Absolute contraindications to RA include lack of patient consent, local skin infection at the site of needle insertion, or when nerve blockade would hinder the surgery or desired postoperative neurologic examination. Relative contraindications include coagulopathy, neuropathy, systemic infection, excessive patient anxiety, cognitive deficits or movement disorders, and anatomic distortion. Peripheral nervous system disorders such as diabetic neuropathy and inflammatory neuropathies may be aggravated by peripheral nerve blockade.