Preferences of air-blood-saline sonographic microbubble contrast agents among emergency medicine resident physicians.

Introduction: The placement of a central venous catheter (CVC) remains an important intervention in the care of critically ill patients in the emergency department, and bedside ultrasound can be used for procedural guidance as well as conformation of placement. Microbubble contrast-enhanced ultrasound may facilitate CVC tip position localization, and the addition of autologous blood can significantly increase its echogenicity. The purpose of this study was to describe the preferences of a group of resident physicians regarding the performance of various concentrations of air-blood-saline sonographic microbubble contrast agents.

Methods: Institutional Animal Care and Use Committee approved prospective study. A CVC was inserted into the right internal jugular vein of a 20-kg Yorkshire swine under general anesthesia. Contrast mixtures were created with air, saline, and varying amounts of blood and were injected while echocardiographic video clips were recorded and reviewed by 25 physician sonographers.

Results: All reading physicians reported increased overall echogenicity, a higher peak echogenicity, and greater personal preference for blood containing solutions. Nearly all reading physicians preferred the lower percentage blood containing mixtures over the higher percentage blood containing mixture.

Conclusion: The inclusion of 1 to 3 parts of 10 of the patient's blood in the preparation of a sonographic contrast mixture increased the echogenicity of the contrast, resulted in better visualization of both the contrast and the endocardial border and was the preferred mixture among the resident physicians studied.