Paramedic Echocardiography in Pulseless Electrical Activity Cardiac Arrest: An Education and Simulation Study

Abstract

BACKGROUND: Patients presenting with pulseless electrical activity (PEA) in out-of-hospital cardiac arrest (OHCA) may receive inappropriate care if a manual pulse check is relied upon to determine pulselessness. This study aimed to investigate whether ultrasound-naïve paramedics could acquire an ultrasound image within a 10-s pause during a pulse check in a simulated cardiac arrest environment and interpret ultrasound-detectable pathology. Secondary aims focus on the quality of ultrasound image acquisition and the retention of learned knowledge.

METHOD: Thirty paramedics participated in three sequential phases. Phase I involved a self-directed e-learning program covering an overview of ultrasound applications, including cultural considerations for indigenous New Zealand Māori in cardiac arrest. Phase II included face-to-face education, simulation assessments, and a knowledge quiz. Phase III included simulation assessments and a knowledge quiz. Ultrasound images were scored against the cardiac ultrasound structural assessment score (CUSAS) for quality.

RESULTS: During simulated cardiac arrest scenarios, the mean time to acquire an ultrasound scan was 9.6 s (SD = 2.9, 95% CI [9.3, 10.0]). Forty-seven per cent of study scans were captured within the 10-s pulse check pause. Of the acquired images, 73% (95% CI [67.8, 79.4]) of scans scored a CUSAS of ≥ 3, demonstrating adequate image quality. Participants correctly interpreted 91% (95% CI [88.5, 94.5]) of 243 pathological scans during the simulations. In Phase II, 83 of 87 interpretations were correct (95%, 95% CI [91.0, 99.7]), while in Phase III, 140 of 156 interpretations were correct (90%, 95% CI [84.9, 94.4]).

CONCLUSIONS: During cardiac arrest simulations, paramedics on average took 9.6 s to acquire an ultrasound scan, with 47% of scans completed within the 10-s pulse-check pause. RESEARCH AIMS: To determine if paramedics can acquire an ultrasound image within the 10-s pulse check pause in simulated pulseless electrical activity (PEA) cardiac arrest. Secondary aims focus on the quality of ultrasound image acquisition, interpretation and retention of learned knowledge.