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. Author manuscript; available in PMC: 2009 Sep 1.
Published in final edited form as: Stroke. 2008 Jul 31;39(9):2531–2537. doi: 10.1161/STROKEAHA.108.514877

Table 1.

Properties and Assumptions of Continuous Autoregulation Monitoring Modalities

Autoregulation Index Modalities Correlated Assumptions Practical Considerations
Mean velocity index4 Transcranial Doppler and CPP Middle cerebral artery flow velocity is a surrogate of CBF. Requires a prolonged, noninvasive, continuous transcranial Doppler signal.
PRx5 ICP and ABP Slow waves of ICP are the result of vascular volume changes caused by dynamic changes in resistance vessels. Requires invasive ICP monitor.
ORx6 Licox and CPP Local oxygen tension is a surrogate of CBF (ie, CMRO2 and HCT are constant). Requires invasive Licox monitor.
COx7 Near-infrared spectroscopy and CPP Tissue oxyhemoglobin saturation is a surrogate of CBF (ie, CMRO2 and HCT are constant). Requires a noninvasive monitor of cerebral oximetry that excludes scalp, cranial, and dural hemoglobin.
LDx9 LD and CPP Local cortical red cell flux is a surrogate of CBF. Requires invasive LD monitor.

Licox indicates parenchymal oxygen tension monitor; CMRO2, cerebral metabolic rate of oxygen; and HCT, hematocrit.