Long-Term Outcomes of Cricothyroidotomy Versus Endotracheal Intubation in Military Personnel: A Retrospective Comparative Analysis Cohort Study.

INTRODUCTION: Emergency airway management is critical in trauma care. Cricothyroidotomy (CRIC) is a salvage procedure commonly used in failed endotracheal intubation (ETI) or difficult airway cases. However, more data is needed regarding the short and long-term complications associated with CRIC. This study aimed to evaluate the Israel Defense Forces experience with CRIC over the past 2 decades and compare the short-term and long-term sequelae of prehospital CRIC and ETI. METHODS: Data on patients undergoing either CRIC or ETI in the prehospital setting between 1997 and 2021 were extracted from the Israel Defense Forces trauma registry. Patient data was then cross-referenced with the Israel national trauma registry, documenting in-hospital care, and the Israel Ministry of Defense rehabilitation department registry, containing long-term disability files of military personnel. RESULTS: Of the 122 patients with short-term follow-up through initial hospitalization, 81% underwent prehospital ETI, while 19% underwent CRIC. There was a higher prevalence of military-related and explosion injuries among the CRIC patients (96% versus 65%, P = 0.02). Patients who underwent CRIC more frequently exhibited oxygen saturations below 90% (52% versus 29%, P = 0.002). Injury Severity Score was comparable between groups.No significant difference was found in intensive care unit length of stay and need for tracheostomy. Regarding long-term complications, with a median follow-up time of 15 y, CRIC patients had more upper airway impairment, with most suffering from hoarseness alone. One patient in the CRIC group suffered from esophageal stricture. CONCLUSIONS: This retrospective comparative analysis did not reveal significant short or long-term sequelae among military personnel who underwent prehospital CRIC. The long-term follow-up did not indicate severe aerodigestive impairments, thus suggesting that this technique is safe. Along with the high success rates attributed to this procedure, we recommend that CRIC remains in the armamentarium of trauma care providers. The findings of this study could provide valuable insights into managing difficult airway in trauma care and inform clinical decision-making in emergency settings.

Efficacy of Cricoid Pressure Application during Esophagogastroduodenoscopy in Patients with Poor Gastric Wall Extension.

INTRODUCTION: Esophagogastroduodenoscopy (EGD) requires adequate air infusion. However, cases of poor gastrointestinal wall extension due to frequent eructation have been reported. Sufficient gastrointestinal wall extension can be achieved by applying cricoid pressure during EGD. Herein, we evaluated the frequency of cases with poor gastrointestinal wall extension and the efficacy and safety of applying cricoid pressure during EGD. METHODS: This interventional study included patients who underwent EGD between January 2020 and December 2020 at the JA Akita Koseiren Yuri Kumiai General Hospital. Cases wherein folds of the greater curvature of the upper gastric body were not sufficiently extended during EGD were considered to have poor gastrointestinal wall extension. In such cases, air infusion was performed while applying cricoid pressure. This procedure was considered effective when gastric wall extension was achieved. RESULTS: A total of 2,000 patients were enrolled and underwent upper gastrointestinal endoscopy; however, five were excluded because of upper gastrointestinal tract stenosis. Observation of gastric wall extension of the greater curvature in the upper gastric body with normal air insufflation was difficult in 113 (5.7%) cases. Applying cricoid pressure was effective in 93 (82.3%) patients with poor gastric wall extension. Sufficient gastric wall extension was achieved within an average of 12.8 s in cases where cricoid pressure application was effective. No adverse events were associated with cricoid pressure application. CONCLUSIONS: Cricoid pressure application for patients with poor gastric wall extension during EGD is useful for ensuring a sufficient field of view during observation of the gastric body.

Palpation Versus Ultrasonography for Identifying the Cricothyroid Membrane in Case of a Laterally Deviated Larynx: A Randomized Trial.

BACKGROUND: Large neck circumference and displacement of the trachea due to pathology increase the risk of failed identification of the cricothyroid membrane and cricothyroidotomy. We investigated whether ultrasound aids in the successful identification of the cricothyroid membrane in a model of an obese neck with midline deviation of the trachea. METHODS: We developed silicone neck models that were suitable for both palpation and ultrasonography and where the trachea deviated laterally from the midline to either side. After reading a book chapter and participating in a 25-minute lecture and a 15- to 23-minute hands-on demonstration and rehearsal of ultrasonography for identification of the cricothyroid membrane, anesthesiologists and anesthesiology residents randomly performed identification with either ultrasound or palpation on 1 of 2 neck models. RESULTS: We included 57 participants, of whom 29 and 28 were randomized to palpation and ultrasound, respectively. Correct identification of the cricothyroid membrane was achieved by 21 (75.0%) vs 1 (3.5%) of participants in the ultrasound versus palpation groups (risk ratio [RR], 21.8 [95% confidence interval {CI}, 3.1-151.0]). The tracheal midline position in the sagittal plane was identified correctly by 24 (85.7%) vs 16 (55.2%) of participants in the ultrasound versus palpation groups (RR, 1.6 [95% CI, 1.1-2.2]). CONCLUSIONS: Identification of the cricothyroid membrane in a model of an obese neck with midline deviation of the trachea was more often successful with ultrasound compared to palpation. Our study supports the potential use of ultrasound before induction of anesthesia and airway management in this group of patients, and it may even be applied in emergency situations when ultrasound is readily available. Further studies in human subjects should be conducted.

Comparison of the effects of paratracheal pressure and cricoid pressure on placement of the i-gel® supraglottic airway: a randomized clinical trial.

PURPOSE: Anesthesiologists can use supraglottic airway devices as a rescue technique for failed intubation even in patients with an increased risk of gastric regurgitation. In this randomized study, we aimed to evaluate the effects of cricoid pressure and paratracheal pressure on placement of the i-gel® (Intersurgical Ltd., Wokingham, Berkshire, UK). METHODS: After induction of anesthesia in 76 adult patients, we inserted the i-gel under paratracheal or cricoid pressure, and assessed the success rate of i-gel insertion, resistance during insertion, time required for insertion, accuracy of the insertion location, tidal volumes, and peak inspiratory pressure with or without each maneuver after i-gel insertion. RESULTS: The overall success rate of insertion was significantly higher under paratracheal pressure than under cricoid pressure (36/38 [95%] vs 27/38 [71%], respectively; difference, 24%; 95% confidence interval [CI], 8 to 40; P = 0.006]. Resistance during insertion was significantly lower under paratracheal pressure than under cricoid pressure (P < 0.001). The time required for insertion was significantly shorter under paratracheal pressure than under cricoid pressure (median [interquartile range], 18 [15-23] sec vs 28 [22-38] sec, respectively; difference in medians, -10; 95% CI, -18 to -4; P < 0.001). Fibreoptic examination of the anatomical alignment of the i-gel in the larynx revealed no significant difference in the accuracy of the insertion location between the two maneuvers (P = 0.31). The differences in tidal volume and peak inspiratory pressure with or without the maneuvers were significantly lower with paratracheal pressure than with cricoid pressure (P = 0.003, respectively). CONCLUSIONS: Insertion of the i-gel supraglottic airway was significantly more successful, easier, and faster while applying paratracheal pressure than cricoid pressure. STUDY REGISTRATION: ClinicalTrials.gov (NCT05377346); first submitted 11 May 2022.

RéSUMé: OBJECTIF: Les anesthésiologistes peuvent utiliser des dispositifs supraglottiques comme technique de sauvetage en cas d'échec de l'intubation, même chez les personnes présentant un risque accru de régurgitation gastrique. Dans cette étude randomisée, nous avons cherché à évaluer les effets de la pression cricoïdienne et de la pression paratrachéale sur le positionnement du dispositif i-gel® (Intersurgical Ltd., Wokingham, Berkshire, Royaume-Uni). MéTHODE: Après l'induction de l'anesthésie chez 76 adultes, nous avons inséré l'i-gel en utilisant une pression paratrachéale ou cricoïdienne, et avons évalué le taux de réussite de l'insertion de l'i-gel, la résistance pendant l'insertion, le temps nécessaire à l'insertion, la précision de l'emplacement d'insertion, les volumes courants ainsi que la pression inspiratoire maximale avec ou sans chacune des manœuvres après l'insertion de l'i-gel. RéSULTATS: Le taux global de réussite de l'insertion était significativement plus élevé avec une pression paratrachéale qu'avec une pression cricoïdienne (36/38 [95 %] vs 27/38 [71 %], respectivement; différence, 24 %; intervalle de confiance [IC] à 95 %, 7,6 à 39,8; P = 0,006]. La résistance lors de l'insertion était significativement plus faible en utilisant une pression paratrachéale par rapport à une pression cricoïdienne (P < 0,001). Le temps nécessaire à l'insertion était significativement plus court après avoir exercé une pression paratrachéale plutôt que cricoïdienne (médiane [écart interquartile], 18,4 [15,3­23,1] secondes vs 28,4 [22,3 à 37,8] secondes, respectivement; différence dans les médianes, −10,0; IC 95 %, −18,4 à −3,6; P < 0,001). L'examen par fibre optique de l'alignement anatomique de l'i-gel dans le larynx n'a révélé aucune différence significative dans la précision de l'emplacement d'insertion entre les deux manœuvres (P = 0,31). Les différences de volume courant et de pression inspiratoire maximale avec ou sans les manœuvres étaient significativement plus faibles avec la pression paratrachéale qu'avec la pression cricoïdienne (P = 0,003, respectivement). CONCLUSION: L'insertion du dispositif supraglottique i-gel a été significativement plus réussie, plus facile et plus rapide lors de l'application d'une pression paratrachéale que d'une pression cricoïdienne. ENREGISTREMENT DE L'éTUDE: ClinicalTrials.gov (NCT05377346); soumis pour la première fois le 11 mai 2022.

The Effect of an Increasing Subglottal Stenosis Constriction That Extends From the Vocal Folds to the Inferior Border of the Cricoid Cartilage.

Acquired subglottal stenosis is an unpredicted complication that can occur in some patients who have undergone prolonged endotracheal intubation. It is a narrowing of the airway at the level of the cricoid cartilage that can restrict airflow and cause breathing difficulty. Stenosis is typically treated with endoscopic airway dilation, with some patients experiencing multiple recurrences. The study highlights the potential of computational fluid dynamics as a noninvasive method for monitoring subglottic stenosis, which can aid in early diagnosis and surgical planning. An anatomically accurate human laryngeal airway model was constructed from computerized tomography (CT) scans. The subglottis cross-sectional area was narrowed systematically using ≈10% decrements. A quadratic profile was used to interpolate the transformation of the airway geometry from its modified shape to the baseline geometry. The numerical results were validated by static pressure measurements conducted in a physical model. The results show that airway resistance follows a squared ratio that is inversely proportional to the size of the subglottal opening (R∝A-2). The study found that critical constriction occurs in the subglottal region at 70% stenosis (upper end of grade 2). Moreover, removing airway tissue below 40% stenosis during surgical intervention does not significantly decrease airway resistance.

Congenital crico-thyroid dysplasia: a comprehensive description.

INTRODUCTION: We describe a first case of human congenital crico-thyroid dysplasia associated to a right sided aortic arch and an aberrant subclavian artery. CASE PRESENTATION: Our patient presented with a two-weeks history of acute dyspnea, and reported hoarseness since his childhood. An urgent tracheotomy was performed, followed by direct laryngoscopy. Endoscopic examination showed a deviation of the dorsoventral axis of the larynx, with an obstructive submucosal swelling the area of the right false cord and aryepiglottic fold. Computed tomography conducted the following day confirmed the crico-thyroid dysplasia, an infected laryngocele, and the presence of a right sided aortic arch and an aberrant subclavian artery. CONCLUSION: The embryological basis of these anomalies is attributed to congenital defects of the development of the fourth and sixth pharyngeal arches. To our knowledge, the congenital crico-thyroid dysplasia has not been previously reported in human. This case underscores the importance of recognizing anatomical variations in laryngeal cartilages, understanding their embryological origins, and potential associated malformations.

The previously undescribed variant of the thyrohyoid muscle and its potential impact on surgical procedures.

The thyrohyoid muscle belongs to the infrahyoid group located in the carotid triangle. It normally originates from thyroid cartilage and inserts into hyoid bone. Quite often, it is continuous with the sternohyoid muscle. Furthermore, there are variants that have their origin in the cricoid cartilage only, however, this occurs very rarely. During anatomical dissection, a two-headed variant of this muscle was found. One head had its origin in the cricoid cartilage and the other in the thyroid cartilage. This variant of thyrohyoid had not been previously described in the available literature. Therefore, we believe that it may be referred to as the cricothyrohyoid muscle. As the thyrohyoideus is often used as a landmark during surgical procedures in the prelaryngeal area and as a muscle graft, a thorough knowledge of its anatomy and variation is extremely important. We speculate that the two-headed version of this muscle may be problematic during surgical procedures in this region, however, it may also provide more options as a muscular graft.

Radiological assessment of the dissection area in supraomohyoid neck dissection.

PURPOSE: The current supraomohyoid neck dissection (SOHND) is performed above the omohyoid muscle to dissect levels I, II, and III in the levels of cervical lymph nodes. However, the anatomical boundary between levels III and IV is the inferior border of the cricoid cartilage. We investigated the anatomical relationship between the omohyoid muscle and cricoid cartilage using contrast-enhanced CT (CE-CT) images to assess the validity of the current SOHND. METHODS: CE-CT images of the head and neck regions in patients were reviewed. The patients were divided into two groups: "malignant tumors" and "others". The vertebral levels corresponding to the positions of anatomical structures such as the intersection of the omohyoid muscle and internal jugular vein (OM-IJ), and the inferior border of the cricoid cartilage (CC), were recorded. RESULTS: The OM-IJ was located around the seventh cervical to the first thoracic vertebra. There was a significant difference between the malignant tumor and others groups in females (p = 0.036). The CC was located around the sixth to seventh cervical vertebrae. There was a significant sex difference in each group (malignant tumor: p < 0.0001; others: p = 0.008). Both sexes tended to have lower OM-IJ than CC, and females had significantly lower OM-IJ than males. CONCLUSION: This study provides clear anatomical evidence showing the difference between the SOHND dissection area and levels I, II, and III. It could be considered that in most cases SOHND invades level IV, not just levels I, II, and III, especially in female patients.

[Help, I can't burp! A brief overview and case discussion of retrograde cricopharyngeal dysfunction]. / Hilfe, ich kann nicht rülpsen: Falldarstellung und Kurzübersicht zur retrograden krikopharyngealen Dysfunktion.

In this short communication, we discuss the recently described syndrome of retrograde cricopharyngeal dysfunction (R-CPD) with its first description in 2019 by the laryngologist Dr. Bastian. Diagnosis is generally based on typical clinical symptoms, e.g., the inability to belch, a bloated abdomen and retrosternal gurgling noises. We also describe high-resolution esophageal manometry as a new tool to further secure the diagnosis of R­CPD, as well as therapeutic options such as botulinum toxin injections in the cricopharyngeal muscle or cricopharyngeal myotomy and the published data thereon.

The Effect of Thyroid Surgery on the Accuracy of Palpation-Based Cricothyroid Membrane Identification in Female Patients: A Prospective Observational Cohort Study.

Background and Objectives: This study examined how a history of thyroid surgery impacts the precision of cricothyroid membrane (CTM) identification through palpation (validated by ultrasound) in female patients visiting the operating room for surgeries unrelated to neck procedures. Materials and Methods: This prospective observational cohort study enrolled adult female patients undergoing elective non-neck surgery, dividing them into control (no thyroid surgery history; n = 40) and experimental (with thyroid surgery history; n = 40) groups. CTM identification was performed by palpation and confirmed via ultrasound. Results: There were no significant differences between two groups in the demographic characteristics of the patients. The success rate and accuracy of CTM identification through palpation were significantly higher in the control group compared to the experimental group (90% vs. 42.5%, respectively; p < 0.001). For female patients with a history of thyroid surgery, the sensitivity of successful CTM palpation was 42.5%, and the specificity was 10%. These figures are based on the calculated true positives (17), false positives (36), true negatives (4), and false negatives (23). Conclusions: Thyroid surgery history in female patients may hinder the accurate palpation-based identification of the CTM, suggesting a need for enhanced clinical practices and considerations during airway management training.

T-tube implantation combined with cricoid cartilage reconstruction in the treatment of congenital laryngeal webs with subglottic stenosis.

OBJECTIVE: To discuss the presentation, evaluation, and management of congenital laryngeal webs with subglottic stenosis. METHODS: The clinical data of six children were retrospectively analyzed. RESULTS: The median age of these children who came to our hospital was 14 months (range 1-26 months). A tracheotomy was performed in all these six children. The median age of the patients who underwent tracheotomy was 4 months (range 1-11 months). The surgical method was T-tube implantation combined with cricoid cartilage reconstruction. The median age of these patients at the time of operation was 22 months (range 13-35 months). The T-tube remained in place for 3-8 months, with a median time of 6 months. The tracheal tubes in all these children were successfully removed. All patients were followed up for more than 2 years without recurrence. CONCLUSIONS: Children who have congenital laryngeal webs with subglottic stenosis required early tracheotomy. Open laryngoplasty combined with T-tube implantation and cricoid cartilage reconstruction may play a crucial role in the treatment of these children.

Cricopharyngeal muscle origin transection for oropharyngeal dysphagia, a novel surgical technique.

BACKGROUND: Cricopharyngeal myotomy improves pharyngeal dysphagia by resecting the cricopharyngeal muscle. METHODS: Our procedure, cricopharyngeal muscle origin transection (CPM-OT) is performed through a midline skin incision at the cricoid cartilage level under local anesthesia. CONCLUSIONS: Sixteen patients demonstrated preservation of vocal fold movement without laryngeal nerve injury immediately after CPM-OT in the awake state during aspiration prevention surgery using the glottic closure technique. Postoperative videofluoroscopic examination of swallowing revealed the cricopharyngeal bar was absent and pharyngeal passage of the bolus and Food Intake LEVEL Scale was improved in all patients. CPM-OT is a feasible and less invasive treatment option.

Equivalence of the top-down manoeuvre and bottom-up manoeuvre in speed and accuracy of identifying the cricothyroid membrane: a prospective randomised cross-over study.

BACKGROUND: Accurate identification of the cricothyroid membrane is crucial for successful cricothyrotomy; however, a manoeuvre that helps identify it both accurately and quickly remains unclear. The effectiveness of the so-called 'bottom-up manoeuvre' has never been investigated. This study aimed to examine whether the bottom-up manoeuvre is as rapid and accurate as the conventional 'top-down manoeuvre' at identifying the cricothyroid membrane. METHODS: This study was a prospective randomised cross-over trial conducted at an academic medical centre between 2018 and 2019. Fifth-year medical students participated. The students were trained in the use of either the top-down manoeuvre or the bottom-up manoeuvre first. Each student subsequently performed the technique once on a volunteer. The students were then taught and practiced the other manoeuvre as well. The accuracy of cricothyroid membrane identification and the time taken by successful participants only were measured and compared between the manoeuvres using equivalence tests with two one-sided tests. RESULTS: A total of 102 medical students participated in this study and there was no missing data. The accuracy of identification and time required for success were similar between the top-down manoeuvre and the bottom-up manoeuvre (65.7% vs. 70.6%, taking 13.8 s [interquartile range (IQR): 9.4-17.5] vs. 15.5 s [IQR: 11.5-19.9], respectively). The success rate was statistically equivalent (rate difference, 4.9%; 90% confidence interval [CI], -5.8 to 15.6; equivalence margin, -20.0 to 20.0). The time required for success was also statistically equivalent (median difference, 1.7 s; 90% CI, -0.2 to 3.3; equivalence margin, -4.0 to 4.0). CONCLUSION: Among students first trained in both manoeuvres for identifying the cricothyroid membrane, the speed and accuracy of identification were similar between those using the bottom-up manoeuvre and those using the top-down manoeuvre.

[Histomorphometric characteristics of age-related changes in cricoid cartilage.]

The paper presents the results of a histomorphometric study of age-related changes in hyaline cartilage tissue by the example of studying cricoid cartilage from 88 corpses of males of various ages. A comparative assessment of the parameters between the groups was carried out and the dynamics of age-related changes in the main ones was studied. As a result of the studies, the greatest correlation with age was recorded in the following indicators: length (r=0,88) and width (r=0,89) of the ossification zone, the area of bone (r=0,87), adipose (r=0,77) and reticular tissue (r=0,86), the number of chondroblasts (r=-0,7). It was found that the transformations of cricoid cartilage occurring with age are characterized by a decrease in the area of cartilage tissue, the average number of chondrocytes and chondroblasts also tends to decrease steadily with increasing age. Age-related bone tissue transformations are characterized by an increase in the area of bone tissue and the transformation of the tissue structure itself: the number of bone beams and their dimensional characteristics (length and width) change. The results of the study allow us to evaluate the age dynamics of quantitative markers of involution processes of hyaline cartilage tissue in men by the example of studying cricoid cartilage and supplement the existing ideas about the pathogenesis of age-associated cartilage diseases.

Low Grade Laryngeal Chondrosarcoma of the Cricoid Cartilage: A Case Report.

INTRODUCTION: Laryngeal chondrosarcomas are an extremely rare class of tumor accounting for only 1% of all laryngeal tumors. The cricoid cartilage is the most common cartilage from which laryngeal chondrosarcomas arise however, it is also the most difficult to treat as the cricoid cartilage is vital for structural support in the larynx. In this study, we describe a case of low-grade laryngeal chondrosarcoma that arose in the cricoid cartilage and was treated with laser resection while retaining full function of the larynx. CASE REPORT: The patient was a 61-year-old man who presented with a two-year history of hoarseness and recent intermittent swelling of the neck. After initial exam, a CT scan was ordered and showed a 2.7 cm calcified mass in the patient's larynx. Subsequent bronchoscopy found a dome shaped mass of the cricoid cartilage resulting in a 50% airway reduction. A biopsy was taken and diagnosed as low-grade laryngeal chondrosarcoma. Laser resection by way of anterior commissure laryngoscope was determined to be the best treatment course as it would result in the best chance of functional retention. Using this method, the mass was debulked to the point that a ridged Hopkins rod telescope could be passed through the airway although complete resection was not possible. The patient reported significant improvement to his symptoms. This improvement was sustained 5 months post- operatively and the mass showed no signs of progression to that point. CONCLUSIONS: This case presented a rare tumor in a location where functional retention is difficult. Through laser resection, the tumor was removed with complete functional retention and abolition of symptoms. Though recurrence is an ever-present possibility, the low grade of the tumor combined with the slow progression of symptoms pre-operatively suggests this surgery could provide extended relief of symptoms.

[Age determination by microstructural features of human cricoid cartilage]. / Opredelenie vozrasta po mikrostrukturnym parametram perstnevidnogo khryashcha cheloveka.

THE AIM OF THE STUDY: Was to develop the age determination's technology by the morphometric features of the human cricoid cartilage using a regression analysis method. Cricoid cartilages of 65 variously-aged males were examined. The number of histomorphometric parameters equal 16 for each sample were determined and measured on the histological sections. A descriptive statistical processing of data using the regression analysis method was done, as a result of which the model of age determination was developed. This model has a high predictive accuracy, where the prediction error was less than 5 years in 64.62% of cases. The practical use of this model may be limited by the morphometric parameters' number translating complication to calculate the formula. The developed method can be improved while increasing the sample and conducting further statistical processing, and in the future it can be used in the age determination in forensic medical examination.

Success and Time to Oxygen Delivery for Scalpel-Finger-Cannula and Scalpel-Finger-Bougie Front-of-Neck Access: A Randomized Crossover Study With a Simulated "Can't Intubate, Can't Oxygenate" Scenario in a Manikin Model With Impalpable Neck Anatomy.

BACKGROUND: Emergency front-of-neck access (FONA) is particularly challenging with impalpable neck anatomy. We compared 2 techniques that are based on a vertical midline neck incision, followed by finger dissection and then either a cannula or scalpel puncture to the cricothyroid membrane. METHODS: A manikin simulation scenario of impalpable neck anatomy and bleeding was created. Sixty-five anesthesiologists undergoing cricothyrotomy training performed scalpel-finger-cannula (SFC) and scalpel-finger-bougie (SFB) cricothyrotomy in random order. Primary outcomes were time to oxygen delivery and first-attempt success; data were analyzed using multilevel mixed-effects models. RESULTS: SFC was associated with a shorter time to oxygen delivery on univariate (median time difference, -61.5 s; 95% confidence interval [CI], -84.7 to -38.3; P < .001) and multivariable (mean time difference, -62.1 s; 95% CI, -83.2 to -41.0; P < .001) analyses. Higher first-attempt success was reported with SFC than SFB (47 of 65 [72.3%] vs 18 of 65 [27.7%]). Participants also had higher odds at achieving first-attempt success with SFC than SFB (odds ratio [OR], 10.7; 95% CI, 3.3-35.0; P < .001). Successful delivery of oxygen after the "can't intubate, can't oxygenate" (CICO) declaration within 3 attempts and 180 seconds was higher (84.6% vs 63.1%) and more likely with SFC (OR, 5.59; 95% CI, 1.7-18.9; P = .006). Analyzing successful cases only, SFC achieved a shorter time to oxygen delivery (mean time difference, -24.9 s; 95% CI, -37.8 to -12.0; P < .001), but a longer time to cuffed tube insertion (mean time difference, +56.0 s; 95% CI, 39.0-73.0; P < .001). After simulation training, most participants preferred SFC in patients with impalpable neck anatomy (75.3% vs 24.6%). CONCLUSIONS: In a manikin simulation of impalpable neck anatomy and bleeding, the SFC approach demonstrated superior performance in oxygen delivery and was also the preferred technique of the majority of study participants. Our study findings support the use of a cannula-based FONA technique for achieving oxygenation in a CICO situation, with the prerequisite that appropriate training and equipment are available.

Effectiveness of Cricoid and Paratracheal Pressures in Occluding the Upper Esophagus Through Induction of Anesthesia and Videolaryngoscopy: A Randomized, Crossover Study.

BACKGROUND: Maneuvers for preventing passive regurgitation of gastric contents are applied to effectively occlude the esophagus throughout rapid sequence induction and intubation. The aim of this randomized, crossover study was to investigate the effectiveness of cricoid and paratracheal pressures in occluding the esophagus through induction of anesthesia and videolaryngoscopy. METHODS: After the induction of anesthesia in 40 adult patients, the location of the esophageal entrance relative to the glottis and location of the upper esophagus relative to the trachea at the low paratracheal region were assessed using an ultrasonography, and the outer diameter of the esophagus was measured on ultrasound before and during application of cricoid and paratracheal pressures of 30 N. Then, videolaryngoscopy was performed with the application of each pressure. During videolaryngoscopy, location of the esophageal entrance relative to the glottis under cricoid pressure was examined on the screen of videolaryngoscope, and the upper esophagus under paratracheal pressure was evaluated using ultrasound. The occlusion rate of the esophagus, and the best laryngeal view using the percentage of glottic opening scoring system were also assessed during videolaryngsocopy. Esophageal occlusion under each pressure was determined by inserting an esophageal stethoscope into the esophagus. If the esophageal stethoscope could not be advanced into the esophagus under the application of each pressure, the esophagus was regarded to be occluded. RESULTS: During videolaryngoscopy, esophagus was occluded in 40 of 40 (100%) patients with cricoid pressure and 23 of 40 (58%) patients with paratracheal pressure (difference, 42%; 95% confidence interval, 26-58; P < .001). Both cricoid and paratracheal pressures significantly decreased the diameter of the esophagus compared to no intervention in the anesthetized paralyzed state ( P < .001, respectively). Ultrasound revealed that the compressed esophagus by paratracheal pressure in the anesthetized paralyzed state was partially released during videolaryngoscopy in 17 of 40 patients, in whom esophageal occlusion was unsuccessful. The best laryngeal view was not significantly different among the no intervention, cricoid pressure, and paratracheal pressure (77 [29] % vs 79 [30] % vs 76 [31] %, respectively; P = .064). CONCLUSIONS: The occlusion of the upper esophagus defined by inability to pass an esophageal stethoscope was more effective with cricoid pressure than with paratracheal pressure during videolaryngoscopy, although both cricoid and paratracheal pressures reduced the diameter of the esophagus on ultrasound in an anesthetized paralyzed state.

Characterization of Puncture Forces of the Human Trachea and Cricothyroid Membrane.

Accurate human tissue biomechanical data represents a critical knowledge gap that will help facilitate the advancement of new medical devices, patient-specific predictive models, and training simulators. Tissues related to the human airway are a top priority, as airway medical procedures are common and critical. Placement of a surgical airway, though less common, is often done in an emergent (cricothyrotomy) or urgent (tracheotomy) fashion. This study is the first to report relevant puncture force data for the human cricothyroid membrane and tracheal annular ligaments. Puncture forces of the cricothyroid membrane and tracheal annular ligaments were collected from 39 and 42 excised human donor tracheas, respectively, with a mechanized load frame holding various surgical tools. The average puncture force of the cricothyroid membrane using an 11 blade scalpel was 1.01 ± 0.36 N, and the average puncture force of the tracheal annular ligaments using a 16 gauge needle was 0.98 ± 0.34 N. This data can be used to inform medical device and airway training simulator development as puncture data of these anatomies has not been previously reported.

Performance time of anesthesiology trainees for cricothyroid membrane identification and characteristics of cricothyroid membrane in pediatric patients using ultrasonography.

BACKGROUND: Identifying the cricothyroid membrane is an essential technical skill for front-of-neck access procedures. AIMS: This study evaluated the usefulness of cricothyroid membrane identification in pediatric patients using ultrasonography by anesthesiology trainees without experience in airway ultrasound and collected anatomical data on the cricothyroid membrane and its surrounding airway structures in children. METHODS: This prospective observational study included children aged <18 years scheduled to undergo general anesthesia and anesthesiology trainees who identified the cricothyroid membrane in five sequential anesthetized patients using ultrasonography. A pediatric anesthesiologist confirmed the accuracy of the identified cricothyroid membrane and recorded the performance time. The primary aims were the cricothyroid membrane identification success rate and performance time. The secondary aims were the characterization of the cricothyroid membrane and its surrounding structures. RESULTS: Overall, 150 pediatric patients and 30 anesthesiology trainees were analyzed. The cricothyroid membrane identification success rate using ultrasonography was 100% in all the attempts using a transverse approach. The mean (standard deviation) performance time was 27.2 (18.6) s and 31.0 (23.8) s using the transverse and longitudinal approaches, respectively. The performance time decreased by 3.1 (p = .003, 95% confidence interval [CI] = -5.1--1.0) and 5.2 (p = .007, 95% CI = -8.9--1.4) seconds per increase in number of attempts with the transverse and longitudinal approaches, respectively. The cricothyroid membrane length was mostly correlated with the patients' height (r = .75, p < .001), and the blood vessels surrounding the cricothyroid membrane were observed in 95.9% of the patients. CONCLUSIONS: Anesthesiology trainees without experience in airway ultrasound successfully identified the cricothyroid membrane in pediatric patients using ultrasonography after a brief training period. Further research is required as the identification of a structure does not predict the success of the actual procedure, particularly if done in an emergency situation.