Interscalene Brachial Plexus Block

Peripheral nerve blocks are performed using local anesthetics that are commonly performed prior to surgery to either be the sole anesthetic and/or for postoperative pain management. Interscalene blocks are a specific type of nerve block that targets the superior and middle trunks of the brachial plexus inhibiting transmission of pain signals from the upper extremities to the central nervous system making them useful in mitigating pain following surgeries involving the shoulder, upper arm, and elbow. Previously, interscalene blocks were performed with a nerve stimulator, which is an instrument designed to generate a twitch in surrounding muscles to verify the anesthetic block was placed in the correct location. However, this approach with a nerve stimulator alone is being done less frequently as physicians now often employ ultrasound either by itself or in conjunction with a nerve stimulator to in the block. Several clinical studies have shown that the use of ultrasound leads to improved safety and effectiveness of the interscalene block as compared to performing the block using a nerve stimulator alone. Clinical studies comparing interscalene blocks done with ultrasound versus ultrasound in conjunction with a nerve stimulator have shown the combination to be slightly safer and more efficacious with reduced side effects, though the difference in these metrics between the two is small. Interscalene blocks are highly effective for postoperative pain related to shoulder and upper extremity surgeries. Ultrasound guided blocks are more effective with reduced adverse effects when compared to nerve stimulation alone. The combination of both ultrasound and nerve stimulation allows for increased efficacy and decreaed side effects in limited clinical investigations. Therefore, more studies are needed to further compare and determine best practice interscalene techniques for shoulder and upper extremity surgeries.

The rising incidence of shoulder surgeries highlights significant postoperative challenges, including moderate-to-severe pain, restricted mobility, and opioid-related adverse effects. While interscalene brachial plexus block (ISBPB) utilizing bupivacaine (B) provides effective analgesia, the clinical utility is constrained by a limited duration of action. Liposomal bupivacaine (LB), an extended-release formulation, offers a promising alternative for prolonging analgesia. However, current evidence regarding the comparative efficacy and safety profile remains conflicting. Consequently, a systematic evaluation of the co-administration of B and LB (B + LB) in ISBPB is essential to determine the role of LB in optimizing postoperative pain management for shoulder surgery patients. This study included seven randomized controlled trials (RCTs) identified through a comprehensive search of PubMed, Embase, Web of Science, Cochrane Library, and ProQuest databases. Primary outcomes were opioid consumption and multidimensional pain scores (average, resting, activity, and worst pain scores) on each postoperative day (POD). Secondary outcomes included patient satisfaction and adverse events. The meta-analysis was performed using RevMan 5.4, with continuous outcomes analyzed as mean differences (MDs) or standardized mean differences (SMDs), and dichotomous outcomes as risk ratios (RRs). All effect estimates are reported with their 95% confidence intervals (CIs). Compared to B alone or B with other adjuvant group, the B + LB group exhibited significantly lower opioid consumption on POD 3, and reduced average, resting, and activity pain scores on POD 2. Additionally, the B + LB group showed improvements in worst pain scores on PODs 1-4. Patient satisfaction and adverse event profiles were generally similar between the groups. While an increased risk of hoarseness was specifically observed in the B + LB group on POD 1, the incidence of respiratory complications was similar between the two groups. B + LB during ISBPB for shoulder surgery provided superior pain relief on POD 2 and significantly reduced opioid consumption by POD 3, while being associated with an increase in hoarseness risk on POD 1 but comparable overall safety and patient satisfaction.

Patients with humeral fracture often suffer from post-traumatic neuropsychiatric sequelae, which can cause immense anxiety or fear and worsen recovery. In this report, we examined the effect of low-dose esketamine versus dexmedetomidine on postsurgical recovery among patients who underwent humerus surgery with interscalene brachial plexus block. In this prospective, randomized, controlled study, 141 patients aged 18 to 65 years who underwent humerus reduction and internal fixation were recruited. Patients were randomly assigned to two groups: esketamine (Group E: received 0.2 mg/kg (i.v.) esketamine administration, with subsequent continuous 0.15mg/kg/h infusion); dexmedetomidine (Group D: received 10-min 0.8µg/kg dexmedetomidine infusion, with 0.4ug/kg/h maintenance infusion). All infusions were terminated at closure of surgical incisions. Our major endpoint was the Quality of Recovery-40 (QoR-40) score on postoperative day 1 (POD-1). The secondary outcomes were QoR-40 POD-3, the intraoperative modified observer's assessment of alert/Sedation (MOAA/S) scores at 5 min (T1) and 10 min (T2) post i.v. administration, at operation initiation (T3), at 10 min interval (T4), 30 min interval (T5) post operation, and at the end of operation (T6), Numeric Rating Scale (NRS) at POD-1, additional postoperative analgesic usage and hospital stays. In addition, we analyzed safety indices, such as hemodynamic profile, postoperative nausea and vomiting, adverse events (AEs) involving the central nervous system. The QoR-40 scores on POD-1 for Group E were substantially elevated relative to Group D. The T4 and T5 MOAA/S scores of Group D were lower relative to Group E. In comparison to Group E, Group D exhibited reduced T1 and T2 Mean arterial pressure (MAP) and T1-T6 Heart rate (HR). Lastly, we observed no marked alteration in other postsurgical AEs between the two patient cohorts. Continuous low-dose esketamine infusion seems safely and tolerably, it significantly improves the postoperative recovery quality among patients with ASA I or II receiving elective humeral trauma surgery.

Brachial plexus blocks at the interscalene level are frequently chosen by physicians and recommended by textbooks for providing regional anesthesia and analgesia to patients scheduled for shoulder surgery. Published data concerning interscalene single-injection or continuous brachial plexus blocks report good analgesic effects. The principle of interscalene catheters is to extend analgesia beyond the duration of the local anesthetic's effect through continuous infusion, as opposed to a single injection. However, in addition to the recognized beneficial effects of interscalene blocks, whether administered as a single injection or through a catheter, there have been reports of consequences ranging from minor side effects to severe, life-threatening complications. Both can be simply explained by direct mispuncture, as well as undesired local anesthetic spread or misplaced catheters. In particular, catheters pose a high risk when advanced or placed uncontrollably, a fact confirmed by reports of fatal outcomes. Secondary catheter dislocations explain side effects or loss of effectiveness that may occur hours or days after the initial correct function has been observed. From an anatomical and physiological perspective, this appears logical: the catheter tip must be placed near the plexus in an anatomically tight and confined space. Thus, the catheter's position may be altered with the movement of the neck or shoulder, e.g., during physiotherapy. The safe use of interscalene catheters is therefore a balance between high analgesia quality and the control of side effects and complications, much like the passage between Scylla and Charybdis. We are convinced that the anatomical basis crucial for the brachial plexus block procedure at the interscalene level is not sufficiently depicted in the common regional anesthesia literature or textbooks. We would like to provide a comprehensive anatomical survey of the lateral neck, with special attention paid to the safe placement of interscalene catheters.

Interscalene Brachial Plexus Blocks (ISBPB) are highly effective forms of anesthesia for surgeries involving the upper arm, shoulder, and neck. Recently, there has been a growing interest in comparing the advantages and limitations of the anterior and posterior approaches. This systematic review and meta-analysis aimed to determine whether the anterior or posterior approach to ISBPB offers a clinical advantage regarding complete block rates and time to block completion. We included randomized controlled trials comparing the anterior and posterior techniques for ISBPB while excluding studies with overlapping populations, comparisons of blocks other than interscalene, and articles written in a non-English language. The search strategy identified 2229 articles, of which six Randomized Controlled Trials (RCTs) met the inclusion criteria for the meta-analysis. A total of 414 patients were included, with 210 patients in the anterior group and 204 in the posterior group. The Odds Ratio (OR) for a complete sensory block between the two techniques did not reach statistical significance (OR = 0.56 [0.20, 1.58], 95% CI, p = 0.27). Similarly, the Standardized Mean Difference (SMD) for the time to complete the block also did not reach statistical significance (SMD: -0.77 [-2.12, 0.59], 95% CI, p = 0.27). Heterogeneity for complete block was not significant (I2 = 0%), while procedure time showed high heterogeneity (I2 = 97%). Both techniques have shown effectiveness in providing surgical analgesia. The choice of technique should be determined by the provider's comfort and proficiency, as well as ensuring the highest level of safety for the patient.

Interscalene brachial plexus block (ISBPB) has gained popularity as a pain-relief method following shoulder arthroscopic surgery, significantly reducing the need for analgesics. This study was designed to evaluate whether the addition of dexamethasone to different effective concentrations of ropivacaine in ultrasound-guided ISBPB affects postoperative analgesic effect in patients undergoing shoulder arthroscopy surgery. A total of 140 participants elected for shoulder arthroscopy under ISBPB and general anesthesia, randomized into 6 equal groups. Group A, B, and C received 10 mL 0.25%, 0.5%, and 0.75% ropivacaine mixed with 1 mL 0.9% saline, respectively. Likewise, groups A1, B1, and C1 received the same volumes of ropivacaine with 5 mg dexamethasone. The primary goal was to assess the duration of analgesia with ISBPB, with secondary objectives concerning postoperative nausea and vomiting (PONV) and numerical rating scale (NRS) pain scores. Across a range of ropivacaine concentrations, there was no significant difference in the analgesic efficacy between participants receiving dexamethasone treatment and those who did not. Notably, there was no demonstrable difference in the duration of analgesia among the treatment groups (group A vs. group A1: 510.13±262.39 min, 518.21±395.49 min; P =0.054); (group B vs. group B1: 672.42±306.63 min, 646.05±348.48 min; P =0.281); (group C vs. group C1: 724.42±384.14 min, 680.29±414.30 min; P =0.782). Furthermore, there was no significant difference in the incidence of intraoperative and postoperative complications. The present study indicated that the addition of dexamethasone to ropivacaine did not appear to provide any additional advantages in postoperative analgesic efficacy compared with the use of ropivacaine alone for patients undergoing shoulder arthroscopy surgery with ISBPB.

Surgical procedures on the shoulder pose distinctive challenges in managing pain during the perioperative period, underscoring the importance of exploring innovative anesthesia techniques. This comprehensive review article delves into integrating dexmedetomidine, an alpha-2 adrenergic agonist, within interscalene brachial plexus blocks for shoulder surgery. The review initiates by underscoring the pivotal role of effective anesthesia in shoulder surgery and elucidates the rationale behind investigating dexmedetomidine as an adjunct. It meticulously examines the anatomy and physiology of the brachial plexus, emphasizing its critical significance in shoulder surgery. Furthermore, the article expounds on dexmedetomidine's mechanisms of action and pharmacokinetics, encompassing its safety profile and potential side effects. The conventional interscalene brachial plexus block techniques, along with their limitations and challenges, are discussed, laying the foundation for the integration of dexmedetomidine. The review subsequently delves into exploring the role of dexmedetomidine in regional anesthesia, covering previous studies, mechanisms of action, and the potential advantages of incorporating it into nerve blocks. The review's core concentrates on the practical application of dexmedetomidine-enhanced interscalene brachial plexus blocks. This includes discussions on administration techniques, dosage guidelines, and compelling evidence supporting its utilization. Clinical scenarios where this approach proves most advantageous are thoroughly explored, comparing its effectiveness with traditional techniques in terms of pain control and patient outcomes. A comprehensive examination of relevant clinical trials and case studies highlights the evidence supporting its efficacy. The review also underscores safety considerations associated with dexmedetomidine. It proposes strategies for mitigating risks to ensure patient safety. Insights into future directions and research are provided, encompassing ongoing studies, areas necessitating further investigation, and potential refinements in technique. Finally, the article summarizes key findings, emphasizing the practicality of dexmedetomidine-enhanced interscalene brachial plexus blocks in shoulder surgery and its far-reaching implications for clinical practice and patient care.