Photo Credit: Akarawut Lohacharoenvanich

The following is a summary of “Association between emergency medical services intervention volume and out-of-hospital cardiac arrest survival: A propensity score matching analysis,” published in the June 2024 issue of Emergency Medicine by Vincent et al.

Survival rates for out-of-hospital cardiac arrest (OHCA) are very low, and while a link between institutional OHCA case volume and patient outcomes exists, the relevance to prehospital emergency medical services (EMS) remains unclear.

Researchers conducted a retrospective study examining the relationship between the volume of mobile intensive care unit (MICU) interventions and patient outcomes with OHCA.

They included adult patients with OHCA treated by medical EMS across 5 French centers (2013 to 2020). Patients were categorized into 2 groups based on the annual volume of MICU interventions in low-volume and high-volume. The primary endpoint was 30-day survival, while secondary endpoints included prehospital return of spontaneous circulation (ROSC), ROSC at hospital admission, and favorable neurological outcomes. Patients were matched 1:1 using propensity scores, and conditional logistic regression was employed for analysis.

The result showed that 2014 adult patients (69% male, median age 68 [57–79] years) were analyzed, with 50.5% (n = 1017) managed by low-volume MICU and 49.5% (n = 997) by high-volume MICUs. The 30-day survival rate was 3.6% in the low-volume group compared to 5.1% in the high-volume group. No significant association was found between MICU intervention volume and 30-day survival (OR = 0.92, 95% CI [0.55; 1.53]), prehospital return of spontaneous circulation (ROSC) (OR = 1.01, 95% CI [0.78; 1.30]), ROSC at hospital admission (OR = 0.92, 95% CI [0.69; 1.21]), or favorable neurological outcome on day 30 (OR = 0.92, 95% CI [0.53; 1.62]).

Investigators concluded that no association was found between MICU intervention volume and outcomes for patients with OHCA, indicating that further research across more centers is needed for definitive conclusions.

Source: jem-journal.com/article/S0736-4679(24)00195-1/fulltext