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For Cardiac Arrest, Too-Hasty Transport Gets in the Way of Good CPR

— Study suggests EMS practice is counterproductive

MedpageToday
Two emergency medical technicians perform CPR on an unconscious man laying on the pavement

Years of transporting out-of-hospital cardiac arrest (OHCA) patients mid-arrest could have put a damper on resuscitation quality, registry data suggested.

Intra-arrest transport during resuscitation was associated with worse odds of survival to hospital discharge compared with continued on-scene resuscitation (4.0% vs 8.5%, adjusted RR 0.48, 95% CI 0.43-0.54), according to a propensity-matched analysis by a group led by Brian Grunau, MD, MHSc, of St. Paul's Hospital in Vancouver, British Columbia.

"Thus the logistical obstacle of moving the patient with ongoing resuscitation may impair or delay best practices including CPR [cardiopulmonary resuscitation] quality," the researchers wrote . The study supports a strategy where emergency medical systems (EMS) should "dedicate effort and expertise on scene rather than prioritizing transport to hospital," the team added.

The findings persisted across subgroups of initial shockable and nonshockable rhythms, as well as EMS-witnessed and unwitnessed cardiac arrests, the investigators reported. Moreover, prioritizing early transport was also associated with less survival with favorable neurological outcome (modified Rankin scale 0-2) at hospital discharge (2.9% vs 7.1%, adjusted RR 0.60, 95% CI 0.47-0.76).

The registry study, including 192 EMS agencies across 10 North American sites, supported previous reports of wide regional variability in the use of intra-arrest transport.

"Historically, management of OHCA in the U.S. was guided by the model of rapidly transporting the patient to a hospital, in contrast to the model used in France and Germany of treating the patient at the scene," noted Alexander Lo, MD, PhD, of Northwestern University Feinberg School of Medicine in Chicago, writing in an .

"The promise of multiple potential in-hospital OHCA therapies and recent research into potential innovations in the out-of-hospital management have only fueled the debate between these two models ... 'scoop and run' and 'stay and play,'" Lo said.

He highlighted the finding in the study that 61% of intra-arrest transport survivors who were transported after 30 minutes had been successfully resuscitated prior to hospital arrival: "In those cases, survival may reasonably be considered more likely to have been attributable to out-of-hospital resuscitation rather than the in-hospital interventions," Lo stated.

Nevertheless, before having EMS fully embrace "stay and play" and revise the out-of-hospital approach to OHCA, "more definitive studies, including high-quality randomized trials, will be needed," he cautioned.

The study was based on the Resuscitation Outcomes Consortium Cardiac Epidemiologic Registry, which counted 43,969 consecutive cases of nontraumatic adult EMS-treated OHCA (median age 67, 37% of whom were women) in 2011-2015.

Overall, just over a quarter of people underwent intra-arrest transport. They were matched 1:1 with patients in refractory arrest who underwent on-scene resuscitation.

"[T]he potentially significant heterogeneity between the patient populations and between EMS systems challenge both the generalizability of the study findings and the likelihood that individual communities and EMS systems would enthusiastically adopt a practice change as a result of this study," Lo pointed out.

The observational study design left room for potential confounding, the investigators acknowledged. In addition, more recent data were not available as the registry had been discontinued in June 2015.

"Based on data from this study, caution may be warranted with regards to changes in EMS policy favoring routine intra-arrest transport for the purpose of candidacy assessment at the hospital as most will likely prove ineligible, and overall survival statistics may actually worsen," the study authors said.

They suggested various ways that intra-arrest transport could end up hurting patients in OHCA. For example, extrication and transport may impair quality of manual compression. "The physical tasks of patient movement may also interfere or delay resuscitative maneuvers such as defibrillation or drug delivery. Transport during an active resuscitation may also produce a cognitive distraction and inhibit a paramedic's ability to deliver high-quality resuscitative efforts and treat possible reversible causes," the researchers wrote.

Lo noted that optimal EMS protocol for OHCA is a timely issue because of the aging population (which can be expected to bring about a greater incidence of cardiac arrests and ) and the ongoing COVID-19 pandemic.

"If continued on-scene resuscitation confers a true benefit in outcome for OHCA, then it must also be accompanied by the necessary policy and logistical considerations to ensure that all EMS personnel have the necessary personal protective equipment to minimize their risk of COVID-19 infection," he stated.

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    Nicole Lou is a reporter for 51˶, where she covers cardiology news and other developments in medicine.

Disclosures

The Resuscitation Outcomes Consortium was supported by the National Heart, Lung, and Blood Institute in partnership with the National Institute of Neurological Disorders and Stroke, U.S. Army Medical Research and Material Command, the Canadian Institutes of Health Research, Defence Research and Development Canada, the Heart and Stroke Foundation of Canada, and the American Heart Association.

Grunau disclosed a speaking honorarium from Stryker.

Lo had no disclosures.

Primary Source

JAMA

Grunau B, et al "Association of intra-arrest transport vs continued on-scene resuscitation with survival to hospital discharge among patients with out-of-hospital cardiac arrest" JAMA 2020; DOI: 10.1001/jama.2020.14185.

Secondary Source

JAMA

Lo AX, et al "Challenging the 'scoop and run' model for management of out-of-hospital cardiac arrest" JAMA 2020; DOI: 10.1001/jama.2020.9245.