Figure 1
Least mean squares estimates of regional cerebral oxygen saturation (rSO 2 ) in each hemisphere over time for all patients (n = 125). rSO2 values for both hemispheres were seen to decrease over the course of study (P < 0.0001). The largest rSO2 decline coincided with tourniquet deflation and reperfusion of the extremity. Three hours after surgery rSO2 had not recovered to baseline (59.46% [95% CI, 58.25%–60.66%] and 59.20% [95% CI, 58.14%–60.27%] (P < 0.001) for right and left hemispheres respectively. CI = confidence interval. Ind = induction. Tourn = tourniquet. Postop = postoperative.