Out-of-Hospital Cardiac Arrests Terminated without full Resuscitation Attempts: Characteristics and Regional Variability

Selection of patients for mechanical circulatory support for refractory out-of-hospital cardiac arrest

OBJECTIVE

To describe characteristics of patients admitted with refractory cardiac arrest for possible extracorporeal cardiopulmonary resuscitation (ECPR) and gain insight into the reasons for refraining from treatment in some.

METHODS

Nationwide retrospective cohort study involving all tertiary centres providing ECPR in Denmark. Consecutive patients admitted with ongoing chest compression for evaluation for ECPR treatment were enrolled. Presenting characteristics, duration of no-flow and low-flow time, end-tidal carbon dioxide (ETCO₂), lactate and pH, and recording of reasons for refraining from ECPR documented by the treating team were recorded. Outcomes were survival to intensive care unit admission and survival to hospital discharge.

RESULTS

Of 579 patients admitted with refractory cardiac arrest for possible ECPR, 221 patients (38%) proceeded to ECPR and 358 patients (62%) were not considered candidates. Median prehospital low-flow time was 70 min (IQR 56 to 85) in ECPR patients and 62 min (48 to 81) in no-ECPR patients, p<0.001. Intra-arrest transport was more than 50 km in 92 (42%) ECPR patients and 135 in no-ECPR patients (38%), p=0.25. The leading causes for not initiating ECPR stated by the treating team were duration of low-flow time in 39%, severe metabolic derangement in 35%, and in 31% low ETCO₂. The prevailing combination of contributing factors were non-shockable rhythm, low ETCO₂, and metabolic derangement or prehospital low-flow time combined with low ETCO₂. Survival to discharge was only achieved in six patients (1.7%) in the no-ECPR group.

CONCLUSIONS

In this large nationwide study of patients admitted for possible ECPR, two-thirds of patients were not treated with ECPR. The most frequent reasons to abstain from ECPR were long duration of prehospital low-flow time, metabolic derangement and low ETCO₂.

Factors influencing prehospital physicians' decisions to initiate advanced resuscitation for asystolic out-of-hospital cardiac arrest patients

BACKGROUND

The decision to initiate or continue advanced life support (ALS) in out-of-hospital cardiac arrest (OHCA) could be difficult due to the lack of information and contextual elements, especially in non-shockable rhythms. This study aims to explore factors associated with clinicians' decision to initiate or continue ALS and the conditions associated with higher variability in asystolic patients.

METHODS

This retrospective observational study enrolled 2653 asystolic patients on whom either ALS was attempted or not by the emergency medical services (EMS) physician. A multivariable logistic regression analysis was performed to find the factors associated with the decision to access ALS. A subgroup analysis was performed on patients with a predicted probability of ALS between 35% and 65%. The single physicians' behaviour was compared to that predicted by the model taking into account the entire agency.

RESULTS

Age, location of event, bystander CPR and EMS-witnessed event were independent factors influencing physicians' choices about ALS. Non-medical OHCA, younger patients, less experienced physicians, presence of breath activity at the emergency call and a longer time for ALS arrival were more frequent among cases with an expected higher variability in behaviours with ALS. Significant variability was detected between physicians.

CONCLUSIONS

Significant inter-physician variability in access to ALS could be present within the same EMS, especially among less experienced physicians, non-medical OHCA and in presence of signs of life during emergency call. This arbitrariness has been observed and should be properly addressed by EMS team members as it raises ethical issues regarding the disparity in treatment.