The London Bridge attack: managing multiple victims of penetrating trauma

Incidents and strategies

Broadly speaking, the approach to major incidents involving significant casualty numbers has not changed in many decades. The process involves emergency staff arriving first on the scene to gain a prompt overview in order to establish an appropriate response in terms of incident approach and resourcing.

Systems are then put in place to facilitate primary triage, casualty extrication and re-triage, appropriate field treatment, and priority-driven transport of the injured to designated centres (National Ambulance Resilience Unit (NARU), 2015). These processes take time to establish and can stretch the capability of services considerably.

The major incident response rightly focuses on the aggregate needs of the many rather than of any individual, so that the best can be done for the most. Understandably therefore, treatment and transport of individual patients (even some priority patients) may be delayed if the services responding are overwhelmed with casualties.

By contrast, the approach to a single victim of penetrating trauma is quite different. It is widely acknowledged that in this patient group, definitive management of bleeding happens in an in-hospital or physician-based setting—and, therefore, prehospital paramedic targets are set for short on-scene times (less than 5 minutes in London), with most immediate treatment delivered enroute to hospital (Faulkner, 2013).

The London Bridge attacks generated many patients who had suffered serious knife wounds, but who may have been compensating and otherwise looked well. Indeed, some were fully mobile. Such patients can cause a degree of deception, especially when viewed so soon after their wounds have been inflicted. It is understood that these types of patients will not always display the classic signs of shock (Guly et al, 2011), until they perhaps suddenly and irrevocably deteriorate.

However, in the context of a major incident, any mobile compensating patient (including those with an insidious life-threatening penetrating wound) will be ‘triage sieved’ as P3 (low priority) (NARU, 2014). By the time they present as P2 or P1 casualties (immobile or with obvious altered physiology, respectively), they may already be on an irreversible trajectory.

Processing a victim of a blunt force trauma can differ considerably from penetrating trauma. Blunt trauma can result in more pain which, from a humanitarian as well as practical viewpoint, may need addressing prior to patient movement. Injuries sustained may result in the casualty being less mobile and requiring greater handling and carrying. Fractures will require splinting, and extensive lacerations may require dressing and haemorrhage control. Additionally, the patient may need packaging with consideration to immobilising the spine (Association of Ambulance Chief Executives (AACE), 2016). Realistically, only one of these patients can occupy any one ambulance vehicle. In short, they are ‘resource intensive’.

The immediate aftermath

In the wake of the London Bridge attacks, patients with stab wounds arrived at hospital by various means. Some were taken by ambulance, some were driven by the police, and some used alternative transport. Interestingly, and as reported in the media, all the patients who arrived alive at any hospital survived regardless of their mode of transport (Lydall, 2017).

The initial ambulance response to the incident involved a modest number of resources sent to a reported road traffic collision. Although not known immediately, this intentional collision with pedestrians directly preceded the knife attacks. Once it became clear that both elements were terrorist-related, further ambulance personnel were held back for safety reasons until the police secured the scene.

By contrast, police numbers were much higher than ambulance responders earlier on in the incident. Once the terrorist threat had been neutralised, the police became involved in the treatment, emotional support and hospital conveyance of some victims.

Police officers and designated police ‘medics’ are of course very able to deliver first aid. With this in mind, and when considering the needs of the stabbed victim, there may be less temptation for those with a lower scope of clinical practice to protract on-scene time by undertaking unnecessary assessment, treatment and history-taking.

Despite the prevalence of penetrating trauma cases in London, it makes up only a small proportion of overall paramedic workload. Also, it contrasts significantly in terms of patient approach against a more frequent, low acuity patient group (minor injury/illness) that requires detailed and considered patient assessment, treatment, and referral.

Adapting the approach

Another unique dimension of this incident was the dispersed patient distribution. In the past, major terrorist incidents have often involved an epicentre; for example, the detonation of an explosive. These scenarios have a clearly defined geographical focus with radiating circumferential ‘zones’ dictating damage, danger and casualty severity. In some ways, managing this type of incident might be more straightforward. In more recent years, consideration has been given to more dispersed incidents involving mobile attackers (Harris, 2016). Indeed, at London Bridge, patients were scattered and often mobile. Furthermore, constant reassessment was required as patients later declared themselves having hidden away from danger. It is possible that the standard major incident response might not always be in the best interest of patients who have sustained life-threatening knife injuries with a very limited window of reversibility.

Role of the APP

Following the London Bridge attack, an experienced APP in critical care attending the scene from very early on was able to recognise the potential implications of those presenting injuries (prior to developing more ominous signs), and adjusted patient priority accordingly, thus circumventing the traditional triage sieve approach.

This approach was, and needed to be, dynamic for the reasons highlighted and may well have saved lives. At a time when ambulance resources were low, clinical leadership and oversight was provided for paramedics, police, members of the public and ‘off-duty’ health professionals, enabling more lateral options to be explored for immediate haemorrhage control, casualty movement, and transport of victims to hospital.

This perhaps worked well owing to the high number of police vehicles and the short journey times to London's receiving major trauma centres. Of course, consideration needed to be given to patient-tracking to avoid overloading the nearest hospital.

Over the more ‘normal’ and familiar patient approach, APP experience of penetrating trauma, complex incident scenes and a sound understanding of the aetiology, presentation, and treatment requirements, helped to ensure minimal on-scene times for ambulance crews. Furthermore, difficult decisions to stop resource-intensive—yet futile—resuscitations could be made, allowing efforts to be redirected to maximise overall patient benefit.

Conclusion

The clinical approach to a major incident has developed on the foundations of experience and good reasoning, and should be the default path for managing large casualty incidents. However, as every incident is different, an experienced critical care practitioner may be able to bring an advanced level of critical decision-making that helps balance individual patient need (and survival) against the wider system processes. Furthermore, there may a need for more formal recognition that a ‘one-size-fits-all’ approach may no longer be appropriate in all cases. Support should be provided to encourage modification of major incident principles in the best interest of patients where required.

Key Points