Effect of dexmedetomidine-assisted ultrasound-guided lower extremity nerve block on postoperative cognitive function in elderly patients undergoing hip surgery.

Objective: To investigate the effect of dexmedetomidine (Dex)-assisted ultrasound-guided lower extremity nerve block on elderly patients undergoing total hip arthroplasty (THA).

Methods: This retrospective study analyzed data of 60 elderly patients treated with unilateral artificial THA from January 2021 to February 2022. Among them, 30 patients anesthetized using Dex-assisted ultrasound-guided lower extremity nerve block were regarded as the research group (RG), and 30 patients anesthetized with the use of subarachnoid block were considered as the control group (CG). Serum interleukin 6 (IL-6) and interleukin 1β (IL-1β) levels were measured by enzyme linked immunosorbent assay (Elisa) in patients. Also, the heart rate (HR) and mean arterial pressure (MAP) were measured before, 10 min and 60 min after the anesthesia. The cognitive function was evaluated before anesthesia, as well as 2 h, 6 h and 36 h after anesthesia. The adverse reactions during hospitalization were recorded, and the incidence of adverse reactions was calculated.

Results: IL-1β and IL-6 levels in both groups after operation were higher than those before operation (P>0.05), but those in the RG were lower than those in the CG (P<0.05). The HR and MAP at 10 min after anesthesia were lower than those before anesthesia (P<0.05). After anesthesia, the HR and MAP at 60 min in the RG were higher than those at 10 min in the CG, while the two in the RG were lower than those in the CG at 60 min (P<0.05). In addition, the postoperative pain score of the RG was lower than that of the CG, while the cognitive score of the RG was higher than that of the CG (P<0.05). There was no marked difference in the incidence of adverse reactions between the two groups (P>0.05).

Conclusion: Dex-assisted ultrasound-guided lower extremity nerve block can effectively inhibit the postoperative inflammation, improve the cognitive function, and benefit the postoperative rehabilitation in elderly patients undergoing THA.