Anatomy and Pathophysiology of Spinal Cord Injury Associated With Regional Anesthesia and Pain Medicine: 2015 Update

Background and Objectives: In March 2012, the American Society of Regional Anesthesia and Pain Medicine convened its second Practice Advisory on Neurological Complications in Regional Anesthesia and Pain Medicine. This update is based on the proceedings of that confer- ence and relevant information published since its conclusion. This arti- cle updates previously described information on the pathophysiology of spinal cord injury and adds new material on spinal stenosis, blood pressure control during neuraxial blockade, neuraxial injury subse- quent to transforaminal procedures, cauda equina syndrome/local anes- thetic neurotoxicity/arachnoiditis, and performing regional anesthetic or pain medicine procedures in patients concomitantly receiving gen- eral anesthesia or deep sedation. Methods: Recommendations are based on extensive review of research on humans or employing animal models, case reports, pathophysiology re- search, and expert opinion. Results: The pathophysiology of spinal cord injury associated with re- gional anesthetic techniques is reviewed in depth, including that related to mechanical trauma from direct needle/catheter injury or mass lesions, spinal cord ischemia or vascular injury from direct needle/catheter trauma, and neurotoxicity from local anesthetics, adjuvants, or antiseptics. Specific recommendations are offered that may reduce the likelihood of spinal cord injury associated with regional anesthetic or interventional pain medicine techniques. Conclusions: The practice advisory's recommendations may, in select cases, reduce the likelihood of injury. However, many of the described in- juries are neither predictable nor preventable based on our current state of knowledge. What's New: Since publication of initial recommendations in 2008, new information has enhanced our understanding of 5 specific entities: spinal stenosis, blood pressure control during neuraxial anesthesia, neuraxial injury subsequent to transforaminal techniques, cauda equina syndrome/local an- esthetic neurotoxicity/arachnoiditis, and performing regional anesthetic or pain procedures in patients concomitantly receiving general anesthesia or deep sedation. (Reg Anesth Pain Med 2015;40: 506–525)