[Cricothyrotomy : Data situation, guidelines and techniques for the definitive surgical airway]

Cricothyrotomy represents the final approach to secure the airway, in the course of which less invasive measures have failed. It can also primarily be carried out to establish a secure airway. This is essential to protect the patient from a significant hypoxia. This is a cannot ventilate-cannot oxygenate (CVCO) situation, which presumably all colleagues in emergency intensive care medicine and anesthesia have already been confronted with. Evidence-based algorithms for the management of a difficult airway and CVCO have been established. If oxygenation using an endotracheal tube, an extraglottic airway device or bag-valve mask ventilation all fail, the airway must be surgically secured, i.e. using cricothyrotomy. The prevalence of the CVCO situation in a prehospital setting is ca. 1%. No valid prospective randomized in vivo studies have been carried with respect to the question of the best method.

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).

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.

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.

Evaluation of a novel Surgicric® cricothyroidotomy device for emergency tracheal access in a porcine model

A can't intubate, can't ventilate scenario can result in morbidity and death. Although a rare occurrence (1:50 000 general anaesthetics), it is crucial that anaesthetists maintain the skills necessary to perform cricothyroidotomy, and are well-equipped with appropriate tools. We undertook a bench study comparing a new device, Surgicric(®) , with two established techniques; the Melker Emergency Cricothyroidotomy, and a surgical technique. Twenty-five anaesthetists performed simulated emergency cricothyroidotomy on a porcine model, with the primary outcome measure being insertion time. Secondary outcomes included success rate, tracheal trauma and ease of use. The surgical technique was fastest. The median (IQR [range]) was 81 (62-126 [37-300]) s, followed by the Melker 124 (100-217 [71-300]) s, and the Surgicric 127 (68-171 [43-300]), p = 0.003. The Surgicric device was the most traumatic, as evaluated by a blinded Ear, Nose and Throat surgeon. Subsequently, the authors contacted the device manufacturer, who has now modified the kit in the hope that its clinical application might be improved. Further studies are required to evaluate the revised model.

Innate Immune Response of the Pig Laryngeal Mucosa to Endotracheal Intubation

Objective

The aim of this study was to measure the effects of endotracheal intubation on innate immune response within the pig laryngeal mucosa.

Study Design

Prospective controlled basic science study.

Setting

The animal experiments and analyses were conducted at the University of Bristol.

Samples and Methods

Eighteen pigs, matched at the major histocompatibility complex (MHC), were used in the study. The pigs were divided into 9 pairs. One of each pair (9 pigs in total) was intubated with an endotracheal tube under general anesthesia for 90 minutes. Two days later, pinch biopsies were taken from the supraglottis (specifically the false cords) and subglottis of both pigs. The experiment was repeated 8 more times. Based on quantitative immunohistochemistry, percentage areas of positive staining for CD172a, CD163, MHC class II, CD14, and CD16 were calculated separately for the epithelium and lamina propria of each biopsy.

Results

Total areas of laryngeal mucosa (epithelium and lamina propria) expressing CD172a and coexpressing CD163 and CD172a were significantly reduced at 2 days following endotracheal intubation ( P = .039 and P = .037, respectively). MHC class II expression and MHC class II coexpression with CD172a were similarly reduced following intubation ( P = .003 and P = .005, respectively). In the supraglottis, MHC class II coexpression with CD16 and CD14 was also reduced following endotracheal intubation ( P = .037).

Conclusions

Our results indicate that endotracheal intubation reduces the number of innate immune cells within the upper airway mucosa. This may be an important first step in a cascade leading to chronic wound and scar formation causing airway stenosis.

The 'Can't intubate can't oxygenate' scenario in pediatric anesthesia: a comparison of the Melker cricothyroidotomy kit with a scalpel bougie technique

BACKGROUND

While the majority of pediatric intubations are uncomplicated, the 'Can't intubate, Can't Oxygenate' scenario (CICO) does occur. With limited management guidelines available, CICO is still a challenge even to experienced pediatric anesthetists.

OBJECTIVES

To compare the COOK Melker cricothyroidotomy kit (CM) with a scalpel bougie (SB) technique for success rate and complication rate in a tracheotomy on a cadaveric 'infant airway' animal model.

METHODS

Two experienced proceduralists repeatedly attempted tracheotomy in eight rabbits, alternately using CM and SB (4 fr) technique. The first attempt was performed at the level of the first tracheal cartilage with subsequent experimental trials of insertion progressively more caudad. Success was defined as intratracheal placement of cannula as seen on bronchoscope. Complications were assessed both by bronchoscopic and macropathological appearance.

RESULTS

32 attempts were made at tracheotomy. CM had an overall success rate of 100% compared to a 75% success rate for SB. Success rate for the first attempt was dependent on the level of the tracheotomy (Level 1 100%, level 2 62.5% and level 3 & 4 25%). While CM was associated with lateral and/or posterior wall damage on bronchoscopy/macropathology in 6% of 19% and 25% of 50% respectively, the damage observed was greater and more frequent with SB (19%/44% and 31%/50%, respectively).

CONCLUSIONS

At level 1, the first attempt success rate was 100% for both devices. Overall CM showed a better success rate than SB; however, both techniques were associated with significant complication rates, which were more pronounced following the scalpel bougie technique.

A new strategy for difficult airway management with visual needle cricothyroidotomy: a manikin study

BACKGROUND

Conventional needle cricothyroidotomy uses blind manipulation. We investigated the feasibility and efficiency of a new visually guided needle cricothyroidotomy technique.

METHODS

A 0.9-mm microimaging fiber was delivered into a 14G needle to develop a visual puncture system. 10 inexperienced physicians were randomly assigned to perform 10 repeated needle cricothyroidotomy in each group with both conventional method and visual puncture in a manikin. Tracheal lumen puncture time and number of procedure-related complications were recorded.

RESULTS

Under visual guidance, the needle successfully reached the tracheal lumen. The anatomy of the upper and lower airways was acquired by further advancing the microimaging fiber into the tracheal lumen of the visual group. The tracheal lumen puncture time was significantly less in the visual group than in the conventional group (3.85 ± 1.54 vs. 9.84 ± 1.08 seconds, P < .001). Damage to the posterior tracheal wall was not observed in the visual group; however, 21% of manikins in the conventional group had procedure-related complications.

CONCLUSIONS

Our results demonstrate that visual needle cricothyroidotomy is feasible, and may lead to a decrease in procedure time and procedure-related complications compared to the conventional procedure. In addition, this strategy may also provide useful information for diagnostic purposes; therefore, visual needle cricothyroidotomy may be a new strategy for the management of difficult airways in future care.

Effect of Simulation Training on Compliance with Difficult Airway Management Algorithms, Technical Ability, and Skills Retention for Emergency Cricothyrotomy

Background:

The effectiveness of simulation is rarely evaluated. The aim of this study was to assess the impact of a short training course on the ability of anesthesiology residents to comply with current difficult airway management guidelines.

Methods:

Twenty-seven third-year anesthesiology residents were assessed on a simulator in a “can’t intubate, can’t ventilate” scenario before the training (the pretest) and then randomly 3, 6, or 12 months after training (the posttest). The scenario was built so that the resident was prompted to perform a cricothyrotomy. Compliance with airway management guidelines and the cricothyrotomy’s duration and technical quality were assessed as a checklist score [0 to 10] and a global rating scale [7 to 35].

Results:

After training, all 27 residents (100%) complied with the airway management guidelines, compared with 17 (63%) in the pretest (P &lt; 0.005). In the pretest and the 3-, 6-, and 12-month posttests, the median [range] duration of cricothyrotomy was respectively 117 s [70 to 184], 69 s [43 to 97], 52 s [43 to 76], and 62 s [43 to 74] (P &lt; 0.0001 vs. in the pretest), the median [range] checklist score was 3 [0 to 7], 10 [8 to 10], 9 [6 to 10], and 9 [4 to 10] (P &lt; 0.0001 vs. in the pretest) and the median [range] global rating scale was 12 [7 to 22], 30 [20 to 35], 33 [23 to 35], and 31 [18 to 33] (P &lt; 0.0001 vs. in the pretest). There were no significant differences between performance levels achieved in the 3-, 6-, and 12-month posttests.

Conclusion:

The training session significantly improved the residents’ compliance with guidelines and their performance of cricothyrotomy.

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.

Emergency cricothyrotomy--a systematic review

Background

An emergency cricothyrotomy is the last-resort in most airway management protocols and is performed when it is not possible to intubate or ventilate a patient. This situation can rapidly prove fatal, making it important to identify the best method to establish a secure airway. We conducted a systematic review to identify whether there exists superiority between available commercial kits versus traditional surgical and needle techniques.

Methods

Medline, EMBASE and other databases were searched for pertinent studies. The inclusion criteria included manikin, animal and human studies and there were no restrictions regarding the professional background of the person performing the procedure.

Results

In total, 1,405 unique references were identified; 108 full text articles were retrieved; and 24 studies were included in the review. Studies comparing kits with one another or with various surgical and needle techniques were identified. The outcome measures included in this systematic review were success rate and time consumption. The investigators performing the studies had chosen unique combinations of starting and stopping points for time measurements, making comparisons between studies difficult and leading to many conflicting results. No single method was shown to be better than the others, but the size of the studies makes it impossible to draw firm conclusions.

Conclusions

The large majority of the studies were too small to demonstrate statistically significant differences, and the limited available evidence was of low or very low quality. That none of the techniques in these studies demonstrated better results than the others does not necessarily indicate that each is equally good, and these conclusions will likely change as new evidence becomes available.

Invasive and surgical procedures in pre-hospital care: what is the need?

BACKGROUND

On occasion, advanced invasive procedures in pre-hospital care can be life saving. This study aimed to identify the contemporary use of these procedures on a regional doctor-led air ambulance unit, and to define the need, skill set and training requirements for a regional pre-hospital team in the UK.

METHODS

Mission data were recorded prospectively and the database reviewed to identify invasive procedures over a 76-month period. These cases were reviewed with indications, mechanism of injury, presence of cardiac arrest at any time point (±return of spontaneous circulation) and procedural failure or morbidity.

RESULTS

Two hundred and thirty-five procedures were performed: 16 for injuries affecting the airway, 111 for breathing and 108 for circulation. Almost a third of patients in cardiac arrest regained spontaneous circulation. Procedures performed increased fivefold from 2003 to 2009, with a marked increase in the use of thoracostomy and intra-osseous access. Procedural failure or inadequacy was high with needle cricothyroidotomy, needle chest decompression and early intra-osseous access experience.

CONCLUSIONS

A steady increase in the number of procedures was observed over time. Less invasive methods of airway and breathing support were frequently inadequate, though definitive surgical airway or chest decompression was effective each time it was performed. Thoracotomy was performed infrequently. There are implications for the training of pre-hospital doctors who work in the majority of the UK.

Emergency cricothyroidotomy: a randomized crossover trial comparing percutaneous techniques: classic needle first versus "incision first"

OBJECTIVES

Emergency cricothyroidotomy is potentially lifesaving in patients with airway compromise who cannot be intubated or ventilated by conventional means. The literature remains divided on the best insertion technique, namely, the open/surgical and percutaneous methods. The two are not mutually exclusive, and the study hypothesis was that an "incision-first" modification (IF) may improve the traditional needle-first (NF) percutaneous approach. This study assessed the IF technique compared to the NF method.

METHODS

A randomized controlled crossover design with concealed allocation was completed for 180 simulated tracheal models. Attending and resident emergency physicians were enrolled. The primary outcome was time to successful cannulation; secondary outcomes included needle insertion(s), incision, and dilatation attempts. Finally, proportions of intratracheal insertion on the first attempt and subjective ease of insertion were compared.

RESULTS

  The IF technique was significantly faster than the standard NF technique (median = 53 seconds, interquartile range [IQR] = 45.0 to 86.4 seconds vs. median = 90 seconds, IQR = 55.2 to 108.6 seconds; p < 0.001). The median number of needle insertions was significantly higher for the NF technique (p = 0.018); there was no significant difference in dilation or incision attempts. Intratracheal insertion on the first attempt was documented in 90 and 93% of the NF and IF techniques, respectively (p = 0.317). All the study participants found the IF hybrid approach easier.

CONCLUSIONS

The IF modification allows faster access, fewer complications, and more favorable clinician endorsement than the classic NF percutaneous technique in a validated model of cricothyroidotomy. We suggest therefore that the IF technique be considered as an improved method for insertion of an emergency cricothyroidotomy.

Emergency cricothyroidotomy performed by inexperienced clinicians--surgical technique versus indicator-guided puncture technique

Background

To improve the ease and safety of cricothyroidotomy especially in the hand of the inexperienced, new instruments have been developed. In this study, we compared a new indicator-guided puncture technique (PCK) with standard surgical technique (ST) regarding success rate, performance time and complications.

Methods

Cricothyroidotomy in 30 human cadavers performed by 30 first year anaesthesia residents. The set chosen for use was randomised: PCK-technique (n=15) and ST (n=15). Success rates, insertion times and complications were compared. Traumatic lesions were anatomically confirmed after dissection.

Results

The ST-group had a higher success rate (100% vs 67%; p=0.04). There was no difference in time taken to complete the procedure (PCK 82 s. vs ST 95 s.; p=0.89). There was a higher complication rate in the PCK-group (67% vs 13%; p=0.04). Most frequent complication in the PCK-group was injury to the posterior tracheal wall (n=8), penetration to the oesophageal lumen (n=4) and injury to the thyroid and/or cricoid cartilage (n=5). In the ST-group in only 2 cases minor complications were observed (small vessel injury).

Conclusions

In this human cadaver study the PCK technique produced more major complications and more failures than the ST. In the hand of the inexperienced operator the standard surgical approach seems to be a safe procedure, which can successfully be performed within an adequate time. The PCK technique cannot be recommended for inexperienced operators.