What are complications of paravertebral block for pain management?

Updated: Jun 19, 2018
  • Author: Anthony H Wheeler, MD; Chief Editor: Meda Raghavendra (Raghu), MD  more...
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Complications of paravertebral block include accidental injection into the subarachnoid, subdural, or epidural space. This is particularly hazardous in the cervical region, where anesthetic may diffuse and cause phrenic nerve and respiratory paralysis. Accidental injection of LA into the vertebral artery may lead to transient loss of function in vital brainstem areas and cause impaired consciousness, coma, and seizures.

This complication requires immediate cardiorespiratory and circulatory support until the LA is redistributed and metabolized. Other possible adverse events include anesthesia or injury to the cervical sympathetic chain (with development of Horner syndrome), the superior or recurrent laryngeal nerve, or the trunk of the vagus nerve. Because of the risks of unintended recurrent laryngeal and phrenic nerve block, limiting the procedure to a unilateral injection at any one treatment setting is advisable.

Inadvertent needle trauma and/or injection into the spinal cord can cause quadriplegia and death. Intravascular placement or injection may cause systemic LA toxicity or inadvertently spread local infectious agents, even creating sepsis. An unintentional breach of the dura may lead to total spinal anesthesia with associated loss of consciousness, hypotension, and apnea. Needle trauma to epidural veins may cause bleeding that results in an epidural hematoma with spinal cord compression and associated neurological deficit. Epidural introduction of infection may lead to an abscess or to widespread infection in immunocompromised patients (eg, AIDS, cancer).

Needle placement for selective cervical nerve root blocks is characteristically targeted just outside the neural foramen so that deposition of the injectate does not enter the epidural, subdural, or subarachnoid space. Furthermore, some experts advocate the deposition of a small amount of corticosteroids provides a therapeutic influence. However, adverse events due to transforaminal placement of LA and corticosteroids can be tragic, with trauma or occlusion of the foraminal radicular artery. Recently, this has been implicated as causative when particulate steroids are used. [19, 20, 21]

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