神経ブロック

WordNet

a three-dimensional shape with six square or rectangular sides (同)cube
(computer science) a sector or group of sectors that function as the smallest data unit permitted; "since blocks are often defined as a single sector, the terms `block and `sector are sometimes used interchangeably"
support, secure, or raise with a block; "block a plate for printing"; "block the wheels of a car"
a solid piece of something (usually having flat rectangular sides); "the pyramids were built with large stone blocks"
housing in a large building that is divided into separate units; "there is a block of classrooms in the west wing"
a rectangular area in a city surrounded by streets and usually containing several buildings; "he lives in the next block" (同)city block
an inability to remember or think of something you normally can do; often caused by emotional tension; "I knew his name perfectly well but I had a temporary block" (同)mental_block
a number or quantity of related things dealt with as a unit; "he reserved a large block of seats"; "he held a large block of the companys stock"
interrupt the normal function of by means of anesthesia; "block a nerve"; "block a muscle"
run on a block system; "block trains"
shape by using a block; "Block a hat"; "block a garment"
shape into a block or blocks; "block the graphs so one can see the results clearly"
stamp or emboss a title or design on a book with a block; "block the book cover"
any bundle of nerve fibers running to various organs and tissues of the body (同)nervus
completely obstructed or closed off; "the storm was responsible for many blocked roads and bridges"; "the drain was plugged" (同)plugged
closed to traffic; "the repaving results in many blocked streets" (同)out of use
a group of countries in special alliance (同)axis
the act of obstructing or deflecting someones movements (同)block

PrepTutorEJDIC

(木・石などの,通例平らな面のある)『かたまり』 / 《米》(四団を街路に囲まれた)『区画』,街区 / 街区の1辺の距離(一般に40メートル前後) / 《英》ブロック(アパート・事務所・商店などに区切られている大きな建物) / 『妨害物』,障害物(obstacle);(障害によって生じた)停滞,渋滞 / 台木,台(まないた・肉切り台・まき割り台・せり売り台・帽子の木型など);《the~》炭頭台 / (特にアメリカンフットボールで)ブロック(相手の選手の突進を阻止する) / 滑車(pulley) / (座席券・株券などの)一組《+『of』+『名』》 / 〈通路など〉'を'『ふさぐ』,〈通行・進行など〉'を'妨げる / 〈帽子など〉の型取りをする / (特にアメリカンフットボールで)〈相手選手の突進〉'を'ブロックする;(ボクシングで)〈相手のパンチ〉'を'ブロックする
〈C〉『神経』 / 〈C〉《複数形で》『神経過敏』,いらだち / 〈U〉『勇気』,度胸(courage) / 〈U〉《時にa ~》厚かましさ,ずぶとさ;無礼 / 〈C〉葉脈;(昆虫の)翅脈(しみゃく) / 〈人,特に自分〉‘に'力を与える,‘を'元気づける
ブロック,圏(地理・共通の利害・政治・経済上の目的などのために団結した団体・国家などの結合体)

Wikipedia preview

出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2013/04/30 10:57:59」(JST)

wiki en

Regional nerve blockade, or more commonly nerve block, is a general term used to refer to the injection of local anesthetic onto or near nerves for temporary control of pain. It can also be used as a diagnostic tool to identify specific nerves as pain generators. Permanent nerve block can be produced by destruction of nerve tissue.

Therapeutic uses

Nerve blocks can help patients who suffer from lower back pain, neck pain, sciatica (from a herniated disc), spinal stenosis, reflex sympathetic dystrophy (a complex regional pain syndrome), shingles, cancer, and painful peripheral vascular disease. It can also be used in the treatment of migraine headaches.

Methods

Sonography guided femoral nerve block.

Temporary nerve blocks are achieved by combining a local anesthetic (such as lidocaine) with epinephrine, a steroid (corticosteroid), and/or opioids. Epinephrine produces constriction of the blood vessels which delays the diffusion of the anesthetic. Steroids can help to reduce inflammation. Opioids are painkillers. Injection nerve blocks can be either single treatments, multiple injections over a period of time, or continuous infusions. A continuous peripheral nerve block can be introduced into a limb undergoing surgery, for example, a femoral nerve block to prevent pain in knee replacement.^[1]

Permanent nerve block can be effected using other drugs or methods including alcohol or phenol to selectively destroy nerve tissue, cryoanalgesia to freeze nerves, and Radiofrequency ablation to destroy nerve tissue using heat.

Nerve blocks are sterile procedures that are usually performed in an outpatient facility or hospital. The procedure can be performed with the help of ultrasound, fluoroscopy (a live X-ray) or CT. Use of any one of these imaging modalities enables the physician to view the placement of the needle. A probe positioning system can be used to hold the ultrasound transducer steady.

In addition, electrical stimulation can provide feedback on the proximity of the needle to the target nerve.

Digital nerve block

Digital nerve blocks involve infiltrating local anesthesia around the two nerves that supply a digit. Historically this has been done with a local anesthetic without epinephrine however the use of a solution with epinephrine appears to be safe.^[2]

Advantages

The use of peripheral nerve blockade offers several advantages when compared to general anesthesia or local anesthesia:

The patient can remain awake and breathing on his/her own, thus protecting himself/herself from aspiration of stomach contents into the lungs. By avoiding general anesthesia, patients with adverse reactions to general anesthetics can be successfully treated. Similarly, patients who experience nuisance side effects from general anesthesia such as nausea and vomiting or excessive sleepiness can minimize these symptoms.
There is no need to perform a tracheal intubation, with its attendant complications.
The sympathetic nerves to the operative limb are anesthetized, leading to vasodilation. This improves blood flow to the affected limb and makes microvascular surgical procedures technically easier.
The limb can remain numb for several hours after surgery, providing excellent pain relief.
Deep and superficial structures of the limb are similarly anesthetized, allowing extensive surgical exploration and correction to occur. This is in contrast to locally injected local anesthetics, which tend only to numb superficial structures in the immediate vicinity of the injection.

Complications

Nerve blocks, like other medical procedures, are not risk-free. There is a possibility of side effects and complications from the procedure, needle puncture, and medications used. The most critical factor in the efficacy of a nerve block is the proper location of the target nerve.

Complications include:

Infection
Allergic reactions
Increased pain*

-In some cases of a badly compressed nerve, particularly of the sciatic nerve, the nerve block process itself can be very painful. The injection of the medicine near the nerve root temporarily compresses it before dispersing, this compression can momentarily cause severe radicular pain until the anesthetizing agent takes effect.

In horses

Short-term nerve blocks are useful in regionalizing the source of pain during lameness examinations in horses. A local anesthetic alone is injected perineurally to desensitize tissues beyond the site of injection.^[3] When the painful area is blocked, the lameness should temporarily improve or resolve.^[4] For example, the palmar digital nerves can be blocked to investigate pain arising from the sole and heel area of the hoof. If pain is arising from this area, the horse will stop limping. If the source of lameness arises from higher up in the leg, the horse will continue to limp, and a nerve block can be performed higher up the leg. Because there are essentially no motor neurons in the lower limbs of horses, the risk of weakness or ataxia is negligible.^[5]

Types

Certain nerve blocks are commonly used in horses and are usually performed in the order they appear below. Each block involves the palmar nerve or its branches which are located in the forelimb.^[6]

Palmar digital nerve block - The palmar digital nerves (formerly known as the posterior digital nerves) run down the back of the pastern, one on each side of the deep flexor tendon. These nerves provide feeling to the back third of the horse's foot including:

sensitive tissues of the hoof wall, sole, and frog
coronet and heel bulbs
lower half of the pastern (back part only)
deeper structures of the foot (digital cushion, back third of the coffin bone, lateral cartilages, navicular bone and bursa, deep flexor tendon and its sheath)

This block is one technique used to diagnose navicular disease because the navicular bone and associated structures are typically desensitized though other structures desensitized by the block may be contributing to the lameness.^[7]

Low palmar nerve block - The low palmar (also known as the abaxial sesamoidian) block desensitizes the palmar nerves. Blocking both the medial and lateral palmar nerves near the base of the sesamoid bones desensitizes the entire foot and at least half of the pastern. Blocking above the sesamoid bones may desensitize part of the fetlock and sesamoid bones with variable success.^[8]

4-point nerve block - The 4-point nerve block involves the two palmar nerves and the palmar metacarpal nerves. Blocking these four nerves desensitizes the foot, pastern, and entire fetlock joint, including the sesamoid bones.^[9]

Other nerve blocks - Nerves above the knee or hock may be blocked to desensitize these joints and the entire lower leg though these blocks are more difficult to perform. Due to the large area that is desensitized these blocks are not very helpful in localizing lameness and may cause the horse to stumble.^[10]

Effectiveness

The effectiveness of a nerve block is tested by checking the skin for loss of sensation. This is usually done with a pointed but dull object such as the tip of a pen. Some veterinarians use a needle though this may cause bleeding as well as unnecessary pain and irritation if the site is not completely blocked. Another nerve block must be performed if skin sensation has not been lost. Block failure is usually due to not enough anesthetic being absorbed which may be influenced by the following factors:^[11]

injection too far away from the nerve
not enough anesthetic injected for the size of the nerve
testing the skin too soon after injection

Most commonly used local anesthetic drugs take 10-15 minutes to desensitize a nerve. The block may last 1-2 hours depending on the product used and volume injected.^[12]

References

^ UCSD. Regional anesthesia
^ Chowdhry S, Seidenstricker L, Cooney DS, Hazani R, Wilhelmi BJ (December 2010). "Do not use epinephrine in digital blocks: myth or truth? Part II. A retrospective review of 1111 cases". Plast. Reconstr. Surg. 126 (6): 2031–4. doi:10.1097/PRS.0b013e3181f44486. PMID 20697319.
^ Bassage II, Lance; Ross MW (2003). "Diagnostic Analgesia". In Ross MW, Dyson SJ. Diagnosis and Management of Lameness in the Horse. St. Louis, MO: Saunders. pp. 93–124. ISBN 0-7216-8342-8. |accessdate= requires |url= (help)
^ King, Christine, BVSc, MACVSc, and Mansmann, Richard, VDM, PhD. (1997). "Lameness Evaulation". Equine Lameness. Equine Research, Inc. pp. 32.
^ Bassage II Diagnosis and Management of Lameness in the Horse p. 93–124.
^ King Equine Lameness p. 33.
^ King Equine Lameness p. 33.
^ King Equine Lameness p. 33-34.
^ King Equine Lameness p. 34.
^ King Equine Lameness p. 34.
^ King Equine Lameness p. 35.
^ King Equine Lameness p. 36.

External links

UltrasoundBlock.com

Video demonstrating a Continuous Nerve Block Technique in Orthopaedics
Video demonstrating ultrasound-guided interscalene nerve block using a probe positioning system

UpToDate Contents

全文を閲覧するには購読必要です。 To read the full text you will need to subscribe.

1. 末梢神経ブロックの概要 overview of peripheral nerve blocks
2. Lower extremity nerve blocks: Techniques
3. 末梢神経ブロック：手技 peripheral nerve block techniques
4. 指神経ブロック digital nerve block
5. Upper extremity nerve blocks: Techniques

English Journal

Spread of injectate around hip articular sensory branches of the femoral nerve in cadavers.

Nielsen ND1,2,3, Greher M4, Moriggl B5, Hoermann R5, Nielsen TD3, Børglum J6, Bendtsen TF2,3.
Acta anaesthesiologica Scandinavica.Acta Anaesthesiol Scand.2018 Aug;62(7):1001-1006. doi: 10.1111/aas.13122. Epub 2018 Apr 17.
PMID 29664158

Infraclavicular and supraclavicular approaches to brachial plexus for ambulatory elbow surgery: A randomized controlled observer-blinded trial.

Dhir S1, Brown B2, Mack P3, Bureau Y4, Yu J5, Ross D6.
Journal of clinical anesthesia.J Clin Anesth.2018 Aug;48:67-72. doi: 10.1016/j.jclinane.2018.05.005. Epub 2018 May 26.
PMID 29778971

Perineural dexamethasone successfully prolongs adductor canal block when assessed by objective pinprick sensory testing: A prospective, randomized, dose-dependent, placebo-controlled equivalency trial.

Turner JD1, Henshaw DS2, Weller RS3, Jaffe JD4, Edwards CJ5, Reynolds JW6, Russell GB7, Dobson SW8.
Journal of clinical anesthesia.J Clin Anesth.2018 Aug;48:51-57. doi: 10.1016/j.jclinane.2018.05.009. Epub 2018 May 9.
PMID 29753264

Japanese Journal

Hidden Charcot-Marie-Tooth 1A as Revealed by Peripheral Nerve Imaging

Shibuya Kazumoto,Nakamura Keigo,Kuwabara Satoshi,Yoshida Toshiki,Misawa Sonoko,Sekiguchi Yukari,Beppu Minako,Amino Hiroshi,Suzuki Yo-ichi,Suichi Tomoki,Tsuneyama Atsuko
Internal Medicine, 2020
… <p>Peripheral nerve imaging techniques have recently increasingly revealed their usefulness. … We herein describe a man who had a subacute progression of symptom, diffuse and prominent proximal demyelination and conduction block, suggesting a diagnosis of inflammatory demyelinating polyneuropathy. … Additional nerve imaging techniques revealed homogeneous and prominent nerve hypertrophy without proximal accentuation and the findings implied inherited polyneuropathies. …
NAID 130007677080

抗血小板薬2剤内服中で在宅酸素療法導入後の維持血液透析患者の右前足部切断術を坐骨神経ブロック膝窩部アプローチと大腿神経ブロックで管理した1症例

入江知恵子,宮﨑直樹,岩崎伊代,柚留木朋子,小松修治,松川豪策,古庄千代,瀧賢一郎
麻酔 = The Japanese journal of anesthesiology : 日本麻酔科学会準機関誌 68(6), 599-601, 2019-06
NAID 40021936627

創意と工夫超音波ガイド下神経ブロックによる下腿創外固定器抜去の試み

濱田知,松原秀憲,宇賀治修平,土屋弘行
整形外科 = Orthopedic surgery 70(7), 789-791, 2019-06
NAID 40021932742

Related Pictures

★リンクテーブル★

リンク元	「神経ブロック」
拡張検索	「mental nerve block」「infraorbital nerve block」「superior laryngeal nerve block」
関連記事	「block」「nerve」