To investigate the efficacy of ultrasound-guided modified lumbosacral plexus block (MLPB) in elderly patients undergoing hip replacement.

Sixty-six elderly patients, aged from 65 to 90 years old, ASA II or III subjected to hip surgery, were collected. The patients were randomly allocated into 3 groups, MLPB group, general anesthesia combined with modified lumbosacral plexus block (GA&MLPB) group, and subarachnoid block (SAB) group. Both the MLPB group and the GA&MLPB group were given ultrasound-guided modified lumbosacral plexus block before skin incision, and 30 ml of 0.25% ropivacaine was injected into the lumbar plexus and sacral plexus respectively. In the SAB group, 2 ml of 0.75% ropivacaine hydrochloride and 0.5 ml of sterile normal saline was intrathecal injected for a single spinal anesthesia. All patients underwent patient-controlled analgesia (PCA) after surgery, with the formula of 100 µg sufentanil and 6 mg granisetron diluted to 120 ml normal saline solution with a background dose of 2 ml/h, a load dose of 2 ml, and a locking time of 15 min. The primary outcome was sufentanil consumption in 48 h postoperatively. The secondary outcomes were the following: the concentrations of serum glucocorticoids and adrenocorticotropic hormone (before skin incision and the end of surgery), the VAS of pain intensity, and perioperative adverse events.

There were significant differences in sufentanil consumption and number of effective PCA compressions during 48 h after the surgery among the 3 groups (F=4.48, P=0.027; F=5.29, P=0.008). Dosage of sufentanil consumption and number of effective PCA compressions were higher in SAB group at 48 h after surgery than those in the other two groups (all P<0.05). At 6 h after surgery, VAS and cases of VAS 0-3 were significantly different among the 3 groups (F=6.86, P=0.002; F=7.78, P=0.020), and VAS was higher in SAB group, cases of VAS 0-3 was smaller than those in the other two groups (all P<0.05). There were significant differences in serum GC between the three groups before and after surgery, and the level of GC was higher in the SAB group than that in the other two groups (all P<0.05). There was significant difference in serum ACTH between the three groups before skin resection, and that was higher in the SAB group than that in the MLPB and GA&MLPB groups (all P<0.05). There was no significant difference in the incidence of adverse events among the 3 groups (all P>0.05).

The application of MLPB can reduce the intraoperative stress level of patients and provide reliable perioperative analgesia, which is a safe and effective anesthesia method for elderly patients undergoing hip arthroplasty.

Lumbosacral plexus; Nerve block; Arthroplasty, replacement, hip; Anesthesia, general; Subarachnoid block