Effects of different BP management strategies on postoperative delirium in elderly patients undergoing hip replacement: A single center randomized controlled trial

Study objective: Postoperative delirium (POD) is a common after hip replacement. Intraoperative blood pressure management may affect postoperative delirium. The aim of this study was to compare the effects of different blood pressure management strategies on POD.

Design: A single center randomized controlled trial.

Setting: The Second Hospital of Anhui Medical University, Hefei, China.

Patients: A total of 150 patients aged 65-80 years underwent hip arthroplasty.

Interventions: A random number table was used to divide the patients into three groups: mean blood pressure (MAP) was maintained from 10% to 20% below the baseline (group D), MAP was maintained from baseline to 10% below the baseline (group M), and MAP was maintained from baseline to 10% above the baseline (group H).

Measurements: The primary endpoint was POD at 1-3 days. The secondary endpoint was the intraoperative MAP and regional cerebral oxygen saturation (rSO₂) value, MAP, Visual Analogue Scale (VAS score) 1-3 days after surgery, the lengths of post anesthesia care unit (PACU) stay and hospital stay and emergence agitation were recorded.

Main results: Patients in group H showed a lower incidence of POD on the first day than those in groups D and M (22% and 16% vs 4%; P = 0.031). There is no difference of incidence of POD on the 2rd and 3rd day postoperatively. Patients in group H received a higher MAP as well as rSO₂ during the operation compared the other two groups (P < 0.05). Compared with groups D and M, emergence agitation was significantly reduced (P = 0.029) and the lengths of PACU stay (P = 0.018) and hospital stay (P = 0.008) were shortened in group H.

Conclusions: Maintenance of intraoperative blood pressure from baseline to 10% above the baseline helps to reduce the incidence of POD and emergence agitation and shorten the lengths of PACU stay and hospital stay, and it may be related to increased rSO₂ during the operation.