is an ideal standalone preanesthetic predictor of difficult laryngoscopy based on its high sensitivity and high positive predictive value.

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.