Page 139 - Ultrasonography in Prehospital and Emergency Medicine - Rein Ketelaars

Prehospital chest ultrasound by a Dutch helicopter emergency medical service 137
Introduction
Due to technological advancements and miniaturization in the field of microprocessors, bat- teries, and digital screens, the use of portable ultrasound (US) machines is rapidly increasing in the out-of-hospital setting.1 Different authors have shown that the use of prehospital US can yield both diagnostic and therapeutic advantages. It does not delay patient treatment, and its performance is feasible and safe during helicopter transport.2–4 The use of prehospital US in the Netherlands was first documented in 2010 by Gerritse.5
Prehospital US examinations are often performed by physicians who are relatively inexperi- enced in the use of US, compared to radiologists. The recognition of pathologic conditions in a trauma patient seems to be easily taught to physicians. This makes it a suitable diagnostic tool for use out-of-hospital.6–9
The objective of this study was to evaluate the impact of US on the therapeutic plan for pa- tients treated by a Helicopter Emergency Medical Service (HEMS) team. This is a retrospec- tive analysis of four years of data from the Nijmegen, the Netherlands HEMS on portable chest US examinations in prehospital emergencies.
Materials and methods
The Nijmegen HEMS is one of four Dutch HEMS. It services an area of 10,088 square kilo- meters (3895 square miles) in the eastern part of the Netherlands, and a population of 4.5 million.10 On average, there are 1400 flights undertaken every year, 45% of which are cancelled while in flight.11 Paramedics arrive at the scene by ambulance before the HEMS arrives in most cases. They are authorized to assess the situation and to consequently cancel the heli- copter.
The Nijmegen HEMS started using a portable US machine in January of 2007. Thirteen (of 14) physicians working at the HEMS perform US examinations of the chest and abdo- men according to the standardized method of the Polytrauma Rapid Echo-Evaluation Pro- gram (Programme Rapide d’Échographie d’un Polytraumatisé [PREP]; École Internationale d’Échographie, Nîmes, France). This method is comparable to the extended focused assess- ment with sonography for trauma (eFAST) protocol complemented with measurements of the abdominal aorta. The use of portable chest US for reasons other than cardiac ones is relatively new. The PREP method makes use of an artifact that occurs when, in the absence
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