Page 154 - Ultrasonography in Prehospital and Emergency Medicine - Rein Ketelaars

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Chapter 7
Methods
Study setting
The Nijmegen HEMS, a department of the Radboud university medical center (Rad- boudumc), is one of four HEMS in the Netherlands. It services the largely rural eastern part of the country and cooperates with German emergency services. An area is covered of 10,088 square kilometers (3,895 square miles) and roughly 4.5 million people. The Dutch HEMS teams consist of a physician (anesthesiologist or trauma surgeon), an emergency care nurse (HEMS Crew Member) and a pilot. The service is supplementary to a network of paramed- ic-staffed ground ambulances and is deployed by the regional dispatch center based on either the emergency call or on the paramedic’s request, resulting in over 17,000 scrambles within the study period (2007–2016). Most often, the ambulance paramedics are the first to arrive on-scene and whenever patients are found to be vitally stable, deceased, or not present, HEMS scrambles are canceled in flight in consultation with the HEMS physician. Likewise, it can be decided not to wait but to transport immediately to the nearest appropriate hos- pital.
All PHUS examinations are performed by HEMS physicians according to the Polytrauma Rapid Echo-Evaluation Program (PREP), a French protocol similar to the Extended Focused Assessment with Sonography for Trauma (eFAST). All physicians have successfully complet- ed a two-day PREP course that consists of lectures, and mainly hands-on training. During the course, all participants perform at least 20 PREP examinations on each other and on peritoneal dialysis patients (having free intraperitoneal fluid). The goal is expeditious screen- ing of the chest, heart, pericardium, and abdomen, in under three minutes.
During the study period, three ultrasound devices were used: MicroMaxx, NanoMaxx, and M-Turbo (Fujifilm SonoSite Inc., Bothell, WA, USA), all equipped with a 5–1 MHz broad- band phased-array transducer. For every scramble and every patient, physicians create an electronic medical record (EMR) in the custom-built HEMS database. This includes patient characteristics, trauma mechanism, working diagnosis, mode of transport and destination before PHUS, impact of PHUS on treatment plan, and a concise narrative report.
Design
We conducted a retrospective analysis of every patient in whom an abdominal PHUS exam- ination was performed by the Nijmegen HEMS in the period from the 1st of January 2007 until the 31st of December 2016. The regional ethics review board of Arnhem/Nijmegen ap-