Cricothyroidotomy is the rescue technique for can’t intubate, can’t ventilate (CICV) situations. Theoretical knowledge, regular training of the skill on a manikin or simulator and teamwork are the key to success during an airway crisis.1,2 This is particularly true in dynamic domains of healthcare such as anaesthesia, surgery and intensive care, in which teamwork has shown to be effective in patient care.3
National Audit Project 4, the only published prospective comprehensive audit of airway complications in anaesthesia in the UK, noted a high failure rate of emergency cannula cricothyroidotomy (63% with narrow bore and 43% with wide bore). Although multiple factors may have contributed towards the failure, these have not been clearly identified. The purpose of this study was to evaluate the knowledge and skills of operating department practitioners (ODPs) and circulation nurses in setting up cannula cricothyroidotomy and assisting the anaesthetist in the management of CICV on a simulator.
Fully qualified ODPs and circulation nurses from our department were invited to participate in the study. Prior to the study all the participants were taught the Difficult Airway Society guidelines4 in managing an unanticipated difficult intubation. An overview of available cricothyroidotomy devices and technique of cricothyroidotomy were also presented. A senior anaesthetist with significant airway experience played the role of anaesthetist in all the scenarios to maintain consistency. The anaesthetist was also briefed to guide and assist the ODPs and circulation nurses if required.
The standard scenario chosen for this study was that of a patient of ASA grade 1 presenting for elective surgery requiring tracheal intubation using a medium fidelity simulator. The simulator was set up in the anaesthetic room of an operating theatre with an ODP or circulation nurse assisting the anaesthetist. Two difficult airway trolleys were available in their usual location of the theatre complex (about 50 m away from the anaesthetic room). The difficult airway trolleys were equipped with 13G cricothyroidotomy cannulae, jet ventilation catheter (VBM, Medizintechnick GmbH, Germany) and Manujet III (VBM). One trolley had Manujet III with mini Schrader probe and the other had standard Schrader probe. Standard monitoring including noninvasive blood pressure, ECG, oxygen saturation and end tidal carbon dioxide were displayed on the monitor.
The difficult intubation scenario was simulated by instituting restricted neck extension and pharyngeal oedema on the SimMan following induction of anaesthesia. After the second attempt at intubation, a CICV situation was initiated by complete glottic occlusion (and masseter spasm if required) and a standard decline in oxygen saturation was programmed over 2 min to 70%.
The ODPs/circulation nurses were asked to assist in unanticipated difficult airway scenario leading to cricothyroidotomy. The ability to locate the difficult airway trolley, identify the correct cricothyroidotomy set and setting up the high-pressure ventilation device were all assessed.
Twenty-three participants with clinical experience varying between 1 and 5 years took part in the study. Only one of the participants had prior experience of a CICV scenario in a real clinical setting. All the participants were able to locate the difficult airway trolley. Fourteen participants (61%) were able to identify the Manujet III and connect it to the correct oxygen source. Six (26%) required prompting from the anaesthetist to set up and connect it to the correct oxygen source, whereas three (13%) were unable to do so despite promptings from the anaesthetist. Table 1 lists the other outcome measures that were recorded during the study. The clinical experience of ODPs or the circulation nurse did not have any significant effect on the reventilation time (Table 2).
An important finding was that nearly 40% of the participants were either unable to set up Manujet III or required help to connect to the correct oxygen source. This was attributed to a lack of familiarity with managing the CICV scenario, inexperience of the participants and the presence of two different types of probes on the Manujet III to connect to the oxygen source (Fig. 1). The standard Schrader probe connects to the oxygen outlet socket at the wall and the mini-Schrader probe connects to a special oxygen outlet at the rear of the anaesthetic machine. Modern anaesthetic machines have a mini-Schrader valve socket for oxygen, which may be used to power Venturi systems for a bronchoscope or a Manujet.5
The main aim of this study was to assess the ODPs/circulation nurses familiarity with the equipment and their ability to assist in a CICV scenario. There are limitations in our study. We only studied the one aspect of cannula cricothyroidotomy that contributes to the success such as the skilled assistance from ODPs/circulation nurses. However, adaptations of coordinated activities is related to improved team performance in healthcare6 and also as Meeusen et al. suggest standardisation of the training and practice of nurse anaesthetists is desirable for patient safety and quality of care if they seek to work in more than one European country.7
CICV is a rare scenario, but if managed poorly can lead to severe morbidity and mortality. We emphasise that regular training sessions for ODPs/circulation nurses in a simulated environment will help to increase their confidence and their skill levels in dealing with this difficult and stressful situation. The positive feedback from the participants has further strengthened the value of this study as they found it to be a very useful and an educational experience.
Assistance with the letter: none declared.
Financial support and sponsorship: none declared.
Conflicts of interest: none declared.
1. John B, Suri I, Hillermann C, Mendonca C. Comparison of cricothyroidotomy on manikin vs. simulator: a randomised cross-over study. Anaesthesia
2. Wong DT, Prabhu AJ, Coloma M, et al. What is the minimum training required for a successful cricothyrotomy? A Study in mannequins. Anesthesiology
3. Manser T. Team work and patient safety in dynamic domains of healthcare: a review of the literature. Acta Anaesthesiol Scand
4. Henderson JJ, Popat MT, Latto IP, Pearce AC. Difficult Airway Society guidelines for management of the unanticipated difficult intubation. Anaesthesia
5. Sinclair CM, Thadsad MK, Barker I. Modern anaesthetic machines. Br J Anaesth: CEACCP
6. Burtscher MJ, Manser T, Kolbe M, et al. Adaptation in anaesthesia team coordination in response to a simulated critical event and its relationship to clinical experience. Br J Anaesth
7. Meeusen V, Van Zundert A, Hoekman J, et al. Anaesthesia team members: a European survey. Eur J Anaesthesiol