Presented at the 2013 AAPM Annual Meeting « Back

'Wet Tap' with Root Level Nerve Block

Trusha Govindji, MD, tgovindji@gmail.com¹, Andre P. Boezaart, MD PhD¹, (1) University of Florida, Gainesville, Florida

Introduction: A 52-year-old female scheduled for removal of a soft tissue postero-medial left upper thigh mass. A single-injection lumbosacral paravertebral block was selected for pain control. Case Report: The lumbar paravertebral block was performed as described by Capdevila, except that a Tuohy needle, with its hub open to ambient pressure was used(1). The open needle was advanced another centimeter and as soon as a quadriceps muscle motor response was elucidated, fluid, established to be CSF, started to flow from the hub of the Tuohy needle. The needle was withdrawn, replaced at another location, 20 mL 0.5% ropivacaine was injected after a test dose of 2 mL of 2% lidocaine and epinephrine proved negative. The patient had pain control for 12 hours and the patient had no symptoms of a postdural puncture headache(2). Discussion and Conclusions: Paravertebral blocks are placed outside the varying length dural sleeve covering nerve roots(3) Unintentional dural puncture,is possible, which, if undetected, could lead to total spinal(4,5) if the bolus is injected subdural, or paraplegia(6) if the bolus injection is into the parenchyma of the nerve root. It is recommended that when paravertebral block are preformed avoid using non-Tuohy thin needles(7) to have the needle hub open to ambient pressure(8) and to utilize a test dose(9) for para-neuraxial epidural block (paravertebral block) similar than for neuraxial epidural block. Also, the relatively frequent existence of perineural cysts(10) should be recognized. References: 1) Capdevila X. In: Boezaart AP (Ed), Orthopaedic Anesthesia 2006. p. 359. 2) Sharrock NE. Anesthesiology 1980; 52:360 – 2 3) Gaston Labat. Regional Anesthesia, 1st edition. 1923, p. 228. 4) Pousman et al. Anesthesiology 2003; 98 1281 – 1282 5) Litz et al. Reg Anesth Pain Med 2004; 29: 60 - 64 6) Houton et al. The Spine J 2002; 2: 70 – 75 7) Boezaart AP, Franco CD. Reg Anesth Pain Med. 2006; 31: 388 - 389. 8) Moore DC. Regional Block, 4th edition. 1967, p. 62. 9) Moore DC. Complications of Regional Anesthesia. 1955, p. 53 10) Nabors M, et al. J Neurosurg 1988; 68: 366 – 377.

Funding: None

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