Abstract 140: Utilization of Mechanical CPR Is Highly Variable Within the National EMS Information System Dataset

Abstract

Background: Randomized controlled trials have demonstrated neither survival benefit nor harm from use of mechanical CPR (mCPR). Retrospective analyses have shown an association between mCPR and worse survival outcomes, even when controlling for differences in patient mix and arrest duration. Nonetheless, studies have suggested mCPR use increased from 2013 to 2016. Objective: We sought to quantify the proportion of out-of-hospital cardiac arrest (OHCA) cases in the US with utilization of mCPR and use in conjunction with other procedures. Methods: Using Emergency Medical Services (EMS) call data from the National EMS Information System (NEMSIS) Dataset, we identified non-traumatic OHCA with EMS resuscitation. Procedure codes were classified as “Mechanical CPR”, “Advanced Airway”, “IO”, “IV”, “Defibrillation”, “Other” and “No Procedures”. The NEMSIS Dataset includes US Census Region, Division, and urbanicity for each call. Results: In 2016, there were 29,919,652 EMS activations reported, 151,333 met inclusion criteria and 138,555 included procedure codes. Of the OHCA cohort, the mean age was 63±20 yrs, 39% were female, 86% occurred prior to EMS arrival, 62% occurred in a home/residence, 18% in public, and 14% in healthcare facilities. mCPR was used in 10% of all cases. Reported regional utilization varied from 4.8% in the Northeast to 14.9% in the South (p<0.001). mCPR did not vary significantly based on urbanicity (range: 10.4% to 11.4%, p=0.34). In multiple logistic regression controlling for age, gender, location of arrest, race and ethnicity, and region, mCPR utilization was more likely if an advanced airway was placed (OR: 1.74, CI: 1.58-1.91), and less likely if an IV or IO was placed (IV: OR 0.75, CI 0.71 - 0.79; IO: OR 0.37, CI 0.28 - 0.48). 4,928 cases contained information on survival to admission. Of these, overall survival to admission was 27%, with no significant difference between mCPR and no mCPR groups. Survival to discharge data was available for 2,476 subjects (1.8% of OHCA cohort). Survival to discharge was higher among the non-mCPR group (13.8% vs. 10.3%, p = 0.011). Conclusion: In NEMSIS, reported mCPR utilization is highly variable across the US. The overall proportion of cases receiving mCPR is lower than previous registry-based studies.