Cricothyrotomy technique: standard versus the Rapid Four-Step Technique

Dimensional compatibility of currently available equipment for cricothyroidotomy and adult airway anatomy: an in vitro analysis

BACKGROUND

There are scant data on the dimensional compatibility of cricothyroidotomy equipment and related airway anatomy. We compared the dimensional design of devices for cricothyroidotomy with anatomical airway data for adult patients.

METHODS

For all available cricothyroidotomy equipment the outer diameter was recorded from manufacturer information or, if not available, measured using a sliding calliper. Outer diameters were compared with recently published mean (standard deviation [sd]) values for the height of the cricothyroid membrane obtained from computed tomography, separately for males (7.9 [2.2] mm) and for females (5.9 [1.7] mm).

RESULTS

Twenty-one cricothyroidotomy sets (10 uncuffed, 11 cuffed) with 15 differently designed devices were included. Inner diameters of the tubes ranged from 3.5 to 6.0 mm and outer diameters from 5.0 to 11.7 mm. The outer diameter of the 15 different tubes was found to be greater than the mean membrane height of the adult male cricothyroid membrane in eight devices and greater than the mean membrane height for female adults in 10 devices. Considering the lower range of cricothyroid membrane height, 12 tube outer diameters would be too large for male adults and all 15 for female adults in this range.

CONCLUSION

The outer diameter of many devices currently marketed for cricothyroidotomy are oversized for adult airway anatomy, particularly for females. For emergency front-of-neck access through the cricothyroid membrane, anatomical data suggest that cricothyroidotomy devices with outer tube diameters of <7 mm for male and <6 mm for female adult patients should be preferred.

Surgeons With Five or More Actual Cricothyrotomies Perform Significantly Better on a Virtual Reality Simulator

BACKGROUND

Discriminating performance of learners with varying experience is essential to developing and validating a surgical simulator. For rare and emergent procedures such as cricothyrotomy (CCT), the criteria to establish such groups are unclear. This study is to investigate the impact of surgeons' actual CCT experience on their virtual reality simulator performance and to determine the minimum number of actual CCTs that significantly discriminates simulator scores. Our hypothesis is that surgeons who performed more actual CCT cases would perform better on a virtual reality CCT simulator.

METHODS

47 clinicians were recruited to participate in this study at the 2018 annual conference of the Society of American Gastrointestinal and Endoscopic Surgeons. We established groups based on three different experience thresholds, that is, the minimal number of CCT cases performed (1, 5, and 10), and compared simulator performance between these groups.

RESULTS

Participants who had performed more clinical cases manifested higher mean scores in completing CCT simulation tasks, and those reporting at least 5 actual CCTs had significantly higher (P = 0.014) simulator scores than those who had performed fewer cases. Another interesting finding was that classifying participants based on experience level, that is, attendings, fellows, and residents, did not yield statistically significant differences in skills related to CCT.

CONCLUSIONS

The simulator was sensitive to prior experience at a threshold of 5 actual CCTs performed.

3D force/torque characterization of emergency cricothyroidotomy procedure using an instrumented scalpel

Emergency Cricothyroidotomy (CCT) is a surgical procedure performed to secure a patient's airway. This high-stakes, but seldom-performed procedure is an ideal candidate for a virtual reality simulator to enhance physician training. For the first time, this study characterizes the force/torque characteristics of the cricothyroidotomy procedure, to guide development of a virtual reality CCT simulator for use in medical training. We analyze the upper force and torque thresholds experienced at the human-scalpel interface. We then group individual surgical cuts based on style of cut and cut medium and perform a regression analysis to create two models that allow us to predict the style of cut performed and the cut medium.

A hierarchical task analysis of cricothyroidotomy procedure for a virtual airway skills trainer simulator

BACKGROUND

Despite the critical importance of cricothyroidotomy (CCT) for patient in extremis, clinical experience with CCT is infrequent, and current training tools are inadequate. The long-term goal is to develop a virtual airway skills trainer that requires a thorough task analysis to determine the critical procedural steps, learning metrics, and parameters for assessment.

METHODS

Hierarchical task analysis is performed to describe major tasks and subtasks for CCT. A rubric for performance scoring for each task was derived, and possible operative errors were identified.

RESULTS

Time series analyses for 7 CCT videos were performed with 3 different observers. According to Pearson's correlation tests, 3 of the 7 major tasks had a strong correlation between their task times and performance scores.

CONCLUSIONS

The task analysis forms the core of a proposed virtual CCT simulator, and highlights links between performance time and accuracy when teaching individual surgical steps of the procedure.

Emergency Cricothyroidotomy for Difficult Airway Management After Asynchronous Bilateral Neck Dissections: A Case Report and Literature Review

PURPOSE

This report describes a case that required emergency cricothyroidotomy for an upper airway obstruction owing to laryngeal edema after asynchronous bilateral neck dissections.

PATIENT AND METHODS

A 57-year-old man was diagnosed with multicentric squamous cell carcinoma of the tongue (T1 and 2N0M0), and partial glossectomy with primary closure was performed. Three months after surgery, secondary metastases in the right cervical lymph nodes were detected, and a right radical neck dissection was performed. Contrast-enhanced computed tomographic (CT) scan taken 2 weeks after the right neck dissection visualized a possible third metastasis in the left cervical lymph node. Four weeks after the right radical neck dissection, left supraomohyoid neck dissection was carried out. In this surgery, the left internal jugular vein (IJV) was preserved. Nine hours after surgery, severe swelling of the face and pharynx was recognized, resulting in a stoppage of respiration and then an emergency cricothyroidotomy.

RESULTS

The patient's life was saved without any encephalopathy or airway trouble. Contrast-enhanced CT scan taken the next day confirmed the preserved left IJV patency.

CONCLUSION

Oral and maxillofacial surgeons should be aware of the possibility of life-threatening laryngeal edema associated with bilateral neck dissections even if the unilateral IJV is preserved and should know the procedure for emergency cricothyroidotomy.

Comparison of a percutaneous device and the bougie-assisted surgical technique for emergency cricothyrotomy: an experimental study on a porcine model performed by air ambulance anaesthesiologists

Background

A large number of techniques and devices for cricothyroidotomy have been developed. In this study, the Portex™ Cricothyroidotomy Kit (PCK, Smiths Medical Ltd, Hythe, UK) was compared with the bougie assisted emergency surgical cricothyrotomy technique (BACT).

Methods

Twenty air ambulance anaesthesiologists performed emergency cricothyrotomy on a cadaveric porcine airway model using both PCK and BACT. Baseline performance and performance after the intensive training package were recorded. Success rate, time to secured airway and tracheal damage were the primary endpoints, and confidence rating was a secondary endpoint.

Results

During baseline testing, success rates for PCK and BACT were 60% and 95%, respectively. Tracheal injury rate with PCK was 60% while no such injury was found in BACT. A lecture was given and skills were trained until the participants were able to perform five consecutive successful procedures with both techniques. In the post-training test, all participants were successful with either technique. The mean time to successful insertion was reduced by 15.7 seconds (from 36.3 seconds to 20.6 seconds, p< 0.001) for PCK and by 7.8 seconds (from 44.9 seconds to 37.1 seconds, p=0.021) for BACT. In the post-training scenario, securing the airway with PCK was significantly faster than with BACT (p<0.001). Post-training tracheal laceration occurred in six (30%) of the PCK procedures and in none of the BACT procedures (p=0.028).

The self-evaluated confidence level was measured both pre- and post-training using a confidence scale with 10 indicating maximum amount of confidence. The median values increased from 4 to 8 for PCK and from 6.5 to 9.5 for BACT. All participants reported that BACT was their preferred technique.

Conclusions

Testing the base-line PCK skills of prehospital anaesthesiologists revealed low confidence, sub-optimal performance and a very high failure rate. The BACT technique demonstrated a significantly higher success rate and no tracheal damage. In spite of PCK being a significantly faster technique in the post-training test, the anaesthesiologists still reported a higher confidence in BACT. Limitations of the cadaveric porcine airway may have influenced this study because the airway did not challenge the clinicians with realistic tissue bleeding.

Parker Flex-Tip or standard tracheal tube for percutaneous emergency airway access?

BACKGROUND

Percutaneous emergency airway access (PEAA) can be established utilising a scalpel, bougie and cuffed tracheal tube. The study compared the Parker Flex-Tip tracheal tube with a standard tracheal tube for PEAA in cadavers. We hypothesised that a standard tracheal tube would be more likely to advance over a bougie into the trachea during a PEAA procedure than a Parker Flex-Tip tracheal tube.

METHODS

Three anaesthetists performed a PEAA with a scalpel, bougie and cuffed tracheal tube, 12 times each. Recorded times included: loading the tracheal tube onto the bougie and advancing the tube over the bougie to the skin, advancing the tube through the skin into the trachea and completion of the whole procedure. Subjective opinion regarding the ease of tube insertion was recorded by visual analogue scoring.

RESULTS

Subjective opinion, overall time and time to complete each component of the procedure were not significantly affected by the type of tube used. The mean time for three novice anaesthetists to complete PEAA on a cadaver was 37.5 (8.8) s, after 1 h of training. In two of the 12 cadavers, the cricothyroid membrane could not be palpated or located with the scalpel.

CONCLUSION

The Parker Flex-Tip tube and a standard tracheal tube perform equally well during PEAA procedures on adult cadavers.

Emergency cricothyrotomy in infants--evaluation of a novel device in an animal model

BACKGROUND

According to different algorithms of airway management, emergency cricothyrotomy is the final step in managing an otherwise not accessible airway. As an alternative to an open surgical procedure, minimally invasive approaches exist. Quicktrach baby™ is a commercially available set for a minimal invasive cricothyrotomy in infants. The set consists of a plastic cannula over a metal needle for direct placement in the trachea. So far, this device has not been evaluated for its intended use.

OBJECTIVES

We hypothesize that Quicktrach baby™ allows the establishment of an emergency airway. The aim was to prove that the device is easy to handle and the cricothyrotomy fast to perform.

METHODS

After approval of the local ethics committee, the study was performed on the cadavers of 10 adult rabbits. Cricothyrotomy was performed with Quicktrach baby™. Successful placement, performance time, and complication rate were documented. Possible ventilation with a breathing bag was evaluated. Data are reported as mean and interquartile range.

RESULTS

Successful placement of Quicktrach baby™ was possible in all attempts. The placement took 31 [23-43] s. In two cases, a fracture of the cricoid's cartilage was seen. In one animal, damage to the posterior wall mucosa was observed. In all cases, sufficient ventilation was possible.

CONCLUSIONS

Quicktrach™ baby proved to be a reliable technique. In the animal model, it is easy and fast to perform. Only a few minor complications occurred. Sufficient ventilation was possible in all attempts.

A STANDING-ORDERPROTOCOL FORCRICOTHYROTOMY INPREHOSPITALEMERGENCYPATIENTS

OBJECTIVE

To study utilization, indications, and outcomes associated with the use of a statewide, emergency medical services (EMS) standing-order protocol for cricothyrotomy.

METHODS

A statewide EMS database was queried for patients who received cricothyrotomy under a standardized, standing-order protocol. Patient EMS and hospital records were reviewed in a defined sequence with information recorded on a standardized collection form.

RESULTS

EMS records included eight years of practice with 1.5 million patient encounters. For each year studied, approximately 540 emergency medical technicians (EMTs) were certified to perform cricothyrotomy. State EMS providers performed a collective mean of eight cricothyrotomy procedures per year (range, 1-17), for a total of 68 cricothyrotomies performed within the eight-year period. Hospital records were available for review in 61 patients. Fifty-six patients received cricothyrotomy by open surgical incision, six by needle with jet ventilation, and one by both methods. Categorization of cricothyrotomy patients as trauma or medical was 61% trauma and 39% medical. Thirty-six patients (59%) were in cardiac arrest on EMS arrival and 12 patients (20%) died during transport. Thirteen trauma patients (21%) were admitted with eight patients surviving to discharge (13%). The neurologic impairment at time of hospital discharge was severe in four, moderate in two, and minimal or none in two patients (3%).

CONCLUSION

A considerable percentage of cricothyrotomy procedures were performed on patients with non-trauma-related diagnoses in this investigation describing a standing-order EMS protocol for cricothyrotomy. The majority of patients undergoing cricothyrotomy with this protocol were in cardiac arrest at the time of cricothyrotomy, with a small minority of patients surviving to hospital discharge and fewer surviving neurologically intact.

Retrograde intubation

Airway management in the emergency department is a critical skill that must be mastered by emergency physicians. When rapid-sequence induction with oral-tracheal intubation performed by way of direct laryngoscopy is difficult or impossible due to a variety of circumstances, an alternative method or device must be used for a rescue airway. Retrograde intubation requires little equipment and has few contraindications. This technique is easy to learn and has a high level of skill retention. Familiarity with this technique is a valuable addition to the airway-management armamentarium of emergency physicians caring for ill or injured patients. Variations of the technique have been described, and their use depends on the individual circumstances.

Surgical approach in difficult airway management

In all difficult airway algorithms, cricothyroidotomy is the life-saving procedure and is the final 'cannot ventilate, cannot intubate' option, whether in pre-hospital, emergency department, intensive care unit, or operating room patients. Cricothyroidotomy is a relatively safe and rapid means of securing an emergency airway. As with all other critical procedures in emergency medicine, a thorough knowledge of the technique and adequate practice prior to attempting to perform an emergency cricothyroidotomy are essential.

Emergency care in facial trauma--a maxillofacial and ophthalmic perspective

Facial trauma, with or without life- and sight-threatening complications, may arise following isolated injury, or it may be associated with significant injuries elsewhere. Assessment needs to be both systematic and repeated, with the establishment of clearly stated priorities in overall care. Although the American College of Surgeons Advanced Trauma Life Support (ATLS) system of care is generally accepted as the gold standard in trauma care, it has potential pitfalls when managing maxillofacial injuries, which are discussed. Management of facial trauma can arguably be regarded as "facial orthopaedics", as both specialities share common management principles. This review outlines a working approach to the identification and management of life- and sight-threatening conditions following significant facial trauma.

Invasive Techniken in der Notfallmedizin

Cricothyrotomy is a very invasive technique to secure the airway in an emergency but is irreplacable when less invasive techniques fail or cannot be instigated under the prevailing circumstances. Various techniques have been reported which can be subdivided into anatomical-surgical preparation or puncture techniques. The preferred strategy is mostly oriented towards the departmental standard procedure which will be decided by the clinical situation. Training for each procedure can be carried out in intensive care departments, and using autopsy material or a manekin. Various methods of cricothyrotomy will be discussed here, and additionally an anatomical preparation and two puncture techniques will be demonstrated in detail.

Emergency cricothyrotomy: a randomised crossover trial comparing the wire-guided and catheter-over-needle techniques

In a randomised crossover trial, we compared a wire-guided cricothyrotomy technique (Minitrach) with a catheter-over-needle technique (Quicktrach). Performance time, ease of method, accuracy in placement and complication rate were compared. Ten anaesthesiology and 10 ENT residents performed cricothyrotomies with both techniques on prepared pig larynxes. The catheter-over-needle technique was faster than the wire-guided (48 compared to 150 s, p < 0.001) and subjectively easier to perform (VAS-score 2.1 vs. 5.6, p < 0.001). Correct positioning of the cannula could be achieved in 95% and 85%, respectively (NS). There was one complication in the catheter-over-needle group compared to five in the wire-guided group. We conclude that the wire-guided minitracheotomy kit is unsuitable for emergency cricothyrotomies performed by inexperienced practitioners. On the other hand, the catheter-over-needle technique appears to be quick, safe and reliable.

Difficult Airway Society guidelines for management of the unanticipated difficult intubation

Problems with tracheal intubation are infrequent but are the most common cause of anaesthetic death or brain damage. The clinical situation is not always managed well. The Difficult Airway Society (DAS) has developed guidelines for management of the unanticipated difficult tracheal intubation in the non-obstetric adult patient without upper airway obstruction. These guidelines have been developed by consensus and are based on evidence and experience. We have produced flow-charts for three scenarios: routine induction; rapid sequence induction; and failed intubation, increasing hypoxaemia and difficult ventilation in the paralysed, anaesthetised patient. The flow-charts are simple, clear and definitive. They can be fully implemented only when the necessary equipment and training are available. The guidelines received overwhelming support from the membership of the DAS.

DISCLAIMER

It is not intended that these guidelines should constitute a minimum standard of practice, nor are they to be regarded as a substitute for good clinical judgement.

Cricoid ring integrity: implications for cricothyrotomy

STUDY OBJECTIVES

The rapid 4-step technique for cricothyrotomy was originally described as making use of a single traction hook on the cricoid ring. However, it is possible that such hook placement could lead to damage of the cricoid ring. As an alternative, a double-hook device was developed to augment the rapid 4-step technique by dispersing forces applied to the cricoid ring. The objectives of this study were to compare the requisite forces for intubation and the structural tolerances of the cricoid ring between the single- and double-hook techniques.

METHODS

We randomized 56 human cadaver specimens to undergo either cricothyrotomy with intubation followed by cricoid ring breakage or cricoid ring breakage alone. We randomized those cadaver specimens undergoing cricothyrotomy with intubation with respect to the initial hook technique used and then crossed over to the alternate technique for repeat intubation and subsequent cricoid ring breakage. We performed all cricothyrotomies in a similar manner with a consistent technique. We measured the intubation and breakage forces for the single- and double-hook techniques and calculated 95% confidence intervals (CIs).

RESULTS

The mean force to intubate with the single-hook technique was 18 N (95% CI 14 to 22 N), and the mean force to intubate with the double-hook technique was 23 N (95% CI 17 to 29 N). There was a significant difference between the mean forces required to break the cricoid ring with the single-hook technique (54 N; 95% CI 47 to 62 N) versus with the double-hook technique (101 N; 95% CI 89 to 113 N; difference in means 47 [95% CI 34 to 60 N]).

CONCLUSION

When applying the rapid 4-step technique for cricothyrotomy, the force required to intubate with either the single- or double-hook technique is small. The cricoid ring, however, tolerates significantly more force without breakage when the double-hook technique is used.

Emergency airway management

Airway control is one of the most critical interventions required for saving a life. It is essential that practitioners be as well trained as possible in the numerous techniques available to establish airway control. This article reviews some of the available techniques, though other techniques that are not discussed (such as fiberoptic-assisted endotracheal intubation) may also be useful. Perhaps the most important aspect of advanced airway management is the ability to anticipate and prepare for the difficult airway. This article gives numerous options for the difficult airway situation.

Cricothyrotomy: a 5-year experience at one institution

We describe the prevalence, primary indications and immediate complications of emergency cricothyrotomy (cric) techniques, in a single institution's Emergency Department (ED) and associated air-medical transport service. This is a retrospective review at an academic, level-one trauma center with an annual ED census of 65,000 and an associated air-medical transport service (AMTS). All patients undergoing cric in the field or in the ED between July 1995 and June 2000 were included. Expert reviewers from Emergency Medicine, Trauma Surgery and the AMTS prospectively defined the complication criteria. All charts with a possible complication underwent a blinded evaluation by reviewers representing each of the three clinical services. Descriptive statistics were used to summarize the data. Fifty crics were performed over 5 years. Seventy-six percent of crics were performed in trauma patients. The prevalence of cric in patients requiring airway management in the ED was 1.1% (95% CI, 0.7-1.6) and 10.9% (95% CI, 6.9-16.1) in the field by the AMTS. The prevalence of complications was 14% (95% CI, 4-32.6) in ED patients and 54.5% (95% CI, 32-75.6) for prehospital patients. The overall inter-rater agreement for complication rate was excellent (kappa =.87). Overall, 77% of crics were performed using the rapid four-step technique (RFST). There were no reports of complications associated with the RFST when performed in the ED. Non-RFST crics in the ED had an associated complication rate of 25% (95% CI, 2.8-60). Emergency cricothyrotomy was performed in approximately 1% of all emergency airway cases in the ED and at a higher rate by the AMTS. The most frequent indications were trauma related. Additionally, the RFST was the most commonly used technique for cric at this institution. The complication rate of cric was significantly higher in the prehospital environment than in the ED.

Difficult airway management in the emergency department

Most airway management in the emergency department is straightforward and readily accomplished by the emergency physician. The exact incidence of difficult intubations is difficult to discern from available evidence, but these are probably more frequent in the Emergency Department than in the operating room, given the urgent nature of the procedure and the lack of preparation of the patient population. A variety of adjuncts for airway management are available to assist in both intubation and ventilation. The utility of these adjuncts is detailed in this review, with emphasis on techniques most useful to the emergency physician.