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Objective:Though airway ultrasonography (USG) is used to assess difficult laryngoscopy (DL), there is still ambiguity about approach followed and parameters assessed. There is need of a simple, stepwise sonographic assessment with clearly defined parameters for DL prediction. The primary objective of this study was to find diagnostic accuracy of sonographic parameters measured by a stepwise Airway-USG in DL prediction (DLP).Methods:This prospective, observational cohort study was done in 217 elective surgical adult patients administered general anaesthesia with tracheal intubation using conventional laryngoscopy from 1st May 2019 to 31st July 2020, after ethical approval. A sagittal Airway-USG was done using 2-6 Hz transducer in three steps specifying probe placement and head position. Demographic, clinical and Airway-USG measurements were noted. Correlation of the clinical/sonographic parameters was made with Cormack-Lehane score on DL. After receiver operating characteristic curve plotting, the sensitivity, specificity, positive predictive value, negative predictive value (NPV) of DL was calculated for each parameter using open-epi software.Results:DL was observed in 19/217 patients. Airway-USG parameters of skin to epiglottis distance >2.45 cm, hyomental distance with head extension 3.93 cm and maximum skin to tongue distance >5.45 cm were statistically significant in predicting DL. DLP score with presence of >3 positive parameters showed 98% specificity, 98% NPV and 96% diagnostic accuracy to predict DL.Conclusion:DLP score derived from Airway-USG may be used as a screening and diagnostic tool for DL.

Objective: Though airway ultrasonography (USG) is used to assess difficult laryngoscopy (DL), there is still ambiguity about approach followed and parameters assessed. There is need of a simple, stepwise sonographic assessment with clearly defined parameters for DL prediction. The primary objective of this study was to find diagnostic accuracy of sonographic parameters measured by a stepwise Airway- USG in DL prediction (DLP). Methods: This prospective, observational cohort study was done in 217 elective surgical adult patients administered general anaesthesia with tracheal intubation using conventional laryngoscopy from 1st May 2019 to 31st July 2020, after ethical approval. A sagittal Airway- USG was done using 2-6 Hz transducer in three steps specifying probe placement and head position. Demographic, clinical and Airway- USG measurements were noted. Correlation of the clinical/sonographic parameters was made with Cormack-Lehane score on DL. After receiver operating characteristic curve plotting, the sensitivity, specificity, positive predictive value, negative predictive value (NPV) of DL was calculated for each parameter using open-epi software. Results: DL was observed in 19/217 patients. Airway-USG parameters of skin to epiglottis distance >2.45 cm, hyomental distance with head extension <5.13 cm, head neutral <4.5 cm, their ratio <1.18, maximum tongue thickness >3.93 cm and maximum skin to tongue distance >5.45 cm were statistically significant in predicting DL. DLP score with presence of >3 positive parameters showed 98% specificity, 98% NPV and 96% diagnostic accuracy to predict DL. Conclusion: DLP score derived from Airway-USG may be used as a screening and diagnostic tool for DL. [ABSTRACT FROM AUTHOR]

Objective: The authors aimed to determine the interobserver reliability during routine preoperative airway assessments by experienced and inexperienced assessors. For the current, Thai registered-nurse-anesthetist-student training curriculum for preoperative airway assessment classes, the accuracy of airway evaluations performed by those trainees has not yet been evaluated. Methods: An experienced anesthesiologist, a resident, a nurse anesthetist and thirty-one registered nurse anesthetist students were enrolled in a prospective observational study to assess eight obese and ten lean volunteers using seven airway assessment methods at the beginning of an academic year. The sternomental distance (SMD), the thyromental distance (TMD), the hyomental distance (HMD), the inter-incisor gap (IIG), malformation of the teeth, the Mallampati classification (MPT) and the range of neck movement (RNM) were assessed. Interobserver reliability was determined using intraclass correlation coefficient (ICC) and kappa coefficient (K). Results: Higher strengths of interobserver agreements; and good to very good agreements were found among the two, more experienced assessors, namely, the resident and the nurse anesthetist. When seven airway assessment methods were evaluated by registered nurse anesthetist students, the interobserver agreements ranged from poor to moderate. For the subgroup analysis of lean and obese volunteers, higher reliabilities of airway assessments were found for the lean volunteers. Conclusion: The accuracies of the airway assessments performed by the registered nurse anesthetist students were lower than those of the more-experienced groups. Thus, there is some room for improvement in the current nurse- anesthetist curriculum.

Background: The upper airway is an extraordinarily complex anatomical region. Anticipating and preparing for difficulty in airway management is crucial to avoid airway catastrophes. Objective: Aim of our study was to evaluate the combination of El-Ganzouri airway risk index (EGRI) with the ultrasound of the airway (measuring the hyomental distance and distance from epiglottis to midpoint between the two vocal cords) as a fast, easy and noninvasive method in the examination of the airway and prediction of difficult airway. Patients and methods: Preoperative airway assessment will be carried out for 60 adult patients randomly allocated in Al-Azhar University Hospitals. Results: The hyomental distance at cutoff point of 5.6 cm, (below which the intubation difficulty is high), sensitivity and specificity of Cormack-Lehane grade with hyomental distance in study group was75.0% and 94.4% respectively with accuracy of 85%. For the epiglottis to vocal cord distance the cut off value of = 1.2 (below which the intubation difficulty is high) the sensitivity of epiglottis to vocal cord distance was 75.0% and the specificity was 100% with accuracy of 92%. Conclusion: We concluded that combination of EGRI with epiglottis to vocal cord distance and hyomental distance is a very sensitive and specific tool for prediction of difficult airway and may be superior to standard methods of assessment. [ABSTRACT FROM AUTHOR]

Objective: The authors aimed to determine the interobserver reliability during routine preoperative airway assessments by experienced and inexperienced assessors. For the current, Thai registered-nurse-anesthetist-student training curriculum for preoperative airway assessment classes, the accuracy of airway evaluations performed by those trainees has not yet been evaluated. Methods: An experienced anesthesiologist, a resident, a nurse anesthetist and thirty-one registered nurse anesthetist students were enrolled in a prospective observational study to assess eight obese and ten lean volunteers using seven airway assessment methods at the beginning of an academic year. The sternomental distance (SMD), the thyromental distance (TMD), the hyomental distance (HMD), the inter-incisor gap (IIG), malformation of the teeth, the Mallampati classification (MPT) and the range of neck movement (RNM) were assessed. Interobserver reliability was determined using intraclass correlation coefficient (ICC) and kappa coefficient (K). Results: Higher strengths of interobserver agreements; and good to very good agreements were found among the two, more experienced assessors, namely, the resident and the nurse anesthetist. When seven airway assessment methods were evaluated by registered nurse anesthetist students, the interobserver agreements ranged from poor to moderate. For the subgroup analysis of lean and obese volunteers, higher reliabilities of airway assessments were found for the lean volunteers. Conclusion: The accuracies of the airway assessments performed by the registered nurse anesthetist students were lower than those of the more-experienced groups. Thus, there is some room for improvement in the current nurse-anesthetist curriculum.

Background: There are few predictors of difficult mask ventilation and a simple, objective, predictive system to identify patients at risk of difficult mask ventilation does not currently exist. We present a retrospective - subgroup analysis aimed at identifying predictive factors for difficult mask ventilation (DMV) in patients undergoing pre-operative airway assessment before elective surgery at a major teaching hospital. Methods: Data for this retrospective analysis were derived from a database of airway assessments, management plans, and outcomes that were collected prospectively from August 2008 to May 2010 at a Level 1 academic trauma center. Patients were stratified into two groups based on the difficulty of mask ventilation and the cohorts were analyzed using univariate analysis and stepwise selection method. Results: A total of 1399 pre-operative assessments were completed with documentation stating that mask ventilation was attempted. Of those 1399, 124 (8.9%) patients were found to be difficult to mask ventilate. A comparison of patients with and without difficult mask ventilation identified seven risk factors for DMV: age, body mass index (BMI), neck circumference, history of difficult intubation, presence of facial hair, perceived short neck and obstructive sleep apnea. Although seven risk factors were identified, no individual subject had more than four risk factors. Conclusion: The results of this study confirm that in a real world clinical setting, the incidence of DMV is not negligible and suggest the use of a simple bedside predictive score to improve the accuracy of DMV prediction, thereby improving patient safety. Further prospective studies to validate this score would be useful.

There have been many contradicting studies as to how well preoperative airway assessments predict difficult intubation. One of these measures, thyromental distance (TMD), has often been called into question. However, there have been no published studies evaluating whether anesthesia practitioners are measuring TMD accurately, especially if they use fingerbreadths as opposed to a centimeter ruler. A convenience sample of 60 anesthesia providers were asked to participate in a brief study. The subjects were asked a series of questions, including the type of anesthesia provider they were, how often they used TMD, and their estimates in centimeters of the following fingerbreadth combinations: index finger, index and second finger, index plus second and third fingers, and index plus second, third, and fourth fingers. After their estimates were recorded, exact measurements of the fingerbreadth combinations were made at the distal interphalangeal (DIP) joints. The differences between the means of the estimated and the actual measurements were analyzed using an independent t test. There was a statistically significant difference between estimated and actual fingerbreadth measurement for the index finger (P < .006) but not for the combinations of fingers. [ABSTRACT FROM AUTHOR]