IV and Perineural Dexmedetomidine Similarly Prolong the Duration of Analgesia after Interscalene Brachial Plexus Block: A Randomized, Three-arm, Triple-masked, Placebo-controlled Trial.

BACKGROUND: Perineural and IV dexmedetomidine have each been suggested to prolong the duration of analgesia when administered in conjunction with peripheral nerve blocks. In the first randomized, triple-masked, placebo-controlled trial to date, the authors aimed to define and compare the efficacy of perineural and IV dexmedetomidine in prolonging the analgesic duration of single-injection interscalene brachial plexus block (ISB) for outpatient shoulder surgery. METHODS: Ninety-nine patients were randomized to receive ISB using 15 ml ropivacaine, 0.5%, with 0.5 µg/kg dexmedetomidine administered perineurally (DexP group), intravenously (DexIV group), or none (control group). The authors sequentially tested the joint hypothesis that dexmedetomidine prolongs the duration of analgesia and reduces the 24-h cumulative postoperative morphine consumption. Motor blockade, pain severity, hemodynamic variations, opioid-related side effects, postoperative neurologic symptoms, and patient satisfaction were also evaluated. RESULTS: Ninety-nine patients were analyzed. The duration of analgesia was 10.9 h (10.0 to 11.8 h) and 9.8 h (9.0 to 10.6 h) for the DexP and DexIV groups, respectively, compared with 6.7 h (5.6 to 7.8) for the control group (P < 0.001). Dexmedetomidine also reduced the 24-h cumulative morphine consumption to 63.9 mg (58.8 to 69.0 mg) and 66.2 mg (60.6 to 71.8 mg) for the DexP and DexIV groups, respectively, compared with 81.9 mg (75.0 to 88.9 mg) for the control group (P < 0.001). DexIV was noninferior to DexP for these outcomes. Both dexmedetomidine routes reduced the pain and opioid consumption up to 8 h postoperatively and did not prolong the duration of motor blockade. CONCLUSION: Both perineural and IV dexmedetomidine can effectively prolong the ISB analgesic duration and reduce the opioid consumption without prolonging motor blockade.

Adductor Canal Block Provides Noninferior Analgesia and Superior Quadriceps Strength Compared with Femoral Nerve Block in Anterior Cruciate Ligament Reconstruction.

BACKGROUND: By targeting the distal branches of the femoral nerve in the mid-thigh, the adductor canal block (ACB) can preserve quadriceps muscle strength while providing analgesia similar to a conventional femoral nerve block (FNB) for inpatients undergoing major knee surgery. In this randomized, double-blind, noninferiority trial, the authors hypothesized that ACB provides postoperative analgesia that is at least as good as FNB while preserving quadriceps strength after outpatient anterior cruciate ligament reconstruction. METHODS: A total of 100 patients were randomized to receive ACB or FNB with 20 ml ropivacaine 0.5% (with epinephrine). The authors sequentially tested the joint hypothesis that ACB is noninferior to FNB for cumulative oral morphine equivalent consumption and area under the curve for pain scores during the first 24 h postoperatively and also superior to FNB for postblock quadriceps maximal voluntary isometric contraction. RESULTS: The authors analyzed 52 and 48 patients who received ACB and FNB, respectively. Compared with preset noninferiority margins, the ACB-FNB difference (95% CI) in morphine consumption and area under the curve for pain scores were -4.8 mg (-12.3 to 2.7) (P = 0.03) and -71 mm h (-148 to 6) (P < 0.00001), respectively, indicating noninferiority of ACB for both outcomes. The maximal voluntary isometric contraction for ACB and FNB at 45 min were 26.6 pound-force (24.7-28.6) and 10.6 pound-force (8.3-13.0) (P < 0.00001), respectively, indicating superiority of ACB. CONCLUSION: Compared with FNB, the study findings suggest that ACB preserves quadriceps strength and provides noninferior postoperative analgesia for outpatients undergoing anterior cruciate ligament reconstruction.

Preoperative Femoral Nerve Block for Hip Arthroscopy: A Randomized, Triple-Masked Controlled Trial.

BACKGROUND: Arthroscopy has become a standard method of treatment for a variety of intra-articular hip disorders. While most arthroscopic hip procedures are performed as outpatient surgeries, patients can still experience significant postoperative pain and opioid-associated side effects. PURPOSE: The potential benefits of a preoperative femoral nerve block (FNB) in hip arthroscopy were explored in a previous retrospective review. The study objective was to confirm these findings in a prospective randomized study. STUDY DESIGN: Randomized controlled trial; Level of evidence, 1. METHODS: Fifty patients undergoing hip arthroscopy were included in this prospective, single-center, randomized controlled trial that was patient-, operator-, and assessor-blinded. Patients received either a preoperative ultrasound-guided FNB with 20 mL of 0.5% bupivacaine (FNB group) or normal saline (control group). Nerve blockade was confirmed via standardized sensory testing before the induction of general anesthesia. The primary endpoint was cumulative consumption of oral morphine equivalent at 24 hours after discharge. Secondary endpoints included opioid use at various time points, pain scores, Quality of Recovery (QoR-27) score, incidence of nausea and vomiting, time to discharge, block-related complications, falls at 24 hours, and patient satisfaction. RESULTS: Fifty patients completed the study, including 27 in the FNB group and 23 in the control group. Most patient characteristics were statistically similar between groups except for operative time, which was longer in the control group. Cumulative oral morphine consumption was lower in the FNB group at 48 hours; there was no difference at 24 hours or 7 days postoperatively. Pain scores were significantly lower up to 6 hours postoperatively in the FNB group compared with control; however, rebound pain was observed at 24 hours after discharge in patients who received FNB. There was no difference in most secondary outcomes. Importantly, a total of 6 patients in the FNB group reported falls (without injury) within the first 24 hours postoperatively compared with none in the control group. Patient satisfaction with pain control was high in both groups at all time points. CONCLUSION: Preoperative FNB may improve early pain control after hip arthroscopy. However, given the observed risk of falls, the routine use of FNB for outpatient hip arthroscopy cannot be recommended.

Prognostic significance of circulating tumour cells enumerated after filtration enrichment in early and metastatic breast cancer patients.

BACKGROUND: We previously found a higher incidence of circulating tumour cells (CTCs) in women with metastatic breast cancer compared to early disease. In this study, we present follow-up data to explore the prognostic significance of these findings. METHODS: CTCs were quantified by immunostaining and direct visualization after centrifugation and filtration enrichment of peripheral blood from 131 patients. Time to progression (TTP) and overall survival (OS) were defined as interval from first blood sampling to first documented disease progression, or death respectively. Lifetime data was analysed using Kaplan-Meier method, log-rank test and Cox proportional hazards model. RESULTS: Follow-up data is available for 123 patients. In early disease, median CTC>or=4 best distinguished patients with shorter TTP (p=0.05, log-rank test). In univariate analysis, tumour size, grade, lymphovascular invasion (LVI) and receptor status significantly related to TTP but none of the covariates related to OS. In multivariate analysis, T stage was the only independent predictor of TTP. In metastatic disease, median CTC>or=13 optimally identified patients with shorter TTP (p=0.01). In univariate analysis, median CTC level >or=13 and prior lines of chemotherapy predicted for TTP while in multivariate analysis, median CTC level >or=13 was the only significant independent prognostic factor (p=0.02). No relationship between CTC level and OS was found in this subgroup. CONCLUSION: Median CTC level determined in the course of treatment predicts for TTP in metastatic breast cancer. In early breast cancer, an association was found between CTC level and TTP although this did not reach statistical significance (p=0.05).