Abstract

This research work was carried out to understand how dexmedetomidine (Dex) administration caused changes in hemodynamics [systolic blood pressure (SBP), diastolic blood pressure (DBP), and heart rate (HR)] and cerebral state index (CSI) in aged patients undergoing total hip replacement (THR) surgery and general anesthesia. Sixty (60) years aged patients undergoing total hip replacement THR surgery and general anesthesia were recruited and randomly assigned into observation group and control group. The 30 patients in the observation group were given intravenous 0.3 µg/kg Dex through an implanted minipump, and the control group patients were given saline. The hemodynamics including SBP, DBP and HR, as well as, CSI were recorded at the start of the surgery (T0), start of the drug administration (T1), 10 min with drug (T2), skin incision (T3), 30 min after skin incision (T4), extubation (T5), and 30 min after extubation (T6). The wakening time, extubation time, and vigilance/ sedation (OAA/S) score 30 min after surgery were also recorded. In both groups, the SBP, DBP, and HR decreased at T2 and began to increase at T5, with significant differences from T0 (P<0.05). In the observation group, the SBP, DBP, and HR showed lower values at T5 and T6 in compared to the control group (P<0.05); in both groups the CSI decreased at T2 and began to increase at T5, with significant differences from T0 (P<0.05). In observation group, the CSI showed lower values at T5 and T6 in comparison to the control group (P<0.05); additionally, the observation group showed decreased extubation time and wakening time as well as a higher vigilance/sedation (OAA/S) score in comparison to the control group (P<0.05). The Dex administration stabilizes hemodynamics (SBP, DBP, and HR) and decreases CSI in aged patients undergoing THR surgery and general anesthesia. This also reduces the extubation time and wakening time after surgery.

Key words: Dexmedetomidine, aged patients, total hip replacement, general anesthesia, hemodynamics, cerebral function index, extubation time, wakening time.