Local Anesthetics

Introduction

Local anesthetics are used to block nerve conduction, preventing pain sensation. They are used for minor procedures.

Local anesthetics can be used in place of general anesthetic to reduce nausea and vomiting, decrease cardiovascular risk, encourage earlier hospital discharge.

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Indications

Local anesthetics are used for minor procedures, such as wound exploration and cleaning, suturing, fracture reduction, and excisions.

They can also be used intraoperatively to reduce pain during recovery.

Anesthetics with epinephrine are very useful for reducing bleeding at the site of injection via vasoconstriction. This can be especially helpful when attempting to visualize the field of view. Epinephrine also keeps the anesthetic local, allowing greater doses to be given by reducing the risk of systemic adverse events.

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Clinical Usage and Tips

tip to remember amides from esters

amides: generic drug names have two I's

ester: generic drug has only one I

amide

lidocaine (4-6 hours)
bupivicaine (10-12 hours); slower onset

ester

procaine
cocaine

One can also give lidocaine and bupivicaine mix to provide rapid onset and longer duration.

Lidocaine can be quite painful subcutaneously; bicarbonate can be given at a 1:10 ratio. Slower injection can also help with pressure

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Subcutaneous Injections

Video: Injection of Local Anesthetic. Used with permission.

The video is not a substitute for medical advice."

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Regional Blocks

Digital blocks

SIMPLE - single injection median palmar lidocaine with epinephrine.

SIMPLE digital block, injected into proximal crease just above bone

inject into the prximal crease of the palmar surface of the finger.
Will cover entire volar finger and the dorsal side up to the PIP joint.
better as there is only one injection

Dorsal block

place your finger under theirs
inject once you can see or feel tenting on their palmar side

Metacarpal block

does the ray
good for boxer's fracture reduction
ensure you are not too proximal
inject dorsally straight down until you see/feel tenting
aspirate slightly before injecting

Hematoma block

Used for fractures; inject directly into the fracture hematoma. Often used by emergency room physicians and orthopedics, often under conscious sedation.