Serratus anterior plane (SAP) block is effective for analgesia after breast surgery. Whether a higher local anesthetic concentration prolongs sensory block duration and improves postoperative analgesia remains unclear. The aim of this study was to compare the analgesic effects of SAP block with different concentrations of ropivacaine. Patients and Methods: Sixty patients scheduled for breast surgery were enrolled in this randomized double-blind trial. SAP block was induced with 20 mL of 0.375%, 0.5%, or 0.75% ropivacaine in Group R0.375, Group R0.5, and Group R0.75, respectively. The primary endpoint was the area under the curve (AUC) of numerical rating scale (NRS) pain intensity scores at rest over time. The secondary endpoints were AUC of NRS pain intensity scores on movement over time, active sensory block duration, tramadol consumption, and the elapsed time between completion of surgery and the first administration of rescue analgesia. Results: The AUC of NRS pain intensity scores at rest of Group R0.375 was significantly higher than that of Groups R0.5 and R0.75 (P=0.025, and P=0.001). The AUC of NRS pain intensity scores on movement of Group R0.375 was also significantly higher than that of Groups R0.5 and R0.75 (both P<0.001). At higher ropivacaine concentrations, the duration of SAP sensory block increased (P<0.001). Tramadol consumption and the elapsed time between completion of surgery and the first administration of rescue analgesia were similar in the three groups (P>0.05). Conclusion: A comparison of 0.5% and 0.75% ropivacaine showed no significant difference in postoperative analgesia, but both were superior to 0.375% ropivacaine, although higher ropivacaine concentration lengthened the duration of SAP block. Therefore, SAP block with 0.5% ropivacaine is recommended for postoperative analgesia in breast surgery.

ObjectiveThe transmuscular quadratus lumborum (TQL) block and the oblique subcostal transversus abdominis plane (OSTAP) block both contribute to multimodal analgesia after laparoscopic surgery. The objective of this study was to compare the analgesic effects of the TQL block versus OSTAP block after laparoscopic hysterectomy.DesignProspective single-centre randomised single-blind trial.SettingUniversity-affiliated hospital.ParticipantsPatients aged between 18 and 65 years scheduled for laparoscopic hysterectomy.InterventionsPatients were randomised into two groups (1:1 ratio) and received bilateral TQL block or bilateral OSTAP block with 0.375% ropivacaine 20 mL on each side before surgery.Primary and secondary outcome measuresThe primary outcome measure was the cumulative morphine dose in the first 24 hours. The secondary outcome measures were the morphine consumption at each time interval after surgery, the time from the end of surgery to the first need for morphine, the Numerical Rating Scale (NRS) scores for visceral and incisional pain intensity, and the incidence of adverse events.ResultsThe cumulative morphine dose was significantly lower in the TQL group than in the OSTAP group (17.2 (12.5) vs 26.1 (13.3) mg, p=0.010). Compared with the OSTAP group, the morphine doses from 6 to 12, 12 to 18, and 18 to 24 hours were significantly lower, the time of first need for morphine was significantly longer and the NRS scores for visceral pain intensity were significantly lower in the TQL group.ConclusionCompared with the OSTAP block, the TQL block reduced morphine consumption and provided better visceral pain relief with a longer duration of effect after laparoscopic hysterectomy.Trial registration numberChinese Clinical Trial Registry (ChiCTR1800017995); pre-results.

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Background: A larger volume of local anesthetic provides a wider range of blocked sensory but carries a greater risk. The purpose of this trial was to compare the effect of different volumes of ropivacaine injected to deep serratus anterior plane in patients undergoing breast surgery.Methods: In this randomized double-blind trial, 60 patients undergoing breast surgery were randomly allocated to R10, R20 and R30 groups (n=20), and received deep serratus anterior plane block with 10, 20 and 30 mL of 0.5% ropivacaine respectively. 30 minutes after block, the cutaneous sensory was tested by cold stimulus in the craniocaudal direction along the midaxillary line. We recorded the numerical rating scale pain scores over 24 h after surgery and estimated the area under curve by numerical rating scale pain scores. The cases of rescue analgesia and the prevalence of adverse events were also recorded.Results: The blocked dermatomes were 3 (3, 4), 6 (5, 7) and 7 (6, 8) in the R10, R20 and R30 groups, respectively (R10 vs. R20, P<0.001; R10 vs. R30, P<0.001; R20 vs. R30, P=0.005). The area under curve of R10 group was significantly higher compared with the R20 and R30 groups (P=0.014, P=0.003, at rest; P<0.001, P<0.001, on movement). Conclusions:The blocked dermatomes increased with increasing volume when 10, 20 and 30 mL ropivacaine was used for deep serratus anterior plane block. The analgesic effects of 20 and 30 mL were similar to each other and better than 10 mL. Therefore, in breast surgery, volume of 20 mL ropivacaine is considered to be appropriate for deep serratus anterior plane block.

Continuous femoral nerve block (cFNB) is effective for analgesia after total knee arthroplasty (TKA). However, it is not clear which low-dose regimen of ropivacaine infusion for cFNB provides adequate analgesia and enables rapid recovery. The aim of this study was to compare the effects of different cFNB regimens on rehabilitation of patients after TKA. Patients and Methods: Sixty patients scheduled for TKA were enrolled in this trial. After surgery, patients in the 0.1%, 0.15%, and 0.2% groups received infusion of 10 mL of 0.1%, 6.7 mL of 0.15%, and 5 mL of 0.2% ropivacaine per hour, respectively (n=20), at the dose of 10 mg/h for 48 h. The primary endpoint was time to readiness for discharge. The secondary endpoints were time to first walk, manual muscle testing (MMT) scores, numerical rating scale (NRS) scores at rest and movement, morphine consumption, rescue analgesia, and the incidence of adverse events. Results: The time to readiness for discharge and the time to first walk of the 0.1% group were significantly longer than that of the 0.15% and 0.2% groups. MMT scores of the 0.2% group at 18 h after surgery were significantly lower than those of the 0.1% group. MMT scores of the 0.2% group at 24 and 48 h after surgery were also significantly lower than those of the 0.1% and 0.15% groups. NRS scores at rest and at movement in the 0.1% group were significantly higher than those in the 0.15% and 0.2% groups. Conclusion: Patients administered the regimens of 0.15% and 0.2% ropivacaine infusion for cFNB were ready for discharge earlier than the 0.1% group after TKA, at the dose of 10 mg/h for 48 h. The regimen of 0.15% ropivacaine, which is associated with less quadriceps muscle strength weakness than 0.2%, is recommended for postoperative analgesia after TKA.