Comparison of Cricothyroid Membrane Puncture Anesthesia and Topical Anesthesia for Awake Fiberoptic Intubation: A Double-Blinded Randomized Controlled Trial

Background: Awake fiberoptic intubation (AFOI) is commonly used for patients with a difficult airway. The purpose of this study was to evaluate the efficacy of cricothyroid membrane puncture anesthesia and topical anesthesia during AFOI.Methods: A total of 70 patients (the American Society of Anesthesiologists score I-III) with anticipated difficult airways scheduled for nonemergency surgery with AFOI were randomly slated to receive cricothyroid membrane puncture anesthesia (n = 35) or topical anesthesia (n = 35). Each group received dexmedetomidine at a dose of 1.0 μg/kg and sufentanil at a dose of 0.2 μg/kg over 10 min for conscious sedation before intubation. The endoscopy intubation, post-intubation condition, and endoscopy tolerance as scored by the anesthetists were observed. The satisfaction of the operator regarding the procedure and the satisfaction of the patient 24 h after the surgery were also recorded. We recorded the success rate of the first intubation, intubation time, and hemodynamic changes during the procedure and also the adverse events.Results: Better intubation scores, operator satisfaction, and satisfaction of the patient were observed in the cricothyroid membrane puncture anesthesia group than in the topical anesthesia group (p < 0.05). The intubation time in the cricothyroid membrane puncture anesthesia group was less than that in the topical anesthesia group (p < 0.05). There were no significant differences in the patient tolerance scores, the success rate of the first intubation, hemodynamic changes, and adverse events between both the groups.Conclusion: Compared with topical anesthesia, cricothyroid membrane puncture anesthesia provided better intubation conditions and less intubation time with greater satisfaction of the patient and operator during endoscopic intubation.Clinical Trial Registration: URL: http://www.chictr.org.cn/showproj.aspx?proj=42636, Identifier: ChiCTR 1900025820.

Quantification of the effect of body mass index on cricothyroid membrane depth: a cross-sectional analysis of clinical CT images

ObjectivesThe recommended front of neck access procedure in can’t intubate, can’t oxygenate scenarios relies on palpation of the cricothyroid membrane (CTM), or dissection of the neck down to the larynx if CTM is impalpable. CTM palpation is particularly challenging in obese patients, most likely due to an increased distance between the skin and the CTM (CTM depth). The aims of this study were to measure the CTM depth in a representative clinical sample, and to quantify the relationship between body mass index (BMI) and CTM depth.MethodsThis is a retrospective analysis of 355 clinical CT scans performed at a teaching hospital over an 8-month period. CTM depth was measured by two radiologists, and mean CTM depth calculated. Age, gender, height and weight were recorded, and BMI calculated. Linear relationships between patient characteristics and CTM depth were assessed in order to derive a predictive equation for calculating CTM depth. The variables included for this model were those with a strong association with CTM depth, that is, a p value of 0.10 or less.ResultsMean CTM depth was 8.12 mm (IQR 6.36–11.70). There was no association between CTM depth and sex (β −0.33, 95% CI −1.33 to 0.68, p=0.53), height (cm) (β 0.01, 95% CI −0.05 to 0.06, p=0.79) or age (years) (β −0.01, 95% CI 0.10 to 0.15, p=0.62). Increasing weight (kg) (β 0.12, 95% CI 0.10 to 0.15, p<0.001) and BMI (kg/m3) (β 0.52, 95% CI 0.44 to 0.60, p<0.001) were strongly associated with CTM depth. Predicted CTM depth increased from 6.4 mm (95% CI 4.9 to 8.1) at a BMI of 20 kg/m2 to 16.8 (95% CI 13.7 to 20.1) at BMI 40 kg/m2.ConclusionCTM depth was strongly associated with BMI in a retrospective analysis of patients having clinical CT scans.

Application of Treatment Simulation Software for War Injury in Emergency Treatment Training on the Battlefield based on Chinese Visible Human Datasets

Background: Proficiency in self-help and mutual aid skills is correlated with the prognosis of injured patients, and this study aims to create treatment simulation software for war injuries that reflect the physical constitution of Chinese people and study its application in first aid training on the battlefield. Methods: Based on thin-sectional, highly precise Chinese Visible Human (CVH) data with high resolution, combined with self-help and mutual medical aid measures such as digital pressure hemostasis, cricothyroid membrane puncture, pneumothorax puncture and bone marrow puncture for battlefield first aid, useing Amira and other softwares to building the simulation software for the technical training of military medical students and basic medical officers was constructed. Eighty medical service students were trained on battlefield first aid technology, and a new training mode for the treatment of war injuries was developed and optimized. Results: Simulation software of hemostasis and puncture for battlefield first aid that was suitable for the technical training of military medical students and its supporting teaching materials 3D-PDF were established. The software included modules of hemostasis of the vertex, face, head-shoulder, shoulder-arm, forearm, upper forearm, lower limb and foot and puncture of the cricothyroid membrane , pneumothorax, and bone marrow cavity. Collaborating with interactive 3D-PDF, it was successfully used for on-site first aid training of military medical students. The questionnaire results showed that the trainees had a high recognition of the human-computer interactive performance of the software with a clear interface and easy operation. The accuracy and richness of the three-dimensional model structure, knowledge of hemostasis and puncture and applied anatomy contained in this software were high, helping trainees to quickly master the knowledge points and operation techniques related to hemostasis and puncture. Conclusion: The system can effectively mobilize the learning enthusiasm of students and fully improve the learning efficiency of the basic materials and applied anatomy of battlefield first aid, as well as the teaching efficiency of teachers. The training simulation of battlefield first aid, comprising a combination of various modes, effectively complemented each other, met many training needs, and achieved satisfactory training results. Additionally, this software could be used in the emergency training of traffic accident injuries and disaster-related injuries.