Out-of-hospital cardiac arrest due to refractory pulseless ventricular tachycardia and/or ventricular fibrillation

Background

Survival rates for out-of-hospital cardiac arrest (OOHCA) are extremely low and neurologic recovery is poor. Extracorporeal cardiopulmonary resuscitation (ECPR), which combines extracorporeal membrane oxygenation (ECMO) with cardiopulmonary resuscitation (CPR), has emerged as a viable strategy to improve outcomes in OOHCA. A collaborative ECPR program for out-of-hospital refractory pulseless ventricular tachycardia (VT) and/or ventricular fibrillation (VF) has been developed between The Ohio State University Wexner Medical Center and Columbus Division of Fire Emergency Medical Services (EMS).

Purpose

Outcomes for patients who present as an ECPR alert from the field, but did not meet predefined criteria for placement of extracorporeal membrane oxygenation (ECMO) in the cardiac catheterization laboratory (CCL) is described.

Methods

Between September 15, 2017 and October 12, 2019, 50 subjects presented as an ECPR alert for OOHCA secondary to pulseless VT/VF refractory to defibrillation. All subjects were placed on an automated CPR device prior to transfer to the CCL. From these 50 individuals, 28 (56%) did not meet prespecified laboratory criteria (lactate ≤15 mg/dL, partial pressure of oxygen (PaO2) ≥50 mm Hg, end-tidal carbon dioxide (ETCO2) of ≥10) and did not have a shockable rhythm in the CCL, thus ECMO was not placed and usual care for cardiac arrest was administered.

Results

Nine (32%) of the 28 patients achieved return of spontaneous circulation (ROSC), while the remaining 19 (68%) where pronounced deceased in the CCL. All 9 patients who achieved ROSC underwent a coronary angiography with 4 (44%) requiring percutaneous coronary intervention and 4 (44%) requiring an acute mechanical circulatory support device (Impella with 1 change out to ECMO). Of the patients that achieved ROSC, 4 (44%) were discharged from the hospital with good neurologic recovery; the remaining 5 (56%) ultimately expired during the hospitalization. From the initial 28 patient cohort, there were 4 (14%) patients discharged alive. Patients who achieved ROSC as compared to no ROSC were found on presentation in the CCL to have a significantly lower lactate (12.3±4.3 vs 16.2±3.6, respectively; p=0.03) and greater PaO2 (145±125 vs 47±9, respectively; p=0.01); there was no significant differences between groups in ETCO2, age or emergency services dispatch to CCL arrival time.

Conclusion

This study demonstrates that an ECPR program for OOHCA due to refractory VT/VF may provide benefit to patients that do not meet the predefined criteria for ECMO. This may be due to minimizing no flow/low flow time by early recognition and ongoing CPR en route to the CCL by a skilled EMS team, high efficiency citywide expedited transport/triage, the provision of high quality uninterrupted chest compressions using the mechanical CPR device during transport, and the care provided by highly trained multidisciplinary team members in the CCL.

Funding Acknowledgement

Type of funding sources: None.