Regionalization of out-of-hospital cardiac arrest (OOHCA) care is a topic that is continuously evolving. Recently, there has been a large amount of investigation on the relationship between transport time and survivability. While regionalization of care has been shown to improve patient outcomes, there have been concerns about transport times needed to reach these centers.

According to the American Heart Association, one of the most common causes of OOHCA is acute coronary occlusion; early angiography or coronary intervention is recommended for patients with and without ST-segment elevation if a cardiac or coronary cause is suspected.¹ Early CPR and defibrillation have drastically increased the rate of survival over the past few years, and successful OOHCA resuscitation by EMS is viewed as the norm and not the exception in today’s society.² Recent data have shown that if patients are taken to a tertiary center, especially if it was a witnessed arrest, there was bystander CPR ongoing, or the initial rhythm was ventricular fibrillation, regardless of transport time, survival is improved. ^3-5

In 2009, Spaite et al found that transport time was not associated with a decreased survival rate, supporting the safety of bypassing smaller, local hospitals to take patients to regional cardiac centers.⁶ In 2010, another study explored this question and concluded that survival to discharge was highest when OOHCA were taken to the more specialized hospitals, even though they were father away, and transport distance was not associated with survival. These findings were independent of patient characteristics.⁷ Another study in 2017 showed similar results, with increased survival to hospital discharge in those transported to an invasive heart center versus those who were not, despite transport time.⁸

While it is important to realize that the care provided to the OOHCA patient after arrival to the hospital is not unimportant or trivial, it is also well established that the two most significant variables associated with survival are excellent chest compressions and early defibrillation. EMS providers can easily perform these early interventions. As Cheskes et al demonstrated, high-quality chest compressions can be done regardless of location, despite the notion that CPR quality deteriorates during the transport phase.⁹ It is also known that cardiac arrest patients who do not achieve return of spontaneous circulation in the field have a lower chance of survival. Therefore, EMS plays an important role for the OOHCA patient.

Yet an important question still remains: What is an appropriate time for transport?

While there is not a straight forward answer to this question, most of the studies published to date have reported transport times less than 10 minutes from the scene. Transport time in the reported studies did not take into account time at the scene or time from dispatch. However, it would make sense that the longer the patient has been down, the smaller the chance of survival, versus a patient that had an arrest witnessed by EMS.

Bypassing a local, minimal-capability hospital might be the correct step for EMS to take if they can transport the OOHCA patient to a more specialized facility that offers cardiac catheterization and invasive cardiac procedures, even if the transport time is longer. However, this could be different in rural prehospital systems where transport times are much greater than ten minutes.

References

1. Neumar RW, Shuster M, Callaway CW, et al. 2015 American Heart Association guidelines update for cardiopulmonary resuscitation and emergency cardiovascular care. Circulation. 2015;132(suppl 2):S315-S367.
2. Kronick ST, Kurz MC, Lin S, et al. Systems of care and continuous quality improvement. 2015 American Heart Association guidelines update for cardiopulmonary resuscitation and emergency cardiovascular care. Circulation. 2015;132:S397-S413.
3. Jabbour RJ, Sen S, Mikhail GW, et al. Out of hospital cardiac arrest: concise review of strategies to improve outcome. Cardiovasc Revasc Med. March 15, 2017. [Epub ahead of print]
4. Cha WC, Lee SC, Shin SD, et al. Regionalisation of out of hospital cardiac arrest for patients without prehospital return of spontaneous circulation. Resuscitation. 2012;83:1338-1342.
5. Geri G, Gilga J, Wu W, et al. Does transport time of out of hospital cardiac arrest patients matter? A systematic review and meta-analysis. Resuscitation. 2017;115:96-101.
6. Spaite DW, Stiell IG, Bobrow BJ, et al. Effect of transport interval on out of hospital cardiac arrest siurvival in the OPLAS study: implications for triaging patients to specialized cardiac arrest centers. Ann Emeg Med. 2009;54(2):248-255.
7. Cudnik, MT, Schmicker RH, Vaillancourt C, et al. A geospatial assessment of transport distance and survival to discharge in out of hospital cardiac arrest patients: implications for resuscitation centers. Resuscitation. 2010;81(5):518-523.
8. Tranber T, Lippert FK, Christense EF, et al. Distance to invasive heart centre, performance of acute coronary angiography, and angioplasty and associated outcome in out of hospital cardiac arrest: a nationwide study. Eur Heart J. 2017;00:1-8.
9. Cheskes, S, Byeres A, Zhan C, et al. CPR quality during out of hospital cardiac arrest transport. Resuscitation. 2017;114:34-39.

Dr. Lipe is a captain in the Medical Corps of the U.S. Army and a physician in the emergency department at Martin Army Community Hospital in Fort Benning, Georgia.