Near infrared spectroscopy (NIRS)

Description
Calculated as a moving Pearson's correlation coefficient between changes in MAP and rSCO2 such that values range from -1 to 1, with 0 meaning no correlation between CBF and blood pressure suggesting intact autoregulation.

Utility
In a prospective cohort study of 91 comatose patients (GCS ≤8) of various etiologies, both degree and duration of MAP values outside of a tight optimal MAP range (with lowest COx) were assocaited with higher mortality.

In a prospective cohort of 65 patients undergoing thrombectomy for ischemic stroke, the percentage of time exceeding values outside of ideal range correlated with risk of hemorrhagic transformation and worsened neurological outcomes.