From: Spinal cord injury: is monitoring from the injury site the future?
Brain parameter | Spinal cord parameter | Similarities | Differences | Reference |
---|---|---|---|---|
Intracranial pressure (ICP) | Intraspinal pressure (ISP) | ICP and ISP waveforms similar with same three peaks and similar Fourier transforms | Injury site ISP > ISP above or below, but ICP similar throughout. ICP but not ISP reduced with mannitol or hyperventilation. | |
Cerebral perfusion pressure (CPP) = MAP – ICP | Spinal cord perfusion pressure (SCPP) = MAP – ISP | CPP and SCPP waveforms similar. CPP and SCPP can be increased with vasopressors | SCPP at injury site differs from SCPP above or below, but CPP similar in brain | |
Optimum cerebral perfusion pressure (CPPopt) | Optimum spinal cord perfusion pressure (SCPPopt) | U-shape PRx vs CPP, sPRx vs SCPP. Minimum is CPPopt or SCPPopt. CPPopt and SCPPopt individualized | Overall CPPopt ~75 mmHg whereas overall SCPPopt ~90 mmHg | |
Pressure reactivity index (PRx) | Spinal Pressure reactivity index (sPRx) | Running correlation between MAP and ICP/ISP | PRx is global, but sPRx is for injury site | |
Compensatory volume reserve (RAP) | Spinal compensatory volume reserve (sRAP) | Running correlation between mean ICP/ISP and ICP/ISP pulse amplitude | RAP is global, but sRAP is for injury site |