Continuous lumbar plexus block reduces the incidence of early postoperative cognitive dysfunction in elderly patients undergoing hip arthroplasty

OBJECTIVE: To observe the impacts of continuous lumbar plexus block (CLPB) on postoperative cognitive dysfunction (POCD) in elderly patients undergoing hip arthroplasty.
 Methods: Sixty elderly patients scheduled for hip arthroplasty with general anesthesia, were randomly allocated into a CLPB group and a PCIA group (n=30 each). In the CLPB group, lumbar plexus block was performed before trachea intubation, and CLPB was used for postoperative analgesia. In the PCIA group, intravenous analgesia was controlled in patients after operation. Visual Analogue Scale (VAS) at 12, 24, and 48 h after operation was recorded. Mini-Mental State Examination (MMSE) scale was used to evaluate the cognitive dysfunction at the 1st day before operation (D0) and at the 1st (D1), 3rd (D3), and 7th (D7) days after operation and the occurrence of POCD was recorded. S-100β concentrations were detected by ELISA at D1, D3, and D7. Postoperative adverse events were recorded.
 Results: VAS scores at 12, 24, and 48 h after operation in the CLPB group were significantly lower than those in the PCIA group (P<0.05). Compared with the PCIA group, the MMSE scores were significantly higher (P<0.05), and the incidence of POCD at D1 and D3 was obviously reduced in the CLPB group (P<0.05). S-100β concentration at D1 and D3 in the CLPB group was significantly lower than that in the PCIA group (P<0.05).
 Conclusion: Application of CLPB in elderly patients undergoing hip arthroplasty could obviously relieve their postoperative pain, inhibit the production of S-100β, and reduce the incidence of early postoperative cognitive dysfunction.