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Developing a Longer-lasting Nerve Block

At Hospital for Special Surgery, we treat pain after foot and ankle surgery with pills and nerve blocks (an injection of local anesthetic, or numbing medicine, near the nerve to the foot). The pills help relieve pain, but have side effects such as drowsiness and nausea. Pain relief from nerve blocks comes without these side effects.

The longer we can make a nerve block last, the longer we can keep the pain away while reducing nausea and drowsiness.

The authors of this study at HSS added a medicine called clonidine to the drug usually placed around nerves to numb them. After surgery, they asked patients if they had any side effects, and when their foot began to hurt.

By adding clonidine to the nerve blocks, the patients first felt pain over 18 hours after surgery, compared to 14 hours in the standard medicine group.

Nerve block side effects such as pins and needles were the same, with or without clonidine.

In conclusion, this study shows that adding clonidine to the local anesthetic for the nerve block prolongs pain relief after surgery.

Full reference:
YaDeau JT, LaSala VR, Paroli L, Kahn RL, Jules-Elysée KM, Levine DS, Wukovits BL, Lipnitsky JY. Clonidine and analgesic duration after popliteal fossa nerve blockade: randomized, double-blind, placebo-controlled study. Anesth Analg. 2008 Jun;106(6):1916-20.