Analgesic Effects of Different Local Infiltration Anesthesia Techniques Combined with Femoral Nerve Block in Patients Undergoing Total Knee Arthroplasty: A Randomized Controlled Clinical Trial.

Objective: Pain after total knee arthroplasty (TKA) remains an unresolved problem. Femoral nerve block (FNB) could relieve pain; however, it alone is insufficient. The local infiltration anesthesia technique (LIA) has been suggested as a supplement to FNB. This study aimed to evaluate the analgesic effects of different LIA combined with FNB in TKA patients. Methods: The femoral nerve was blocked with 0.375% ropivacaine 20mL, and all patients routinely received general anesthesia. The primary indicator was the proportion of patients who did not receive post-operative remedial analgesia. Seventy-eight patients were randomly assigned to PAI (periarticular injection combined with FNB), IAI (intra-articular injection combined with FNB), or control (FNB alone) groups. All patients underwent FNB under general anesthesia. The primary outcome was the proportion of patients who did not receive additional postoperative analgesia within the first 48 h after surgery. Results: Compared with the PAI and control groups, the IAI group had a higher proportion (69.23%) of patients who did not receive remedial analgesia within 48 hours after surgery (P = 0.009; P = 0.009), a lower consumption of diclofenac sodium lidocaine (P = 0.021; P < 0.001), and an earlier time of walking with a walker (P < 0.001; P < 0.001). The time of first need for remedial analgesia postoperatively in IAI group was longer than the PAI group (P = 0.008) and IAI group has a shorter hospital stay than the control group (P = 0.008). The maximum NRS during the first 48 hours postoperatively and NRS 24 hours after surgery in the IAI group were lower than those in the control and PAI groups. The incidences of POD and PONV were similar among the three groups (P = 0.610; P = 0.264). Conclusion: When combined with FNB, intra-articular injection offers a superior analgesic effect and favorable recovery compared to periarticular injection and separate application of FNB.

Dexmedetomidine Combined with Femoral Nerve Block Provides Effective Analgesia Similar to Femoral Nerve Combined with Sciatic Nerve Block in Patients Undergoing Total Knee Arthroplasty: A Randomized Controlled Study.

BACKGROUND: Total knee arthroplasty (TKA) is a severe traumatic procedure, and femoral nerve block (FNB) combined with a sciatic nerve block (SNB) is widely used in TKA. However, injury of the sciatic nerve is clinically reported. Dexmedetomidine (DEX) could reduce stress and inflammation, as well as improve pain in TKA. This study aims to observe the analgesic impact of DEX combined with FNB in TKA. METHODS: Eighty-eight patients undergoing TKA were included and randomly divided into two groups: DF group (FNB combined with DEX 0.6µg/kg before surgery, followed by DEX 0.2-0.4µg/kg/h until articular closure) and SF group (FNB combined with SNB). Each nerve was blocked with 0.375% ropivacaine 20mL, and all patients received general anesthesia routinely. The primary endpoint was the pain visual analog scale (VAS) score during activities at postoperative 24 hours. RESULTS: There was no statistical difference in the pain VAS scores at any time point. The mean duration of analgesia for patients with rescue analgesic requests was comparable between the two groups: 25.4 ± 6.3 hours in the DF group vs 24.8 ± 6.4 hours in the SF group (two-sample t-test, p=0.738). The total dose of sufentanil was similar between groups (P=0.355). The maintenance dose of propofol and dose of rescue analgesics were comparable (all P>0.05). There were no statistical differences in the incidence of adverse events. However, the time to extubate in the DF group was significantly longer than those in the SF group (P<0.001). CONCLUSION: DEX combined with FNB could provide effective analgesia similar to SNB combined with FNB in TKA. CLINICAL TRIAL REGISTRATION: The trial was registered at the Chinese Clinical Trial Registry on November 17, 2019 (identifier: ChiCTR1900027552).

Effect of Different Modes of Administration of Dexmedetomidine Combined with Nerve Block on Postoperative Analgesia in Total Knee Arthroplasty.

INTRODUCTION: Dexmedetomidine (DEX) as a nerve block adjuvant can significantly prolong analgesia. However, whether perineural or systemic administration of DEX is more beneficial in patients undergoing total knee arthroplasty (TKA) has not been thoroughly investigated. To this end, we evaluated the effects of perineural and systemic DEX administration on postoperative analgesia in patients undergoing TKA surgery. METHODS: We randomly assigned patients undergoing TKA under general anesthesia combined with femoral nerve block and sciatic nerve block to one of three groups: (1) ropivacaine plus perineural dexmedetomidine (DP): 0.25% ropivacaine 40 mL plus 0.5 µg/kg dexmedetomidine; (2) ropivacaine plus systemic dexmedetomidine (DS): 0.25% ropivacaine 40 mL plus systemic 0.5 µg/kg dexmedetomidine; (3) control group (C): 0.25% ropivacaine 40 mL. RESULTS: The average length of time until patients first experienced postoperative pain was significantly longer in the DP group (26.0 h [22.0-30.0 h]) than in the DS group (22.4 h [18-26.8 h]) and the control group (22.9 h [19.5-26.3 h], P = 0.001). For this result there was no significant difference between the DS and the control group. Compared with the DS and control groups, patients in the DP group had lower resting visual analogue scale (VAS) scores at 24, 48, and 72 h after surgery (P < 0.05). VAS activity scores at 12, 24, and 48 h after surgery in the DP group were lower than those in the DS and control groups, with a statistically significant difference (P < 0.05). Compared with the DS and control groups, the amount of postoperative opioids in the DP group was also significantly reduced, and the number of people needing postoperative rescue analgesia was significantly lower, with a statistical difference (P < 0.05). Meanwhile, the sleep satisfaction of patients in the DP group on the first night after surgery and the satisfaction with pain control at 72 h after surgery were both higher than those in the DS group and control group (P < 0.05). CONCLUSIONS: Perineural administration of DEX can significantly prolong the interval until patients report pain for the first time after TKA, relieve postoperative pain, reduce postoperative opioid dosage, and improve postoperative sleep quality and satisfaction with pain control. TRIAL REGISTRATION: The trial was registered at the Chinese Clinical Trial Registry, identifier ChiCTR1900025808.

Ultrasound Guidance and Nerve Stimulation Combined Versus Nerve Stimulation alone for Lumbar Plexus Block: A Randomized Controlled Trial.

A nerve stimulation-guided lumbar plexus block is a well-established technique. It is not clear whether ultrasound guidance has additional value for this deep block technique. This study aimed to examine whether ultrasound guidance using a paramedian transverse scan through the intertransverse space (PMTS-ITS) approach in combination with nerve stimulation reduces the onset time of a complete sensory block. Forty-four patients who were scheduled to undergo arthroscopic knee surgery with an ultrasound visibility score (UVS) of ≥10 for the lumbar plexus were enrolled and randomly allocated to the ultrasound guidance with nerve stimulation group (group U-N) or nerve stimulation group (group N) in this prospective, randomized, parallel-group, active-controlled study. The primary outcome was the onset time of a complete sensory block. The results showed that the onset time of a complete sensory block to pinprick and cold was 10 (10-40) min and 10 (10-40) min in group U-N, respectively, and 30 (10-40) min and 20 (10-40) min in group N (P=0.005, P=0.004), respectively. The performance time was 658±87 s in group U-N and 528±97 s in group N (P<0.001). There was no (0%) patient who required 5 or more needle passes in group U-N and 6 (27.3%) in group N (P=0.028). The block failure rate was 9.1% in group U-N and 31.8% in group N (P>0.05). In conclusion, ultrasound guidance using the PMTS-ITS approach in combination with nerve stimulation led to a faster onset of a complete sensory block than nerve stimulation alone for a lumbar plexus block in patients with a UVS ≥10. Ultrasound guidance with nerve stimulation significantly decreased the number of patients who required 5 or more needle passes.