Real-time vs. static ultrasound-guided needle cricothyroidotomy: a randomized crossover simulation trial

Cricothyroidotomy is a key technique for securing airways when tracheal intubation and oxygenation are difficult to achieve. In recent years, it has become clear that ultrasonography is more accurate than palpation for identifying the cricothyroid membrane. However, it is unclear how ultrasound should be administered. We investigated whether real-time or static ultrasound techniques were more useful for needle cricothyrotomy in patients with simulated anatomical abnormalities of the neck. Three cervical simulators with anatomical abnormalities were created. After education and hands-on training in needle cricothyroidotomy, 48 participants (27 junior residents, 12 anesthesia residents, and nine anesthesiologists) performed needle cricothyroidotomy using either a real-time or static ultrasound technique (crossover study). Fisher's exact test was used to assess the success rate and accuracy of the puncture (p < 0.05 was considered statistically significant). The success rate of cricothyrotomy puncture was significantly higher with the real-time ultrasound technique than with the static ultrasound technique. The real-time ultrasound technique led to significantly higher puncture accuracy and shorter procedure time than the static ultrasound technique. Needle cricothyroidotomy using real-time ultrasonography may be more useful than that using static ultrasonography.

The Evolution of Emergency Front of Neck Access: A Historical Review

Airway patency loss causes acute deoxygenation and carbon dioxide clearance failure and requires immediate intervention to prevent death. When less-invasive airway management approaches and technologies fail, the rescue algorithm end point is emergency front of neck access (eFONA), a high-risk, low-frequency intervention necessitating specialized training and regular skill maintenance. The historical evolution of surgical airway rescue reveals a progress arc from initial resistance to neck operations due to fear of complications, through acceptance of tracheal access for life-saving measures despite high complication rates, to the introduction of synthetic devices that maintain tracheal patency and reduce complications. Various civilizations independently and in parallel made significant observations and advancements in eFONA techniques. The evolution of eFONA underscores a balance between technological advancement and the need for a standardized lexicon and skillset that is regularly maintained by training protocols. Emphasizing the importance of eFONA training- akin to cardiopulmonary resuscitation (CPR) certification maintenance-can enhance readiness and proficiency among health care professionals.

Scalpel cricothyrotomy versus punctured cricothyrotomy in the context of the CICO crisis. A systematic review and Meta-analysis

IMPORTANCE

The preferential use of a scalpel (SCT) or puncture techniques (PCT) for cricothyrotomy remains a controversial topic.

OBJECTIVE

We performed a systematic review and meta-analysis comparing puncture cricothyrotomy with scalpel cricothyrotomy using overall success rate, first-time success rate, and time taken to perform the procedure as the primary outcome together with complications as a secondary outcome.

EVIDENCE REVIEW

Pubmed databases, EMBASE databases, MEDLINE, Google Scholar, and Cochrane Central Register of Controlled Trials, from 1980 to October 2022.

FINDINGS

A total of 32 studies were included in the systematic review and meta-analysis. It also showed that PCT was close to SCT in terms of overall success rate (82.2% vs. 82.6%, Odd Ratios OR = 0.91, [95%CI: 0.52-1.58], p = 0.74) as well as first-performance success rate (62.9% vs. 65.3%, OR = 0.52, [0.22-1.25], p = 0.15). PCT does not compare favorably with SCT in terms of required time for the procedure (the mean time required for PCT versus SCT incision in the intervention groups was 0.34 standard deviations higher (Mean Difference MD = 17.12, [3.37-30.87], p = 0.01) as well as complications (21.4% vs. 15.1%, Relative Risk RR = 1.49, [0.80-2.77], p = 0.21).

CONCLUSIONS AND RELEVANCE

The results show that SCT has an advantage over PCT in terms of time required for the procedure, while there is no difference in overall success rate, first-time success rate after training, and complications. The superiority of SCT may be the result of fewer and more reliable procedural steps. However, the level of evidence is low (GRADE).

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.

Emergency cricothyrotomy in morbid obesity: comparing the bougie-guided and traditional techniques in a live animal model

BACKGROUND

Cricothyrotomy is a rare, time sensitive procedure that is more challenging to perform when anatomical landmarks are not easily palpated before the initial incision. There is a paucity of literature describing the optimal technique for cricothyrotomy in patients with impalpable airway structures, such as in morbid obesity. In this study, we used a live sheep model of morbid obesity to compare the effectiveness of two common cricothyrotomy techniques.

METHODS

We randomly assigned emergency medicine residents to perform one of two cricothyrotomy techniques on a live anesthetized sheep. To simulate the anterior soft tissue neck thickness of an adult with morbid obesity we injected 120 mL of a mixture of autologous blood and saline into the anterior neck of the sheep. The traditional technique (as described in the New England Journal Video titled "Cricothyroidotomy") used a Shiley tracheostomy tube and no bougie, and the bougie-guided technique used a bougie and a standard endotracheal tube. The primary outcome was the total procedure time; the secondary outcome was first attempt success.

RESULTS

23 residents were included, 11 assigned to the bougie-guided technique and 12 to the traditional technique. After injection of blood and saline, the median depth from skin to cricothyroid membrane was 3.0 cm (IQR 2.5-3.4 cm). The median time for the bougie technique was 118 s (IQR 77-200 s) compared to 183 s (IQR 134-270 s) for the traditional technique (median difference 62 s, 95% CI 10-144 s). Success on the first attempt occurred in 7/11 (64%) in the bougie group and 6/12 (50%) in the traditional technique group.

CONCLUSION

In this study, which simulated morbid obesity on a living animal model complete with active hemorrhage and time pressure caused by extubation before the procedure, the bougie-guided technique was faster than the traditional technique using a tracheostomy tube without a bougie.

Accuracy of cricothyroid membrane identification using ultrasound and palpation techniques in obese obstetric patients: an observational study

BACKGROUND

During performance of emergency front of neck access, the final step in management algorithms for the 'can't intubate, can't oxygenate' scenario, accurate identification of the cricothyroid membrane, is crucial. Accurate identification using palpation techniques is low, with highest failure rates occurring in obese females.

METHODS

This prospective observational study recruited 28 obese obstetric patients. The cricothyroid membrane was identified using ultrasound, marked with an ultraviolet pen and covered with a dressing. The candidate was asked to perform cricothyroid membrane identification using landmark technique (group L) followed by ultrasound (group U). The primary outcome was the distance between the actual and estimated cricothyroid membrane midpoint. Secondary outcomes were the proportion of accurate assessments, time taken, and subjective ease of identification using a visual analogue score.

RESULTS

Distance from the cricothyroid membrane midpoint was shorter in group U than Group L (2.5 mm vs 5.5 mm, P=0.002). The proportion of correctly identified cricothyroid membranes was greater in group U than group L (71% vs 39%, P=0.015). Time required for identification was shorter in group L than group U (16.9 s vs 23.5 s, P=0.001). Visual analogue scores for ease of identification were lower in group U than group L (2.4 cm vs 4.2 cm, P=0.013).

CONCLUSIONS

Ultrasound-guided cricothyroid membrane localisation was significantly more accurate but slower than the landmark technique in obese obstetric patients. As such, we recommend the use of pre-procedural identification of the cricothyroid membrane in this patient population and formal training of anaesthetists in airway ultrasound.

Cricothyroidotomy competence and injuries using nonmedical equipment: A crossover noninferiority randomised controlled trial in a porcine cadaver model

BACKGROUND

International guidelines recommend cricothyroidotomy as a life-saving procedure for 'cannot intubate, cannot ventilate' situations. Although commercially available sets facilitate surgical cricothyroidotomy, regular training seems to be the key to success.

OBJECTIVES

The goal was to investigate if trained anaesthetists are able to transfer their skill in one surgical cricothyroidotomy technique to another. The primary hypothesis postulated that trained anaesthetists could perform an emergency cricothyroidotomy equally fast and successfully with a pocketknife compared with a surgical cricothyroidotomy set.

DESIGN

Crossover noninferiority randomised controlled trial.

SETTING

After written informed consent and ethics committee approval, this single-centre study was performed at the University Hospital of Bern, Bern, Switzerland.

PARTICIPANTS

Altogether, 61 study participants already familiar with surgical cricothyroidotomy were included.

INTERVENTION

The use of a commercially available cricothyroidotomy set was compared with a short-bladed pocketknife and ballpoint pen barrel. A pig-larynx cadaver model including trachea, with pig skin overlaid, was used. Participants underwent additional training sessions in both procedures.

MAIN OUTCOME MEASURES

The primary outcome was the time necessary to position the tracheal tube or pen barrel in the trachea. Other outcome parameters were success rate, tracheal and laryngeal injuries and preferred device.

RESULTS

Cricothyroidotomy with the pocketknife was performed significantly faster and equally successfully as compared with the cricothyroidotomy sets. Tracheal and laryngeal injuries were similar in both groups. Paratracheal or submucosal placement of the pen barrel occurred in 32%, compared with 29% for the tracheal tube. Sixty-six per cent of participants preferred the cricothyroidotomy set.

CONCLUSION

Regularly trained anaesthetists are able to accomplish cricothyroidotomy irrespective of the equipment used. A pocketknife with a ballpoint pen barrel was just as effective as a commercially available surgical set.

Rescue oxygenation success by cannula or scalpel-bougie emergency front-of-neck access in an anaesthetised porcine model

In the obese, the evidence for the choice of the optimal emergency front-of-neck access technique is very limited and conflicting. We compared cannula and scalpel-bougie emergency front-of-neck access techniques in an anaesthetised porcine model with thick pretracheal tissue. Cannula and scalpel-bougie cricothyroidotomy techniques were performed in 11 and 12 anaesthetised pigs, respectively. Following successful tracheal access, oxygenation was commenced and continued for 5 min using Rapid-O2 device for cannula and circle breathing system for scalpel-bougie study groups. The primary outcome was a successful rescue oxygenation determined by maintenance of arterial oxygen saturation >90% 5 min after the beginning of oxygenation. Secondary outcomes included success rate of airway device placement, time to successful airway device placement, and trauma to the neck and airway. The success rate of rescue oxygenation was 18% after cannula, and 83% after scalpel-bougie technique (P = 0.003). The success rate of airway device placement was 73% with cannula and 92% with scalpel-bougie technique (P = 0.317). Median (inter-quartile-range) times to successful airway device placement were 108 (30–256) and 90 (63–188) seconds (P = 0.762) for cannula and scalpel-bougie emergency front-of-neck access, respectively. Proportion of animals with iatrogenic trauma additional to the procedure itself was 27% for cannula and 75% for scalpel-bougie technique (P = 0.039). Thus, in the porcine model of obesity, the scalpel-bougie technique was more successful in establishing and maintaining rescue oxygenation than cannula-based technique; however, it was associated with a higher risk of severe trauma.