Difficulty Of Tracheal Intubation Research Articles

Comparison of modified Mallampati test with and without phonation for prediction of difficult laryngoscopy and intubation among adult surgical patients: cross-sectional study

Background: The modified Mallampati test (MMT) is one of the most widely used airway assessment tests, for predicting laryngoscopy and tracheal intubation difficulty. The MMT without phonation is routinely performed, but its specificity in identifying easy intubation is controversial. This study aimed to compare the MMT with and without phonation in predicting difficult laryngoscopy and tracheal intubation in adult elective surgical patients who underwent general anesthesia. Materials and methods: An institution-based cross-sectional study was performed on 258 adult elective surgical patients who required tracheal intubation. A systemic random sampling technique was employed to select study participants, and the MMT, with and without phonation, was performed during the preoperative assessment. A laryngoscopic view was recorded at the time of tracheal intubation and classified as easy or difficult for tracheal intubation. The collected data were entered into Epi-info and analyzed using the statistics package of social science software version 26. Statistical significance was defined as a P value of less than 0.05. This study used specificity, sensitivity, accuracy, and positive and negative predictive values as the statistical measures. Results: The prevalence of laryngoscopy and intubation difficulties was observed to be 13.6% and 10.5%, respectively. MMT conducted without phonation had the higher sensitivity for predicting difficult laryngoscopy and intubation, than MMT with phonation. But MMT performed with phonation had higher specificity for identifying easy intubation, than MMT without phonation. Conclusion: The MMT with phonation has higher accuracy, specificity, and positive predictive value for difficult laryngoscopy and intubation than the non-phonation approach. MMT combined with phonation can be used as an alternative assessment tool to predict difficult airways.

Diabetes Mellitus Is Not a Risk Factor for Difficult Intubation Among Critically Ill Adults: A Secondary Analysis of Multicenter Trials.

Diabetes mellitus has been associated with greater difficulty of tracheal intubation in the operating room. This relationship has not been examined for tracheal intubation of critically ill adults. We examined whether diabetes mellitus was independently associated with the time from induction of anesthesia to intubation of the trachea among critically ill adults. A secondary analysis of data from five randomized trials completed by the Pragmatic Critical Care Research Group (PCCRG). Emergency departments (EDs) or ICUs at 11 centers across the United States that enrolled in randomized trials of a pre-intubation checklist, fluid bolus administration, bag-mask ventilation between induction and laryngoscopy, and intubation using a bougie vs. stylet. Critically ill adults undergoing tracheal intubation with a laryngoscope in an ED or an ICU. None. A total of 2654 patients were included in this analysis, of whom 638 (24.0%) had diabetes mellitus. The mean time from induction of anesthesia to intubation of the trachea was 169 seconds (sd, 137s). Complications occurred during intubation in 1007 patients (37.9%). Diabetes mellitus was not associated with the time from induction of anesthesia to intubation of the trachea (-4.4 s compared with nondiabetes; 95% CI, -17.2 to 8.3 s; p = 0.50). Use of a video vs. direct laryngoscope did not modify the association between diabetes mellitus and the time from induction to intubation (p for interaction = 0.064). Diabetes mellitus was not associated with the probability of successful intubation on the first attempt (85.6% vs. 84.3%; p = 0.46) or complications during intubation (39.8% vs. 37.4%; p = 0.52). Among 2654 critically ill patients undergoing tracheal intubation in an ED or an ICU, diabetes mellitus was not independently associated with the time from induction to intubation, the probability of successful intubation on the first attempt, or the rate of complications during intubation.

Prospective development and validation of a universal classification for paediatric videolaryngoscopic tracheal intubation: the PeDiAC score.

The VIDIAC score, a prospectively developed universal classification for videolaryngoscopy, has shown excellent diagnostic performance in adults. However, there is no reliable classification system for videolaryngoscopic tracheal intubation in children. We aimed to develop and validate a multivariable logistic regression model and easy-to-use score to classify difficult videolaryngoscopic tracheal intubation in children and to compare it with the Cormack and Lehane classification. A secondary aim was to externally validate the VIDIAC score in children. We conducted a prospective observational study within a structured universal videolaryngoscopy implementation programme. We used C-MAC™ videolaryngoscopes in all children undergoing tracheal intubation for elective surgical procedures. We validated the VIDIAC score externally and assessed its performance. We then identified eligible co-variables for inclusion in the PeDiAC score, developed a multivariable logistic regression model and compared its performance against the Cormack and Lehane classification. We studied 809 children undergoing 904 episodes of tracheal intubation. The VIDIAC score outperformed the Cormack and Lehane classification when classifying the difficulty of videolaryngoscopic tracheal intubation, with an area under the receiver operating characteristic curve of 0.80 (95%CI 0.73-0.87) vs. 0.69 (95%CI 0.62-0.76), respectively, p = 0.018. Eight eligible tracheal intubation-related factors, that were selected by 100-times repeated 10-fold cross-validated least absolute shrinkage selector operator regression, were used to develop the PeDiAC model. The PeDiAC model and score showed excellent diagnostic performance and model calibration. The PeDiAC score achieved significantly better diagnostic performance than the Cormack and Lehane classification, with an area under the receiver operating characteristic curve of 0.97 (95%CI 0.96-0.99) vs. 0.69 (95%CI 0.62-0.76), respectively, p < 0.001. We developed and validated a specifically tailored classification for paediatric videolaryngoscopic tracheal intubation with excellent diagnostic performance and calibration that outperformed the Cormack and Lehane classification.

A Comparison of Tracheal Intubation Using Direct Laryngoscope and Video Laryngoscope in the Sellick and Trendelenburg Position with That Using Direct Laryngoscope in the Supine Sniffing Position: A Randomized Controlled Trial.

Background: Tracheal intubation in the Sellick and Trendelenburg position (ST position) can prevent pulmonary aspiration but increase the difficulty of tracheal intubation. We compared tracheal intubation using video and direct laryngoscopy in the ST position with direct laryngoscopy in the supine sniffing position to evaluate the overall intubation performance. Methods: One hundred and twenty patients were randomly assigned to three groups: direct laryngoscope in the supine sniffing position (control), direct laryngoscope in the ST position (ST direct), and video laryngoscope in the ST position (ST video). The primary outcome was the intubation time; secondary outcomes included the first attempt success rate of tracheal intubation, intubation difficulty scale score, operator's subjective assessment of intubation difficulty, and modified Cormack-Lehane grades. Results: The median intubation times were greater in the ST direct (36.0 s) and video (34.5 s) than the control (28.0 s) groups. The first attempt success rate decreased in the ST direct (77.5%) but not the video (95.0%) group compared with the control group (100%). Conclusions: The challenges of tracheal intubation in the ST position, aimed at reducing the risk of pulmonary aspiration, can be mitigated by using a video laryngoscope, despite slightly longer intubation times.

Physiological changes and the Mallampati classification: Tracheal intubation complications

Introduction: Difficulty in tracheal intubation is a significant factor in morbidity and mortality. Mallampati has therefore made it possible to predict it in advance. Its classification is based on the visualization of pharyngeal structures and is a simple anesthetic assessment. In practice, some circumstances can modify Mallampati's classification, making intubation more complex, and knowledge of these is of medical importance. Objectives: To review the literature on circumstances that alter Mallampati's classification. Methods: A literature review was carried out on possible physiological alterations responsible for changes in the Mallampati classification. We searched the Medline, Scielo and CRD databases for the terms: “Mallampati modification” and “Mallampati score” associated with “anaphylaxis” and “labor” and the articles were submitted to critical analysis. Results: Among the interferences in the Mallampati score is anaphylaxis, which results in upper airway edema, affecting the classification. In addition, pregnancy and labor can influence the score. Some factors such as breast growth, weight gain and pharyngeal edema increase the index in pregnant women. In addition, there is airway edema, explained by exertion and increased venous pressure in the upper body. In addition, fluid overload and the antidiuretic effect of oxytocin cause changes in the airways. Another situation is that of pediatric patients, where 13% of respiratory problems during anesthesia are related to intubation difficulties. In children between 4 and 8 years old without malformations, the index has proved applicable. However, it is impossible to use it in children under 4 years of age. Conclusions: The Mallampati score complements the judgment of a general examination that includes anamnesis and physical inspection of the craniofacial structure to identify risk factors, taking into account other situations that may interfere with the classification. Therefore, an understanding of its limitations is necessary for its correct application.

Development of an Artificial Intelligence-Based Image Recognition System for Time-Sequence Analysis of Tracheal Intubation.

Total intubation time (TIT) is an objective indicator of tracheal intubation (TI) difficulties. However, large variations in TIT because of diverse initial and end targets make it difficult to compare studies. A video laryngoscope (VLS) can capture images during the TI process. By using artificial intelligence (AI) to detect airway structures, the start and end points can be freely selected, thus eliminating the inconsistencies. Further deconstructing the process and establishing time-sequence analysis may aid in gaining further understanding of the TI process. We developed a time-sequencing system for analyzing TI performed using a #3 Macintosh VLS. This system was established and validated on 30 easy TIs performed by specialists and validated using TI videos performed by a postgraduate-year (PGY) physician. Thirty easy intubation videos were selected from a cohort approved by our institutional review board (B-ER-107-088), and 6 targets were labeled: the lip, epiglottis, laryngopharynx, glottic opening, tube tip, and a black line on the endotracheal tube. We used 887 captured images to develop an AI model trained using You Only Look Once, Version 3 (YOLOv3). Seven cut points were selected for phase division. Seven experts selected the cut points. The expert cut points were used to validate the AI-identified cut points and time-sequence data. After the removal of the tube tip and laryngopharynx images, the durations between 5 identical cut points and sequentially identified the durations of 4 intubation phases, as well as TIT. The average and total losses approached 0 within 150 cycles of model training for target identification. The identification rate for all cut points was 92.4% (194 of 210), which increased to 99.4% (179 of 180) after the removal of the tube tip target. The 4 phase durations and TIT calculated by the AI model and those from the expert exhibited strong Pearson correlation (phase I, r = 0.914; phase II, r = 0.868; phase III, r = 0.964; and phase IV, r = 0.949; TIT, r = 0.99; all P < .001). Similar findings were obtained for the PGY's observations (r > 0.95; P < .01). YOLOv3 is a powerful tool for analyzing images recorded by VLS. By using AI to detect the airway structures, the start and end points can be freely selected, resolving the heterogeneity resulting from the inconsistencies in the TIT cut points across studies. Time-sequence analysis involving the deconstruction of VLS-recorded TI images into several phases should be conducted in further TI research.

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

Background: The main clinical manifestations of patients with Pierre Robin sequence (PRS) include micrognathia, the glossoptosis and dyspnoea. The difficulty of tracheal intubation (TI) in such patients is increased. Objective: The purpose of the study was to evaluate the reliability and efficacy of the PRS simulator. Methods: A PRS simulator was developed by using 3-dimensional (3D) printing technology under computer-aided design. A total of 12 anaesthesiologists each trained 5 times for TI on the PRS Training Simulator-1 and recorded the simulation time. After the training, they were randomly divided into three groups with a total of 12 nontrained anaesthesiologists, and the simulation was completed on PRS Simulator-2, 3 and 4. The simulation time was recorded, and the performance was evaluated by three chief anaesthesiologists. Then, all 24 anaesthesiologists completed the questionnaire. Results: A PRS simulator developed by 3D printing was used to simulate the important aspects of TI. The average number of years worked was 6.3 ± 3.1years, and 66.7% were female. The time for the 12 anaesthesiologists to complete the training gradually decreased (p < 0.01). Compared with the trained anaesthesiologists, the simulation time of TI in the nontrained anaesthesiologists was much longer (all p < 0.01). In addition, the simulation performance of the trained anaesthesiologists was relatively better (all p < 0.01). Conclusion: The reliability and efficacy of the PRS simulator is herein preliminarily validated, and it has potential to become a teaching and training tool for anaesthesiologists.

Relationship Between Airway Examination with LEMON Criteria and Difficulty of Tracheal Intubation with IDS Criteria.

Tracheal intubation is a common technique used to secure a patient's airway, which is crucial in anesthesia. Successful tracheal intubation depends on various factors, including the assessment of the patient's airway before the procedure. In recent years, scoring systems, such as LEMON (an acronym for the assessment of the airway's appearance, identification of any dental issues, evaluation of Mallampati classification, assessment of airway obstruction, and examination of neck mobility) and intubation difficulty scale (IDS) have gained attention. This study aimed to investigate the relationship between the LEMON criteria and IDS in tracheal intubation. The goal was to provide valuable insights that can assist medical professionals in optimizing their approach to airway management by analyzing clinical data, assessing patient outcomes, and evaluating the consistency between these scoring systems. This study was based on a descriptive-analytical study involving a group of patients requiring intubation. This study examined 105 patients scheduled for elective surgeries, aged between 19 and 60 years, without specific underlying diseases, such as laryngeal cancer, temporomandibular joint stiffness, or significant tongue enlargement, and with a body mass index (BMI) below 40 kg/m². Initially, expert anesthesiologists assessed the patients using the LEMON criteria, and then the degree of intubation difficulty was measured using the IDS scoring system. Finally, these two criteria were compared. In this study, there was a significant correlation between the LEMON score and the IDS score (P < 0.001). The difficult intubation group (IDS score higher than 0) had higher LEMON scores (with the highest score equal to 4) than the non-difficult intubation group (IDS score of 0) (P = 0.017). The average LEMON and IDS scores were 3.11 and 1.35, respectively. Among the participants, 96.2% had an intubation difficulty score of ≤ 5; nevertheless, 3.8% had a score of > 5. Additionally, limited neck mobility emerged as the sole independent predictor of intubation difficulty (P = 0.002, odds ratio = 6.152). The LEMON score is associated with difficult intubation in adult patients requiring intubation.

Pilot multicenter study to determine the utility of point-of-care ultrasound to predict difficulty of tracheal intubation using videolaryngoscopy with the McGrath™ Mac videolaryngoscope.

Clinical airway screening tests used to predict difficulties during airway management have low sensitivity and specificity. Point-of-care airway ultrasound has described measurements related to problems with difficult direct laryngoscopy. Nevertheless, the correlation between ultrasound parameters and videolaryngoscopy has not been published yet. The aim of this multicenter, prospective observational pilot study was to evaluate the applicability of clinical parameters and ultrasound measurements to find potential tracheal intubation difficulties when videolaryngoscopy is used. Preoperatively, six clinical airway assessments were performed: (1) modified Mallampati score, (2) thyromental distance, (3) sternomental distance, (4) interincisal distance, (5) upper lip bite test, and (6) neck circumference. Six ultrasound parameters were measured in awake patients: (1) distance from skin to hyoid bone, (2) distance from skin to epiglottis, (3) hyomental distance in neutral head position, (4) hyomental distance in head-extended position, (5) distance from skin to the deepest part of the palate, and (6) sagittal tongue area. And finally, there was one ultrasound measure obtained in anesthetized patients, the compressed sagittal tongue area during videolaryngoscopy. The difficulty for tracheal intubation using a McGrath™ Mac videolaryngoscope, the percentage of glottic opening, and Cormack-Lehane grade were also assessed. In this cohort of 119 subjects, tongue dimensions, particularly the sagittal tongue area, showed a robust association with increased intubation difficulty using videolaryngoscopy. A multiparametric model combining the following three ultrasound variables in awake patients: (a) the distance from skin to epiglottis, (b) the distance from skin to the deepest part of the palate, and (c) the sagittal tongue area, yielded a sensitivity of 92.3%, specificity of 94.5%, positive predictive value of 82.8%, and negative predictive value of 97.8% (p < 0.001). Point-of-care airway ultrasound emerges as a more useful tool compared to traditional clinical scales to anticipate possible challenges during videolaryngoscopic intubation.

Current challenges faced by transgender and gender-diverse patients and providers in anesthesiology.

Current challenges faced by transgender and gender-diverse patients and providers in anesthesiology.

Airway management of huge thyroid swelling having tracheal deviation: Challenges faced

Airway management in huge goiters present with challenges among anesthesiologists worldwide. Usually thyroid swelling presents with retrosternal extension, tracheal compression poses certain airway challenges. In our case there was no retrosternal extension or tracheal compression but tracheal deviation was present which make airway management difficult.55yr old male pt, weight 60 kg, moderately built, came with chief complaints of gradually increasing swelling in front of neck since 3 years. He was k/c/o systemic hypertension on regular treatment taking tab. amlodipine 5mg OD. He was having no change in voice, no other systemic illness. He was evaluated for left sided huge goitre having neck swelling of size 14 cm × 15 cm × 10 cm. The mass was extending from lower jaw to below sternal notch, get below the swelling was possible. Xray neck AP and lateral view revealed tracheal deviation to right by the mass, this patient was posted for the hemithyroidectomy considering difficult airway plan of anaesthesia was awake fibreoptic intubation (under topical anaesthesia and sedation). In this case because of tracheal deviation to right the glottic structures were distorted, view to vocal cords was obscured by left arytenoid making the airway management difficult.In general the difficulty of tracheal intubation in cases with thyroid disease is affected by compression or deviation of the trachea, the position and hardness of the tumour. Generally recommended techniques for securing airway in such patients are 1. Awake fiberoptic intubation 2. Awake direct laryngoscopy aided intubation 3. Inhalational induction. Awake fibreoptic intubation using local anaesthesia - sedation technique is a suitable option in selected group of patients having possibility of airway obstruction.

Critical element prediction of tracheal intubation difficulty: Automatic Mallampati classification by jointly using handcrafted and attention-based deep features

Preoperative assessment of the difficulty of tracheal intubation is of great importance in anesthesia practice because failed intubation can lead to severe complications and even death. The Mallampati score is widely used as a critical assessment criterion in combination with other measures to assess the difficulty of tracheal intubation. The performance of existing methods for Mallampati classification with artificial intelligence (AI) is unreliable to the extent that the current clinical judgment of the Mallampati score relies entirely on doctors' experience. In this paper, we propose a new method for automatic Mallampati classification. Our method extracts deep features that are more favorable for the Mallampati classification task by introducing an attention mechanism into the basic deep convolutional neural network (DCNN) and then further improves the classification performance by jointly using attention-based deep features with handcrafted features. We conducted experiments on a dataset consisting of 321 oral images collected online. The proposed method has a classification accuracy of 97.50%, a sensitivity of 96.52%, a specificity of 98.05%, and an F1 score of 96.52% after five-fold cross-validation. The experimental results show that our proposed method is superior to other methods, can assist doctors in determining Mallampati class objectively and accurately, and provide an essential reference element for assessing the difficulty of tracheal intubation.

A model to predict difficult airway alerts after videolaryngoscopy in adults with anticipated difficult airways - the VIDIAC score.

A model to classify the difficulty of videolaryngoscopic tracheal intubation has yet to be established. The videolaryngoscopic intubation and difficult airway classification (VIDIAC) study aimed to develop one based on variables associated with difficult videolaryngoscopic tracheal intubation. We studied 374 videolaryngoscopic tracheal intubations in 320 adults scheduled for ear, nose and throat or oral and maxillofacial surgery, for whom airway management was expected to be difficult. The primary outcome was whether an anaesthetist issued a 'difficult airway alert' after videolaryngoscopy. An alert was issued after 183 (49%) intubations. Random forest and lasso regression analysis selected six intubation-related variables associated with issuing an alert: impaired epiglottic movement; increased lifting force; direct epiglottic lifting; vocal cords clearly visible; vocal cords not visible; and enlarged arytenoids. Internal validation was performed by a 10-fold cross-validation, repeated 20 times. The mean (SD or 95%CI) area under the receiver operating characteristic curve was 0.92 (0.05) for the cross validated coefficient model and 0.92 (0.89-0.95) for a simplified unitary score (VIDIAC score with component values of -1 or 1 only). The calibration belt for the coefficient model was consistent with observed alert probabilities, from 0% to 100%, while the unitary VIDIAC score overestimated probabilities < 20% and underestimated probabilities > 70%. Discrimination of the VIDIAC score for patients more or less likely to be issued an alert was better than discrimination by the Cormack-Lehane classification, with mean (95%CI) areas under the receiver operating characteristic curve of 0.92 (0.89-0.95) vs. 0.75 (0.70-0.80), respectively, p < 0.001. Our model and score can be used to calculate the probabilities of difficult airway alerts after videolaryngoscopy.

Comparative study to evaluate the effect of intubation box on tracheal intubation difficulty with King Vision ® and TRUVIEW video laryngoscope in manikin in a tertiary care hospital

The Sri Lankan Journal of Anaesthesiology is the official journal of the College of Anaesthesiologists of Sri Lanka. It publishes clinical investigations, research articles, audits, case reports, review articles and CME articles relating to anaesthesiology, critical care and pain. It is published bi annually in January and June. Sri Lankan Journal of Anaesthesiology is included on DOAJ and Scopus.

Diagnostic Efficacy and Clinical Value of Ultrasonography in Difficult Airway Assessment: Based on a Prospective Cohort Study.

Diagnostic Efficacy and Clinical Value of Ultrasonography in Difficult Airway Assessment: Based on a Prospective Cohort Study.

Tracheal Intubation Difficulties: Systematic Literature Review

Background: Tracheal intubation is a common procedure in medical practice, being performed mainly in surgical centers and emergencies in trauma patients. Objective: This systematic literature review aims to understand the main difficulties and complications related to tracheal intubation. Methods: Systematic literature review, conducted in the Virtual Health Library databases between 2016 and 2021, restricted to articles in English and Portuguese with the descriptors: Airway, Difficult intubation, and Complications. After reading the abstracts, 34 articles were found, and, after reading them, 9 articles were selected. Results: This review analyzed 9 scientific studies that rigorously met the previously established characteristics in the sample selection. The synthesis included the following aspects (author/year of publication, article title, objective, type of study, and database. Discussion: Several factors that influence the success of intubation were identified, such as technical, professional, and patient issues. In addition, measures to minimize the risks involving the procedure were highlighted. Conclusion: Tracheal intubation is a common procedure in surgical centers and emergencies. However, its risks, while low, should not be ignored. Unsuccessful procedures can occur and have consequences for the patient, such as trauma to the upper airway.

Unexpected difficult intubation with a double-lumen tube in a case of asymptomatic vallecular cyst.

Vallecular cyst (VC) can cause difficult intubation. If a double-lumentube (DLT) has to be placed, difficulty in tracheal intubation becomes more complicated. The gum elastic bougie (GEB) is a widely used device for facilitating tracheal intubation.However, there is not enough study with DLT to make a predictionfor success of GEB-guided intubation. Here, we aimed to describe our approach during unexpected difficult intubation due to VC in a patient required DLT insertion. We emphasize that, in case of confronting a patient with asymptomatic VC as a cause of difficult intubation, a successful DLT intubation is possible by sliding endobronchial lumen of DLT over pediatric GEB.

Evaluation of thyromental height as a predictor of difficult laryngoscopy and difficult intubation: a cross-sectional observational study

Background and objectivesSeveral anthropometric measurements have been suggested to identify a potentially difficult airway. We studied thyromental height (TMH) as a predictor of difficult laryngoscopy and difficult intubation. We also compared TMH, ratio of height to thyromental distance (RHTMD), and thyromental distance (TMD) as predictors of difficult airway. MethodsThis cross-sectional observational study was conducted in 300 adult surgical patients requiring tracheal intubation. Preoperatively airway characteristics were assessed. Standard anesthesia was administered. Degree of difficulty with mask ventilation, laryngoscopic view, duration of laryngoscopy, and difficulty in tracheal intubation (intubation difficulty scale score) were noted. Multivariate logistics regression analysis was performed to identify independent predictors for difficult laryngoscopy. ResultsLaryngoscopy was difficult in 46 of 300 (15.3%) patients; all 46 patients had Cormack-Lehane grade 3 view. Duration of laryngoscopy was 27........11...s in patients with difficult laryngoscopy and 12.7........3.9...s in easy laryngoscopy; p...=...0.001. Multivariate analysis identified that TMH, presence of short neck, and history of snoring were independently associated with difficult laryngoscopy. Incidence of difficult intubation was 17.0%. A shorter TMH was associated with higher IDS scores; r...=...-0.16, p...=...0.001. TMH and duration of laryngoscopy were found to be negatively correlated; a shorter TMH was associated with a longer duration of laryngoscopy; r...=...-0.13, p...=...0.03. The cut-off threshold value for TMH in our study is 4.4 cm with a sensitivity of 66% and a specificity of 54%. ConclusionThyromental height predicts difficult laryngoscopy and difficult intubation.TMD and RHTMD did not prove to be useful as predictors of difficult airway.

English

BACKGROUND Failure in managing the airway is the most important cause of death in patients undergoing general anaesthesia (GA). For effectively preventing airway catastrophe it is essential to have a meticulous airway assessment pre-operatively. Many methods are in use to predict difficult airway like Mallampati, Wilson’s scoring, percentage of glottic opening (POGO) scoring, Cormack - Lehane classification, thyromental distance, mandibular hyoid distance, atlantooccipital joint extension etc. In this study, we compared between two popular methods of airway assessment, upper lip bite test (ULBT) and height to thyromental distance ratio (RHTMD) to predict the difficulty in tracheal intubation. METHODS This descriptive study was conducted at Government Medical college, Thrissur, over a period of one year , on 76 patients of American society of Anaesthesiologist (ASA) - PS l - lll, requiring general anaesthesia. ULBT and RHTMD were used to assess the patient’s airway. It was correlated with Cormack - Lehane classification during direct laryngoscopy. The data was analysed using Fisher exact test (P &lt; 0.05) and Kappa statistics. RESULTS Out of the 76 patients, 41 (53.9%) were women 35 were men (46.1 %). ULBT predicted 89.6 % [25 + 43] belonging to class 1 and 2 as easy, while 10.5 % [8] of class 3 as difficult. RHTMD predicted 35 patients (46 %) as easy (grade 1) and 41 patients (54 %) as grade 2. Using ULBT, of the 8 patients predicted to have difficult intubation (Class 3), 2 were found practically difficult and 6 were easy. In remaining 68 patients, 23 patients had difficult view and 45 had easy view. According to Cormac and Lehane, among 41 patients who predicted difficult by RHTMD, 19 patients were practically difficult and 22 were easy. Of 35 patients, 6 patients were difficult and 29 were easy. CONCLUSIONS The RHTMD is more sensitive compared to ULBT in predicting difficult intubation. As assessed by Cormack - Lehane classification. KEYWORDS Difficult Intubation, Ratio of Height to Thyromental Distance, Upper Lip Bite Test

Evaluation of the Effect of Intubation Box use on Tracheal Intubation Difficulty with King Vision® and Truview Videolaryngoscope in Manikin in a Tertiary Care Hospital.

The procedures of introducing an airway by intubation are associated with increased risk of aerosolisation of SARS-CoV-2 virus, posing a high risk to the personnel involved. Newer and novel methods such as the intubation box have been developed to increase the safety of healthcare workers during intubation. In this study, 33 anaesthesiologist and critical care specialists intubated the trachea of the airway manikin (US Laerdal Medical AS™) 4 times using a King Vision® videolaryngoscope and TRUVIEW PCD™ videolaryngoscope (with and without an intubation box as described by Lai). Intubation time was primary outcome. Secondary outcomes were first-pass intubation success rate, percentage of glottic opening (POGO) score and peak force to maxillary incisors. Intubation time and the number of times a click was heard during tracheal intubation were considerably higher in both groups when an intubation box was used (Table 1). When comparing the two laryngoscopes, the King Vision® videolaryngoscope enabled much less time to intubate than did the TRUVIEW laryngoscope, both with and without the intubation box. (P<0.001) In both laryngoscope groups, first-pass successful intubation was higher without the intubation box, although the difference was statistically insignificant. POGO score was not affected by intubation box but a higher score was observed with King Vision® laryngoscope (Tables 1,2). This study indicates that use of an intubation box makes intubation difficult and increases the time needed to perform it. King Vision® videolaryngoscope results in lesser intubation time and better glottic view as compared to TRUVIEW laryngoscope.