[Application of nerve block in total knee arthroplasty under general anesthesia]

To evaluate the effect of femoral and sciatic nerve block in total knee replacement of elderly patients under general anesthesia.

From July 2017 to July 2019, 60 patients with unilateral total knee replacement were selected, including 35 males and 25 females; aged 66 to 74(70.2±10.3) years;BMI 18 to 25 (21.3 ± 3.5) kg /m²;course 2 to 3 (1.2±0.3) days. The patients were divided into general anesthesia group (G group) 30 cases and general anesthesia plus nerve block group(GNB group) 30 cases. In GNB group, the femoral nerve sciatic nerve block was guided by ultrasound before anesthesia induction, 20 to 25 ml was injected into the femoral nerve puncture point with 0.5% ropivacaine, 15 to 20 ml was injected into the sciaticnerve puncture point, and the total volume was no more than 40 ml. Postoperative intravenous analgesia (PCIA) was performed in two groups. The dosage of propofol and remifentanil was recorded. Forty-eight hours after operation, the incidence of postoperative nausea and vomiting (PONV) and postoperative farsightedness were recorded. When VAS>3, tramadol 2 mg / kg was injected intravenously, and the additional times of tramadol were recorded. Forty-eight hours after operation, patients' satisfaction score was used to record the length of stay.

Compared with group G, the dosage of propofol and remifentanil decreased, the incidence of PONV and the number of additional tramadol decreased, and the patients' satisfaction increased (P<0.05). There was no significant difference in the length of stay between two groups (P>0.05). The ROM and HSS scores of two groups after treatment were higher than those before treatment (P<0.05), and the VAS scores were lower than those before treatment (P<0.05). There was no significantdifference in ROM, VAS scores and HSS scores between two groups before treatment (P>0.05). The ROM and HSS scores of the GNB group after treatment were higher than those of the G group (P<0.05), and the VAS scores were lower than those of the G group (P<0.05).

The application of femoral sciatic nerve block in total knee replacement under general anesthesia in elderly patients has good postoperative analgesic effect, and can reduce the dosage of general anesthesia, reduce PONV, and increase patient satisfaction.