Ultrasound-Guided Airway Evaluation: Is It a Game Changer for Predicting Difficult Endotracheal Intubation?

INTRODUCTION: Airway ultrasound has recently promised to be a valuable addition to preoperative airway assessment tools. This study was undertaken to determine the efficacy of ultrasound-guided measurement of soft tissue thickness (STT) at various levels of the anterior neck in predicting difficult airways in an eastern Indian population. OBJECTIVE:  The primary objective was to find out the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of anterior neck soft tissue thickness at the level of the hyoid (STT-Hyoid) and vocal cords (STT-VC), distance from the skin to the epiglottis midway (DSEM), and the ratio of the depth of the pre-epiglottic space (Pre-E) to the distance from the epiglottis to the mid-point of the vocal cords (E-VC). The secondary objective was to develop a scoring system using these parameters. MATERIALS AND METHODS: One hundred eighty-eight patients aged 18-65 years who received general anesthesia and endotracheal intubation for surgery were included in the study. Anterior neck soft tissue thickness measurements were done preoperatively using ultrasound. The actual difficulty of the airway was graded by the anesthesiologist while performing endotracheal intubation using the intubation difficulty scale (IDS). RESULTS: The incidence of a difficult airway (IDS > 5) was 9.04%. The STT-Hyoid and STT-VC had a moderate correlation with IDS. The DSEM and Pre-E/E-VC ratios had a weak correlation with IDS. For difficult airway prediction, the cutoff points of STT-Hyoid and STT-VC were 7.95 mm and 24.25 mm, respectively. The combined cutoff measurements of STT-Hyoid and STT-VC (29.95 mm) were better predictors of difficult airway. CONCLUSION: Preoperative airway ultrasound examination measuring the soft tissue thickness at the hyoid and vocal cord levels is an effective modality in predicting a difficult airway. However, further studies are needed to validate this finding in populations of varied ethnicity and demographic distribution.

An Inquiry on Airway Management by McCoy Blade with Elevated Tip and Miller Straight Blade with Paraglossal Technique: Relevance for Difficult Airway Management in Current Infectious Times.

Background: Modifications of curved and straight laryngoscope blades have been used for airway management since a long time. While McCoy blade with an elevated tip is commonly used to intubate patients with anticipated difficult airway, the Miller's straight blade is used for intubations in children and less commonly adults. In this study, we revisit the paraglossal technique of Miller's straight blade as a method to improve laryngeal view especially in difficult intubations. Aim: This study aimed to compare laryngoscopic view and ease of intubation (EOI) using McCoy blade elevated tip and Miller's straight blade paraglossal technique. Materials and Methods: A prospective single-blind study was conducted on 170 patients undergoing elective surgery under general anesthesia. They were randomly allotted to two groups. In Group A, laryngoscopy was performed by Miller's blade paraglossal approach, whereas in Group B, laryngoscopy was performed by McCoy blade with an elevated tip. Laryngeal view was graded using the modified Cormack-Lehane grading, and EOI was graded using EOI score. These were compared with preoperative intubation prediction score. Statistical analysis was done using "Medcalc" version 19.0.3. Numerical and categorical data were analyzed by Student's t-test and Chi-square test, respectively. A P < 0.05 was considered statistically significant. Results: The paraglossal approach with Miller's blade offered better laryngoscopic view as compared with McCoy blade with an elevated tip in normal (54.1% vs. 25.9%) and difficult airway (44.7% vs. 11.8%). Tracheal intubation was easier with McCoy blade with an elevated tip although the success rate of intubation improved with the assistance of a bougie with Miller's straight blade paraglossal approach. Conclusion: The laryngeal view was significantly better with the paraglossal approach of Miller's straight blade even in difficult airway. McCoy blade with an elevated tip was also found to be a useful tool to have in difficult airway, as EOI is significantly higher. The study also highlights the usefulness of adjuncts such as a gum elastic bougie while intubating.

Comparison of sensitivity, specificity, and accuracy of Wilson's score and intubation prediction score for prediction of difficult airway in an eastern Indian population-A prospective single-blind study.

INTRODUCTION: Unidentified difficult airway leads to significant adverse events and therefore prediction of a difficult airway is of importance. Independent bedside tests for the prediction of a difficult airway have poor accuracy. The airway assessment scores have not gained popularity as they are cumbersome to perform at the bedside. They also have a varying degree of interobserver variability because of their subjective parameters. Therefore, there is a need to search for a simple score with objective parameters that can be performed at the bedside. AIM: To determine the diagnostic accuracy of the Wilson score andiIntubation prediction score for predicting difficult airway in the Eastern Indian population. MATERIAL AND METHOD: A prospective single-blind study was done including 150 consecutive patients, ASA grade I and II between the ages of 18 and 70 years, undergoing surgery requiring general anesthesia with endotracheal intubation. Preoperatively, the airway was assessed in all patients using Wilson Score and Intubation Prediction Score. General anesthesia with endotracheal intubation was done in all patients. The airway was assessed for ease laryngoscopy and intubation using the Intubation Difficulty Scale. An IDS >5 was taken as difficult airway. The sensitivity, specificity, PPV, NPV, and accuracy of the two predictive tests to predict a difficult was calculated. RESULTS: The sensitivity, positive predictive value and accuracy of Intubation Prediction Score was 77.8%, 58.3%and 90.7% respectively as compared to 38.9%, 25.95% and 78.33% respectively of Wilsons score. CONCLUSION: Intubation Prediction score with its objective parameters can be preferred as a simple and accurate bedside test to predict a difficult airway in an Eastern Indian population.

Laryngeal rhinosporidiosis: An airway catastrophe averted.

Rhinosporidiosis is a type of nasal polypoidal growth arising from the mucosa of nasal cavity and often extending to nasopharynx. Occasionally, this growth may invade the lower airways and cause airway obstruction. The clinical presentation of such cases is often contradictory and airway management during induction of anesthesia requires caution to prevent potential life-threatening situations. A case of large pedunculated rhinosporidiosis involving the epiglottis and laryngeal inlet, with significant airway management challenge has been presented here. Clinical significance: Primary care physicians should be diligent in evaluating patients with rhinosporidiosis and look for signs of airway obstruction to rule out lower airway involvement.

Trigeminal Neuralgia in Pregnancy: A Management Challenge.

Pregnancy is known to aggravate pre-existing chronic painful conditions. Trigeminal neuralgia (TN), albeit a disease of the elderly, may afflict pregnant females, which can further complicate its management. Teratogenic effects of the commonly used drugs on the developing fetus limit pharmacological treatment. Moreover, safety of commonly performed interventional therapies is marred by their inherent fetomaternal effects and more importantly the risk for radiation effects on the fetus due to the use of fluoroscopy. This rare coexistence of TN in pregnancy has not been reported before. Here we present a case of TN in a young woman, whose pain was aggravated when she became pregnant, and she was treated successfully by conventional radiofrequency ablation of the Gasserian ganglion.