Prospective experience with a 20-guage tuohy needle for lumbar epidural steroid injections: Is confirmation with fluoroscopy necessary?

BACKGROUND AND OBJECTIVES: Small (20-gauge) Tuohy needles have been introduced for epidural steroid injection to optimize patient comfort and decrease the risk of spinal headache. These needles may be less reliable for indentification of the epidural space than standard 17- or 18-gauge needles because of their small size. We prospectively examined the success rate of lumbar epidural steroid placement with loss-of-resistance (LOR) technique compared with fluoroscopy confirmation. METHODS: One hundred patients without history of lumbar spine surgery were enrolled. A 20-gauge Tuohy needle was placed into the epidural space using LOR to saline. Confidence in epidural placement was recorded (Yes/No). Radiologic contrast was then injected and a fluoroscopic epidurogram interpreted by a blinded radiologist for correct placement, (Yes/No) separate from the clinical process. RESULTS: Reliability of LOR was less than our "gold standard" of fluoroscopy (P 70 years) and male sex were associated with poor reliability of LOR (P