Abstract:Objective To analyze the changes of cerebral oxygen saturation and cognitive function after anesthesia in the elderly patients with humeral shaft fracture treated with dexmetomidine and fentanyl. Methods A retrospective analysis was made of 272 elderly patients with humeral shaft fractures in the Department of Anesthesiology, the Second People′s Hospital of Longgang District in Shenzhen from March 2013 to December 2016. According to the anesthesia type, they were divided into study group (dexmetomidine-fentanyl) and control group (sevoflurane-remifentanil) with 136 patients each. The 2 groups were compared in cerebral oxygen saturation at admission into operating room (T1), anesthesia preparation (T2), 30 min into the operation (T3) and the end of operation (T4) and in scores of Wechsler Adult Intelligence scale (WAIS-RC) at preoperative day 1 and postoperative day 1 and day 3. The data were analyzed with SPSS 22.0. Student′s t test, ANOVA or χ2 test was employed for intergroup comparison. Results The study group were significantly better than the control group in terms of blink time, awakening, extubation time, time in resuscitation room, heart rate, respiratory frequency, mean arterial pressure and pain. The difference was statistically significant (P<0.05). The control group had no significant difference in cerebral oxygen saturation at different time points (F=2.04, P=0.11), but the study group had significant difference in the terms (F=41.57, P=0.00). Compared with the control group, the study group had lower cerebral oxygen saturation at T2 [(64.82±9.87)% vs (72.56±9.80)%], T3 [(62.03±11.05)% vs (70.23±11.25)%], and T4 [(69.20±9.47)% vs (72.47±9.88)%], with statistically significant difference (P<0.05). The study group scored lower than the control group in common sense, understanding, arithmetics, similarity, digit span, filling in the chart, block diagram, picture arrangement and graphic patchwork at postoperative day 1 and day 3, the difference being statically significant (P<0.05). Conclusion Dexmetomidine-fentanyl, with short-term reduction of cognitive function and cerebral oxygen saturation, can be a safe option for the treatment of humeral shaft fracture in the elderly patients, and it is necessary to observe and stabilize cerebral oxygen saturation in the procedure.