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).

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.

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.

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.

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.

Incidence, causes, and management of failed awake fibreoptic intubation-A retrospective study of 833 procedures.

Awake fibreoptic intubation has been considered a gold standard in the management of the difficult airway. However, failure may cause critical situations. The aim of this study was to investigate the incidence and causes of failed awake fibreoptic intubation at a tertiary care hospital. The study was conducted at St. Olav University Hospital in Trondheim, Norway. Problems occurring during anaesthesia are routinely recorded in the electronic anaesthesia information system (Picis Clinical Solutions Inc.), including difficult intubations. We applied text search on all anaesthesia records between 2011 and 2021 and identified 833 awake fibreoptic intubations. The anaesthesia records were examined to identify failed awake fibreoptic intubations, the cause of failure and how the airway ultimately was secured. Among 233,938 patients who received anaesthesia, 90,397 received tracheal intubation and 833 received awake fibreoptic intubation. Twenty-nine of the procedures failed. In nine patients the failure caused loss of airway control with desaturation and hypoventilation. The major causes of failure were dislodged tube after induction of general anaesthesia (n = 8), patient distress (n = 5), tube not able to pass (n = 5), and airway bleeding (n = 3). The situations were primarily solved using direct laryngoscopy, with or without bougie, or with video laryngoscopy. Tracheostomy was performed in four patients. Awake fibreoptic intubation failed in 3.5% of patients, most often due to dislocation, problems passing the tracheal tube, or patient discomfort. The failure rate was higher than in previous studies.

A randomized controlled trial comparing three supraglottic airway devices used as a conduit to facilitate tracheal intubation with flexible bronchoscopy.

PURPOSE: Once difficult ventilation and intubation are declared, guidelines suggest the use of a supraglottic airway (SGA) as a rescue device to ventilate and, if oxygenation is restored, subsequently as an intubation conduit. Nevertheless, few trials have formally studied recent SGA devices in patients. Our objective was to compare the efficacy of three second-generation SGA devices as conduits for bronchoscopy-guided endotracheal intubation. METHODS: In this prospective, single-blinded three-arm randomized controlled trial, patients with an American Society of Anesthesiologists Physical Status of I-III undergoing general anesthesia were randomized to bronchoscopy-guided endotracheal intubation using AuraGain™, Air-Q® Blocker, or i-gel® devices. We excluded patients with contraindications to an SGA or drugs and who were pregnant or had a neck, spine, or respiratory anomaly. The primary outcome was intubation time, measured from SGA circuit disconnection to CO2 measurement. Secondary outcomes included ease, time, and success of SGA insertion; success of intubation on first attempt; overall intubation success; number of attempts to intubate; ease of intubation; and ease of SGA removals. RESULTS: One hundred and fifty patients were enrolled from March 2017 to January 2018. Median intubation times were similar across the three groups (Air-Q Blocker, 44 sec; AuraGain, 45 sec; i-gel, 36 sec; P = 0.08). The i-gel was faster to insert (i-gel: 10 sec; Air-Q Blocker, 16 sec; AuraGain, 16 sec; P < 0.001) and easier to insert (Air-Q Blocker vs i-gel, P = 0.001; AuraGain vs i-gel, P = 0.002). Success of SGA insertion, success of intubation, and number of attempts were similar. The Air-Q Blocker was easier to remove than the i-gel (P < 0.001). CONCLUSION: All three second-generation SGA devices performed similarly regarding intubation. Despite minor benefits of the i-gel, clinicians should select their SGA based on clinical experience. STUDY REGISTRATION: ClinicalTrials.gov (NCT02975466); registered on 29 November 2016.

RéSUMé: OBJECTIF: Une fois qu'une ventilation et une intubation difficiles sont déclarées, les lignes directrices préconisent le recours à un dispositif supraglottique comme modalité de sauvetage pour ventiler le patient et, si l'oxygénation est rétablie, être ensuite utilisé comme conduit d'intubation. Toutefois, peu d'études ont formellement analysé l'utilisation des dispositifs supraglottiques récents chez de véritbales patients. Notre objectif était de comparer l'efficacité de trois dispositifs supraglottiques de deuxième génération utilisés comme conduits pour l'intubation endotrachéale guidée par bronchoscopie. MéTHODE: Dans cette étude prospective randomisée contrôlée à trois bras et à simple insu, les patients de statut physique I-III selon l'American Society of Anesthesiologists bénéficiant d'une anesthésie générale ont été randomisés à recevoir une intubation endotrachéale guidée par bronchoscopie via les dispositifs AuraGain™, Air-Q® Blocker ou i-gel®. Nous avons exclu les patients présentant des contre-indications à l'utilisation d'un dispositif supraglottique ou aux médicaments, ainsi que les patientes enceintes et les patients présentant une anomalie au niveau du cou, de la colonne vertébrale ou des voies aériennes. Le critère d'évaluation principal était le temps d'intubation mesuré entre le moment de déconnexion du dispositif supraglottique du circuit et le moment de mesure du CO2. Les critères d'évaluation secondaires comprenaient la facilité, le délai et la réussite de l'insertion du dispositif supraglottique; la réussite de l'intubation à la première tentative; la réussite globale de l'intubation; le nombre de tentatives d'intubation; la facilité d'intubation; et la facilité de retrait du dispositif supraglottique. RéSULTATS: Cent cinquante patients ont été recrutés de mars 2017 à janvier 2018. Les délais d'intubation médians étaient similaires dans les trois groupes (Air-Q Blocker : 44 sec; AuraGain : 45 sec; i-gel : 36 sec; P = 0,08). L'i-gel était plus rapide à insérer (i-gel : 10 sec; Air-Q Blocker : 16 sec; AuraGain : 16 sec; P < 0,001) et plus facile à insérer (Air-Q Blocker vs i-gel : P = 0,001; AuraGain vs i-gel : P = 0,002). La réussite de l'insertion du dispositif supraglottique, la réussite de l'intubation et le nombre de tentatives étaient similaires. L'Air-Q Blocker était plus facile à retirer que l'i-gel (P < 0,001). CONCLUSION: Les trois dispositifs supraglottiques de deuxième génération ont tous affiché une performance similaire en matière d'intubation. Malgré des avantages mineurs de l'i-gel, les cliniciens devraient choisir leur dispositif supraglottique en fonction de leur expérience clinique. ENREGISTREMENT DE L'éTUDE: ClinicalTrials.gov (NCT02975466); enregistrée le 29 novembre 2016.

Management of difficult and failed intubation in the general surgical population: a historical cohort study in a tertiary care centre.

PURPOSE: The objective of this study was to describe the incidence, management, and complications of difficult and failed endotracheal intubation in a general surgical population. METHODS: This historical cohort study included all cases of difficult endotracheal intubation in general surgical patients at Mount Sinai Hospital (Toronto, ON, Canada) from 1 January 2011 to 31 December 2017. Patient charts and electronic records were reviewed to collect data on airway management and complications. Endotracheal intubation was graded as "difficult" if more than two attempts with direct laryngoscopy or if additional equipment for second or subsequent attempts was required, and "failed" if it could not be achieved despite the attempts. The primary outcome was the incidence of difficult and failed intubation. The secondary outcomes were complications, difficult airway parameters, mask ventilation, number of intubation attempts, and rescue devices including the eventually successful method. RESULTS: We identified 111 cases of difficult intubation (0.26%) and 14 cases of failed intubation (0.03%) in 42,805 surgical cases requiring endotracheal intubation over the seven-year period. The incidence was highest in 2012 (0.36%) and lowest in 2017 (0.13%). Difficulty was anticipated in 84 (76%) patients. The median (range) number of intubation attempts was 2 (2-5). Videolaryngoscopy was the eventually successful method in those with unsuccessful first attempt direct laryngoscopy (n = 91) and videolaryngoscopy (n = 17) in 71% and 77% cases, respectively. Intubation failed in 14 patients, three of whom required a surgical airway because the lungs could not be ventilated. Poor visualization of the glottis (93%) and airway bleeding (36%) were the leading causes of failed intubation. Desaturation was seen in 8%, airway bleeding in 7%, and airway edema in 6% of cases of difficult intubation. CONCLUSION: The incidences of difficult and failed intubations in our study were 2.6 and 0.3 per 1,000 surgeries requiring laryngoscopies, respectively, with a decrease over time. Videolaryngoscopy showed a high success rate as a rescue device.

RéSUMé: OBJECTIF: L'objectif de cette étude était de décrire l'incidence, la prise en charge et les complications d'une intubation endotrachéale difficile et d'un échec d'intubation dans une population chirurgicale générale. MéTHODE: Cette étude de cohorte historique a inclus tous les cas d'intubation endotrachéale difficile chez des patients de chirurgie générale à l'Hôpital Mount Sinai (Toronto, ON, Canada) du 1er janvier 2011 au 31 décembre 2017. Les dossiers papier et électroniques des patients ont été passés en revue afin de recueillir des données sur la prise en charge des voies aériennes et les complications. L'intubation endotrachéale a été classée comme « difficile ¼ si plus de deux tentatives avec laryngoscopie directe ou si du matériel supplémentaire pour la deuxième tentative ou les tentatives ultérieures était nécessaire, et « échec ¼ si elle n'avait pas pu être réalisée malgré les tentatives. Le critère d'évaluation principal était l'incidence d'intubation difficile et d'échec. Les critères d'évaluation secondaires comportaient les complications, les critères de voies aériennes difficiles, la ventilation au masque, le nombre de tentatives d'intubation et les dispositifs de sauvetage, y compris la méthode permettant finalement un succès d'intubation. RéSULTATS: Nous avons identifié 111 cas d'intubation difficile (0,26 %) et 14 cas d'échec d'intubation (0,03 %) parmi les 42 805 cas chirurgicaux nécessitant une intubation endotrachéale au cours de la période de sept ans. L'incidence était la plus élevée en 2012 (0,36 %) et la plus basse en 2017 (0,13 %). Des difficultés avaient été anticipées chez 84 (76 %) patients. Le nombre médian (intervalle) de tentatives d'intubation était de 2 (2 à 5). La vidéolaryngoscopie a été la méthode permettant le succès final de l'intubation chez les patients pour lesquels la première tentative avait échoué avec la laryngoscopie directe (n = 91) ou la vidéolaryngoscopie (n = 17), soit dans 71 % et 77 % des cas, respectivement. L'intubation a échoué chez 14 patients, dont trois ont nécessité un accès chirurgical aux voies aériennes car les poumons ne pouvaient pas être ventilés. Une mauvaise visualisation de la glotte (93 %) et des saignements des voies aériennes (36 %) étaient les principales causes d'échec de l'intubation. Une désaturation a été observée dans 8 % des cas d'intubation difficile, alors que des saignements des voies aériennes ont été observés dans 7 % et un œdème des voies aériennes dans 6 % des cas. CONCLUSION: Dans notre étude, les incidences d'intubations difficiles et d'échec étaient de 2,6 et 0,3 pour 1000 chirurgies nécessitant des laryngoscopies, respectivement, avec une diminution au fil du temps. La vidéolaryngoscopie a montré un taux de réussite élevé en tant que dispositif de sauvetage.

The value of multiparameter combinations for predicting difficult airways by ultrasound.

BACKGROUND: Based on the upper airway anatomy and joint function parameters examined by ultrasound, a multiparameter ultrasound model for difficult airway assessment (ultrasound model) was established, and we evaluated its ability to predict difficult airways. METHODS: A prospective case-cohort study of difficult airway prediction in adult patients undergoing elective surgery with endotracheal intubation under general anesthesia, and ultrasound phantom examination for difficult airway assessment before anesthesia, including hyomental distance, tongue thickness, mandibular condylar mobility, mouth opening, thyromental distance, and modified Mallampati tests, was performed. Receiver operating characteristic (ROC) curve analysis was used to evaluate the effectiveness of the ultrasound model and conventional airway assessment methods in predicting difficult airways. RESULTS: We successfully enrolled 1000 patients, including 51 with difficult laryngoscopy (DL) and 26 with difficult tracheal intubation (DTI). The area under the ROC curve (AUC) for the ultrasound model to predict DL was 0.84 (95% confidence interval [CI]: 0.82-0.87), and the sensitivity and specificity were 0.75 (95% CI: 0.60-0.86) and 0.82 (95% CI: 0.79-0.84), respectively. The AUC for predicting DTI was 0.89 (95% CI: 0.87-0.91), and the sensitivity and specificity were 0.85 (95% CI: 0.65-0.96) and 0.81 (95% CI: 0.78-0.83), respectively. Compared with mouth opening, thyromental distance, and modified Mallampati tests, the ultrasound model predicted a greater AUC for DL (P < 0.05). Compared with mouth opening and modified Mallampati tests, the ultrasound model predicted a greater AUC for DTI (P < 0.05). CONCLUSIONS: The ultrasound model has good predictive performance for difficult airways. TRIAL REGISTRATION: This study is registered on chictr.org.cn (ChiCTR-ROC-17013258); principal investigator: Jianling Xu; registration date: 06/11/2017).

Evaluation of the reliability of the upper lip bite test and the modified mallampati test in predicting difficult intubation under direct laryngoscopy in apparently normal patients: a prospective observational clinical study.

BACKGROUND AND AIMS: Difficult endotracheal intubation is one of the most challenging operations in anesthesia. How to better predict difficult airway and make corresponding preparations to reduce the occurrence of accidents is a difficult task faced by anesthesiologists every day. This study decide to evaluate the value of the Upper Lip Bite Test (ULBT) and the Modified Mallampati Test (MMT) in predicting difficult intubation under direct laryngoscopy and find out the most intuitive and simple method to predict difficult intubation under direct laryngoscopy in apparently normal patients. PATIENTS AND METHODS: This descriptive-analytical study was performed on 450 patients for elective surgery under general anesthesia requiring endotracheal intubation. The ULBT and MMT grading were evaluated preoperatively and Cormack and Lehane's (CL) classification was recorded on the day of surgery during intubation under direct laryngoscopy. The accuracy, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), likelihood ratio (LR), Youden index and area under ROC curve of ULBT and MMT respectively and in combination were calculated and compared. And the consistency between the total scores of ULBT and MMT combined in different ways and CL grading was counted. RESULTS: Of the 450 patients, 69 (15.3%) were classified as difficult cases of direct laryngoscopy. The accuracy, sensitivity, specificity, PPV and NPV of ULBT were 81.33, 11.59, 93.96, 25.81, 85.44%; and those the corresponding values for MMT were 66.22, 62.32, 69.29, 26.88 and 91.03%. A combination of ULBT and MMT did not improve the sensitivity in the sample tested. The combined total scores of ULBT and MMT in both ways were less consistent with CL grading in predicting difficult intubation under direct laryngoscopy. CONCLUSION: Based on findings of current study, we conclude that ULBT and MMT for difficult intubation have only poor to moderate discriminative power when used alone. The combination of the two tests in fractional form is also not a good predictor of difficult intubation under direct laryngoscopy. TRIAL REGISTRATION: Chinese Clinical Trial Registry, ChiCTR2100052987, Registered 07 November 2021, http://www.chictr.org.cn.

Predictors of difficult intubation when using a videolaryngoscope with an intermediate-angled blade during the first attempt: a prospective observational study.

The curvature of a videolaryngoscope blade has been diversified from the standard macintosh-type to the hyperacute-angle-type, resulting in different performances. We aimed to determine the intubation success rate and identify predictors of difficult intubation when using an intermediate-angled videolaryngoscope in the first attempt of intubation under routine anaesthesia settings. We enrolled 808 patients between 19 and 79 years of age, scheduled for elective surgeries under general anaesthesia with orotracheal intubation from July 2017 to November 2018; patients who were candidates for awake intubation were excluded. We obtained patient demographic data and performed airway evaluation before induction of anaesthesia for elective surgeries. We used the UEScope for tracheal intubation with a hockey stick-shaped malleable stylet. The intubation time was defined as the total duration from the entry of the blade into the oropharynx to the detection of first end-tidal carbon dioxide capnogram; this duration was recorded along with the number of intubation attempts. Difficult intubation was defined as either > 60 s duration for tracheal intubation, or > 1 intubation attempt. The use of the UEScope demonstrated a 99.4% success rate for intubation; however, increased difficulties were observed in patients who were male, obese, had a short thyromental distance, limited mouth opening, and high upper-lip-bite test class. Despite the high intubation success rate using an intermediate-angled videolaryngoscope, we recommend preparing backup plans, considering the increased difficulty in patients with certain preoperative features.Clinical trial number and registry URL: Clinical Trials.gov Identifier: NCT03215823 (Date of registration: 12 July).

Airway management in a Helicopter Emergency Medical Service (HEMS): a retrospective observational study of 365 out-of-hospital intubations.

BACKGROUND: Airway management is a key skill in any helicopter emergency medical service (HEMS). Intubation is successful less often than in the hospital, and alternative forms of airway management are more often needed. METHODS: Retrospective observational cohort study in an anaesthesiologist-staffed HEMS in Switzerland. Patient charts were analysed for all calls to the scene (n = 9,035) taking place between June 2016 and May 2017 (12 months). The primary outcome parameter was intubation success rate. Secondary parameters included the number of alternative techniques that eventually secured the airway, and comparison of patients with and without difficulties in airway management. RESULTS: A total of 365 patients receiving invasive ventilatory support were identified. Difficulties in airway management occurred in 26 patients (7.1%). Severe traumatic brain injury was the most common indication for out-of-hospital Intubation (n = 130, 36%). Airway management was performed by 129 different Rega physicians and 47 different Rega paramedics. Paramedics were involved in out-of-hospital airway manoeuvres significantly more often than physicians: median 7 (IQR 4 to 9) versus 2 (IQR 1 to 4), p < 0.001. CONCLUSION: Despite high overall success rates for endotracheal intubation in the physician-staffed service, individual physicians get only limited real-life experience with advanced airway management in the field. This highlights the importance of solid basic competence in a discipline such as anaesthesiology.

Evaluation of anthropometric measurements and clinical tests in the diagnosis of difficult airway in patients undergoing head and neck surgery.

BACKGROUND: The aim of this study is to research the incidence of difficult airways and the effectiveness of anthropometric measurements and clinical tests used to predict difficult airways in patients undergoing head and neck surgery. METHODS: This study was performed on a total of 200 patients over the age of 18 who underwent head and neck surgery between December 2019 and March 2020. The demographic data of the patients in the preoperative period, previous operations/ radiotherapy history applied to the head and neck region, and obstructive sleep apnea syndrome symptoms were recorded. In the physical examination, the jaw structure, mouth opening, jaw movement, and tooth structure of the patients, modified Mallampati classification, head and neck movements, neck circumference, thyromental and sternomental distance, atlantooccipital joint mobility, upper lip bite test, Wilson risk scoring, and Cormack-Lehane classification were evaluated. RESULTS: The difficult laryngoscopy rate was identified as 19%, and the difficult intubation rate as 8%. Operation history related to head and neck (p = 0.002), presence of at least two of the obstructive sleep apnea syndrome symptoms (p = 0.008), Modified Mallampati score (p = 0.009), Wilson risk score (p = 0.004), upper lip bite test (p < 0.0001) and mouth opening (p = 0.001) were found to be associated with difficult laryngoscopy. Modified Mallampati score (p = 0.002), Wilson risk score (p < 0.0001), upper lip bite test (p < 0.0001), mouth opening (p < 0.0001), sternomental distance (p = 0.003), Atlantooccipital joint mobility (p = 0.001), and Cormack-Lehane classification (p < 0.0001) were found to be associated with difficult intubation. According to multiple logistic regression analysis, the results obtained for sternomental distance and mouth opening were OR 0.8, 95% CI 0.6-1.1 and OR 0.2, 95% CI 0.1-0.4, respectively. DISCUSSION: In patients who underwent head and neck surgery, it was observed that the frequency of difficult airway was higher, and particularly the Modified Mallampati score, Wilson risk score, upper lip bite test, and mouth opening were associated with both difficult laryngoscopy and difficult intubation.

Tracheal intubation using the Airtraq video laryngoscope vs. Macintosh laryngoscope in patients with anticipated difficult intubation.

Background: Various types of laryngoscopes have been invented to ameliorate the laryngoscopic view of the glottis, in normal and difficult airway, which helps anaesthesiologists to secure the airway during anaesthesia. In this prospective study, we aimed to compare the efficacy of the Airtraq video laryngoscope (AVL) and the Macintosh curved-blade laryngoscope (MBL), by using a common clinical assessment tool in patients with modified Mallampati class III and IV. Methods: A total of 60 patients [group A (AVL) and group M (MBL)] with modified Mallampati class III and IV listed for general anaesthesia were included. Each patient was intubated with either of the laryngoscope based on the group allotted. Time taken for tracheal intubation, grade of visualisation of glottis and need for manoeuvres to optimise the glottic view were compared. Results: The degree of the glottic view during successful intubation attempt was easily appreciated in group A (p < 0.0001). Difference in the requirement of manoeuvres for optimising the laryngeal view/assisting in intubation as assessed by manoeuvre score was easily appreciated in group A (p < 0.010). Rise in heart rate and mean arterial pressure 1 and 2 min after intubation was more in group M than in group A (p < 0.0001). No event of any airway trauma, as evidenced by visible trauma to lips or oral mucosa or blood on laryngoscope, was observed with either of the laryngoscope. Conclusion: The novel AVL provides better intubation conditions with greater ease of intubation, better glottic view and lesser haemodynamic alterations during laryngoscopy than MBL.

A comparison of videolaryngoscopy using standard blades or non-standard blades in children in the Paediatric Difficult Intubation Registry.

BACKGROUND: The design of a videolaryngoscope blade may affect its efficacy. We classified videolaryngoscope blades as standard and non-standard shapes to compare their efficacy performing tracheal intubation in children enrolled in the Paediatric Difficult Intubation Registry. METHODS: Cases entered in the Registry from March 2017 to January 2020 were analysed. We compared the success rates of initial and eventual tracheal intubation, complications, and technical difficulties between the two groups and by weight stratification. RESULTS: Videolaryngoscopy was used in 1313 patients. Standard and non-standard blades were used in 529 and 740 patients, respectively. Both types were used in 44 patients. In children weighing <5 kg, standard blades had significantly greater success than non-standard blades at initial (51% vs 26%, P=0.002) and eventual (81% vs 58%, P=0.002) attempts at tracheal intubation. In multivariable logistic regression analysis, standard blades had 3-fold greater odds of success at initial tracheal intubations compared with non-standard blades (adjusted odds ratio 3.0, 95% confidence interval): 1.32-6.86, P=0.0009). Standard blades had 2.6-fold greater odds of success at eventual tracheal intubation compared with non-standard blades in children weighing <5 kg (adjusted odds ratio 2.6, 95% confidence interval: 1.08-6.25, P=0.033). There was no significant difference found in children weighing ≥5 kg. CONCLUSIONS: In infants weighing <5 kg, videolaryngoscopy with standard blades was associated with a significantly greater success rate than videolaryngoscopy with non-standard blades. Videolaryngoscopy with a standard blade is a sensible choice for tracheal intubation in children who weigh <5 kg.

Difficult tracheal intubation in neonates and infants. NEonate and Children audiT of Anaesthesia pRactice IN Europe (NECTARINE): a prospective European multicentre observational study.

BACKGROUND: Neonates and infants are susceptible to hypoxaemia in the perioperative period. The aim of this study was to analyse interventions related to anaesthesia tracheal intubations in this European cohort and identify their clinical consequences. METHODS: We performed a secondary analysis of tracheal intubations of the European multicentre observational trial (NEonate and Children audiT of Anaesthesia pRactice IN Europe [NECTARINE]) in neonates and small infants with difficult tracheal intubation. The primary endpoint was the incidence of difficult intubation and the related complications. The secondary endpoints were the risk factors for severe hypoxaemia attributed to difficult airway management, and 30 and 90 day outcomes. RESULTS: Tracheal intubation was planned in 4683 procedures. Difficult tracheal intubation, defined as two failed attempts of direct laryngoscopy, occurred in 266 children (271 procedures) with an incidence (95% confidence interval [CI]) of 5.8% (95% CI, 5.1-6.5). Bradycardia occurred in 8% of the cases with difficult intubation, whereas a significant decrease in oxygen saturation (SpO2<90% for 60 s) was reported in 40%. No associated risk factors could be identified among co-morbidities, surgical, or anaesthesia management. Using propensity scoring to adjust for confounders, difficult anaesthesia tracheal intubation did not lead to an increase in 30 and 90 day morbidity or mortality. CONCLUSIONS: The results of the present study demonstrate a high incidence of difficult tracheal intubation in children less than 60 weeks post-conceptual age commonly resulting in severe hypoxaemia. Reassuringly, the morbidity and mortality at 30 and 90 days was not increased by the occurrence of a difficult intubation event. CLINICAL TRIAL REGISTRATION: NCT02350348.

Lessons from COVID-19: A reflection on the strengths and weakness of early consensus recommendations for pediatric difficult airway management during a respiratory viral pandemic using a modified Delphi method.

BACKGROUND: The authors recognized a gap in existing guidelines and convened a modified Delphi process to address novel issues in pediatric difficult airway management raised by the COVID-19 pandemic. METHODS: The Pediatric Difficult Intubation Collaborative, a working group of the Society for Pediatric Anesthesia, assembled an international panel to reach consensus recommendations on pediatric difficult airway management during the COVID-19 pandemic using a modified Delphi method. We reflect on the strengths and weaknesses of this process and ways care has changed as knowledge and experience have grown over the course of the pandemic. RECOMMENDATIONS: In the setting of the COVID-19 pandemic, the Delphi panel recommends against moving away from the operating room solely for the purpose of having a negative pressure environment. The Delphi panel recommends supplying supplemental oxygen and using videolaryngoscopy during anticipated difficult airway management. Direct laryngoscopy is not recommended. If the patient meets extubation criteria, extubate in the OR, awake, at the end of the procedure. REFLECTION: These recommendations remain valuable guidance in caring for children with anticipated difficult airways and infectious respiratory pathology when reviewed in light of our growing knowledge and experience with COVID-19. The panel initially recommended minimizing involvement of additional people and trainees and minimizing techniques associated with aerosolization of viral particles. The demonstrated effectiveness of PPE and vaccination at reducing the risk of exposure and infection to clinicians managing the airway makes these recommendations less relevant for COVID-19. They would likely be important initial steps in the face of novel respiratory viral pathogens. CONCLUSIONS: The consensus process cannot and should not replace evidence-based guidelines; however, it is encouraging to see that the panel's recommendations have held up well as scientific knowledge and clinical experience have grown.

Clinical assessment of upper airway and its complications in Hunter syndrome.

BACKGROUND: Hunter syndrome (HS) is an X-linked, recessive, lysosomal storage disease caused by a deficiency of the lysosomal enzyme, iduronate sulfatase (IDS). It is characterized by multisystem accumulations of glycosaminoglycans and upper airway obstruction is one of the major causes of death. While the current disease severity classifications for HS are mainly based on the degree of neurocognitive impairment, its association with the level of upper airway obstruction has not been assessed. METHODS: A retrospective chart review of HS patients who were followed at the Jikei University School of Medicine was performed. Association between the degree of airway obstruction and the currently used disease severity scores was evaluated. RESULTS: We identified eight HS patients and they were enrolled in the study. The Modified Mallampati classification (MMC) score, used to predict difficulties for oropharyngeal procedures, was significantly correlated with the HS severity. It was also correlated with the Apnea-Hypopnea Index (AHI). No significant correlation between IDS enzymatic activity and the severity of HS disease was identified. CONCLUSIONS: Variable clinical expressivities exist in HS, but the risk of respiratory complications is likely to be associated with disease severity, assessed by the previously recognized neurocognitive function-based severity scoring systems. MMC can be a simple supplementary tool to evaluate disease severity as well as predict difficulties for oropharyngeal procedures and respiratory function complications in HS, such as sleep apnea.

An analysis of anesthetists' awareness, knowledge, and attitudes toward peri-anesthetic dental trauma.

BACKGROUND/AIM: Peri-anesthetic dental trauma is a common anesthesia-related complication. It is the reason for a significant number of malpractice lawsuits against anesthetists through insurance companies. The frequency, outcomes, and risk factors related to peri-anesthetic dental trauma have been well documented. The aim of this study was to evaluate anesthetists' awareness, knowledge, and attitudes toward peri-anesthetic dental trauma. MATERIAL AND METHODS: This nationwide, cross-sectional, descriptive study comprising 220 anesthetists was conducted in Turkey between June 2019 and May 2020. A specific questionnaire was created using Google Forms and delivered to 591 participants via WhatsApp. Pearson's Chi-squared test and the Fisher-Freeman-Halton tests were used to analyze the results. RESULTS: The overall response rate was 37.2% (220 out of 591 participants). Of the 80.5% of the participants who encountered peri-anesthetic dental trauma during their practice, 32.8% had encountered avulsion and 32.8% reported that they had caused soft tissue injuries. More than one-third of the participants (38.9%) stated that the patient group that was the most at-risk for peri-anesthetic dental trauma was older people with missing teeth. Half of the participants (50.9%) stated that avulsed teeth could be replanted; among them, 21.8% and 11.8% specified that the ideal replantation time was <30 min and that the ideal storage medium for the avulsed tooth was fresh milk, respectively. Furthermore, 88.1% of the participants noted that peri-anesthetic dental trauma occurred more frequently during emergency intubations and only 20.9% were aware of custom-made mouthguards. CONCLUSIONS: Anesthetists lack knowledge around peri-anesthetic dental trauma and its interventions.

PREDICTION OF DIFFICULT INTUBATION BY USING UPPER LIP BITE, THYROMENTAL DISTANCE AND MALLAMPATI SCORE IN COMPARISON TO CORMACK AND LEHANE CLASSIFICATION SYSTEM

OBJECTIVE: To evaluate efficacy of Modified Mallampati test (MMT), upper lip bite test (ULBT) and Thyromental distance (TMD) or combination of two method Modified Mallampati test (MMT)+ upper lip bite test (ULBT), Thyromental distance (TMD) + upper lip bite test (ULBT) in prediction of difficult intubation in patients undergoing GA. PATIENTS AND METHODS: Three tests were carried out in all patients by a single anesthesiologist. These were MMT, ULBT and TMD. Laryngoscopy was performed with patient's head in the sniffing position. The laryngoscopy view was graded according to modified Cormack and Lehane classification system. Study was prospective, single cross sectional, in 151 adult patients who required GA with endotracheal intubation for elective surgery. On arrival in the operating room, routine monitoring and venous cannula were introduced. Midazolam, Fentanyl. and rocuronium, ketamine , propofol were given to facilitate endotracheal intubation. RESULTS: Out of 150 assessed patients, 18 (12%) had difficult intubation. Of those 18 patients, 17 (83.33%) patients had Cormack and Lehane classification III and one patient (16.67%) had classification IV. Compared with Cormack and Lehane classification system as the gold standard for difficult intubation, the sensitivity and specificity of MMT was 66.67% and 96.97% respectively, while ULBT had a sensitivity of 77.78% and a specificity of 93.18%, and TMD had a sensitivity of 55.56% and specificity of 94.97% respectively. A combination of different tests improved their efficiencies. The sensitivity and specificity MMT and TMD combinations was 77.78% and 92.42% respectively, while it was 88.89% and 93.18%, respectively for MMT and ULPT. The combination of TMD and ULBT has a sensitivity of 88.33% and a specificity of 91.67%. CONCLUSION: Upper lip biting test has the best sensitivity while MMT had the best specificity. No single test alone can be reliable for predicting of difficult intubation. The combination of ULBT and MMT was the best in terms of both sensitivity and specificity for prediction of difficult intubation.