On-Scene Surgery for Traumatic Cardiac Arrest: When Is It Futile?

The experience of London’s unique physician-paramedic model shed light on the limits of prehospital resuscitative thoracotomy (RT) for traumatic cardiac arrest (TCA), based on records spanning 21 years.

When RT was provided for TCA by London’s Air Ambulance, people survived to hospital discharge in just a grim 5% of cases, three-quarters of those with a favorable neurological outcome. However, survival varied significantly depending on the cause of TCA: 21% with cardiac tamponade, 1.9% with exsanguination, and none of those with combined or other pathologies, according to Zane Perkins, MBBCh, PhD, of The Royal London Hospital, and co-authors in JAMA Surgery.

Notably, there were no survivors beyond 15 minutes of TCA for cardiac tamponade and 5 minutes after exsanguination. TCA had occurred a median 12 minutes after the emergency call, and the advanced trauma team typically arrived about 8 minutes later.

“TCA occurs soon after injury, with only a brief window available for effective intervention. This study found that resuscitative thoracotomy is feasible in a mature, physician-led, urban prehospital system and is associated with improved survival for patients with out-of-hospital TCA, particularly when caused by cardiac tamponade, in situations where other treatment options are limited,” Perkins and colleagues wrote in their report.

“Transfer to the hospital in established TCA is almost always futile,” they cautioned, stressing “the need for effective on-scene interventions for potentially reversible causes of TCA.”

Emergency surgery is the most effective treatment for penetrating cardiac injuries and cardiac tamponade, the authors noted.

London’s Air Ambulance provides 24/7 advanced trauma care and has implemented on-the-scene RT since the early 1990s. Participating physician-paramedic teams are also trained to provide prehospital anesthesia, blood transfusion, and resuscitative balloon occlusion of the aorta.

According to Perkins’ team, successful prehospital RT “requires a system capable of rapid deployment of a highly trained medical team, supported by a robust supervision, training, and clinical governance program. Furthermore, effective integration with [emergency medical services] and hospital trauma services is essential to ensure continuity of care from the prehospital to in-hospital phases.”

“Perkins et al reemphasize that time matters and that outcomes rapidly deteriorate from 5 to 10 minutes after arrest regardless of mechanism or pathophysiology. These data emphasize the need to push advanced therapies closer to the point of injury for the right patients to improve meaningful outcomes,” commented Brian Zuckerbraun, MD, MBA, of the University of Pittsburgh, and two colleagues in an accompanying editorial.

Whether on-scene RT is ultimately worth it — or feasible outside London — is still controversial, however, Zuckerbraun’s group wrote.

“This physician-led, prehospital resource is laudable, yet it is not applicable to trauma care even in most major urban centers in well-resourced environments for most prehospital systems. Physicians rarely participate in direct patient care in the prehospital setting in the U.S., and when available, this care typically requires mobilization of specialized teams outside a meaningful time frame for resuscitative thoracotomy,” the trio noted.

The retrospective cohort study covered the work of London’s Air Ambulance from January 1999 to December 2019. During that time, the service attended to over 45,000 injured people, of whom 601 had out-of-hospital TCA and underwent prehospital RT.

Median age was 25 years and 89.5% were men. TCA was the result of cardiac tamponade (17.6%), exsanguination (70.0%), and exsanguination combined with cardiac tamponade (12.1%). Nearly 90% had a penetrating mechanism of injury, most of these from a nonballistic mechanism (i.e. not gunshot wounds); the remainder had a blunt mechanism of injury related to traffic collisions, falls, and other injuries.

They reported that on multivariable analysis, the predictors of survival were tamponade being the cause of TCA (adjusted OR 21.1, 95% CI 8.1-54.7) and duration of TCA <1 minute (adjusted OR 20.9, 95% CI 4.4-100.6), while the need for internal cardiac massage was linked to mortality (adjusted OR 0.2, 95% CI 0.06-0.5).

Limitations of the study include its retrospective design with the potential for selection bias in how first responders decided to perform RT. Evolving treatments during the study period may have also affected results.

“Moreover, the sample is highly skewed toward a penetrating nonballistic mechanism in a young male population, and thus generalizability beyond this subgroup is limited,” added Zuckerbraun’s group.

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