The carbon chain is increased, the lipophilicity is higher, the anesthetic effect is stronger, the duration is longer, and the toxicity is also increased.

The larger the pKa, the fewer the base parts and the more ionic parts, the less likely it is for the local anesthetic to penetrate the nerve sheath and membrane, and the longer the onset of effect will be.

The higher the binding rate, the longer the action time

The lipid solubility, intensity and duration of action of local anesthetics are also positively related to their protein binding rate

The greater the concentration of local anesthetic, the deeper and more complete the nerve block will be.

Procaine, chloroprocaine, tetracaine

lidocaine, bupivacaine, mepivacaine, ropivacaine

Central Nervous System

Cardiovascular System

respiratory system

The cardiovascular system tolerates local anesthetics better than the central nervous system, and toxic reactions occur earlier in the central nervous system.

Dosage of local anesthetic

Local anesthetic injection site

Add other medications

patient's age

patient’s vital organ function

pregnancy

rapid drug resistance

internal environment state

central nervous system toxicity

Cardiovascular system toxicity

Common causes of systemic toxic reactions include

treat

Allergic reactions to ester local anesthetics are more common

blood vessels → black

Bones and ligaments→white

The cervical plexus is composed of cervical 1 to 4 spinal nerves (C1 to C4). The superficial plexus is at the midpoint of the posterior edge of the sternocleidomastoid muscle. The deep plexus mainly innervates the deep tissues of the front and side of the neck.

deep cervical plexus block

Phrenic nerve block (most common complication)

recurrent laryngeal nerve block

Horner’s syndrome

General spinal and epidural anesthesia

Local anesthetic toxic reactions, damage to the vertebral artery causing bleeding and hematoma

The brachial plexus is composed of the anterior branches of cervical 5 to 8 (C5 to C8) and thoracic 1 (T1) spinal nerves. It forms the upper, middle, and lower trunks in the interscalene groove of the anterior middle scalene muscle. Each trunk is divided into anterior and posterior branches at the middle part of the clavicle. The two strands have 6 strands in total, and then form 3 bundles: lateral bundle, medial bundle, and posterior bundle. Each bundle branches into 5 main nerve terminal branches at the coracoid process plane.

5 roots - 3 stems - 6 strands - 3 bundles - 5 terminal branches

interscalene brachial plexus block

supraclavicular brachial plexus block

axillary brachial plexus block

Pneumothorax (supraclavicular path)

Horner’s syndrom, spinal and epidural anesthesia (interscalene route)

Infection, hematoma, local anesthetic toxicity, phrenic and recurrent laryngeal nerve blocks, nerve injury and block failure