Clinical analyses of ultrasound-guided nerve block in lower-extremity surgery: A retrospective study

Purpose: The purpose of this study is to examine the clinical effects and results of lower-extremity surgery under ultrasound-guided nerve block; time required for nerve block, anesthesia onset time, duration of anesthesia, duration of analgesia, tolerable tourniquet time, visual analog scale (VAS) satisfaction score, and anesthetic-related complications. Methods: A total of 3312 cases (2597 patients) from January 2010 to April 2015 were analyzed retrospectively. A senior author performed ultrasound-guided nerve block of the lateral femoral cutaneous nerve (LFCN, 630 cases), femoral nerve (FN, 2503 cases), obturator nerve (ON, 366 cases), sciatic nerve (SN, 3271 cases), or posterior femoral cutaneous nerve (PFCN, 222 cases) depending on the type of surgery. Time required for nerve block, anesthesia onset time, duration of anesthesia, duration of analgesia, tolerable tourniquet time, VAS satisfaction score, and anesthetic-related complications were analyzed. Results: The mean times required were 1.1 min for SN block, 2.5 min for FN/SN block (1762 cases), and 4.8 min for FN/SN/LFCN/ON block. The mean anesthesia onset time was 48 min. The mean durations of anesthesia were 4.5 h for FN dermatome and 5.6 h for SN dermatome. The mean duration of analgesia was 11.5 h. The mean tolerable tourniquet times after were 35, 51, and 84 min after SN block, FN/SN block, and FN/SN/LFCN/ON block, respectively. The mean VAS satisfaction score was 9.3. There were no anesthetic-related complications, such as infection, hematoma, paralysis, or nerve irritation. Conclusion: Selective block of the LFCN, FN, ON, SN, and PFCN based on the locations of lesions and type of surgery showed favorable clinical results with high efficacy. Ultrasound-guided nerve block may be a good option for anesthesia and analgesia in lower-extremity surgery.