Difficult Airway Prediction in Infants with Apparently Normal Face and Neck Features.

Background/Objectives: Prediction of a difficult airway during pre-anesthetic evaluation is of great importance because it enables an adequate anesthetic approach and airway management. As there is a scarcity of prospective studies evaluating the role of anthropometric measures of the face and neck in predicting difficult airways in infants with an apparently normal airway, we aimed to identify the aforementioned predictors of difficult facemask ventilation and intubation in infants. Methods: A prospective, observational study that included 97 infants requiring general endotracheal anesthesia was conducted. Anthropometric and specific facial measurements were obtained before ventilation and intubation. Results: The incidence of difficult facemask ventilation was 15.5% and 38.1% for difficult intubation. SMD (sternomental distance), TMA (tragus-to-mouth angle distance), NL (neck length) and mouth opening were significantly lower in the difficult facemask ventilation group. HMDn (hyomental distance in neutral head position), HMDe (hyomental distance in neck extension), TMD (thyromental distance), SMD, mandibular development and mouth opening were significantly different in the intubation difficulty group compared to the non-difficult group. HMDn and HMDe showed significantly greater specificities for difficult intubation (83.8% and 76.7%, respectively), while higher sensitivities were observed in TMD, SMD and RHSMD (ratio of height to SMD) (89.2%, 75.7%, and 70.3%, respectively). Regarding difficult facemask ventilation, TMA showed greater sensitivity (86.7%) and SMD showed greater specificity (80%) compared to other anthropometric parameters. In a multivariate model, BMI (body mass index), COPUR (Colorado Pediatric Airway Score), BOV (best oropharyngeal view) and TMA were found to be independent predictors of difficult intubation, while BMI, ASA (The American Society Physical Status Classification System), CL (Cormack-Lehane Score), TMA and SMD predicted difficult facemask ventilation. Conclusions: Preoperative airway assessment is of great importance for ventilation and intubation. Patient's overall condition and facial measurements can be used as predictors of difficult intubation and ventilation.

Simultaneous use of GlideScope® in emergency department: A case report.

The GlideScope® is a videolaryngoscope manufactured by Verathon Medical (Bothell, WA, USA), now widely used to manage planned or unexpected difficult orotracheal intubation situations. According to the current literature, GlideScope® has been used for surgical procedures involving the tongue base, such as biopsies and radiofrequency treatment of obstructive sleep apnea. We describe a case of dual use of GlideScope for pointed foreign body removal in an emergency department.

Retrograde tracheal intubation using the S-guide intubation guide after emergent tracheotomy: A case report.

Retrograde intubation is an historic technique that is now rarely used in difficult airway situations. Although not originally designed for this purpose, the use of an S-guide is a feasible option to aid retrograde intubation because of its malleable rigid body and atraumatic tip.

Evaluation of upper airway ultrasonographic measurements in predicting difficult intubation: A cross-section of the Turkish population.

Objectives: Studies have shown that there are differences in clinical evaluation parameters and difficult intubation rates among different ethnic populations. In our study, we aimed to evaluate the efficacy of upper airway clinical and ultrasonographic measurement methods in Turkish population. Methods: Our study is a single-center, prospective, observational study conducted with 402 patients. All patients underwent clinical airway measurements which are routinely used in pre-anesthetic evaluation. In addition, ultrasonographic anterior neck soft tissue thickness measurements of each patient were made and recorded. Results: Among the clinical measurements, we found the neck circumference/thyromental distance (TMD) ratio to be significant with a cut-off value of 5.5 and a sensitivity of 92.9% and a specificity of 88.3%, while among the ultrasonographic anterior neck measurements, we found the skin-epiglottic distance to be the most sensitive measurement. We found that there was a positive relationship between the neck circumference/TMD ratio and skin-epiglottis. Conclusions: In our study, we found that routine measurement methods used in airway examination alone are not sufficient, and measurements that take into account the body proportions of the patients, such as the neck circumference/TMD ratio and the ultrasonographic evaluations are more useful in predicting difficult intubation.

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.

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.

Asymptomatic Subglottic Stenosis Discovered During Anesthesia Induction and Not Predicted by Preoperative Evaluation: A Case Report.

Subglottic stenosis (SGS) can be asymptomatic in cases with slow-growing granulomas. In this study, we report a case of SGS discovered during tracheal intubation for anesthesia induction. A 74-year-old woman was scheduled for surgery under general anesthesia for a left humeral fracture. Resistance was observed when the tracheal tube passed through the glottis, stopping the tube from advancing. We placed a laryngeal mask (LMA) to secure her airway and examined it using a bronchial fiber to detect circumferential stenosis of the subglottis due to granulation. The airway was secured using an LMA instead of intubation, and the patient was successfully managed under anesthesia. Asymptomatic SGS is difficult to detect preoperatively, and anesthesiologists may encounter unexpected intubation issues. LMA is an important tool for an effective strategy to manage intubation difficulties.

Ultrasound-based assessment of tongue thickness for prediction of difficult laryngoscopy and intubation.

Background and Aims: Predicting difficult airway and preparedness for the same can help prevent catastrophic situations while handling the airway. With the increasing familiarity of anaesthesiologists to the use of ultrasound machine and its easy availability and non-invasiveness, we sought to study its utility in airway assessment, by measuring the thickness of tongue, to predict difficult laryngoscopy and intubation. Material and Methods: A total of 85 patients undergoing elective surgeries under general anaesthesia with endotracheal intubation were examined preoperatively. Tongue thickness was measured using submental ultrasonography in the median sagittal plane along with other tests of airway assessment. Cormack Lehane grade on laryngoscopy and Intubation Difficulty Scale Score was recorded. The sensitivity, specificity, positive and negative predictive value, and accuracy was calculated for tongue thickness for predicting difficult intubation. Results: The tongue thickness in those with difficult intubation (4.83 ± 0.62) was significantly higher than those without difficult intubation (4.38 ± 0.65). The ratio of tongue thickness to thyromental distance was also significantly higher in difficult intubation group. The area under the receiver operating characteristic curve for predicting difficult laryngoscopy and intubation was higher for tongue thickness as compared to other clinical parameters. The sensitivity and specificity of tongue thickness to predict difficult laryngoscopy was 100% and 83%, respectively, and to predict difficult intubation was 72% and 59%, respectively, with an accuracy of 72%. Conclusion: Ultrasound based assessment of tongue thickness can be a useful predictor of difficult airway along with clinical assessment of the airway.

The Assessment of Airway Compression Due to Cervical Fusion in Klippel-Feil Syndrome Patients: A Report of Two Cases.

In general anesthesia for Klippel-Feil syndrome (KFS) patients, there is a potential risk of difficult intubation. However, airway assessment to predict difficult intubation for KFS patients is not known. In Patient 1, cervical spine computed tomography (CT) revealed airway compression due to cervical fusion. For airway assessment, bronchofiberscopy, three-dimensional (3-D) CT, and virtual bronchoscopic image (VBI) construction were performed. Based on these images, fiberoptic nasotracheal awake intubation was performed. In Patient 2, magnetic resonance imaging and bronchofiberscopy showed no airway compression due to cervical fusion; therefore, tracheal intubation was performed using a video laryngoscope after anesthetic administration. Airway compression due to cervical fusion is considered one of the risk factors for difficult intubation in KFS patients.

Comparison of Modified Mallampati Classification in Supine and Sitting Positions to Predict Difficult Tracheal Intubation in Diabetic Patients.

Background: Airway management of patients with long-standing diabetes poses a major challenge for anaesthesiologists due to stiff joint syndrome affecting the atlanto-occipital joint. In certain cases requiring immobilization, the Mallampati test must often be performed in the supine position for obvious reasons. Objectives: Hence, we determined the diagnostic precision (sensitivity and specificity) of the modified Mallampati test in sitting and supine positions among the diabetic population in predicting difficult tracheal intubation. Methods: A single-center prospective observational study on adult diabetic patients undergoing general anesthesia and orotracheal intubation was carried out. An observer recorded the modified Mallampati in the sitting posture during the pre-anesthetic examination. The Mallampati in the supine position was determined while in the operating room, and the difficulty of intubation was noted, and diagnostic precision was calculated. The main objective was to predict a difficult airway by calculating the sensitivity, specificity, positive predictive value, and negative predictive value. Results: Out of the 150 participants, Mallampati grading in a sitting position was correctly able to identify 42.5% of difficult intubation cases, whereas it was 97.5% with Mallampati in the supine position. Mallampati grading in the sitting position was able to correctly identify 89.1% of easy intubation cases, which was 63.6% with Mallampati in the supine position. The correlation of Mallampati in the supine position with CL grading was statistically significant (P < 0.001). Conclusions: Among diabetic patients, the modified Mallampati test in the supine position can be considered a more accurate and sensitive predictor of difficult intubation than the sitting posture.

Use and Efficacy of I-Gel in Complicated Intubations in Newborn Infants: A Review of Case Reports in the Literature.

INTRODUCTION: Current guidelines for neonatal resuscitation suggest the use of a laryngeal mask when ventilation with both facemask and endotracheal tube has failed in newborns weighing >2000 g or delivered ≥ 34 weeks of gestation age. Paediatric I-gel® is one of the latest supraglottic airway management devices suitable for children and newborns. I-gel® use was effective in guaranteeing adequate ventilation in patients with anatomic abnormalities in case of respiratory impairment or during surgical procedures after the induction of anaesthesia. OBJECTIVE: The purpose of our review was to evaluate the use and efficacy of I-gel® in case of complicated intubations. METHODS: In July 2023, two authors of this paper independently conducted searches of the MEDLINE, Web of Science, and Scopus databases without imposing any time constraints or other restrictions. Three case reports were included, each describing the use of I-gel® device in difficult intubations in newborns with anatomical abnormalities. RESULTS: No difficulties were reported in the insertion of the device, which was placed even by inexperienced clinicians. CONCLUSION: The data collected highlighted the possibility of using I-gel® not only as a rescue device after attempted and failed endotracheal placement but also as a first choice in selected patients. Studies on larger cohorts would be needed. Further research involving larger patient cohorts of multicentre NICUs is necessary to confirm the use of laryngeal masks in neonates weighing less than 2000 grams.

A Case of Unsuspected Laryngeal Atresia With Comorbid Tracheoesophageal Fistula and Cardiac Defects.

Laryngeal atresia is a rare congenital condition that presents with hypoxia and failed intubation attempts at birth. When diagnosed prenatally, options exist to obtain airway access during delivery. However, postnatal diagnosis requires a high degree of clinical suspicion and the prompt initiation of surgical airway management in order to avoid morbidity and mortality.

Predictive and protective factors for failing first pass intubation in prehospital rapid sequence intubation: an aetiology and risk systematic review with meta-analysis.

BACKGROUND: Prehospital rapid sequence intubation first pass success rates vary between 59% and 98%. Patient morbidity is associated with repeat intubation attempts. Understanding what influences first pass success can guide improvements in practice. We performed an aetiology and risk systematic review to answer the research question 'what factors are associated with success or failure at first attempt laryngoscopy in prehospital rapid sequence intubation?'. METHODS: MEDLINE, EMBASE, CINAHL, and Cochrane Library were searched on March 3, 2023 for studies examining first pass success rates for rapid sequence intubation of prehospital live patients. Screening was performed via Covidence, and data synthesised by meta-analysis. The review was registered with PROSPERO and performed and reported as per Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. RESULTS: Reasonable evidence was discovered for predictive and protective factors for failure of first pass intubation. Predictive factors included age younger than 1 yr, the presence of blood or fluid in the airway, restricted jaw or neck movement, trauma patients, nighttime procedures, chronic or acute distortions of normal face/upper airway anatomy, and equipment issues. Protective factors included an experienced intubator, adequate training, use of certain videolaryngoscopes, elevating the patient on a stretcher in an inclined position, use of a bougie, and laryngeal manoeuvres. CONCLUSIONS: Managing bloody airways, positioning well, using videolaryngoscopes with bougies, and appropriate training should be further explored as opportunities for prehospital services to increase first pass success. Heterogeneity of studies limits stronger conclusions. SYSTEMATIC REVIEW PROTOCOL: PROSPERO (CRD42022353609).

A review of the current status and progress in difficult airway assessment research.

A difficult airway is a situation in which an anesthesiologist with more than 5 years of experience encounters difficulty with intubation or mask ventilation. According to the 2022 American Society of Anesthesiologists Practice Guidelines for the Management of Difficult Airway, difficult airways are subdivided into seven detailed categories. This condition can lead to serious adverse events and therefore must be diagnosed accurately and quickly. In this review, we comprehensively summarize and discuss the different methods used in clinical practice and research to assess difficult airways, including medical history, simple bedside assessment, comprehensive assessment of indicators, preoperative endoscopic airway examination, imaging, computer-assisted airway reconstruction, and 3D-printing techniques. We also discuss in detail the latest trends in difficult airway assessment through mathematical methods and artificial intelligence. With the continuous development of artificial intelligence and other technologies, in the near future, we will be able to predict whether a patient has a difficult airway simply by taking an image of the patient's face through a cell phone program. Artificial intelligence and other technologies will bring great changes to the development of airway assessment, and at the same time raise some new questions that we should think about.

Difficult intubation in ENT patient: Simultaneous videolaryngoscopy with flexible bronchoscopy. A combined approach. Case report.

INTRODUCTION: Difficult intubation is the situation when a skilled anesthetist has difficulties to manage airway using face mask, laryngoscopy, supraglottic device, tracheal intubation, surgery. Videolaryngoscope and flexible fibroscope (FFS) represent valid alternatives for difficult airway management, with some limitations. However, literature lacks of studies about the efficacy of the combined use of videolaryngoscope and FFS. CASE REPORT: We report a case of a man, with glottic lesion, who needs surgery under general anesthesia. Anesthesiologic pre-operative evaluation revealed that he's a difficult intubation case. So, in a supine position, intubation was performed on first attempt by videolaryngoscope combined with FFS. On post-op, no signs of injuries due to intubation have been found. DISCUSSION: In 2022, the American Society of Anesthesiologists defined the guidelines to manage difficult intubation: based on patient' anatomical and clinical feature and anesthetist' skills, several intubation procedures could be used. Each procedure has pros and cons. CONCLUSION: It's the first case of anticipated difficult intubation in adult man that was intubated under general anesthesia by using videolaryngoscope combined with FFS. We demonstrated that this procedure is safe and useful in case of difficult airway and recommended in case of laryngeal lesions that hinder the visualization of glottic plane.

The diagnostic accuracy of point-of-care ultrasound parameters for airway assessment in patients undergoing intubation in emergency department-an observational study.

BACKGROUND: Endotracheal intubation is an essential resuscitative procedure in the emergency setting. Airway assessment parameters such as the Mallampati classification are difficult to perform in an emergency setting. As point-of-care ultrasound (POCUS) assessment of airway parameters does not require patients to perform any mandatory action, ultrasound may become the potential first-line noninvasive airway assessment tool in the emergency department (ED). The use of POCUS in the ED has not been sufficiently studied. Using POCUS in airway assessment for predicting difficult intubation may be the next step in successful airway management. METHODOLOGY: The study was an observational study conducted at the ED of the All India Institute of Medical Sciences (Rishikesh). The treating emergency physician recorded the patient history and systemic examination along with an indication for intubation. The POCUS assessment of airway parameters pre-epiglottis to epiglottic vocal cord ratio (Pre-E/E-VC), tongue thickness, hyomental distance, and distance from skin to the hyoid bone was performed by the study investigator. During laryngoscopy, Cormack-Lehane (CL) grading was assessed. The data was entered and analyzed. RESULTS: Seventy patients who required intubation in the ED were enrolled in the study. Among the study population, 48.6%, 28.6%, 14.3%, 1.4%, and 7.1% were classified with the following CL grading: 1, 2a, 2b, 3a, and 3b, respectively. At a cutoff of ≥ 1.86, Pre-E/E-VC predicts difficult laryngoscopy (AUC 0.835) with a sensitivity of 83% and a specificity of 94%. At a cutoff of ≥ 5.98 cm, tongue thickness predicts difficult laryngoscopy (AUC 0.78) with a sensitivity of 83% and a specificity of 88%. At a cutoff of hyomental distance ≤ 6 cm, it predicts difficult laryngoscopy with a sensitivity of 83% and a specificity of 88%. All parameters can act as a promising tool for predicting difficult laryngoscopy, with the single best parameter being Pre-E/E-VC. CONCLUSION: Assessment of the airway with POCUS may be helpful to the emergency physician when the clinical airway assessment parameters fail to predict difficult laryngoscopy as most patients requiring intubation are uncooperative. Assessment of the parameters in our study Pre-E/E-VC, tongue thickness, and hyomental distance can act as a promising tool for predicting difficult laryngoscopy in the emergency scenario.

Difficult intubation in syndromic versus nonsyndromic forms of micrognathia in children.

BACKGROUND: We investigated how syndromic versus nonsyndromic forms of micrognathia impacted difficult intubation outcomes in children. Primary outcome was the first-attempt success rate of tracheal intubation, secondary outcomes were number of intubation attempts and complications. We hypothesized that syndromic micrognathia would be associated with lower first-attempt success rate. METHODS: In micrognathic patients enrolled in the Pediatric Difficult Intubation Registry (08/2012-03/2019) we retrospectively compared demographic and clinical characteristics between children with nonsyndromic and syndromic micrognathia using standardized mean differences (SMD) and assessed the association of the presence of syndrome with the primary and secondary outcomes using propensity score matching analysis with and without matching for airway assessment findings. RESULTS: Nonsyndromic patients (628) were less likely to have additional airway abnormalities. Syndromic patients (216) were less likely to have unanticipated difficult intubation (2% vs. 20%, SMD 0.59). First-attempt success rates of intubation were: 38% in the syndromic versus 34% in the nonsyndromic group (odds ratio [OR] 1.18; 95% confidence intervals [95% CI] 0.74, 1.89; p = .478), and 37% versus 37% (OR 0.99; 95% CI 0.66, 1.48; p = .959). Median number of intubation attempts were 2 (interquartile range [IQR]: 1, 3; range: 1, 8) versus 2 (IQR: 1, 3; range 1, 12) (median regression coefficient = 0; 95% CI: -0.7, 0.7; p = .999) and 2 (IQR: 1, 3; range: 1, 12) versus 2 (IQR: 1, 3; range 1, 8) (median regression coefficient = 0; 95% CI: -0.5, 0.5; p = .999). Complication rates were 14% versus 22% (OR 0.6; 95% CI 0.34, 1.04; p = .07) and 16% versus 21% (OR 0.71; 95% CI 0.43, 1.17; p = .185). CONCLUSIONS: Presence of syndrome was not associated with lower first-attempt success rate on intubation, number of intubation attempts, or complication rate among micrognathic patients difficult to intubate, despite more associated craniofacial abnormalities. Nonsyndromic patients were more likely to have unanticipated difficult intubations, first attempt with direct laryngoscopy.

Use of a flexible tip bougie (FlexTip) in the management of the first-attempt failure intubation with the C-MAC D-Blade videolaryngoscope in the intensive care unit: A prospective, case series.

We describe a series of 11 cases in which we used the new flexible tip (FlexTip) bougie as a rescue device following first-attempt failure at intubation with the C-MAC D-Blade video laryngoscope in our UCI. We collected data from all intubations performed using the C-MAC D-Blade video laryngoscope over a 16-month period. Ninety six patients were included in the study: 79 (86.8%) were intubated at the first attempt; 11 (12.1%) required 2 attempts; and 1 patient required 3 attempts. The Frova Intubating Introducer was used in 1 of the 12 patients requiring more than 1 intubation attempt, and the FlexTip was used in the remaining 11. This study shows that the new FlexTip bougie is a good rescue device when the first attempt at video laryngoscope intubation fails.

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

BACKGROUND: Emergency intubations are commonly associated with adverse events when performed in critically ill patients. A detailed look at intubation factors and their association with procedural success and mortality has yet to be fully conducted. METHODS: A total of 299 successive intubations at a tertiary Veteran Affair hospital were analyzed. Situational factors, personnel involved, intubation indications, induction agents, and airway management techniques were prospectively collected and entered into univariable and multivariable analyses to identify factors associated with procedural difficulty and mortality. RESULTS: The use of paralytics was associated with easier intubations (OR: 0.31, 95% CI: 0.11-0.87, p = .03). The use of direct laryngoscopy or video laryngoscopy had no significant association with difficult intubation. Factors associated with increased 30-day mortality were cardiac arrest (OR: 7.90, 95% CI: 2.77-22.50, p < .001), hypoxia as indication for intubation (OR: 2.31, 95% CI: 1.23-4.35, p = .009), and nadir SpO2 < 90% (OR: 2.70, 95% CI: 1.01-7.21, p = .048). Presence of an attending anesthesiologist during intubation was associated with a lower 30-day mortality (OR: 0.11, 95% CI: 0.04-0.29, p < .001). Factors associated with increased 90-day mortality were cardiac arrest (OR: 6.57, 95% CI: 2.23-19.34, p = .001), hypoxia as indication for intubation (OR: 1.97, 95% CI: 1.10-3.55, p = .023), and older age (OR: 1.38, 95% CI: 1.07-1.78, p = .013). Similarly, presence of an attending anesthesiologist was found to be associated with a lower 90-day mortality (OR: 0.19, 95% CI: 0.07-0.50, p = .001). CONCLUSION: Cardiovascular and respiratory instability were associated with increased 30- and 90-day mortality. Presence of an attending anesthesiologist was associated with a better survival following intubation outside operating room.