Brachial plexus block has undergone nearly 140 years of development and evolution. It is not only one of the oldest regional block techniques, but also plays an important role in perioperative anesthesia and pain management. Nowadays, with the development of ultrasound technology and anatomy, ultrasound-guided brachial plexus block has been widely used in different types of upper limb surgeries, and new block approaches and techniques are constantly being proposed and applied in clinical scenarios. However, due to the large variation of the brachial plexus and its trajectory, multiple approaches and techniques, and many factors affecting clinical application, the difficulty of anesthetic decision-making has increased, the block effect is uncertain, the incidence of perioperative complications is high, and the satisfaction is not high. In order to standardize and promote the application of ultrasound-guided brachial plexus block technology, anesthesiology and related experts formed a working group. Based on the historical evolution and research progress of brachial plexus block technology, centered on clinical application and perioperative management, after repeated demonstration, this expert consensus was formulated for clinical reference.
It should be made clear that this consensus cannot include or solve all clinical problems related to brachial plexus block. With the continuous update of the practice, approach, technique, and anatomy of precision block, this consensus will also be continuously supplemented and improved.
Preface
This expert consensus was led by Professor Hei Ziqing (The Third Affiliated Hospital of Sun Yat-sen University), Professor Wang Tianlong (Xuanwu Hospital of Capital Medical University), and Professor Zhang Liangcheng (Union Hospital of Fujian Medical University), and consisted of 21 experts and scholars from 18 well-known domestic medical, school and journal units. Based on clinical issues related to brachial plexus block, relevant literature was searched in PubMed, Embase, Web of Science, Wanfang Database and China National Knowledge Infrastructure, covering ultrasound-guided brachial plexus block approaches and techniques, applications and perioperative management. The types of literature include systematic reviews/meta-analyses, randomized controlled trials, observational studies and case series studies, and the search time limit is from database establishment to September 1, 2023. The working group used evidence-based medicine as evidence, combined with many years of clinical experience, and finally formed this expert consensus through multiple discussions and revisions.
Working Group and Recommendations
This expert consensus is divided into 9 parts, with a total of 13 recommendations:
Recommendation 1: The composition and trajectory of the brachial plexus vary greatly. Anesthesiologists need to be familiar with the anatomy of the brachial plexus and different approaches and techniques, especially the interpretation of the needle tip and injection position.
Recommendation 2: The clinical application of brachial plexus block technology is affected by many factors. Anesthesiologists should choose precise approaches and techniques that can meet the requirements of surgical anesthesia and analgesia, improve patient comfort and reduce complications.
Recommendation 3: It is recommended to use ultrasound technology for brachial plexus block, but anesthesiologists need to master standardized operating procedures, be familiar with ultrasound parameter settings and basic probe operation techniques.
Recommendation 4: It is recommended to use a pre-scan method to identify the trajectory and anatomical variations of the brachial plexus before puncture, providing important reference information for the operator to choose a suitable approach. During the puncture, it is recommended to use a nerve stimulator to assist in identifying the nerve; it is recommended to use hydrodissection to identify the imaging needle tip position and the fascia around the nerve.
Recommendation 5: It is recommended that the brachial plexus block via the interscalene approach be the first choice for anesthesia and analgesia for proximal upper limb surgery. It is recommended to use ultrasound technology for precise positioning and injection, and to minimize the volume of local anesthetic drugs.
Recommendation 6: It is recommended to use the supraclavicular approach brachial plexus block instead of the interscalene approach brachial plexus block, but clinical studies are needed to provide complete evidence of block dynamics.
Recommendation 7: For anesthesia and analgesia for shoulder joint and proximal humerus surgery, ultrasound-guided brachial plexus block via the costoclavicular space approach is a possible effective alternative technology, which awaits further clinical practice and verification.
Recommendation 8: It is recommended that axillary nerve block be used for elbow and distal surgery, and combined or selective median nerve, radial nerve, ulnar nerve, musculocutaneous nerve, medial brachial cutaneous nerve and intercostobrachial nerve block can also be implemented to meet surgical requirements.
Recommendation 9: For shoulder surgery, it is recommended to implement the interscalene approach block on the basis of combined supraclavicular nerve block. For the interscalene approach and supraclavicular approach blocks, it is recommended to optimize the injection location and reduce the volume of local anesthetics to reduce the risk of diaphragmatic paralysis. It is recommended to use supraclavicular approach block, brachial plexus superior trunk block or suprascapular nerve block for perioperative analgesia.
Recommendation 10: For clavicle surgery, it is recommended to implement the interscalene approach or supraclavicular approach combined with supraclavicular nerve block to provide a complete block effect, but the block range should be prevented from being too wide to avoid long-term postoperative motor block that hinders early postoperative recovery.
Recommendation 11: Operation parameters can provide important reference information for anesthesiologists when selecting approaches and techniques. Intrafascial injection and multi-point injection can shorten the onset time, but their safety still needs further clinical verification. It is recommended to standardize the use of a 3-level scale to evaluate the sensory-motor block effect and surgical anesthesia quality.
Recommendation 12: In clinical practice, it is recommended to select the concentration of local anesthetics based on surgical anesthesia and analgesia requirements. When choosing the volume of local anesthetics, the focus should be on the diffusion of local anesthetics under real-time ultrasound observation, and the volume should not be reduced or increased blindly. Local anesthetics should be mixed, adjuvants added, and administered around nerves with caution.
Recommendation 13: For high-risk patients with imaging and/or puncture difficulties, it is recommended to use ultrasound combined with nerve stimulators or pressure monitoring, combined with ultrasound views and comprehensive patterns of patient symptoms to reduce the risk of intraneural injection.
Key points of consensus
1. The composition and trajectory of the brachial plexus vary greatly, and there are many clinical influencing factors. It is recommended that anesthesiologists make reasonable clinical decisions centered on "selecting a good block approach, precise injection technology, and evaluating the block effect."
2. Approach refers to the anatomical position of the brachial plexus targeted by the puncture needle, such as the intermuscular groove, supraclavicular, subclavian, and axillary routes, which represent the levels of the brachial plexus nerve roots, trunks, femoral, bundle, and terminal branches, respectively. Technique refers to the operation process of implementing the block, including scanning, imaging, positioning, puncture routes, and injection methods.
3. Ultrasound technology not only has the functions of identification, positioning and guidance, but also can reduce the incidence of complications, but it also has some limitations.
4. Indications, operation procedures and precautions for brachial plexus block via intermuscular groove, supraclavicular, subclavian and axillary approaches.
5. Clinical practice and focus of shoulder and clavicle surgery.
6. Operation parameters, block dynamics, and evaluation methods of ultrasound-guided brachial plexus block technology.
7. Controversy on how to choose local anesthetics and adjuvants in clinical practice. 8. Complications related to ultrasound-guided brachial plexus block.
Promotion and application
Conducive to the construction of a high-quality regional block technology system
The high-quality development of anesthesia disciplines needs to be based on its own proprietary theories, clinical and skills, adhere to the concepts of "comfortable medical care", "precision anesthesia", "accelerated recovery after surgery", and give full play to innovation-driven capabilities to achieve the transition from anesthesia medicine to anesthesia perioperative medicine. Brachial plexus block is the most commonly used peripheral nerve block technology and one of the clinical skills that anesthesiologists must master. However, there are still regional differences in the clinical application of ultrasound-guided brachial plexus block in China, and some technologies have not yet been promoted or popularized, and the level of perioperative management needs to be further strengthened. Therefore, as an important part of the high-quality regional block technology system, ultrasound-guided brachial plexus block will be clinically applied throughout the entire perioperative process before, during and after surgery. Precise blockade is achieved through precise identification, positioning, and guidance before surgery; personalized anesthesia and analgesia plans are provided during surgery to enable patients to reach the best surgical state as soon as possible; and patients are promoted to recover quickly after surgery and provide a satisfactory diagnosis and treatment experience.
The necessity of ultrasound technology as brachial plexus block
Ultrasound visualization not only has the functions of identification, positioning and guidance, but also can reduce the incidence of complications, especially pneumothorax, accidental vascular puncture, and systemic toxicity of local anesthetics. However, due to the constraints of anatomy and the equipment itself, ultrasound visualization technology also has some limitations, including: ① It is difficult to accurately determine the position of the needle tip and its distance from the nerve; ② The number of nerve bundles imaged is far less than the actual number; ③ The fascia around the brachial plexus is thin, and ultrasound imaging of the fascia layer is challenging and difficult; ④ The ultrasound beam is narrow and easily disturbed by bubbles, and the imaging position and quality are prone to change during the operation. This requires anesthesiologists to master standardized operating procedures, be familiar with ultrasound parameter settings and basic probe operation techniques, so as to give full play to the advantages of ultrasound visualization technology and overcome its limitations.