Brachial plexus block
Encyclopedia
Regional anesthesia of the upper limb
by a "brachial plexus
block" may be a good alternative to general anesthesia
for surgery in this part of the human body. There are numerous brachial plexus methods. They are classified by the level at which the needle is inserted for injection
of local anesthetic
: Interscalene block on the neck, Supraclavicular block immediately above the clavicle, Infraclavicular block below the clavicle and Axillary block
in the axilla.
To achieve an efficient block
of nerves the needle tip needs to be located close to the nerves, before injection of local anesthetic
. There are many techniques for obtaining such a needle position. Some of them will be described in the following.
.
toward the hand. Injection close to the position of a paresthesia may therefore be efficient.
connected to an appropriate needle allows emission of electrical current from the needle tip. When the needle tip is close to or contacts a nerve innervating a muscle, characteristic muscle contraction may be elicited.
apparatuses have the capacity to depict internal anatomy, including the nerves to be blocked, neighbor structures and the needle approaching the nerves. Additionally the local anesthetic can be observed on injection. When it embraces the relevant nerves, an effective block may be predicted.
Limb (anatomy)
A limb is a jointed, or prehensile , appendage of the human or other animal body....
by a "brachial plexus
Brachial plexus
The brachial plexus is a network of nerve fibers, running from the spine, formed by the ventral rami of the lower four cervical and first thoracic nerve roots...
block" may be a good alternative to general anesthesia
General anaesthesia
General anaesthesia is a state of unconsciousness and loss of protective reflexes resulting from the administration of one or more general anaesthetic agents...
for surgery in this part of the human body. There are numerous brachial plexus methods. They are classified by the level at which the needle is inserted for injection
Injection (medicine)
An injection is an infusion method of putting fluid into the body, usually with a hollow needle and a syringe which is pierced through the skin to a sufficient depth for the material to be forced into the body...
of local anesthetic
Local anesthetic
A local anesthetic is a drug that causes reversible local anesthesia, generally for the aim of having local analgesic effect, that is, inducing absence of pain sensation, although other local senses are often affected as well...
: Interscalene block on the neck, Supraclavicular block immediately above the clavicle, Infraclavicular block below the clavicle and Axillary block
Axillary block
- Description :The axillary nerve block is a type of brachial plexus nerve block commonly employed to provide upper limb anesthesia and analgesia. It is particularly useful in providing anesthesia for surgery to the hand, wrist or forearm...
in the axilla.
To achieve an efficient block
Nerve block
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...
of nerves the needle tip needs to be located close to the nerves, before injection of local anesthetic
Local anesthetic
A local anesthetic is a drug that causes reversible local anesthesia, generally for the aim of having local analgesic effect, that is, inducing absence of pain sensation, although other local senses are often affected as well...
. There are many techniques for obtaining such a needle position. Some of them will be described in the following.
Perivascular and transarterial technique
Since the brachial plexus nerves usually are tightly accompanied by a palpable artery, injecting local anesthetic close to such an artery may give an efficient nerve blockNerve block
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...
.
Fascial click technique
A soft tissue sheath is considered to embrace the described nerves and artery. On penetration of this sheath by a needle, a characteristic loss of resistance (“fascial click”) is noticed, which implies proximity of the needle to nerve/nerves.Paresthesia technique
If the needle is close to or contacts a nerve, patients often experience a weak rush of paresthesiaParesthesia
Paresthesia , spelled "paraesthesia" in British English, is a sensation of tingling, burning, pricking, or numbness of a person's skin with no apparent long-term physical effect. It is more generally known as the feeling of "pins and needles" or of a limb "falling asleep"...
toward the hand. Injection close to the position of a paresthesia may therefore be efficient.
Electrical nerve stimulation
An electrical peripheral nerve stimulatorTranscutaneous electrical nerve stimulation
Transcutaneous electrical nerve stimulation is the use of electric current produced by a device to stimulate the nerves for therapeutic purposes...
connected to an appropriate needle allows emission of electrical current from the needle tip. When the needle tip is close to or contacts a nerve innervating a muscle, characteristic muscle contraction may be elicited.
Ultrasound
UltrasoundUltrasound
Ultrasound is cyclic sound pressure with a frequency greater than the upper limit of human hearing. Ultrasound is thus not separated from "normal" sound based on differences in physical properties, only the fact that humans cannot hear it. Although this limit varies from person to person, it is...
apparatuses have the capacity to depict internal anatomy, including the nerves to be blocked, neighbor structures and the needle approaching the nerves. Additionally the local anesthetic can be observed on injection. When it embraces the relevant nerves, an effective block may be predicted.