[Ultrasound supported identification of the ligamentum conicum in teaching head and neck sonography]

OBJECTIVE

Upper airway obstructions are usually acute emergencies. Coniotomy is the last option to secure the airway and can be supported by sonography. The aim of this study was to establish a training program to teach these skills.

MATERIAL AND METHODS

The training consisted of theoretical training with an additional video presentation (10 minutes each) and practical training (45 minutes). Evaluations were completed before (T1) and after (T2) the training to measure prior experience and satisfaction with the training as well as subjective and objective competence levels. At T2, a practical test was also completed by n=113 participants. A standardized evaluation form was used to document the results of the practical test.

RESULTS

A large proportion of the participants had neither seen a coniotomy (64.6%) nor performed one independently (79.6%). Significant improvement (T1 to T2) was measured with regard to the subjective assessment of competence (p<0.001). The training received positive ratings for all items tested (scale ranges 1-2). During practical tests, the participants achieved an average of 89.2% of the possible points and needed a mean of 101 ±23 seconds to identify the conic ligament.

CONCLUSION

Structured training for sonographic identification of the conic ligament leads to significant improvement in the subjective assessment of competence and a high objective competence level in a short period of time. This type of training should be standardized in head and neck ultrasound training in the future.

[The correct way to deal with the definitive surgical airway]

Dealing with a difficult airway is familiar to emergency care providers in both the prehospital and clinical settings. In anesthesiology and emergency medical care different algorithms almost equal in their wording have been introduced, indicating that an emergency front of neck airway access (eFONA) has to be established in the case of a cannot ventilate-cannot oxygenate situation. In a survey (Surveymonkey®) data concerning the level of experience with eFONA, devices required, previous training and complications were allocated among acute and emergency care providers of different backgrounds (doctors and paramedics). Furthermore, we asked about individual attitudes to and frequency of previous situations, in which an eFONA was not established despite strong indications. Of the respondents 15% (n = 63) answered that they had experienced this type of situation. eFONA had been performed by 28% of the interviewed (n = 117), reflecting the high number of military and EMT (emergency medical team) physicians participating in the survey. The number of experiences are rarely representative for the civilian setting. Different adjuncts may be helpful to detect the cricothyroid ligament. To use ultrasound seems obvious but it doubles the time for the detection of the cricothyroid ligament. Laryngeal masks can be employed as a supraglottic airway device (SAD) during "plan B". Stabilizing the airway with a SAD almost doubles the success of identifying laryngeal landmarks in females. The crew resource management (CRM) guidelines are more than essential in threatening situations demanding measures like eFONA. Providers should anticipate emerging problems and whenever feasible call for help and finally speak up. Naming a failed airway should be avoided as it implies a failure of the provider or of the entire airway team. In fact, the term non-accessible airway should be introduced. This might help to avoid the implication of a major failure. So far, an ideal simulator to train eFONA has not been introduced but it is mandatory to train procedures and algorithms on different types of simulators and manikins to achieve mastery.

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.

Emergency cricothyroidotomy in difficult airway simulation – a national observational study of Air Ambulance crew performance

Background

Advanced prehospital airway management includes complex procedures carried out in challenging environments, necessitating a high level of technical and non-technical skills. We aimed to describe Norwegian Air Ambulance-crews’ performance in a difficult airway scenario simulation, ending with a “cannot intubate, cannot oxygenate”-situation.

Methods

The study describes Air Ambulance crews’ management of a simulated difficult airway scenario. We used video-observation to assess time expenditure according to pre-defined time intervals and technical and non-technical performance was evaluated according to a structured evaluation-form.

Results

Thirty-six crews successfully completed the emergency cricothyroidotomy with mean procedural time 118 (SD: ±70) seconds. There was variation among the crews in terms of completed procedural steps, including preparation of equipment, patient- monitoring and management. The participants demonstrated uniform and appropriate situational awareness, and effective communication and resource utilization within the crews was evident.

Conclusions

We found that Norwegian Air Ambulance crews managed a prehospital “cannot intubate, cannot oxygenate”-situation with an emergency cricothyroidotomy under stressful conditions with effective communication and resource utilization, and within a reasonable timeframe. Some discrepancies between standard operating procedures and performance are observed. Further studies to assess the impact of check lists on procedural aspects of airway management in the prehospital environment are warranted.

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.

Guidelines for Tracheostomy From the Korean Bronchoesophagological Society

The Korean Bronchoesophagological Society appointed a task force to develop a clinical practice guideline for tracheostomy. The task force conducted a systematic search of the Embase, Medline, Cochrane Library, and KoreaMed databases to identify relevant articles, using search terms selected according to key questions. Evidence-based recommendations for practice were ranked according to the American College of Physicians grading system. An external expert review and a Delphi questionnaire were conducted to reach a consensus regarding the recommendations. Accordingly, the committee developed 18 evidence-based recommendations, which are grouped into seven categories. These recommendations are intended to assist clinicians in performing tracheostomy and in the management of tracheostomized patients.

Impact of cardiopulmonary resuscitation on a cannot intubate, cannot oxygenate condition: a randomised crossover simulation research study of the interaction between two algorithms

OBJECTIVES

During a 'cannot intubate, cannot oxygenate' situation, asphyxia can lead to cardiac arrest. In this stressful situation, two complex algorithms facilitate decision-making to save a patient's life: difficult airway management and cardiopulmonary resuscitation. However, the extent to which competition between the two algorithms causes conflicts in the execution of pivotal treatment remains unknown. Due to the rare incidence of this situation and the very low feasibility of such an evaluation in clinical reality, we decided to perform a randomised crossover simulation research study. We propose that even experienced healthcare providers delay cricothyrotomy, a lifesaving approach, due to concurrent cardiopulmonary resuscitation in a 'cannot intubate, cannot oxygenate' situation.

DESIGN

Due to the rare incidence and dynamics of such a situation, we conducted a randomised crossover simulation research study.

SETTING

We collected data in our institutional simulation centre between November 2016 and November 2017.

PARTICIPANTS

We included 40 experienced staff anaesthesiologists at our tertiary university hospital centre.

INTERVENTION

The participants treated two simulated patients, both requiring cricothyrotomy: one patient required cardiopulmonary resuscitation due to asphyxia, and one patient did not require cardiopulmonary resuscitation. Cardiopulmonary resuscitation was the intervention. Participants were evaluated by video records.

PRIMARY OUTCOME MEASURES

The difference in 'time to ventilation through cricothyrotomy' between the two situations was the primary outcome measure.

RESULTS

The results of 40 participants were analysed. No carry-over effects were detected in the crossover design. During cardiopulmonary resuscitation, the median time to ventilation was 22 s (IQR 3-40.5) longer than that without cardiopulmonary resuscitation (p=0.028), including the decision-making time.

CONCLUSION

Cricothyrotomy, which is the most crucial treatment for cardiac arrest in a 'cannot intubate, cannot oxygenate' situation, was delayed by concurrent cardiopulmonary resuscitation. If cardiopulmonary resuscitation delays cricothyrotomy, it should be interrupted to first focus on cricothyrotomy.

Percutaneous vs surgical emergency cricothyroidotomy: An experimental randomized crossover study on an animal-larynx model

BACKGROUND

Airway management is a paramount clinical skill for the anaesthesiologist. The Emergency Cricothyroidotomy (EC) constitutes the final step in difficult airway algorithms securing a patent airway via a front-of-neck access. The main distinction among available techniques is whether the procedure is surgical and scalpel-based or percutaneous and needle-based.

METHODS

In an experimental randomized crossover trial, using an animal larynx model, we compared two EC techniques; the Rapid Four Step Technique and the Melker Emergency Cricothyrotomy Kit®. We assessed time expenditure and success rates among 20 anaesthesiologists and related this to previous training, seniority and clinical experience with EC.

RESULTS

All participants achieved successful airway access with both methods. Average time to successful airway access for scalpel-based EC was 54 (±31) seconds and for percutaneous EC 89 (±38) seconds, with 35 (95% CI: 14-57) seconds time difference, P = .003. Doctors with recent (<12 months) EC training performed better compared to the non-training group (37 vs 61 seconds, P = .03 for scalpel-based EC, and 65 vs 99 seconds, P = .02 for percutaneous EC). We found no differences according to clinical seniority or previous real-life EC experience.

CONCLUSIONS

Our study demonstrated that anaesthesiologists achieved successful airway access on an animal experimental model with both EC methods within a reasonable time frame, but the scalpel-based EC is performed more promptly. Recent EC training affected the time expenditure positively, while seniority and clinical EC experience did not. EC procedures should be regularly trained for.

Results of a surgical cricothyrotomy workshop with a pig trachea model

BACKGROUND

The latest Difficult Airway Society (DAS) guidelines recommend that all anaesthesiologists should to be trained in the performing of a surgical cricothyrotomy (CtQ). The aim of this study was to analyse the learning results of a CtQ workshop by assessing the success rate and time to perform CtQ on a porcine tracheal model.

MATERIAL AND METHODS

A workshop was designed in which each student completed a questionnaire with demographic data and theoretical knowledge about surgical approaches of airway. During the following hour, a review was presented theoretical aspects of CtQ. The model was shown and a CtQ was performed using a classical technique. Afterwards, in groups of 3-4 students with an instructor, each one of the students performed 6 CtQ. A record was made on whether the ventilation was correct, the time to perform CtQ, and the ease of performing the CtQ by the students and instructors. Finally, students completed a questionnaire on the theoretical aspects. Students and instructors performed a workshop debriefing. A statistical analysis was performed, considering a P-value <0.05 as statistically significant.

RESULTS

A total of 8 workshop sessions were held with a total of 91 students. At first attempt, 86% of students performed a CtQ with successful ventilation, and 92% at the sixth attempt (P<.0001). Time taken was 163 [107-211] seconds at first attempt, and 70 [55-85] seconds at the sixth (P<.0001). At the end of workshop, students had improved their theoretical knowledge (P<.0001) and perception of the ease of the technique.

CONCLUSION

Workshop performance improved theoretical knowledge and competence in surgical cricothyrotomy.

A bench study comparing between scalpel-bougie technique and cannula-to-Melker technique in emergency cricothyroidotomy in a porcine model

Background

The ideal emergency cricothyroidotomy technique remains a topic of ongoing debate. This study aimed to compare the cannula-to-Melker technique with the scalpel-bougie technique and determine whether yearly training in cricothyroidotomy techniques is sufficient for skill retention.

Methods

We conducted an observational crossover bench study to compare the cannula-to-Melker with the scalpel-bougie technique in a porcine tracheal model. Twenty-eight anesthetists participated. The primary outcome was time taken for device insertion. Secondary outcomes were first-pass success rate, incidence of tracheal trauma, and technique preference. We also compared the data on outcome measures with the data obtained in a similar workshop a year ago.

Results

The scalpel-bougie technique was significantly faster than the cannula-to-Melker technique for cricothyroidotomy (median time of 45.2 s vs. 101.3 s; P = 0.001). Both techniques had 100% success rate within two attempts; there were no significant differences in the first-pass success rates and incidence of tracheal wall trauma (P > 0.999 and P = 0.727, respectively) between them. The relative risks of inflicting tracheal wall trauma after a failed cricothyroidotomy attempt were 6.9 (95% CI 1.5–31.1), 2.3 (95% CI 0.3–20.7) and 3.0 (95% CI 0.3–25.9) for the scalpel-bougie, cannula-cricothyroidotomy, and Melker-Seldinger airway, respectively. The insertion time and incidence of tracheal wall trauma were lower when the present data were compared with data from a similar workshop conducted the previous year.

Conclusions

This study supports the use of a scalpel-bougie technique for cricothyroidotomy by anesthetists and advocates a yearly training program for skill retention.

Front of neck access: A survey among anesthetists and surgeons

BACKGROUND AND AIMS

Emergency front of neck access (FONA) is the final step in a Can't Intubate-Can't Oxygenate (CICO) scenario. In view of maintaining simplicity and promoting standardized training, the 2015 Difficult Airway Society guidelines recommend surgical cricothyroidotomy using scalpel, bougie, and tube (SBT) as the preferred technique.

MATERIAL AND METHODS

We undertook a survey over a 2-week period to evaluate the knowledge and training, preferred rescue technique, and confidence in performing the SBT technique. Data were collected from both anesthetists and surgeons.

RESULTS

One hundred and eighty-nine responses were collected across four hospitals in the United Kingdom. The majority of participants were anesthetists (55%). One hundred and eleven (59%) respondents were aware of the national guidelines (96.2% among anesthetists and 12.9% among surgeons). Only 71 (37.6%) respondents indicated that they had formal FONA training within the last one year. Seventy-five anesthetists (72.8%) knew that SBT equipment was readily available in their department, while most surgeons (81.2%) did not know what equipment available. One hundred and five (55.5%) respondents were confident in performing surgical cricothyroidotomy in a situation where the membrane was palpable and only in 33 (17.5%) where the cricothyroid membrane was not palpable.

CONCLUSION

This survey has demonstrated that despite evidence of good training for anesthetists in FONA, there are still shortfalls in the training and knowledge of our surgical colleagues. In an emergency, surgeons may be required to assist or secure an airway in a CICO situation. Regular multidisciplinary training of all clinicians working with anesthetized patients should be encouraged and supported.

Recent trends in airway management

Tracheal intubation remains a life-saving procedure that is typically not difficult for experienced providers in routine conditions. Unfortunately, difficult intubation remains challenging to predict and intubation conditions may make the event life threatening. Recent technological advances aim to further improve the ease, speed, safety, and success of intubation but have not been fully investigated. Video laryngoscopy, though proven effective in the difficult airway, may result in different intubation success rates in various settings and in different providers’ hands. The rescue surgical airway remains a rarely used but critical skill, and research continues to investigate optimal techniques. This review highlights some of the new thoughts and research on these important topics.