TY - CHAP M1 - Book, Section TI - Epidural Test Dose A1 - Freeman, Brian S. A2 - Freeman, Brian S. A2 - Berger, Jeffrey S. PY - 2014 T2 - Anesthesiology Core Review: Part One Basic Exam AB - A catheter positioned properly in the epidural space can provide excellent surgical anesthesia, postoperative analgesia, and labor analgesia. Inadvertent placement of the catheter into the cerebrospinal fluid (CSF) (intrathecal) or an epidural vein (intravascular) could lead to catastrophic complications. Positive aspiration of blood or CSF from the catheter confirms catheter misplacement. However, the absence of an aspirate cannot rule out whether or not the catheter is actually in the epidural space. The incidence of false negative aspiration is lower for multiorifice epidural catheters (<1%) compared to single-hole catheters (2%). Aspiration of fluid may fail due to low epidural venous pressure, air locking within a filter, mechanical obstruction due to tissue or blood, or simply incorrect identification of the aspirate. For these reasons, a “test dose” should be administered subsequent to epidural catheter placement and prior to incremental dosing of small volumes of local anesthetic. SN - PB - McGraw-Hill Education CY - New York, NY Y2 - 2024/03/29 UR - accessanesthesiology.mhmedical.com/content.aspx?aid=1102567575 ER -