The Theatre Recovery and Anaesthetic nurse Capnography Education (TRACE) project*

Summary

The Theatre Recovery and Anaesthetic Nurse Capnography Education (TRACE) project is a multidisciplinary quality improvement project. The overall aim is to educate anaesthetic and recovery nurses on the correct use of capnography and educate non‐consultant hospital doctors on the guidelines on Preventing Unrecognised Oesophageal Intubation from the Project for Universal Management of Airways group. This project addresses technical aspects of task performance such as correct waveform identification and interpretation, troubleshooting abnormal waveforms and establishing routine checks of capnography both pre‐induction and post‐intubation. The pre‐induction verification of the correct function of capnography is an essential component of this project. In addition, the project focuses on team aspects of task performance with an emphasis on team psychological safety, empowering nurses to speak up using graded assertiveness and flattening hierarchies. As a result of the project, our nurses' knowledge about capnography and waveform identification improved to over 80% correct answers six months after completion of the project. In addition, over 90% of participants reported feeling confident in speaking up to both consultants and non‐consultant hospital doctors when a waveform was not present before induction of anaesthesia or after attempted tracheal intubation.

Introduction

Oesophageal intubation is fatal if not rapidly recognised, and even when recognised, it is associated with significant morbidity [1, 2]. It occurs in both easy and difficult intubations, by novice and experienced intubators. It is recognisable by an absent or distinctive capnography trace. Despite educational efforts, deaths from oesophageal intubation continue to occur [1, 3]. Misinterpretation of capnography and reliance on clinical signs to confirm correct tube position are themes common to all cases [1, 4].

Waveform capnography is a standard monitor which must be used during anaesthesia and sedation [5]. In response to deaths secondary to unrecognised oesophageal intubation, the Project for Universal Management of Airways (PUMA) group, in conjunction with other international airway societies, published the 2022 consensus guideline Preventing Unrecognised Oesophageal Intubation (PUOI) [1]. Eleven recommendations were made, focusing on reducing the occurrence, prompt recognition and swift management of oesophageal intubation. Of note, the use of waveform capnography was highlighted as the method of choice for detecting correct tracheal tube placement.

In addition, the PUMA PUOI guidelines recommend that educational initiatives address hierarchies that prevent staff from speaking up and making their concerns heard. This acknowledges the major role that human factors play in contributing to airway‐related disasters [1, 2].

We are not aware of any existing multidisciplinary education project that addresses the PUMA PUOI guideline recommendations. Until now, education on capnography directed primarily at nurses has been sporadic or non‐existent. This multidisciplinary project aimed to provide education to our nursing colleagues and non‐consultant hospital doctors about capnography and the PUMA PUOI guidelines. We identified the non‐consultant hospital doctors' teaching programme, which can be accessed by all members of the department including consultants, as a suitable opportunity for delivery of the education. ‘Non‐consultant hospital doctor’ is the formal term of employment approved by Ireland's Health Service Executive.

The TRACE project aimed to (1) reinforce capnography as a minimum standard of monitoring; (2) help nurses understand and recognise normal and abnormal capnography waveforms; (3) ensure that the anaesthetic team establish normal function of capnography during pre‐oxygenation; (4) embed the practice of two‐person confirmation of the presence of functioning capnography pre‐induction and confirmation of the presence or absence of capnography post‐intubation; (5) help nurses differentiate between the different waveforms displayed on capnography monitors; (6) empower nurses to raise concerns using graded assertiveness techniques; (7) reinforce the principles of the PUMA guidelines to our non‐consultant hospital doctors.

Methods

The project was registered with the St James's Hospital Research and Innovation Office. Requirement for formal research ethics committee approval was waived as this was considered a quality improvement project.

The project began with an introductory lecture detailing the project followed by a baseline assessment of nurses' knowledge using a questionnaire. After this, a lecture and simulation sessions for nurses and a lecture for non‐consultant hospital doctors took place. Questionnaires were completed by nurses immediately after delivery of the education and at 3 and 6 months to assess longer‐term knowledge retention. All questionnaires were completed anonymously.

The baseline knowledge questionnaire comprised 25 questions categorised into four sections, each focusing on distinct aspects of capnography and its significance in airway management (Appendix S1). Questions 1–4 explored the nurses' understanding of capnography, its appropriate use and role in patient monitoring and the nurses' confidence in assessing the capnography waveform. Confidence was measured using a five‐point scale as follows where 1 = no confidence, 2 = little confidence 3 = somewhat confident, 4 = fairly confident, 5 = very confident. Questions 5–10 related to the use of capnography during pre‐oxygenation and the importance of highlighting and troubleshooting the absence of a capnography trace before induction of anaesthesia. Questions 11–18 concentrated on the presence of a capnography waveform following tracheal intubation and explored potential explanations for its absence. Question 17 presented five distinct capnography waveforms corresponding to five different clinical scenarios, allowing us to evaluate respondents' knowledge in these specific areas. Question 18 presented an illustration of a ventilator screen during controlled ventilation, and asked participants to distinguish the capnography trace from the flow and pressure waveforms. Questions 19 to 25 focused on respondents' confidence levels and the obstacles they face when expressing concerns or speaking up. We assessed respondents' confidence in speaking up to a non‐consultant hospital doctor and a consultant when the capnography trace was absent, either pre‐induction or post‐intubation.

There is a comprehensive educational programme for non‐consultant hospital doctors in St James's Hospital comprising lectures delivered by consultant and non‐consultant hospital doctors on a near daily basis and weekly consultant‐led in situ high‐fidelity simulation in our theatre department. Anaesthetic, recovery and scrub nurses take part in the simulation sessions on a rolling basis. We chose didactic lectures and in situ simulation to deliver the TRACE project as these are already well‐established and embedded in our theatre department and familiar to staff.

The introductory lecture for nurses was used to outline the project, its aims and the requirement for capnography as a standard monitor during anaesthesia and sedation. In the second nurses' lecture we explained the fundamentals of gas exchange physiology, the significance of capnography and its role in airway management. We focused on five waveforms illustrating a normal trace, a flat or absent trace, oesophageal intubation, cardiac arrest with chest compressions and bronchospasm. We highlighted the potentially detrimental effect of professional hierarchy on patient safety. We used real‐life examples of unrecognised oesophageal intubation to illustrate scenarios where staff hierarchies had led to poor team performance and poor patient outcomes. To empower nurses to voice their concerns about patient safety, we introduced graded assertiveness frameworks and aimed to foster a culture of psychological safety. The CUSS framework (Concerned, Uncomfortable, Safety Issue, Stop) was originally developed by United Airlines for use in aviation. It is endorsed in the National Healthcare Communication Programme of the Health Service Executive and in recent guidance from the Difficult Airway Society and the Association of Anaesthetists. The system escalates communication from expression of concern to a command to stop if a threat to patient safety is identified [6, 7].

The simulation sessions for the TRACE project took place in our theatre department using a high‐fidelity manikin (SimMan Essential, Laerdal, Stavanger, Norway). Simulations were led by authors TS and AC, both of whom have completed fellowships in simulation. During the simulations, our nurses were exposed to scenarios leading to an absent capnography trace pre‐induction, such as a leak from a poorly fitting soda lime canister and a trace consistent with unrecognised oesophageal intubation. They role‐played raising concerns regarding the abnormal capnography. They were exposed to a sudden absent trace due to tube dislodgement during movement from the trolley to the operating table. Finally, we simulated a case of anaphylaxis with a correctly placed tube, where an obstructed and attenuated trace was shown.

A separate lecture was given to our non‐consultant hospital doctors which focused on the PUMA PUOI guidelines and the TRACE project. In it, we discussed the unreliability of clinical signs in detecting oesophageal intubation and highlighted the importance of verifying that an appropriate, sustained capnography trace is seen during pre‐oxygenation. In addition, we emphasised the important role that non‐consultant hospital doctors play in creating a psychologically safe environment where nurses feel empowered to speak up.

We placed three educational posters in each anaesthetic room to serve as both cognitive and visual aids. The first poster (Fig. 1a) illustrated five different CO₂ waveforms in five clinical scenarios: normal, absent, oesophageal intubation, bronchospasm and cardiac arrest with adequate chest compressions. It reinforces the need to see a sustained CO₂ capnograph both pre‐induction and post‐intubation and provides guidance on actions to take in the event of an absent capnography trace.

Figure 1.

(a) Anaesthetic room poster illustrating five capnography waveforms: normal trace, absent trace, oesophageal intubation, bronchospasm and cardiac arrest with adequate chest compressions; (b) anaesthetic room poster presenting the importance of a minimum of seven sustained breaths pre‐induction of anaesthesia to confirm equipment function and post‐intubation to confirm correct tracheal tube placement.

The second poster (Fig. 1b) presented the importance of a minimum of seven sustained breaths pre‐induction of anaesthesia to confirm equipment function and post‐intubation to confirm correct tracheal tube placement. The poster also challenges the reliance on clinical signs, such as tube misting, chest rise, lung and epigastric auscultation and bougie hold‐up, as they are not reliable indicators for ruling out oesophageal intubation.

The third poster suggested phrases to use when expressing concerns about the absence of a CO₂ trace. In both lectures and simulations involving non‐consultant hospital doctors and nurses, we modelled the use of graded assertiveness frameworks, such as the PACE (Probe, Alert, Challenge, Emergency) and CUSS mnemonics, which involve the use of standardised critical phrases and trigger words to effectively express concerns.

The questionnaire was repeated on completion of the educational sessions and subsequently at 3 and 6 months. Our aim was to assess whether there was an improvement in knowledge and behaviours following education and whether this improvement was sustained in the following months.

Results

Following the introductory lecture, 54 nurses from anaesthetics, recovery and scrub expressed an interest in taking part in the TRACE project. Forty‐four completed the pre‐education questionnaire. Of these, 37 were anaesthetics/recovery nurses (out of 40 anaesthetics/recovery nurses working at the time of project commencement) and seven scrub nurses (out of 62 scrub nurses working at the time of project commencement). Of these 44, 98% attended the lecture and 81% participated in the simulation sessions. Eighty‐one percent completed the immediate post‐education questionnaire, decreasing to 67% and 50% at 3‐ and 6‐month intervals, respectively.

Before participating in the TRACE programme, 80% of nurses had knowledge of capnography and its importance in airway management. Immediately following the education, this understanding increased to over 95%, which, although sustained at 3 months, fell to 86% at 6 months. Before education, 37% of nurses routinely performed capnography equipment checks, and 46% routinely verified the presence of a capnography trace during pre‐oxygenation. Following education, these figures increased to 90% and 93% respectively, with both remaining at 87% at 6 months. Initially, only 37% of nurses could correctly identify the five different capnography waveforms.

Nurses were asked to identify five different capnography traces: A: normal trace, B: absent trace, C: oesophageal intubation, D: cardiac arrest with adequate chest compressions and E: bronchospasm. Correct identification of trace A was 70% pre‐education, 94% immediately post‐education, 100% at 3 months, and 96% at 6 months post‐education. Correct identification of trace B was 67% pre‐education and 100% immediately post‐education, 69% at 3 months and 96% at 6 months. Correct identification of trace C was 17% pre‐education and 94% immediately post‐education, 83% at 3 months and 96% at 6 months. Correct identification of trace D was 15% pre‐education and 93% immediately post‐education, 80% at 3 months and 44% at 6 months. Correct identification of trace E was 32% pre‐education and 97% immediately post‐education, 94% at 3 months and 93% at 6 months.

Before participating in the TRACE programme, 93% of participants correctly identified the causes of an absent trace following intubation. After education, this percentage increased to 95%, and it remained high at 97% and 81% at 3‐ and 6‐month intervals, respectively. Before education, 79% of individuals knew the appropriate action to take when the capnography trace remained flat after intubation. After education, this figure improved to 98% and was maintained at 92% and 85% at 3‐ and 6‐month intervals, respectively.

Before participating in the TRACE programme, 66% of nurses could correctly identify the capnography trace on a standard ventilator screen, and distinguish it from the pressure and flow waveforms. After education, this knowledge improved to 83% and remained high at 92% and 78% after 3 and 6 months, respectively.

Before participating in the TRACE programme, self‐reported confidence levels in highlighting the absence of a trace to a consultant and non‐consultant hospital doctor both before and after induction of anaesthesia were low. These increased after education and were sustained. These results are detailed in Table 1.

Table 1.

Reported levels of confidence of participants in highlighting the absence of a capnography trace to non‐consultant hospital doctors and consultants before induction and after intubation.

	Pre‐education	Immediately post‐education	3 months	Post 6 months
	n (%)	n (%)	n (%)	n (%)
	n = 44	n = 44	n = 36	n = 26
Before induction
To non‐consultant hospital doctors
Little/no confidence	14 (31)	2 (4)	0	0
Very/fairly confident	17 (39)	38 (86)	34 (94)	24 (92)
To consultants
Little/no confidence	12 (28)	2 (4)	0	1 (4)
Very/fairly confident	19 (43)	34 (77)	30 (83)	23 (88)
After intubation
To non‐consultant hospital doctors
Little/no confidence	5 (12)	0	0	0
Very/fairly confident	27 (63)	36 (82)	34 (94)	24 (92)
To consultants
Little/no confidence	11 (24)	1 (2)	0	1 (4)
Very/fairly confident	23 (53)	36 (82)	29 (81)	24 (92)

Before their participation in the TRACE programme, fewer than 1% of nurses had received training in communicating concerns and speaking up in the workplace. Following our intervention, 52% of nurses felt that this educational series addressed this gap in their training. Forty‐eight percent of participants identified hierarchies as a significant barrier to safe care in the operating theatre, with 61% stating that hierarchies can hinder them from raising patient safety concerns with doctors. When asked about the factors inhibiting them from voicing their concerns, common responses included lack of confidence, inadequate knowledge, fear of being incorrect, hierarchy and communication challenges with doctors. Likewise, when questioned about what encourages them to raise their concerns, common motivators included prioritising patient safety, receiving proper training, leveraging clinical experience and fostering open communication with doctors.

No formal data collection was undertaken for the component of the project involving non‐consultant hospital doctors.

Discussion

To our knowledge, this is the first multidisciplinary project to address some of the recommendations made in the PUMA PUOI guidelines and provide structured education on capnography to a large cohort of nurses. The valuable contribution that nurses make in the management of a deteriorating patient has been a recurring theme in airway‐related disasters. The sustained correct interpretation of waveforms suggests that our nurses are interpreting capnography waveforms in practice. This ability to correctly interpret waveforms and differentiate waveforms on ventilator screens is a valuable contribution that our nurses can now make in both routine and emergency settings.

Although overall knowledge significantly improved immediately post‐education and was maintained at 6 months, the slight decline in knowledge over time across nearly all areas examined highlights the requirement for continued education. In particular, correct interpretation of specific waveforms was sustained at 6 months post‐education with the exception of the waveform depicting cardiac arrest with adequate CPR. This highlights the requirement for further education surrounding the role and interpretation of capnography during cardiac arrest.

Of note, we stressed the importance of confirming the correct capnography function pre‐induction. The PUMA PUOI guidelines do not stipulate that equipment must be checked for function before induction of anaesthesia. This is an important consideration as correct interpretation depends on correct equipment function in the first instance. We therefore deemed it necessary to check for correct function before induction of anaesthesia. We chose seven waveforms pre‐induction to align with the PUMA PUOI guideline requirement for seven appropriate waveforms to confirm sustained exhaled CO₂ to confirm correct tube placement.

Nurses reported factors including a lack of confidence, inadequate knowledge, hierarchies and communication challenges with doctors as being barriers to nurses speaking up. A key component of our project was to empower nurses to speak up during pre‐oxygenation and after intubation using graded assertiveness if an absent or abnormal capnography waveform was seen. Suggested graded assertiveness phrases followed the CUSS framework as follows:

Concerned: ‘I am concerned we do not have a capnography trace’.

Uncomfortable: ‘I am uncomfortable that we have no capnography trace before induction’.

Safety issue: ‘We need capnography to proceed safely’.

Stop: ‘Stop. We must have capnography before proceeding’.

Having a framework and confidence to speak up are valued by our theatre nursing colleagues. The culture of psychological safety that has been fostered by this project is likely to have further positive effects in our theatre and hospital environment.

As a result of the success of TRACE, the College of Anaesthesiologists of Ireland are rolling it out as a national QI project. In addition, it is being modified locally by our Intensive Care Unit and Emergency Department with a view to national engagement.

Supporting information

Appendix S1. Initial questionnaire.