Background

Approximately 1.3 million people die each year globally as a direct result of motor vehicle collisions (MVCs) [1]. Following a MVC some patients will remain trapped in their vehicle; these patients have worse injuries and are more likely to die than their untrapped counterparts [2]. Patients who are trapped may require assistance in leaving their vehicle; this assistance is termed ‘extrication’ and is often delivered by the rescue services [3]. Extrication may be simple, such as releasing a stuck door, or complex, with specifically designed tools and techniques being used to alter the internal and external structures of the vehicle [3].

The current standard approach to extrication prioritises absolute movement minimisation which contributes to prolonged extrication times [4,5,6]. Such ‘traditional’ approaches to extrication have recently been challenged by evidence demonstrating the relative rarity of unstable spinal injury or spinal cord injury compared to other time-critical injuries[2]. In addition biomechanical studies in healthy volunteers have demonstrated that rescue service extrication techniques cause more movement than self-extrication, further questioning the accepted approach to extrication [7,8,9].

Given this new evidence, we need to reconsider the current approach to extrication. The evidence base is wide and diverse, including a large variety of experimental techniques from a broad range of disciplines. These approaches and disciplines include, but are not limited to; rescue service descriptive accounts, biomechanical analyses, clinical case reports, case series, expert opinion, patient experience, crash investigation reports, road safety expert opinion, car design literature and others. A narrative review of this literature is available in the additional file for this paper. The complex nature and wide variety of potential circumstances and subsequent energy transfer that occurs in a MVC, the number, demographics and susceptibility to injury of the patients involved, their injuries and the availability of each aspect of the multi-professional response makes the design and delivery of traditional ‘clinical’ trials in this area an impractical challenge.

The diverse evidence base, requirement for pragmatic expert translation of evidence to practice and the need to achieve multi-professional consensus makes this subject area highly suitable for iterative multi-stage consensus research techniques, such as a Delphi study [10, 11].

The aim of this Delphi study is to develop multi-professional consensus on the evidence-based approach to extrication.

Methods

This Delphi study has been developed, administered and reported to the guidance on Conducting and Reporting Delphi Studies (CREDES) standards [10]. The methods are summarised in Fig. 1.

Fig. 1
figure 1

Summary of methods and progression of statements and SMEs through the study

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The principal researcher (TN), through a review of the literature identified key areas of expertise that should be represented in a Steering Group for a study in this area of practice. This included individuals with expertise in extrication, prehospital care, trauma care, neurotrauma and representatives of patients with spinal cord injury. Experts with an interest in each of these areas were identified and recruited to offer guidance to the principal researcher within their areas of specialist interest, provide feedback on methodology and process, aid in the production and refinement of statements for the Delphi group and ensure methodological rigour. Joining the steering group excluded an individual as a participant in the Delphi (or subject matter expert, SME).

The Steering Group identified professional organisations that are key stakeholders in UK extrication practice. Stakeholder groups identified were the National Fire Chiefs Council (NFCC), the United Kingdom Rescue Organisation (UKRO), the National HEMS Research & Audit Forum (NHRAF), the College of Paramedics (CoP), the Pre-Hospital Trainee Operated Research Network (PHOTON) and the Faculty of Prehospital Care (FPHC). Each stakeholder organisation was invited to identify up to ten representatives (SMEs). To qualify, SMEs needed to have at least five years of operational experience of delivering extrication or caring for patients during or post entrapment.

Statements for consideration originated from the current evidence base (including unpublished work reporting patient experience) and were proposed by the Steering Group and other stakeholders. All responses were collated and similar statements were collapsed. All materials, including surveys, statements and other written information were reviewed by the Steering Group and subsequently piloted with a multi-professional representative group of SMEs prior to further distribution.

The Delphi was conducted over three rounds, each of which were designed and delivered through the web-based platform Jisc online surveys (JSIC, https://www.onlinesurveys.ac.uk/ 2022). Identified SMEs (60 total) were provided with details of this Delphi study, the statements for consideration, an evidence synthesis (available as supplementary material), an invitation to participate in the study and an online consent form. Throughout the study the anonymity of the SME group was preserved. In each round, SMEs were invited to review the evidence synthesis for each domain of extrication practice and then for each statement using a three-point scale (agree, neither agree nor disagree, disagree) to indicate their opinion. In addition, for each statement the SME had the option to ‘opt out’ if the specific question was outside of their area of expertise. For each statement SMEs had the option to provide free text feedback; including the opportunity to refine current statements and suggest alternative statements for consideration in the following round.

Consistent with previous studies, consensus was set a priori at 70% agreement or disagreement of participating SMEs [12, 13]. Between each round, statements that reached consensus were removed. Statements that did not reach consensus were refined if consistent feedback indicated that this would improve or clarify the statement. Additional suggested statements were collapsed and made available in the following round. If SMEs did not participate in a round they were not eligible to participate in subsequent rounds.

Statements that were accepted or rejected were reported with supporting references. Those statements that reached consensus were summarised and presented individually to stakeholder organisations. Following iterative review an agreed set of clinical and operational principles on which future guidance would be based were agreed by participating stakeholders.

The Faculty Research Ethics and Integrity Committee at the University of Plymouth (ref. 19/20–1313) and the Human Research Ethics Committee at the University of Cape Town (ref. 183/2021) approved the study.

Results

Rounds 1–3 were conducted in January and February 2022. The background and experience of SMEs are summarised in Table 1.

Table 1 Professional, employer and experiential background of SMEs
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Figure 1 summarises the study. In Round 1, 88 statements were considered by 60 SMEs. Sixty statements achieved consensus (58 agree, 2 disagree). Free text feedback from SMEs led to three of the original statements from Round 1 progressing to Round 2 for reconsideration (with additional commentary) and the remaining 25 statements were refined and split to make a total of 46 statements presented at Round 2, where 27 statements achieved consensus and 19 did not. Following feedback in Round 2, 22 statements were presented to SMEs in Round 3 of which 5 achieved consensus and 17 did not (Table 2).

Table 2 Statements achieving consensus by theme
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Following iterative review with individual stakeholder organisations the agreed principles for future guidance across the organisations are presented in Table 3.

Table 3 Principles: agreed by stakeholder organisations
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Discussion

This Delphi study achieved consensus on 91 statements in an area of previously limited multidisciplinary, evidence-based guidance. These statements will provide a vital foundation for the development of multidisciplinary consensus guidance and best practice standards for the extrication of patients trapped in motor vehicles following a collision. These statements have been effectively translated into agreed multidisciplinary principals.

A key principle agreed by the SMEs identifies that operational and clinical team members should work together to develop a bespoke patient centred extrication plan with the primary focus of minimising entrapment time. The SMEs rejected the historical focus on absolute movement minimisation and instead recommended gentle patient handling for all patients independent of actual or suspected injuries. The SMEs encouraged FRS team members to take an active role in assessing patients, delivering clinical care and enacting extrication plans (including self-extrication). Inclusion and exclusion criteria for self-extrication or minimally assisted extrication were identified and agreed.

SMEs reached consensus in Round 1 in all the statements in the domain areas: ‘Patient focused extrication’ and ‘Audit standards and Research’. Consensus was also reached following Round 1 across all statements in the theme areas: ‘Terminology’, ‘Extrication Goals and Approach’ and ‘Patients requiring Disentanglement’. Consensus was not achieved for some of the remaining domain areas with the most contentious being the risk stratification of patients for potential cervical spinal injury, which patients should have a collar applied, and which professional groups should be providing “in vehicle” clinical care for those that remained trapped. The subject of immobilisation, patient handling and the use of cervical collars has received much attention in the literature; with increasing acknowledgement of the incomplete evidence base for historic approaches and the support of pragmatic alternative approaches [9, 17, 28,29,30, 39, 45,46,47,48,49,50,51]. These themes are explored in more detail in the SME briefing document included in the Additional file.

In general terms the SMEs were quicker or more likely to reach consensus in areas of practice where there was little evidence available or there was no current guidance e.g. patient focused extrication (Additional file 1). When there was more evidence available or in areas where there is current (often contradictory) guidance, the SME’s less frequently achieved consensus [7,8,9, 27]. This tension was displayed by more SME’s choosing to ‘opt out’ of the evidence rich statements, but the divergence in opinion of those that did participate remained consistent through the 3 rounds.

Consensus was harder to achieve in areas where professional roles and patient ‘ownership’ needed to be considered. Historically medical care has been delivered by clinicians with a health care background with rescue workers only offering minimal clinical assessment and interventions [4, 58, 59]. Recently in clinical and operational practice these boundaries have become more fluid with rescue services offering more clinical development to their personnel [59]. The statements in this Delphi considered the role of rescue services in delivering this care which was met with strong and diverse opinions. Through the rounds of the Delphi, the purpose of the statements was clarified, this along with clearer alternative statements led to consensus being achieved.

The utilisation of the CREDES Delphi standards for this study ensured that it was conducted and reported to an appropriate standard [10]. The SMEs demonstrated a high participation rate in the process with 82% of the original SMEs completing all three rounds. This Delphi was unusual both in the high number of statements presented to the SMEs and the high level of concordance between the SMEs leading to many statements reaching consensus. We took several steps to ensure that our SME selection was robust, unbiased and with minimal sampling bias, but our SMEs may not be truly representative of wider expertise in this subject area, and this may affect the external validity of our results. The CREDES standards support the piloting of questions with SMEs, the influence this may have on our results is unknown. All SMEs were drawn from a UK rescue service or prehospital clinical background and therefore these results may not be valid in countries with significant differences in availability or structure of rescue or clinical provision. It may be appropriate to reproduce some elements of this Delphi for settings which are notable different e.g. lower and middle income countries or military environments.

Following this Delphi, further work will be needed to support the translation of the principles into practice. Some domains from the Delphi will require further clarification; the SMEs identified the following areas for further consensus work: FRS clinical training (87.8%), collars and immobilisation (75.5%), EMS call handling and dispatch (73.5%), and self-extrication (63.3%).

The principles agreed by stakeholder organisations will offer a basis on which future discipline specific guidance will be based. The variability in format, language, scope and approach between clinical and rescue guidance prevents the production of a single cohesive guideline that would meet the needs of all the stakeholder organisations. Further translational work will ensure that the principles developed here are embedded in Joint Royal Colleges Ambulance Liaison Committee (JRCALC) guidance to guide paramedics, FPHC guidance to guide advanced prehospital emergency medicine practitioners and National Operational Guidance (NOG) to guide rescue services.

The principles established in this Delphi benefit from having minimal financial costs associated with bringing them into practice. We envisage the main barrier to adoption of new guidance will be overcoming the institutional and individual inertia established through 50 years of movement minimisation based clinical and operational practice—the challenges of unlearning cannot be underestimated [60]. The adoption of a formal evidence-to-practice process such as the Knowledge to Action (KTA) framework will help guide which steps will be most effective in the next challenging phase of this work [61,62,63].

The stakeholders represented in this Delphi will need to continue to work together to refine these principles for guidance and continue to revise their guidance based on the feedback of early adopters and audit outcomes from longitudinal data collection.

Conclusion

This study has demonstrated consensus across a large panel of multidisciplinary SMEs on many key areas of extrication and related practice that will provide a key foundation in the development of evidence-based guidance for this subject area.