Necessity to depict difficult neck anatomy for training of cricothyroidotomy: A pilot study evaluating two surgical devices on a new hybrid training model

Comparison of emergency surgical cricothyroidotomy and percutaneous cricothyroidotomy by experienced airway providers in an obese, in vivo porcine hemorrhage airway model

BACKGROUND

Emergency front-of-neck airway (eFONA) is a life-saving procedure in "cannot intubate, cannot oxygenate" (CICO). The fastest and most reliable method of eFONA has not been determined. We compared two of the most advocated approaches: surgical cricothyroidotomy and percutaneous cricothyroidotomy, in an obese, in vivo porcine hemorrhage model, designed to introduce real-time physiological feedback, relevant and high provider stress. The primary aim was to determine the fastest method to secure airway. Secondary aims were arterial saturation and partial pressure of oxygen, proxy survival and influence of experience.

METHODS

Twelve pigs, mean weight (standard deviation, SD) (60.3 ± 4.1) kg, were anesthetized and exposed to 25-35% total blood volume hemorrhage before extubation and randomization to Seldinger technique "percutaneous cricothyroidotomy" (n = 6) or scalpel-bougie-tube technique "surgical cricothyroidotomy" (n = 6). Specialists in anesthesia and intensive care in a tertiary referral hospital performed the eFONA, simulating an actual CICO-situation.

RESULTS

In surgical cricothyroidotomy vs. percutaneous cricothyroidotomy, the median (interquartile range, IQR) times to secure airway were 109 (IQR 71-130) s and 298 (IQR 128-360) s (P = 0.0152), arterial blood saturation (SaO₂) were 74.7 (IQR 46.6-84.2) % and 7.9 (IQR 4.1-15.6) % (P = 0.0167), pO₂ were 7.0 (IQR 4.7-7.7) kPa and 2.0 (IQR 1.1-2.9) kPa (P = 0.0667), and times of cardiac arrest (proxy survival) were 137-233 s, 190 (IQR 143-229), from CICO. All six animals survived surgical cricothyroidotomy, and two of six (33%) animals survived percutaneous cricothyroidotomy. Years in anesthesia, 13.5 (IQR 7.5-21.3), did not influence time to secure airway.

CONCLUSION

eFONA by surgical cricothyroidotomy was faster and had increased oxygenation and survival, when performed under stress by board certified anesthesiologists, and may be an indication of preferred method in situations with hemorrhage and CICO, in obese patients.

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.

Evaluation of a novel emergency front of neck access device in a benchtop model of obesity

BACKGROUND

Emergency front of neck access (eFONA) is a critical step in oxygenation in cases of unrelieved airway obstruction. Multiple techniques are used in clinical practice without agreement regarding the optimal approach. We evaluated a novel device, the Cric-Guide (CG), a channelled bougie introducer that enters the airway in a single action and compared it with a scalpel-bougie-tube (SBT) technique in laboratory benchtop model.

METHODS

Seven anaesthesiologists attempted eFONA on both obese and non-obese models using both techniques in randomized order on an excised porcine trachea with an intact larynx with variable subcutaneous tissue depth. The primary outcome was successful tracheal cannulation. Secondary outcomes included false passage rate, time and tissue injury.

RESULTS

Anaesthesiologists performed 4 cricothyroidotomies on each model with each device. The CG was more successful in airway cannulation (47/56 [89.4%] vs. 33/56 [58.9%], P = 0.007). This difference was observed in the obese model only. The CG was associated with fewer false passages than the standard technique in the obese model (8/56 [14.3%] vs. 23/56 [41.1%], P = 0.006). There were no significant differences in time to completion or injury patterns between the techniques in the obese model, but the SBT was faster in the non-obese model. There was no difference in the proportion of specimens injured.

CONCLUSION

The Cric-Guide device was more successful than the standard SBT technique in airway cannulation in an obese neck model and with equivalent frequency and distribution of injury but performed equivalently in the non-obese model.

Developing Cricothyroidotomy Skills Using a Biomaterial-Covered Model

INTRODUCTION

Cricothyroidotomy is an advanced and life-saving technique, but it is also a rare and a difficult procedure. The purpose of the present study was to produce a low-cost simulation model with realistic anatomic features to investigate its effectiveness in developing cricothyroidotomy skills.

METHODS

This study was performed at a university simulation center with 57 second-year student paramedics and a cricothyroidotomy simulation model. Total scores were assessed using a checklist. This consisted of 13 steps and was scored as misapplication/omission=0, correct performance and timing with hesitation=1, and correct performance and timing without hesitation=2. One of these steps, local anesthesia of the area if time is available, was not performed owing to time limitations. The highest possible score was 24. Data are presented as mean±SD with range, as appropriate. Normal distribution was evaluated using the Kolmogorov-Smirnov test, Student t test, and Mann-Whitney U test, and correlation analysis was used for statistical analysis.

RESULTS

Students completed the cricothyroidotomy procedure steps in 116±46 (55-238) s. At performance assessment, the score achieved was 12±5 (2-24). The highest total score of 24 was achieved by 3 students (5%). Total scores exhibited negative and significant correlation with procedure time (r=-0.403, P=0.002).

CONCLUSIONS

The model developed in this study is an inexpensive and effective method that can be used in cricothyroidotomy training for student paramedics. We think that repeating the cricothyroidotomy procedure on the model will increase success levels.