Simulation-based training bundle significantly reduces time to oxygen delivery via needle cricothyroidotomy in airway emergency

Introduction

Needle cricothyroidotomy is a simple but potentially life-saving emergency airway manoeuvre used to provide oxygenation during a ‘cannot intubate, cannot ventilate’ (CICV) emergency.^{1 2} The procedure involves inserting a large bore cannula through the cricothyroid membrane and can be performed in patients of all ages.³ It is, however, only a short-term oxygenation solution prior to insertion of a definitive airway.¹ The procedure is taught on Advanced Paediatric Life Support (APLS) courses where focus is on needle cricothyroidotomy insertion and not subsequent airway utilisation.³ This along with the rarity of this emergency means practical experience is lacking. Problems, such as equipment availability and poor assembly, would likely arise when the manoeuvre is required, which could be disastrous during this time-critical emergency. In this study, we show that introduction of a simulation-based training bundle improves:

1. Successful simulated patient oxygenation

2. Time taken to oxygenation

3. APLS provider confidence

Design

Invited APLS providers within a tertiary paediatric hospital were given the same hypothetical CICV scenario where a simulated patient has a needle cricothyroidotomy airway in situ. The project was registered with the local trust governance department. Candidates were asked, within a maximum time of 10 min, to collect and assemble suitable equipment to oxygenate or ventilate the patient.

Candidates were then shown a standardised video tutorial on needle cricothyroidotomy and introduced to a procedure pack containing all necessary equipment used within the tutorial (figures 1A, B, see online supplementary video and appendix 1).⁴ This pack was then placed into the local resuscitation trolley. The simulation was repeated with the cricothyroidotomy bundle in situ.

Figure 1.

(A) Contents of needle cricothyroidotomy pack. (B) Demonstration of suggested equipment construction. (C) Demonstration of equipment viability test.

If the candidate completed an equipment setup, it was tested for viability by assessing ability to successfully and controllably inflate a glove at the bedside (figure 1C).⁴ All candidates were examined within their normal working environments where acute paediatric cases are managed.

Data were collected before and after the intervention, regarding:

1. Viable setup frequency;

2. Time taken to set up complete or candidate resignation;

3. Candidate confidence rating at start of scenario (where 1=minimum confidence and 10=maximum confidence).

Statistical analysis was carried out using Wilcoxon signed rank test for comparison of non-normally distributed continuous variables and McNemar's test for comparing dichotomous variables.

Results

Twenty APLS providers participated with all agreeing not to discuss the project until completion. Ability to successfully oxygenate the patient increased from 5 (25%) candidates before to 20 (100%) after (p<0.001) the intervention. Time taken to complete the procedure improved from median 232 s (range 56–518 s) before to median 59.5 s (range 36–131 s) after (p<0.001) the intervention. Candidate's self-rated confidence improved from 2.5/10 (range 1–5) before to 9/10 (range 4–10) after (p<0.001) the intervention. A range of different equipment setups were tried initially while all candidates opted to use the emergency pack equipment after its introduction.

Discussion

Complete airway loss is a rare, catastrophic emergency requiring rapid action to be taken. Needle cricothyroidotomy is potentially lifesaving, allowing temporary patient oxygenation until expert help arrives. The procedure is only potentially useful if performed quickly and used to successfully deliver O₂. This study shows that, despite appropriate training, candidates took a median of almost 4 min to connect an O₂ delivery method and only 25% of these attempts were successful. These delays and high failure rates are unacceptable, greatly increasing the likelihood of hypoxic insult or death. It is clear that simply having current APLS provider training is insufficient preparation for this emergency.

Simulation is often cited as a useful tool to allow trainees to practise for clinical emergencies in a safe environment with no risk to patients.⁵ In this study, we used a combination bundle of a training video, simulation and development of a ‘cricothyroidotomy pack’, to try and improve performance of this time-critical emergency.

After bundle implementation, candidates were able to deliver O₂ to all patients in <131 s. Having a pre-prepared procedure set reduced uncertainty regarding required equipment. This ability to consistently deliver O₂ to all patients in a timely fashion is clinically highly desirable. Candidates also demonstrated significantly increased confidence in their ability to perform the procedure. Making the decision to site a needle cricothyroidotomy is often the hardest step in this emergency. Increased confidence could empower clinicians to make this decision in a timely fashion and has potential to reduce hypoxic time further.

This study has a number of limitations. Small study numbers and a single investigation site limit generalisability, however, despite this, we have demonstrated statistically significant and clinically important performance differences. Simulation can never truly replicate the real clinical situation, however, the nature of this emergency is such that it could never be tested on real patients. The simulation was conducted in situ in clinical areas to ensure that the candidates were familiar with the environment and equipment available. Candidates could not ask for assistance during the simulation, which may have reduced the time taken to complete the procedure, however, this approach was consistent before and after the intervention so it does not account for the differences.

This study was not designed to determine which aspect of the bundle improved performance. Candidates acted as their own control pre-introduction, meaning practice alone could account for improvements seen. However, we believe that the substantial increase in success rates plus the consistency of approach adopted postintervention could only be accounted for by a combination of training, practice and standardised equipment. We plan further study to:

1. Evaluate if these improvements are sustained over time,

2. Apply these methods to other uncommon emergency procedural skills including chest drain insertion and pericardiocentesis.

Conclusion

Despite current APLS training, many clinicians are unable to deliver oxygen effectively via a needle cricothyroidotomy. Introduction of a simulation-based training bundle generated clinically important improvements when utilising an in situ needle cricothyroidotomy cannula. Success rates dramatically improved and time taken until O₂ delivery significantly reduced during a time-critical airway emergency simulation involving APLS providers. Following this study, we have recommended training bundle introduction Trust-wide.