The concepts of Intra Spinal Pressure (ISP), Intra Thecal Pressure (ITP), and Spinal Cord Perfusion Pressure (SCPP) in acute, severe traumatic spinal cord injury: Narrative review.

Abstract

There is increasing interest in monitoring pressure from the injured spinal cord to guide the management of patients with acute, severe traumatic spinal cord injuries (TSCI). This is analogous to monitoring intracranial pressure and cerebral perfusion pressure in traumatic brain injury (TBI). Here, we explore key concepts in this field and novel therapies that are emerging from these ideas. We argue that the Monro-Kellie doctrine, a fundamental principle in TBI, may also apply to TSCI as follows: The injured cord swells, initially displacing surrounding cerebrospinal fluid (CSF) that prevents a rise in spinal cord pressure; once the CSF space is exhausted, the spinal cord pressure at the injury site rises. The spinal Monro-Kellie doctrine allows us to define novel concepts to guide the management of TSCI based on principles employed in the management of TBI such as intraspinal pressure (ISP), intrathecal pressure (ITP), spinal cord perfusion pressure (SCPP), spinal pressure reactivity index (sPRx), and optimum SCPP (SCPP_opt). Draining lumbar CSF and expansion duroplasty are currently undergoing clinical trials as novel therapies for TSCI. We conclude that there is acknowledgement that blood pressure targets applied to all TSCI patients are inadequate. Current research aims to develop individualised management based on ISP/ITP and SCPP monitoring. These techniques are experimental. A key controversy is whether the spinal cord pressure is best measured from the injury site (ISP) or from the lumbar cerebrospinal fluid (ITP).