Live stream of prehospital point-of-care ultrasound during cardiopulmonary resuscitation - A feasibility trial

Background: Current resuscitation guidelines recommend that skilled persons could use ultrasound to detect reversible causes during cardiopulmonary resuscitation (CPR) where the examination can be safely integrated into the Advanced Life Support (ALS) algorithm. However, in a prehospital setting performing and rapidly interpreting ultrasound can be challenging for physicians. Implementing remote, expert-guided, and real-time transmissions of ultrasound examinations offers the opportunity for tele-support, even during an out-of-hospital cardiac arrest (OHCA). The aim of this feasibility study was to evaluate the impact of tele-supported ultrasound in ALS on hands-off time during an OHCA.

Methods: In an urban setting, physicians performed point-of-care ultrasound (POCUS) on patients during OHCA using a portable device, either with tele-support (n = 30) or without tele-support (n = 12). Where tele-support was used, the ultrasound image was transmitted via a remote real-time connection to an on-call specialist in anaesthesia and intensive care medicine with an advanced level of critical care ultrasound expertise. The primary safety endpoint of this study was to evaluate whether POCUS can be safely integrated into the algorithm, and to provide an analysis of hands-off time before, during, and after POCUS during OHCA.

Results: In all 42 cases it was possible to perform POCUS during regular rhythm analyses, and no additional hands-off time was required. In 40 of these 42 cases, the physicians were able to perform POCUS during a single regular rhythm analysis, with two periods required only in two cases. The median hands-off time during these rhythm analyses for POCUS with tele-support was 10 (8-13) seconds, and 11 (9-14) seconds for POCUS without tele-support. Furthermore, as a result of POCUS, in a quarter of all cases the physician on scene altered their diagnosis of the primary suspected cause of cardiac arrest, leading to a change in treatment strategy.

Conclusions: This feasibility study demonstrated that POCUS with tele-support can be safely performed during OHCA in an urban environment. Trial Registration (before patient enrolment): ClinicalTrials.gov, NCT04817475.