253 Intraosseous Administration of CT Contrast in a Porcine Model: A Feasibility Study

Abstract

Study Objectives: Obtaining rapid intravenous (IV) access is often difficult in patients who have sustained injuries due to major trauma. Intraosseous (IO) access is a safe and reliable alternative when peripheral IV access cannot be obtained quickly. For many trauma patients, contrast-enhanced computed tomography imaging is an important element of the initial diagnostic evaluation performed in the emergency department (ED). However, minimal information has been published regarding the injection of contrast material using IO access for the purpose of obtaining a contrast-enhanced computed tomography scan. This study was performed to evaluate IO administration of contrast material for a trauma-protocol computed tomography scan in an adult mini-swine model. Methods: Skeletally mature mini-swine were anesthetized and had peripheral IV and IO access established. IO access was obtained in the proximal humerus with fluoroscopic confirmation of correct needle placement. Each animal underwent contrast-enhanced trauma-protocol computed tomography scans using both routes of contrast administration. Contrast was administered using a MedRad® computerized power-injection system. computed tomography confirmation of contrast arterial phase wash-out between studies was established prior to administration of the second contrast injection. The order for route of administration (IV or IO) was randomized for each animal using block randomization. Images were evaluated for adequacy of vascular opacification by 2 board-certified radiologists. Results: All images obtained with both IV and IO contrast administration were judged to be adequately opacified to meet diagnostic criteria. One animal had partial extravasation of contrast after IO administration despite proper needle placement. Conclusion: In this swine model, injection of contrast material through a proximal humerus IO site resulted in adequate opacification of trauma-protocol computed tomography images in all animals. Our results suggest that intraosseous administration of contrast material may be a viable alternative in trauma patients when attempts at obtaining other vascular access are unsuccessful or would lead to unacceptable delays in diagnostic evaluation. Further study is warranted in human subjects to investigate the effectiveness of this methodology as well as the incidence and significance of contrast extravasation.