Retrospective comparison of the effects of remimazolam and dexmedetomidine on postoperative delirium in elderly patients undergoing orthopedic surgery of the lower extremities under spinal anesthesia.

PURPOSE: Remimazolam is often used for perioperative sedation due to its rapid onset and offset. However, the possible association between remimazolam and postoperative delirium (POD) remains undetermined. The present study evaluated whether remimazolam increased the incidence of POD compared with dexmedetomidine in elderly patients undergoing orthopedic surgery of the lower extremities. METHODS: This retrospective study included patients aged ≥ 65 years who had undergone orthopedic surgery of the lower extremities under spinal anesthesia from January 2020 to November 2022 and were sedated with continuous intravenous infusion of dexmedetomidine or remimazolam. The incidence of POD was assessed through a validated comprehensive review process of each patient's medical records. The effect of remimazolam on the occurrence of POD compared with dexmedetomidine was evaluated by propensity score weighted multivariable logistic models. RESULTS: A total of 447 patients were included in the final analysis. The crude incidence of POD within 3 days after surgery was 7.5% (17/226) in the dexmedetomidine group and 11.8% (26/221) in the remimazolam group, increasing to 9.7% (22/226) and 15.8% (35/221), respectively (p = 0.073), within 5 days. The multivariable models showed that, compared with dexmedetomidine, intraoperative sedation with remimazolam significantly increased the occurrence of POD within 3 days (odds ratio [OR] 2.21, 95% confidence interval [CI] 1.31 to 3.82, p = 0.003) and 5 days (OR 2.10, 95% CI 1.32 to 3.40, p = 0.002). CONCLUSION: Compared with dexmedetomidine, remimazolam infusion may be associated with a higher risk of POD in elderly patients undergoing orthopedic surgery of the lower extremities under spinal anesthesia.

Diaphragm-sparing efficacy of subparaneural upper trunk block for arthroscopic shoulder surgery: A randomised controlled trial.

BACKGROUND: Inter-scalene block (ISB) is associated with an inevitable risk of hemi-diaphragmatic paresis (HDP). To reduce the risk of HDP, an upper trunk block (UTB) has been proposed at the brachial plexus division level. OBJECTIVE: We hypothesised that UTB would be associated with a lower incidence of HDP than ISB while providing sufficient analgesia following arthroscopic shoulder surgery. DESIGN: Randomised controlled trial. SETTING: A tertiary teaching hospital. PATIENTS: Seventy patients aged 20 to 80 years undergoing arthroscopic rotator cuff repair. INTERVENTION: Ultrasound-guided ISB or UTB was performed with 5 ml 0.75% ropivacaine. MAIN OUTCOME MEASURES: The primary outcome was the incidence of complete HDP, assessed by diaphragm excursion using ultrasound, defined as a decrease to 25% or less of baseline or occurrence of paradoxical movement. Postoperative pulmonary function change, pain scores, opioid consumption and pain-related outcomes were the secondary outcomes. RESULTS: The UTB group had a significantly lower incidence of complete HDP than the ISB group [5.9% (2/34) vs. 41.7% (15/36); absolute difference, 35.8%; 95% confidence interval (CI), 17.8 to 53.7%; P  < 0.001]. The postblockade decline in pulmonary function was more pronounced in the ISB group than that in the UTB group. The pain score at 1 h postoperatively was not significantly different between the groups (ISB vs. UTB group: median 0 vs. 1; median difference, -1; 95% CI, -2 to 0.5). No significant difference was observed in any other secondary outcomes. CONCLUSION: UTB was associated with a lower incidence of HDP compared with ISB while providing excellent analgesia in arthroscopic shoulder surgery. TRIAL REGISTRATION: Clinical Trial Registry of Korea ( https://cris.nih.go.kr ) identifier: KCT0007002. IRB NUMBER: Chungnam National University Hospital Institutional Review Board No. 2021-12-069.

Apnea during moderate to deep sedation using continuous infusion of remimazolam compared to propofol and dexmedetomidine: A retrospective observational study.

Remimazolam's rapid onset and offset make it an innovative sedative for use during regional anesthesia. However, its respiratory safety profile is not well understood. We compared the continuous infusion of remimazolam with commonly used sedatives, propofol and dexmedetomidine, after regional anesthesia. In this retrospective study, the incidence of apnea (>10 seconds) was assessed in patients who underwent orthopedic surgery under regional anesthesia and received moderate to deep sedation using continuous infusion of remimazolam (group R: 0.1 mg/kg in 2 minutes followed by 0.5 mg/kg/hr). The incidence was compared with that of propofol (group P: 2-3 µg/mL target-controlled infusion) and dexmedetomidine (group D: 1 µg/kg in 10 minutes followed by 0.4-1 µg/kg/hr). Propensity score weighted multivariable logistic regression model was utilized to determine the effects of the sedative agents on the incidence of apnea. A total of 634 (191, 278, and 165 in group R, P, and D) cases were included in the final analysis. The incidence of apnea was 63.9%, 67.3%, and 48.5% in group R, P, and D, respectively. The adjusted odds ratios for apnea were 2.33 (95% CI, 1.50 to 3.61) and 2.50 (95% CI, 1.63 to 3.85) in group R and P, compared to group D. The incidence of apnea in patients receiving moderate to deep sedation using continuous infusion of remimazolam with dosage suggested in the current study was over 60%. Therefore, careful titration and respiratory monitoring is warranted.

Effect of local anesthetic volume (20 vs. 40 ml) on the analgesic efficacy of costoclavicular block in arthroscopic shoulder surgery: a randomized controlled trial.

BACKGROUND: Among the various diaphragm-sparing alternatives to interscalene block, costoclavicular block (CCB) demonstrated a low hemidiaphragmatic paresis (HDP) occurrence but an inconsistent analgesic effect in arthroscopic shoulder surgery. We hypothesized that a larger volume of local anesthetic for CCB could provide sufficient analgesia by achieving sufficient supraclavicular spreading. METHODS: Sixty patients scheduled for arthroscopic rotator cuff repair were randomly assigned to receive CCB using one of two volumes of local anesthetic (CCB20, 0.75% ropivacaine 20 ml; CCB40, 0.375% ropivacaine 40 ml). The primary outcome was the rate of complete analgesia (0 on the numeric rating scale of pain) at 1 h postoperatively. The secondary outcomes included a sonographic assessment of local anesthetic spread, diaphragmatic function, pulmonary function, postoperative opioid use, and other pain-related experiences within 24 h postoperatively. RESULTS: The rates of complete analgesia were not significantly different (23.3% [7/30] and 33.3% [10/30] in the CCB20 and CCB40 groups, respectively; risk difference 10%, 95% CI [-13, 32], P = 0.567). There were no significant differences in other pain-related outcomes. Among the clinical factors considered, the only factor significantly associated with postoperative pain was the sonographic observation of supraclavicular spreading. There were no significant differences in the incidence of HDP and the change in pulmonary function between the two groups. CONCLUSIONS: Using 40 ml of local anesthetic does not guarantee supraclavicular spread during CCB. Moreover, it does not result in a higher rate of complete analgesia compared to using 20 ml of local anesthetic in arthroscopic shoulder surgery.

Perioperative Hypotension in Patients Undergoing Orthopedic Upper Extremity Surgery with Dexmedetomidine Sedation: A Retrospective Study.

(1) Background: limited data exist regarding the occurrence of hypotension associated with dexmedetomidine use and its risk factors in the context of intraoperative sedation for patients receiving peripheral nerve blocks. (2) Method: This single-center retrospective study assessed the incidence of hypotension in patients undergoing orthopedic upper extremity surgery with brachial plexus blockade. Patients were classified into three groups: group N (non-sedated), group M (midazolam), and group D (dexmedetomidine), based on their primary intraoperative sedative use. The primary outcome was the incidence of perioperative hypotension, defined as systolic blood pressure (SBP) < 90 mmHg or mean blood pressure (MBP) < 60 mmHg, at a minimum of two recorded time points during the intraoperative period and post-anesthesia care unit stay. Multivariable logistic models for the occurrence of hypotension were constructed for the entire cohort and group D. (3) Results: A total of 2152 cases (group N = 445, group M = 678, group D = 1029) were included in the analysis. The odds ratio for the occurrence of hypotension in group D was 5.68 (95% CI, 2.86 to 11.28) compared with group N. Concurrent use of a beta blocker, longer duration of surgery, and lower preoperative SBP and higher preoperative heart rate were identified as significant risk factors. (4) Conclusions: the increased risk of hypotension and the associated factors should be taken into account before using dexmedetomidine in these cases.

Optimal view detection for ultrasound-guided supraclavicular block using deep learning approaches.

Successful ultrasound-guided supraclavicular block (SCB) requires the understanding of sonoanatomy and identification of the optimal view. Segmentation using a convolutional neural network (CNN) is limited in clearly determining the optimal view. The present study describes the development of a computer-aided diagnosis (CADx) system using a CNN that can determine the optimal view for complete SCB in real time. The aim of this study was the development of computer-aided diagnosis system that aid non-expert to determine the optimal view for complete supraclavicular block in real time. Ultrasound videos were retrospectively collected from 881 patients to develop the CADx system (600 to the training and validation set and 281 to the test set). The CADx system included classification and segmentation approaches, with Residual neural network (ResNet) and U-Net, respectively, applied as backbone networks. In the classification approach, an ablation study was performed to determine the optimal architecture and improve the performance of the model. In the segmentation approach, a cascade structure, in which U-Net is connected to ResNet, was implemented. The performance of the two approaches was evaluated based on a confusion matrix. Using the classification approach, ResNet34 and gated recurrent units with augmentation showed the highest performance, with average accuracy 0.901, precision 0.613, recall 0.757, f1-score 0.677 and AUROC 0.936. Using the segmentation approach, U-Net combined with ResNet34 and augmentation showed poorer performance than the classification approach. The CADx system described in this study showed high performance in determining the optimal view for SCB. This system could be expanded to include many anatomical regions and may have potential to aid clinicians in real-time settings.Trial registration The protocol was registered with the Clinical Trial Registry of Korea (KCT0005822, https://cris.nih.go.kr ).

Comparison between costotransverse foramen block and thoracic paravertebral block for VATS pulmonary resection: A randomized noninferiority trial.

STUDY OBJECTIVE: The present study assessed whether costotransverse foramen block (CTFB) is noninferior to thoracic paravertebral block (TPVB) for postoperative analgesia in video-assisted thoracoscopic surgery (VATS) pulmonary resection. DESIGN: Single-center, double-blinded, randomized, non-inferiority trial. SETTING: Operating room and intensive care unit or ward in a tertiary hospital. PATIENTS: Patients aged 20 to 80 years with American Society of Anesthesiology physical status 1 to 3 scheduled for elective VATS pulmonary resection. INTERVENTIONS: Sixty patients were randomly allocated 1:1 to receive CTFB or TPVB using 15 mL aliquots of 0.5% ropivacaine at the T4-5 and T6-7 intercostal levels immediately after the induction of general anesthesia. MEASUREMENTS: The primary outcome was the area under the curve (AUC) of numeric rating scale (NRS, 0 to 10) during 24 h postoperatively (noninferiority limit was 24; NRS 1 per hour). The secondary outcomes included postoperative opioid consumption, rescue analgesic use, postoperative nausea and vomiting, pulmonary function, dermatomal spread of the blockade, and quality of recovery. MAIN RESULTS: Forty-seven patients were included for final analysis. The difference between the mean 24-h AUCs of NRS in the CTFB (34.25 ± 16.30, n = 24) and TPVB (39.52 ± 17.13, n = 23) groups was -5.27 (95% confidence interval [CI], -15.09 to 4.55), with the upper limit of 95% CI being far below the predefined noninferiority margin of 24. There was no significant difference in the dermatomal spread of the blockades between the groups, as both reached the upper and lower most levels of T3 and T7 (median). Additionally, there were no significant differences in other secondary outcomes between the two groups. CONCLUSIONS: The analgesic effect of CTFB was noninferior to that of TPVB during 24 h postoperatively in VATS pulmonary resection. Moreover, CTFB may offer potential safety benefits by keeping the tip of the needle far from the pleura and vascular structure.

Regional analgesia techniques for lumbar spine surgery: a frequentist network meta-analysis.

BACKGROUND: Various regional analgesia techniques are used to reduce postoperative pain in patients undergoing lumbar spine surgery. Traditionally, wound infiltration (WI) with local anesthetics has been widely used by surgeons. Recently, other regional analgesia techniques, such as the erector spinae plane block (ESPB) and thoracolumbar interfascial plane (TLIP) block, are being used for multimodal analgesia. The authors aimed to determine the relative efficacy of these using a network meta-analysis. MATERIALS AND METHODS: The authors searched PubMed, EMBASE, the Cochrane Controlled Library, and Google Scholar databases to identify all randomized controlled trials that compared the analgesic efficacy of the following interventions: ESPB, TLIP block, WI technique, and controls. The primary endpoint was postoperative opioid consumption during the first 24 hours after surgery, while the pain score, estimated postoperatively at three different time periods, was the secondary objective. RESULTS: The authors included 34 randomized controlled trials with data from 2365 patients. TLIP showed the greatest reduction in opioid consumption compared to controls [mean difference (MD) =-15.0 mg; 95% CI: -18.8 to -11.2]. In pain scores, TLIP had the greatest effect during all time periods compared to controls (MD=-1.9 in early, -1.4 in middle, -0.9 in late). The injection level of ESPB was different in each study. When only surgical site injection of ESPB was included in the network meta-analysis, there was no difference compared with TLIP (MD=1.0 mg; 95% CI: -3.6 to 5.6). CONCLUSIONS: TLIP showed the greatest analgesic efficacy after lumbar spine surgery, in terms of postoperative opioid consumption and pain scores, while ESPB and WI are also alternative analgesic options for these surgeries. However, further studies are needed to determine the optimal method of providing regional analgesia after lumbar spine surgery.

Current evidence of ultrasound-guided fascial plane blocks for cardiac surgery: a narrative literature review.

Fascial plane blocks are useful for multimodal analgesia after cardiac surgery since they can provide effective analgesia without the serious risks associated with conventional techniques such as neuraxial hematoma and pneumothorax. This narrative review covers blocks performed at the parasternal intercostal, interpectoral, pectoserratus, serratus anterior, erector spinae, and retrolaminar planes, which are targets for fascial plane blocks in cardiac surgery. Brief anatomical considerations, mechanisms, and currently available evidence are reviewed. Additionally, recent evidence on fascial plane blocks for subcutaneous-implantable cardioverter-defibrillator implantation are also reviewed.

Randomised comparison between superior trunk and costoclavicular blocks for arthroscopic shoulder surgery: A noninferiority study.

BACKGROUND: Superior trunk block (STB) provides noninferior analgesia to the interscalene block and reduces the risk of hemidiaphragmatic paralysis (HDP). Recently, supraclavicular spreading has also been shown to occur during costoclavicular block (CCB), presenting as an alternative analgesic technique for shoulder surgery. OBJECTIVE: The aim of this study was to determine whether there is a difference in postoperative pain scores and HDP incidence between STB and CCB. DESIGN: Prospective randomised controlled trial. SETTING: Chungnam National University Hospital in Daejeon from January to July 2021. PATIENTS: Seventy patients, aged 20 to 70 years with ASA Physical Status classifications I to III and scheduled for elective arthroscopic rotator cuff repair were recruited. INTERVENTION: Ultrasound-guided STB or CCB was performed with 20 ml 0.5% ropivacaine. MAIN OUTCOME MEASURES: The primary outcome was the pain score (numeric rating scale, NRS) at 1 h postsurgery. A 1.4 (NRS) noninferiority margin was set a priori . The incidence of HDP, postoperative change of pulmonary function and postoperative opioid use were included as secondary outcomes. RESULTS: The pain score was higher in the CCB group compared with the STB group at 1 h postoperatively (median difference, 2; 95% confidence interval (CI), 1 to 3; noninferiority was not demonstrated). Two patients in the CCB group received a rescue interscalene block due to severe postoperative pain. The incidence of complete HDP was lower in the CCB group (risk difference, -26%; 95% CI, -6 to -45%; P  < 0.001). The median reduction in forced vital capacity and forced expiratory volume in 1 s were also significantly lower in the CCB group. CONCLUSION: Although the incidence of HDP was lower, CCB did not show noninferiority in immediate postoperative analgesia compared with STB in arthroscopic shoulder surgery. CLINICAL TRIAL REGISTRATION: Clinical Trial Registry of Korea (KCT0005822, principal investigator: Boohwi Hong) on 25 January 2021 ( https://cris.nih.go.kr ).

Comparison of the analgesic efficacy of periarticular infiltration and pericapsular nerve group block for total hip arthroplasty: a randomized, non-inferiority study.

BACKGROUND: Motor-sparing regional anesthesia modalities, such as periarticular infiltration (PAI) and pericapsular nerve group (PENG) block, have become the mainstay of multimodal approaches used during total hip arthroplasty (THA). We hypothesized that the postoperative analgesia of the PENG block was non-inferior to that of the PAI. METHODS: Sixty patients were randomly allocated into two groups. The PAI group were injected with 100 mL of cocktail solution (ropivacaine 20 mL, ketorolac 2 mL, and epinephrine 1 mL mixed with normal saline) in periarticular tissues directly by the surgeon. The PENG group were injected with 30 mL of 0.5% ropivacaine in the iliopubic eminence plane by ultrasound. The primary outcome was the resting pain score 12 h after surgery, and the prespecified non-inferiority was 1. Additionally, the cumulative opioid consumption and quality of recovery were evaluated. RESULTS: The mean difference in pain score 12 h postoperatively between the PENG and PAI groups was 0.6 [95% confidence interval (CI): -0.8 to 2.0]. The upper 95% CI exceeded the non-inferiority margin of 1 at all postoperative time points. There was no difference in opioid consumptions and quality of recovery scores. CONCLUSIONS: PENG block provided comparable analgesia with PAI following THA. It is not conclusive that PENG is inferior or non-inferior to PAI based on our study. TRIAL REGISTRATION: Clinical Research information Service (CRIS, https://cris.nih.go.kr, KCT0006049).

Regional analgesia techniques for video-assisted thoracic surgery: a frequentist network meta-analysis.

BACKGROUND: Various regional analgesia techniques are used to reduce postoperative pain in patients undergoing video-assisted thoracic surgery (VATS). This study aimed to determine the relative efficacy of regional analgesic interventions for VATS using a network meta-analysis (NMA). METHODS: We searched the Medline, EMBASE, Cochrane Controlled Trial Register, Web of Science, and Google Scholar databases to identify all randomized controlled trials (RCTs) that compared the analgesic effects of the following interventions: control, thoracic paravertebral block (TPVB), erector spinae plane block (ESPB), serratus plane block (SPB), and intercostal nerve block (INB). The primary outcome was opioid consumption during the first 24-h postoperative period. Pain scores were also collected during three different postoperative periods: the early (0-6 h), middle (6-18 h), and late (18-24 h) periods. RESULTS: A total of 21 RCTs (1391 patients) were included. TPVB showed the greatest effect on opioid consumption compared with the control (mean difference [MD] = -13.2 mg; 95% CI [-16.2, -10.1]). In terms of pain scores in the early period, ESPB had the greatest effect compared to control (MD = -1.6; 95% CI [-2.3, -0.9]). In the middle and late periods, pain scores showed that TPVB, ESPB and INB had superior analgesic effects compared to controls, while SPB did not. CONCLUSIONS: TPVB had the best analgesic efficacy following VATS, though the analgesic efficacy of ESPBs was comparable. However, further studies are needed to determine the optimal regional analgesia technique to improve postoperative pain control following VATS.

The Effect of Intravenous Dexamethasone and Dexmedetomidine on Analgesia Duration of Supraclavicular Brachial Plexus Block: A Randomized, Four-Arm, Triple-Blinded, Placebo-Controlled Trial.

Intravenous dexamethasone and dexmedetomidine, in conjunction with peripheral nerve blockade, have each been reported to prolong the duration of analgesia. This study tested whether combined use further prolongs analgesia duration after supraclavicular brachial plexus block (BPB) in patients undergoing orthopedic upper extremity surgery. One hundred twenty patients were randomized 1:1:1:1 to Control (saline bolus and midazolam infusion [0.05 mg/kg loading, 20 µg/kg/h thereafter]); DMED (saline bolus and dexmedetomidine infusion [1 µg/kg loading, 0.4 µg/kg/h thereafter]); DEXA (dexamethasone [10 mg] bolus and midazolam infusion); and DMED-DEXA (dexmedetomidine infusion and dexamethasone bolus) groups. The primary outcome was the duration of postoperative analgesia, defined as the time from the end of the BPB to the first dose of analgesia via a patient-controlled device. Median (interquartile range) times to first dose of analgesia in the Control, DMED, DEXA, and DMED-DEXA groups were 8.1 (6.2-11.6), 9.0 (8.1-11.3), 10.7 (8.1-20.5), and 13.2 (11.5-19.1) hours, respectively (p < 0.001). Pairwise comparisons showed significant prolongation of analgesia in the DEXA included groups compared with the non-DEXA included groups (DEXA vs. control, p = 0.045; DEXA vs. DMED, p = 0.045; DMED-DEXA vs. control, p < 0.001; DMED-DEXA vs. DMED, p < 0.001). A mixed effect model showed that dexamethasone was the only significant factor for the prolongation of analgesia (p < 0.001). Intravenous dexamethasone prolonged the analgesia duration of supraclavicular BPB after orthopedic upper extremity surgery. The concurrent use of mild to moderate sedation dose of intravenous dexmedetomidine in addition to intravenous dexamethasone showed no additional benefit to the prolongation of analgesia.

Changes in the Plasma Apurinic/Apyrimidinic Endonuclease 1/Redox Factor-1(APE1/Ref-1) Level during Cancer Surgery: An Observational Study.

Background and Objectives: Propofol-based total intravenous anesthesia (TIVA) is presumed to have more favorable effects on the prognosis of patients with cancer compared with volatile inhaled anesthesia (VIA). We hypothesized that these anesthetics target plasma apurinic apyrimidinic endonuclease/redox effector factor-1 (APE1/Ref-1) as a possible mechanism of action. Materials and Methods: The plasma APE1/Ref-1 level was evaluated three times during surgery for cancer, i.e., before anesthesia, immediately after cancer resection, and finally, in the recovery room. Blood (3 cc) was drawn from the radial artery catheter, and plasma APE1/Ref-1 levels were compared according to measurement time and between the two groups. Spearman's Rho correlation analysis was performed to determine relationships among body mass index, American Society of Anesthesiologists classification, age, sex, cancer type, and tumor-node-metastasis (TNM) stage. A total of 166 patients (VIA: 129; TIVA: 37) were enrolled. Results: Plasma APE1/Ref-1 level increased significantly (p = 0.028) after cancer resection compared with before surgery, but no significant difference was observed between anesthetics (p = 0.134). The post-resection plasma APE1/Ref-1 level showed a positive correlation with the NM stages, but not the T stage. Conclusions: The plasma APE1/Ref-1 level increased during surgery with more severe lymph node invasion, but there were no significant differences according to the anesthetics used.

A retrospective comparison for prediction of optimal length of right subclavian vein catheterization in infants: landmark-based estimation vs. linear regression model.

BACKGROUND: The optimal insertion length for right subclavian vein catheterization in infants has not been determined. This study retrospectively compared landmark-based and linear regression model-based estimation of optimal insertion length for right subclavian vein catheterization in pediatric patients of corrected age < 1 year. METHODS: Fifty catheterizations of the right subclavian vein were analyzed. The landmark related distances were: from the needle insertion point (I) to the tip of the sternal head of the right clavicle (A) and from A to the midpoint (B) of the perpendicular line drawn from the sternal head of the right clavicle to the line connecting the nipples. The optimal length of insertion was retrospectively determined by reviewing post-procedural chest radiographs. Estimates using a landmark-based equation (IA + AB - intercept) and a linear regression model were compared with the optimal length of insertion. RESULTS: A landmark-based equation was determined as IA + AB - 5. The mean difference between the landmark-based estimate and the optimal insertion length was 1.0 mm (95% limits of agreement -18.2 to 20.3 mm). The mean difference between the linear regression model (26.681 - 4.014 × weight + 0.576 × IA + 0.537 × AB - 0.482 × postmenstrual age) and the optimal insertion length was 0 mm (95% limits of agreement -16.7 to 16.7 mm). The difference between the estimates using these two methods was not significant. CONCLUSION: A simple landmark-based equation may be useful for estimating optimal insertion length in pediatric patients of corrected age < 1 year undergoing right subclavian vein catheterization.

Perineural Epinephrine for Brachial Plexus Block Increases the Incidence of Hypotension during Dexmedetomidine Infusion: A Single-Center, Randomized, Controlled Trial.

BACKGROUND: Sedation using dexmedetomidine is frequently associated with hypotension. In contrast, epinephrine, a commonly used adjunctive agent in regional anesthesia, is a potent vasopressor. We hypothesized that perineural epinephrine used in brachial plexus blockade may reduce hypotension during dexmedetomidine infusion. METHODS: Patients scheduled for upper extremity surgery were randomly allocated into a control and an epinephrine group. All patients received brachial plexus blockade, consisting of 25 mL of a 1:1 mixture of 1% lidocaine and 0.75% ropivacaine, with patients in the epinephrine group also receiving 125 µg epinephrine. Intraoperative sedation was induced using dexmedetomidine at a loading dose of 1 µg/kg and maintenance dose of 0.4 µg/kg/hr. The primary outcome was the incidence of intraoperative hypotension or hypotension in the post-anesthesia care unit (PACU). RESULTS: One hundred and thirty patients were included (65 per group). The incidence of hypotension was significantly higher in the epinephrine than in the control group (80.6% vs. 56.9%, p = 0.009). The duration of hypotension and the maximal change in blood pressure were also greater in the epinephrine group. CONCLUSIONS: Perineural epinephrine for brachial plexus blockade does not reduce hypotension due to dexmedetomidine infusion and may actually augment the occurrence of hypotensive events.

Comparison of the ulnar nerve blockade between intertruncal and corner pocket approaches for supraclavicular block: a randomized controlled trial.

BACKGROUND: The corner pocket (CP) approach for supraclavicular block (SCB) prevents ulnar nerve (UN) sparing due to needle proximity to the lower trunk. Improved ultrasound resolution has suggested that the intertruncal (IT) approach is a suitable alternative method. We compared efficiency of these two approaches on the UN blockade. METHODS: Sixty patients were randomized to undergo SCB using the ultrasound-guided CP or IT approach. For lower trunk blockade, 10 ml of local anesthetic agents (1 : 1 mixture of 0.75% ropivacaine and 1% lidocaine) were injected in the CP (CP approach) or between the lower and middle trunks (IT approach). Additional 15 ml was injected identically to block the middle and upper trunks in both groups. Sensory and motor blockade was evaluated after intervention. RESULTS: Complete sensory blockade (75.9% [22/29] vs. 43.3% [13/30], P = 0.023) and complete motor blockade (82.8% [24/29] vs. 50.0% [15/30], P = 0.017) of the UN at 15 min after SCB were significantly more frequent in the IT than in the CP group. Sensory block onset time of the UN was significantly shorter in the IT compared to the CP group (15.0 [10.0, 15.0] min vs. 20.0 [15.0, 20.0] min, P = 0.012). CONCLUSIONS: The IT approach provided a more rapid onset of UN blockade than the CP approach. These results suggest that the IT approach is a suitable alternative to the CP approach and can provide faster surgical readiness.