Highlights
- Early defibrillation remains a pivotal determinant of survival in out-of-hospital cardiac arrest (OHCA).
- Utilization of EMS monitors/defibrillators for initial rhythm checks in the emergency department (ED) significantly reduces the time to first rhythm analysis and defibrillation.
- EMS equipment use in ED may increase defibrillation frequency but could slightly delay ED bed transfer.
- Despite reduction in time metrics, survival to hospital discharge remains low, underlining the complexity of OHCA management.
Background
Out-of-hospital cardiac arrest (OHCA) poses an ongoing global public health challenge with high mortality despite advances in resuscitation science. Early recognition and defibrillation of shockable rhythms markedly improve survival and neurological outcomes. Emergency Medical Services (EMS) play a central role in early resuscitative efforts and often initiate defibrillation before hospital arrival. Once patients reach the emergency department (ED), the continuation of timely rhythm assessment and defibrillation is critical to maintain chances of survival and neurological recovery.
Traditional ED protocols involve transitioning patients to ED monitors and defibrillators for rhythm analysis and treatment. However, delays may occur during equipment changeover, patient transfer, and rhythm reassessment, cumulatively lengthening the time to intervention. Investigating the impact of using EMS equipment directly in the ED for initial rhythm analysis and defibrillation may identify opportunities to reduce treatment delays and improve outcomes.
Key Content
Chronological Development of Evidence on EMS Equipment Use in ED for OHCA
Earlier research has emphasized the importance of minimizing no-flow and low-flow times in cardiac arrest resuscitation. Guidelines consistently recommend rapid rhythm assessment and defibrillation within minutes. However, few studies have specifically evaluated the process metrics related to equipment transition in the ED post-OHCA. The study by Ramraj et al. (2026) is notable as one of the first large-scale, video-reviewed investigations into EMS equipment use in the ED and its association with timing of rhythm analysis and defibrillation.
Study Design and Patient Population
This single-center retrospective study reviewed 223 patients aged 18 years or older presenting with OHCA to an urban ED between October 2018 and February 2024. Patients who attained return of spontaneous circulation (ROSC) prior to hospital arrival or those with traumatic cardiac arrest were excluded to maintain a homogeneous cohort for timing and rhythm analysis assessments.
Patients were stratified into two groups based on the initial rhythm assessment equipment used in the ED:
- EMS Group: Utilization of EMS monitors/defibrillators and pads for the first ED rhythm analysis.
- ED Group: Use of ED monitors/defibrillators and pads for initial rhythm analysis following transfer.
Primary and Secondary Outcomes
- Primary: Time from ED arrival to first rhythm analysis.
- Secondary: Time to first defibrillation in the ED.
Additional exploratory outcomes included time to ED bed transfer, ROSC rates in the ED, survival to hospital admission and discharge, and neurological outcomes at discharge.
Key Findings and Statistical Analysis
- The EMS group (33.6% of patients) demonstrated a significantly shorter median time to first ED rhythm analysis by 143 seconds compared to the ED group (95% CI: 116 to 169 seconds).
- Similarly, time to first ED defibrillation was reduced by 131.5 seconds in the EMS group (95% CI: 8 to 272 seconds), indicating earlier intervention delivery.
- The EMS equipment group had a longer time to ED bed transfer by 15 seconds (95% CI: 0 to 21 seconds), likely reflecting procedural nuances in keeping EMS equipment attached prior to transition.
- Defibrillation occurred more frequently in the EMS group by 18% (95% CI 4.2 to 31.8%), reflecting potentially better identification or management of shockable rhythms.
- Survival to hospital admission was achieved in 44 patients, whereas only 8 patients survived to hospital discharge, aligning with known poor outcomes in this population.
Contextualization Within Broader Literature
Prior research establishes early defibrillation as the cornerstone of improving OHCA survival, with the cerebral and myocardial ischemic time critically influencing outcomes. EMS-to-ED handover coordination is a recognized phase where delays and miscommunication can prolong no-flow times. Literature exploring pre-hospital to in-hospital transition emphasizes minimizing equipment changes and maintaining continuous monitoring.
Studies assessing advanced life support protocols highlight that delays at ED arrival, including monitor hookup and rhythm reevaluation, can extend critical time to defibrillation. However, a lack of large-scale evidence has limited consensus on whether sustaining EMS equipment use in ED confers measurable clinical benefits.
The findings by Ramraj et al. provide quantifiable data supporting the tactical retention of EMS equipment during early hospital evaluation to abbreviate rhythm analysis and shock delivery times. This aligns with guidelines advocating streamlined transitions and potentially informs protocol optimization.
Expert Commentary
The study underscores the practical impact of system-level interventions on time-sensitive processes in OHCA resuscitation. By maintaining EMS equipment use initially in the ED, teams potentially avoid delays inherent in switching monitors or pads, quickening rhythm recognition and defibrillation—a critical determinant of neurologically intact survival.
Nevertheless, the slight prolongation of ED bed transfer merits attention; balancing the gains in early rhythm analysis with logistical workflow must be considered. Defibrillation timing improvement comes at the cost of marginal transfer delay, possibly requiring process redesign or staff training to optimize transitions.
Survival outcomes, although modest, reflect the challenging nature of OHCA. The study does not establish causality of EMS equipment use on survival but suggests a potential pathway to improve care timeliness, which is a prerequisite for outcome improvements.
Implementation of these findings into clinical practice should factor in equipment compatibility, staff familiarity with EMS devices, standardized handover protocols, and multidisciplinary coordination.
From a mechanistic standpoint, shorter intervals to defibrillation decrease ischemic injury duration, which is critical for myocardial salvage and cerebral preservation. The study highlights how operational factors within the ED intersect with clinical physiology to influence arrest outcomes.
Conclusion
In conclusion, evidence indicates that utilizing EMS equipment for initial rhythm analysis and defibrillation in the ED significantly reduces time to critical interventions in OHCA patients. This operational approach aligns with the emphasis on rapid rhythm recognition and shock delivery to optimize survival and neurological outcomes.
Though survival benefits remain to be definitively proven, reduction in procedural delays is a pragmatic and achievable target within resuscitation systems of care. Future prospective, multicenter studies should evaluate the impact on functional outcomes and examine the interplay with other ED processes.
Hospitals and EMS agencies should consider workflow adaptations to enable EMS equipment continuity at arrival. Integrating this practice could reinforce the chain of survival, promoting earlier defibrillation and potentially improving OHCA prognosis.
References
- Ramraj R, Chen E, Huang X, Haddad G, McCann-Pineo M, Young E, Li T, Becker L, Rolston D, Jafari D. Emergency Medical Services Equipment Use in the Emergency Department and Time to Care for Those With Out-of-Hospital Cardiac Arrest. Ann Emerg Med. 2026 Jun 11;88(3):370-375. PMID: 42274435.
- Neumar RW, et al. Part 8: Adult Advanced Cardiovascular Life Support: 2015 American Heart Association Guidelines Update for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Circulation. 2015;132:S444–S464.
- Perkins GD, et al. Adult resuscitation: 2017 ILCOR consensus on science and treatment recommendations. Resuscitation. 2018;128:33–47.
- Meaney PA, et al. Cardiopulmonary resuscitation quality: Improving cardiac resuscitation outcomes both inside and outside the hospital. Circulation. 2013;128(4):417-435.
- Wik L, et al. Delays in arrival of defibrillation diminish survival chances after OHCA. Resuscitation. 2003;58(3):223-231.
