Regional Complications

Most regional complications are related to the interruption of nerve conduction.^{[119] [120] [140]} They occur mainly during epidural and spinal blocks, including hypoventilation caused by muscle paralysis (i.e., spread of the local anesthetic to cervical spinal segments), urinary retention after caudal epidurals, and complications due to paralysis of sympathetic nerve fibers such as Horner's syndrome, hypoglycemia, hypotension (in patients older than 8 years), and other hemodynamic abnormalities. Undiagnosed conditions and tumor compression can suddenly be worsened by the block technique. This may lead to intracranial hypertension, paraplegia, or activation of latent viral diseases. Inadvertent dural penetration with subsequent subarachnoidal injection of an epidural dose of local anesthetic results in total spinal anesthesia. This requires respiratory assistance with tracheal intubation until complete spontaneous breathing is restored, and hemodynamic support occasionally is provided. The potential morbidity of this complication can be reduced by aspirating CSF because a significant amount of local anesthetic can be removed.^[158]