Prehospital TEE in Cardiac Arrest

This study shall investigate the feasibility of prehospital performed trans-esophageal echocardiography in out of hospital cardiac arrest. The investigators will include ten patients undergoing advanced life support in this study and determine if it is possible to acquire adequate trans-esophageal images within 10 minutes after arrival of the study team on scene.

Out of hospital cardiac arrest (OOHCA) remains a leading cause of death in Austria. Current guidelines recommend to address potentially reversible causes for OOHCA early to improve survival and some of these causes can be recognized using echocardiography. The usefulness of trans-thoracic echocardiography during OOHCA seems to be limited as image acquisition may prolong now flow time and image quality is variable. These limitations might be overcome with trans-esophageal echocardiography. The investigators will investigate the feasibility of prehospital performed trans-esophageal echocardiography in ten OOHCA patients undergoing advanced life support. In addition to routine care by paramedics and emergency physicians, a dedicated expert in emergency ultrasound will perform trans-esophageal echocardiography in these patients. Primary outcome parameter: Is it possible to obtain trans-esophageal images of the heart within 10 minutes after arrival of the study team?

Transesophageal Echocardiography during advanced life support for out of hospital cardiac arrest will be performed.

Time from arrival of the study team on scene, until the following questions are answered by trans esophageal echocardiography: "is spontaneous cardiac movement present", "how ist LV function", "how is RV function", "is a pericardial effusion or tamponade present". The time will be measured in seconds and a maximum of 600 seconds is allowed. If answering the questions within 600 seconds is possible, the case will be counted as "feasible" and the duration of the time measured will be recorded. If answering the questions takes longer than 10 minutes, the case will be counted as "not feasible"

what are the "hands off times" (defined as time during which no chest compressions are performed during the resuscitation) during ALS with or without TEE.

The number of events that hinder the established advanced life support measures will be counted graded by severity (minimal, minor, major)

What complications are caused by trans esophageal echocardiography occur during ALS: displacement of the endotracheal tube, dental injury, pharyngeal injury

How is image quality of trans esophageal echocardiography during advanced life support measures? This will be determined by the investigator performing the trans esophageal echocardiography and also by a blinded specialist afterwards. The rating will be "excellent", "good", "moderate", "poor", "extremely poor"

Inclusion Criteria: adult patients undergoing advanced life support for out of hospital cardiac arrest Exclusion Criteria: patients who should undergo rapid transport to the hospital with ongoing CPR (ECMO candidates, pregnant, trauma, obvious reversible which can be treated in hospital only) known esophageal pathology contraindicating TEE no definite secure airway present (endotracheal intubation, tracheostomy)