Page 173 - Ultrasonography in Prehospital and Emergency Medicine - Rein Ketelaars

Prehospital echocardiography during resuscitation impacts treatment in a physician-staffed HEMS 171
drugs and IV fluids, securing the airway, adequate ventilation, release of (suspected) tension pneumothorax, stopping any life-threatening bleeding, and treatment of other possible re- versible causes.
After these interventions, or concurrent when enough caregivers were available, HEMS phy- sicians were requested to perform an ultrasound examination of the heart and pericardium through a sub-xiphoidal view at pre-defined moments in the ALS algorithm. The physician prepared the examination by positioning the ultrasound probe in the subxiphoidal region with an estimated optimum location, probe angle, and machine settings while continuing compressions.
The physician performed the first examination as soon as possible after arrival on-scene, then after every five two-minute cycles of compressions, and finally, right after return of spontaneous circulation (ROSC) or when considering the termination of CPR, as suggested by Breitkreutz et al.5
The timing of echocardiography had to be in the same window where chest compressions are interrupted to allow for heart rhythm analysis. Interruption of chest compressions had to be kept to a minimum. The algorithm of the American Heart Association (AHA) emphasizes to minimize the duration of the interruptions to stay (well) below ten seconds.3 The European Resuscitation Council (ERC) states the entire process of defibrillation should be achievable within a five-second interruption.1 We instructed the participating physicians to respect the latter timeframe.
Additional ultrasound examinations of the chest and abdomen were performed depending on the discretion of the physician, but without interrupting chest compressions.
Data processing
If time allowed, the flight nurses recorded on-scene data simultaneous with every ultrasound examination: time, heart rhythm, palpable pulse, end-tidal CO2, and the physician-reported ultrasound image quality and global myocardial function.
The CRF, specifically designed for this study, was filled out by the physician after return to base. Data recorded were: (estimated) time of cardiac arrest, start of BLS, initial observed heart rhythm, occurrence and timing of ROSC or termination of resuscitation. Additionally, we recorded ventricular dimensions, pericardial fluid, other findings on ultrasound, impact- ed decisions, the location where ROSC occurred or the team terminated CPR (e.g. during transport or in-hospital). We scored the perceived ease of the entire procedure on a 1–10
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