To the Editor:—
I read with interest the article recently published by Chen et al. ,1“Ultrasound Guidance in Caudal Epidural Needle Placement.” The authors demonstrated that ultrasound can be used as an alternative tool to guide needle placement. The advantage of ultrasound is radiation free. The disadvantage is that ultrasound cannot monitor the depth of the inserted needle, as the authors indicated.1However, other disadvantages of ultrasound guiding caudal epidural needle placement should be discussed.
Complications of caudal epidural injection include intravascular placement or dural puncture. Aspirating the needle to check for blood or cerebrospinal fluid is helpful if positive, but the incidence of false-negative aspiration is too high to rely on this technique alone.2Fluoroscopic guidance and radiographic contrast administration can confirm needle position and rule out intravascular or subarachnoid placement immediately. The complication rate is significantly low when contrast is also used to verify the epidural needle placement. Johnson et al. 3reported only 4 minor complications in 5,334 cases when epidural steroid injection was done using fluoroscopy and contrast at various spinal level.
Placement of epidural steroid injection close to the level of pathology can optimize patient response to treatment.4,5Fluoroscopic guidance and contrast administration are essential to assess spread of epidural injectate into the desired target level during caudal epidural steroid injection.
Anesthesiologists of Greater Orlando, Orlando, Florida. firstname.lastname@example.org