What Are Nerve Blocks?

Local anesthetics are injected around nerve trunks, plexuses, and ganglia to block their impulse conduction and cause anesthetic effects in the area they control. This is called nerve block. With a single injection of the nerve block, a larger area of anesthesia can be obtained. However, it may cause serious complications, so you must be familiar with local anatomy, understand the tissues that the puncture needle passes, and nearby blood vessels, organs, and body cavities. Commonly used nerve blocks are interblock, suborbital, sciatic, finger (toe) nerve block, cervical plexus, brachial plexus block, and stellate ganglion and lumbar sympathetic ganglion block for diagnosis and treatment.

Nerve block

Brachial plexus

The brachial plexus is mainly composed of the anterior branches of the spinal nerves C 5-8 and T 1 (C and T respectively represent the neck and chest) and dominate the senses and movements of the upper limbs. After these nerves pass through the intervertebral foramen, they pass through the intermuscular groove between the anterior and medial oblique muscles and merge with each other in the intermuscular groove to form a brachial plexus. Then it crosses on the first rib surface above the clavicle and enters the axillary, and forms the main terminal nerves, namely the median, flexor, ulnar and musculocutaneous nerves. In the intermuscular sulcus, the brachial plexus is wrapped by a sheath formed by anterior vertebral fascia and oblique fascia. This sheath extends above the clavicle into the subclavian artery sheath, forming an axillary sheath in the axilla. Brachial plexus block can be performed in the intermuscular sulcus, supraclavicular and axillary regions, which are called intermuscular sulcus pathway, supraclavicular pathway and axillary pathway (Figure 8-8). Local anesthetics must be injected into the sheath during blockade to be effective.

Intermuscular approach

The patient lies on his back with his head tilted to the opposite side and his arms hanging close to his shoulders. Ask the patient to raise his head slightly to reveal the clavicle end of the sternocleidomastoid muscle, and slide his fingers outward at the posterior edge to touch a small muscle, the anterior scalene muscle. The depression between the anterior and medial oblique muscles is the intermuscular groove. The intermuscular sulcus shows a triangle that is small and large. Use your fingers to touch the subclavian artery to reach the subclavian artery. The intersection point of a horizontal line made from circular cartilage and the intermuscular groove is the puncture point, which is equivalent to the level of the transverse process of the 6th cervical vertebra. Use a 7-gauge needle to insert the needle perpendicular to the skin. There can be a breakthrough feeling when penetrating the anterior vertebral fascia, and then enter a little inward to the foot. When the needle touches the brachial plexus, the patient often complains of strangeness. At this time, no blood or cerebrospinal fluid is drawn back, and local anesthetic can be injected. Generally use 25% of 1.3% lidocaine containing 1: 200,000 epinephrine (5 g / ml).

Supraclavicular approach

The patient's position is the same as the intermuscular sulcus path, but a thin pillow is placed under the shoulder of the affected side to fully expose the neck. The anesthesiologist stood on the side of the patient's head, determined the midpoint of the clavicle, and felt the pulse of the subclavian artery deep in the supraclavicular fossa, with the brachial plexus on the outside. Insert the needle 1cm above the midpoint of the clavicle and push it backward, inward, and downward. When the patient complains of a strange sensation radiating to the fingers, wrist, or forearm, stop moving forward. If there is no blood or air, you can inject Liquid medicine. If you do not encounter any abnormal feeling, the first rib will be touched when the needle tip enters a depth of 1 ~ 2cm. You can explore the longitudinal direction of the first rib from the longitudinal axis forward and backward to induce the abnormal feeling and inject the medicine or seal it along the rib to block it. Brachial plexus.

Axillary pathway

The patient was lying on his back, shaved his armpit hair, the limb was abducted by 90 °, his arms were flexed upwards by 90 °, and he was in a martial arts posture. The anesthesiologist stood on the affected side, felt the axillary artery pulse at the junction of the lower edge of the pectoralis major muscle and the medial edge of the arm, and touched the highest point of the pulse toward the top of the axillary (Figure 8-9). During operation, hold the needle with the right hand, and fix the skin and the artery with the left and middle fingers, and pierce the skin at the flexural or ulnar edge of the artery perpendicular to the skin. There is a clear sense of breakthrough when piercing the sheath, that is, stopping the advance. Release the finger, and the needle beats with the arterial pulse, indicating that the needle tip is inside the axillary sheath. After the blood is drawn back, 25 ~ 30ml of local anesthetic solution is injected. Compression of the distal end of the injection point during injection is conducive to the spread of the medicinal solution to the proximal and proximal ends of the axillary pin, which is beneficial to block the musculocutaneous nerve. Since the musculocutaneous nerve has left the axillary sheath at the level of the globus process and entered the coracalis brachialis, it is often difficult for the god to block completely, and the anesthesia effect of the outer side of the forearm and the base of the thumb under its control is poor.

Indications and complications: Brachial plexus block is suitable for upper limb surgery, intermuscular groove approach can be used for shoulder surgery, and axillary approach is more suitable for forearm and hand surgery. However, all three methods may cause local anesthetic toxicity. Intermuscular sulcus and supraclavicular pathways can also occur with phrenic nerve palsy, recurrent laryngeal nerve palsy, and Horner syndrome (Homer syndrom). Horner syndrome is caused by blockage of the stellate ganglion, ipsilateral pupil shrinkage, drooping eyes, nasal congestion, and facial flushing. If improper puncture is performed, pneumothorax may occur in the supraclavicular approach, the intermuscular sulcus approach may cause high epidural block, or the injection of medicinal fluid into the subarachnoid space may cause total spinal anesthesia.

Cervical nerve plexus

The cervical plexus is composed of C1 ~ 4 spinal nerves. After the spinal nerve exits the intervertebral foramen, it passes through the vertebral artery to reach the tip of the transverse process. After crossing the transverse process, it forms a series of rings to form the cervical nerve plexus. The cervical plexus is divided into deep plexus and superficial plexus, which dominate the neck yang tissue and skin. The deep plexus is at the same level as the brachial plexus between the oblique muscles, and is also covered by the anterior vertebral fascia. The superficial plexus emerges from the subfascia to the surface along the posterior edge of the papillary muscles, and is divided into many branches that dominate the skin and superficial structures. The areas of skin dominated by C4 and T2 are adjacent. C1 is mainly a motor nerve, so it is not necessary to consider this spinal nerve when blocking

Advances in nerve block technology

Self- controlled analgesia in patients with nerve block

Patient-controlled analgesia (PCA) for postoperative acute pain and childbirth analgesia and cancer pain

1. The goal of postoperative pain treatment is to reduce postoperative complications, promote patient recovery, and improve the effect of surgical treatment through analgesic effects. PCA technology is a kind of microcomputer analgesia produced by the close combination of computer technology and medicine. It is pre-programmed by the anesthesiologist and has a limited amount of painkillers. The patient himself controls the analgesia with an easy-to-operate compression twist. Pain medicine to quickly achieve the purpose of postoperative relief or relief of pain. Entered China in the mid-to-late 1990s. The route of administration can be selected according to the patient's condition (PCIA), epidural (PCEA) or subcutaneous (PCSA). The main advantage of PCA is that the administration of analgesics conforms to the pharmacokinetic principle of analgesics, and it is easier to maintain the minimum effective analgesic concentration; the use of analgesics can be truly timely and rapid, which basically solves the individual needs of patients for analgesics The difference; it is beneficial for patients to obtain the best analgesic effect at any moment and under different pain intensity; it reduces the adverse reactions caused by pain, such as stress, myocardial ischemia, atelectasis and delayed functional exercise. The drugs used in PCA are mainly opioids and local anesthetics. In clinical practice, low-concentration local anesthetics (such as 0.125% bupivacaine) combined with low-dose opioids (such as fentanyl, morphine, and sufentanil). The new local anesthetic ropivacaine, because of its low concentration (0.1% to 0.2%), shows a marked separation of sensory nerves and motor nerve blocks, which has special significance in postoperative analgesia. In recent years, the concept of "walkable epidural analgesia" has been proposed to enable patients to obtain satisfactory analgesia without affecting lower limb movements and to get out of bed early. The commonly used formula is 0.1% ropivacaine plus morphine or fentanyl. It is worth mentioning the problem of postoperative analgesia in children. Severe pain after surgery has a greater impact on children's mental health, which is not conducive to their mental health development, especially for children who have undergone repeated orthopedic surgery. Some experts believe that children over 5 years of age can be considered for postoperative analgesia.

2 Pain during childbirth comes from contraction of the uterus and expansion of the vagina. Analgesic requirements do not affect maternal contractions, do not prolong the labor process, and ensure the safety of the fetus. The PCEA method meets the above requirements. The specific methods are as follows: The mother enters a regular contraction (the uterine opening is about 3 ~ 5cm), performs a conventional epidural puncture, a lumbar 2-3 or a lumbar 3-4 gap, and the head is placed into a tube 3.5cm. After successful puncture, 2-3 ml of 1% lidocaine was observed. After observing the anesthesia for 5 minutes, continued administration to control the level of anesthesia below T10. Then turn on the analgesic pump. The commonly used formula is 0.125% bupivacaine (or 0.1% bupivacaine plus 0.0016% fentanyl for a total of 60Ml. When entering the second stage of labor to see the fetal head, raise the head of the delivery bed by 30 ·, and give the first The dose is 8ml. The purpose is to concentrate the medicine in the perineum so that there is no pain during suture. The fetus will not be administered after delivery.

3Cancer pain can reduce the amount of systemic analgesics or adjuvants, reduce the drowsiness during the day, and when you need analgesia, you can take the medicine yourself, shorten the pain to obtain analgesic time, and improve the quality of life of pain patients Reduce the burden on patients' families. Devices such as catheters can be buried subcutaneously if necessary. There have been reports of 351 days of epidural cavity tube in China. In terms of drugs, in addition to commonly used opioids, ketamine and N-type calcium channel blocker ziconotide can also be selected.

Nerve block for chronic pain

Prithvi R believes that when the pain is more than 3 months, it is necessary to find a new pain treatment method to achieve long-term analgesia. Such as epidural self-controlled analgesia technology, implantable drug release system (drug pump), spinal cord and peripheral nerve stimulation, radiofrequency treatment and cryotherapy.

1 Nerve Cryotherapy Frozen nerve block is to use cryoprobe to generate extremely low temperature (-80 -100 ), and the low temperature biological effect will degenerate the nerve ending myelin sheath of the corresponding part and lose the conduction function to achieve the purpose of analgesia. Advantages: Reversible lesions are generated, neuritis rarely occurs, and equipment costs are less than radiofrequency neurolysis. Disadvantages: Temporary nerve block is generated, and cold injury needs to be repeated. The cold probe is large and the percutaneous process is uncomfortable. The success of the block depends to a large extent on the closeness of the ice ball to the nerve. Chen Jianwen and others believe that the spinal nerve posterior branch freezing is the best treatment for lumbar back pain with lumbar muscle strain and facet joint disorders.

2 Radiofrequency thermocoagulation therapy Radiofrequency thermocoagulation therapy uses controlled temperature to act on ganglion, stem, root and other parts, and uses the difference of temperature tolerance of different nerve fibers to selectively block A and C fibers that conduct pain The purpose is to both relieve pain and retain local touch. (The myelin-free fine fibers (A, C) that conduct pain sense degenerate at 70 ° C to 75 ° C, while the myelinated thick fibers (A) that conduct touch sense can tolerate higher temperatures). Compared with chemical nerve destruction therapy, it has the following characteristics: the size of the lesion can be accurately controlled; the temperature of the lesion can be accurately monitored; the puncture needle can be accurately placed with the help of electrical stimulation tests and impedance monitoring; most operations Can be done under mild sedation or local anesthesia. Most of the focal coagulation lesions can be quickly recovered with less residual symptoms; With correct operation, the incidence of complications and side effects is low; If the pain symptoms recur, radiofrequency thermocoagulation can be repeated. Disadvantages: equipment is expensive; operators need to be trained and have certain work experience. Radiofrequency thermocoagulation of the meniscus ganglia, cervical and lumbar spinal nerve posterior branches, and intercostal nerves can treat trigeminal neuralgia, cervical headache, low back pain, and intercostal neuralgia, respectively. Radiofrequency thermocoagulation facet joint neurotomy has also achieved good results in the treatment of neck and low back pain.

Principle of nerve block

Neural Block Content Introduction

This concise, colorful textbook written by experts from the New York Academy of Local Anesthesia, the world's leading training system that integrates clinical practice, teaching and research in the field of local anesthesia, seeks to help readers master and update neurological resistance Expertise in lagging technology. Through more than 240 vivid and vivid clinical pictures and line drawings. This book provides the reader with the most practical value and artistic knowledge of most important peripheral nerve block techniques. The book uses a unified "reader-friendly" format, which provides a rigorous step-by-step guide for each nerve block operation.

Each chapter of the book begins with a unique "Overview of Yin Technology", as a "browse card" and a simple list of indications for each nerve block technology, positioning signs, appliances, the amount of local anesthetic medicine and the complexity of the operation technology Heaviest; essential and distinctive features. In addition, a separate section entitled "Keys to Successful Peripheral Nerve Blocking Techniques" provides a concise summary of general guidelines for the selection of nerve block techniques.

Neural Block Book Features

With real patients, it provides clear, accurate, and step-by-step instructions for most important nerve block techniques. A large number of meticulous elaborations and diagrams that uphold clinical insights reflect both theory and practice. Vivid images, colorful original illustrations and clinical pictures illustrate each nerve block operation technique in an unusually detailed manner. Includes many operational "points" and "targets for puncture needles" for each nerve block technique. Includes a table of local anesthetic choices for each nerve block technique. Includes specialized chapters on equipment and patient monitoring, basic anatomy, clinical pharmacology, and neurological complications. Each chapter includes and recommends references for reading.

Highly instructive, perfect interpretation and capable writing make this book a "desk series" for each reader, for learning and using artistically rich nerve block technology, which is used in the reader's daily clinical anesthesia practice Increasingly wide range of operating techniques. This book should be one of the necessary readings in the reader's anesthesiology collection.

Nerve block author profile

Xue Fushan, male, 43 years old, chief physician, professor, doctoral supervisor. He is currently a member of the New York Academy of Sciences and the Institute of Scientific Progress; a member of the American Journal of Clinical Anesthesia and Anesthesiology review committees; a judge of the National Natural Science Foundation of China; the editor of the basic column of the Anesthesia and Monitoring Forum; the editorial board of the China Anesthesiology Forum; and China Pain Member of the Editorial Board of the Chinese Academy of Sciences; Member of the Reviewing Committee of the Journal of Clinical Anesthesiology; Editorial Board of Chinese Medicine; Member of the Anesthesia Branch of the Chinese Academy of Stomatology; And member of the Center for Quality Control and Improvement of Pain Therapy.

In the past ten years, it has received more than 20 funding from various scientific research funds. In 1997, it was awarded the Ministry of Health Special Fund for Young Talents. In 1999, it was awarded the Special Fund for Young Scientists in Science and Technology of the Chinese Academy of Medical Sciences in 1999. He has won 1 International Excellent Research Award and 3rd Prize of the Ministry of Health Science and Technology Progress Award; his edited monograph "Modern Respiratory Management-Key Techniques of Anesthesia and Critical Care Treatment" won the first prize of 2002 Excellent Book of Henan Province and National Excellent Third prize for science and technology books; won 10 national patents, and the invention of the esophageal obstruction laryngeal mask airway was awarded the "Golden Crown Award" by the Honorary Selection Committee of the British Science Centre. In April 2003, he was awarded the honorable title of Top Ten Youth in Shijingshan District, Beijing.

He has published more than 200 papers in various professional magazines at home and abroad, of which 21 have been published in foreign academic journals. A large number of articles have been included in the "International Scientific Citation Index, SCI", "Dutch Medical Abstracts", "American Medical Abstracts", "Pharmaceutical Abstracts", "Chemical Abstracts" and "Biological Abstracts" and other internationally renowned citations and retrieval tools. In recent years, many papers have been cited hundreds of times in important anesthesiology monographs and magazines published at home and abroad. In 2001, he won the first prize of the Young Doctor Scholarship of West China Yichang Renfu Pharmaceutical Anesthesiology Forum.

The monographs edited are "Modern Anesthesia Technology", "Modern Respiratory Management", "Perioperative Nursing", "Difficult Tracheal Intubation Technology", "Clinical Pain Treatment Technology", "Special Treatment Technology of Anesthesiology", " "Special Treatment Techniques for Plastic Surgery" and "Clinical Local Anesthesia Techniques"; The translator's monographs include "Peripheral Nerve Block Techniques"; the deputy editor's monographs include "Anesthesia Therapy", "Pain Diagnostic Therapy", "Neurosurgery Anesthesiology" "And" Special Treatment Techniques for Plastic Surgery "; participated in writing 15 monographs. The edited monograph "Modern Anesthesiology Technology" was recommended as a graduate teaching book by the Graduate Office of the Ministry of Education in 2000.

Nerve Block Catalog

Chapter 1. Training of Peripheral Nerve Block Techniques

Chapter 2 Anatomical Basis of Local Anesthesia

Chapter 3 Equipment and Patient Monitoring for Local Anesthesia

Chapter 4 Peripheral Nerve Stimulators and Nerve Stimulation Techniques

Chapter 5 Clinical Pharmacology of Local Anesthetics

Chapter 6 Neurological Complications of Peripheral Nerve Block Techniques

Chapter 7 Keys to Successful Implementation of Peripheral Nerve Block Techniques

Chapter 8 Cervical Plexus Block Techniques

Chapter 9 Intermuscular Sulcus Brachial Plexus Block

Chapter 10 Subclavian Brachial Plexus Block Technique

Chapter 1l Axillary Brachial Plexus Block Technique

Chapter 12 Wrist Nerve Block Techniques

Chapter 13 Refers to Nerve Block Techniques

Chapter 14 Venous Local Anesthesia Technique

Chapter 15 Technique of Upper Limb Cutaneous Nerve Block

Chapter 16 Thoracic Paravertebral Block

Chapter 17 Thoracic-Lumbar Paravertebral Block

Chapter 18 Lumbar Plexus Blocking Techniques

Chapter 19: Rear Approach Sciatic Nerve Block Technique

Chapter 20: Anterior Approach Sciatic Nerve Block Technique

Chapter 2l Femoral Nerve Block Technique

Chapter 22 Techniques of Root Nerve Block in Intertendon Approach

Chapter 23 Techniques of the Neurological Block in the Rouge

Chapter 24 Ankle Nerve Block Technique

Chapter 25 Skin Limb Block Techniques

index

Nerve block editor recommendation

This book is vividly displayed through more than 240 life-like, colorful clinical pictures and line drawings. This book provides the reader with the most practical value and artistic knowledge of most important peripheral nerve block techniques. The book uses a unified "reader-friendly" format, which provides a rigorous step-by-step guide for each nerve block operation. Highly instructive, perfect interpretation and sophisticated writing make this book a "desk series" for each reader, for learning and using art-enriched nerve block technology, that is, in the daily clinical anesthesia practice of readers Use an increasingly wide range of operating techniques. This book should be one of the necessary readings in the reader's anesthesiology collection.