Page 172 - Ultrasonography in Prehospital and Emergency Medicine - Rein Ketelaars
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Chapter 8
Materials and methods
Design
We performed an observational study between February 2014 and November 2016. Ethical approval was obtained from the regional ethics review board of Arnhem/Nijmegen and they waived the requirement to obtain written informed consent (2014/112).
Recruitment and setting
In the Netherlands, four physician-staffed HEMS are operational 24 hours per day, all carry- ing a portable ultrasound machine. They are supplemental to a high-quality network of para- medic-staffed ground ambulances. The Nijmegen HEMS is stationed at the Volkel Air Force Base, covering an area of approximately 10,000 square kilometers, servicing a population of 4.5 million. Every physician is trained to perform an extended focused assessment with sonography for trauma (eFAST) examination, and basic echocardiography. In recent years, our HEMS conducted on average 2341 missions, increasing yearly by 13%. Typically, ground ambulances handle most resuscitations. However, on their or the dispatch center’s request the HEMS aids in about 200 resuscitations including 50 children (< 18 years of age) yearly.
We included every patient that underwent CPR with concurrent echocardiography per- formed by our HEMS of which a dedicated case report form (CRF) was filled out. Exclusion criteria were the discontinuation of CPR or an indication to perform immediate thoracot- omy in case of a (single) penetrating chest injury with loss of circulation no longer than 10 minutes.
The HEMS database that holds a record of every mission and every patient treated was exam- ined to describe the base population of which this study’s population is a subset.
Protocol
We used two different portable ultrasound machines during the study: a NanoMaxx and a MicroMaxx machine (Fujifilm SonoSite Inc., Bothell, WA, USA) both equipped with a 5–1 MHz broadband phased-array cardiac transducer.
Physicians were requested to treat the cardiac arrest patients in the usual way. ALS protocols with minimal interruptions of chest compressions had to be respected. Priority had to be given to heart rhythm analysis and defibrillation, establishing IV access, administration of
  






















































































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