Epidurograms in the management of patients with long-term epidural catheters

Standardized test doses have been established in the practice of anesthesiology to determine the location of the epidural catheter tip. The resulting data obtained after test dosing is open to interpretation, and comparison is difficult. A more objective method of catheter verification and epidural space measurement is indicated in long-term epidural catheterization. The goal of this review is to define a standard procedure for epidurography, explore the use of an epidurogram algorithm in differential diagnosis, and review the temporal relationship of a series of epidurograms.

A standard epidurogram procedure was defined and used for the study. Routine postoperative epidurograms were obtained following epidural catheter placement. Serial epidurograms were obtained when clinically indicated, as described in the epidurogram algorithm. Radiographs taken after injection of the dye were used for determination of epidural catheter tip location and volume dye flow. Two cases are presented to demonstrate the effectiveness of the epidurogram algorithm.

Epidurograms show dye dispersion within the space, allowing for visualization of anomalies, resulting in a permanent record for later review. Case reports demonstrate the use of epidurograms in determining the cause of changes in epidural analgesia.

The review of repeated epidurograms and presented case reports support the use of epidurograms as a diagnostic tool for clinical practice. Abnormal epidurograms helped determine epidural space infection, tumor obstruction, space compression from vertebral compression fractures, and epidural fibrosis. The addition of a contrast computed tomographic scan after epidurography allows for more accurate diagnostic interpretation of epidural space pathology. The use of a standard epidurogram technique allows this procedure to be used in the differential diagnosis of suspected problems in the epidural space.