Prehospital Ultrasound: Nationwide Incidence from the NEMSIS Database

We sought to describe prehospital ultrasound (PHUS) use and trends in PHUS utilization over time using a national database.

Using the 2018 - 2021 National Emergency Medical Services Information System databases, we identified those EMS activations where PHUS was performed. We evaluated the association between year and number of PHUS exams performed using univariable and multivariable regression analysis. Analysis was performed on the overall group and various subgroups.

In total, there were 148,709,000 EMS activations by 13,899 agencies over the 4 years. Of these, 3,291 unique activations (0.002%) involved PHUS, performed by 71 EMS agencies (0.5%). The annual rate of ultrasound evaluations per 1 million EMS activations significantly increased over the study period: 5.2 in 2018, 14.8 in 2019, 18.6 in 2020, and 38.9 in 2021 (p < 0.01). The number of agencies performing PHUS each year increased over the study period from 11 in 2018 to 54 in 2021 (p < 0.05). Each year after 2018 had an increased odds of PHUS use demonstrated with logistic regression (p < 0.01). PHUS was used in each US census region, and paramedics performed most of the PHUS exams (75.5%). We identified 1,060 out-of-hospital cardiac arrest, 820 trauma, and 427 respiratory PHUS cases. These three cohorts accounted for 70.1% of all PHUS cases.

Prehospital ultrasound use in the United States increased significantly over the study period, but remains exceedingly rare. The performance of PHUS was recorded throughout the United States, with paramedics performing the majority of PHUS studies included in this database.