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anesthesia quick
glossary
what is anesthesia?
who administers anesthesia?
who gets what type
of anesthesia?
local anesthesia:
topical, cold, cream
local anesthesia: injection, tumescent, ring block,
regional block
IV sedation / monitored
anesthesia care
general anesthesia
stages of general
anesthesia
preparing for anesthesia
anesthesia and herbal
drug interactions
anesthesia and prescription
drug interactions
post-anesthesia
guidelines
anesthesia fees
LOCAL ANESTHESIA
Injection
Infiltration or injection into the surgical area
with a needle is the most frequently used local anesthesia
technique. Because direct injection can change
the contour and appearance of the site, the surgeon
may mark the area beforehand to identify certain landmarks.
Lidocaine, lasting 30 to 60 minutes, is the most commonly
injected medicine; however, for longer procedures,
longer-lasting medicines such as Marcaine or Procaine
can be added. Small doses of epinephrine (adrenaline)
are often added to the local anesthetic solution to
constrict the blood vessels and delay absorption of
the medicine. This benefits the patient by producing
less bleeding, longer anesthesia, and the need for
less medicine, however it can sometimes cause the
heart to beat faster and stronger as it is absorbed
into the bloodstream.
Tumescent
Tumescent anesthesia is a technique commonly used
for liposuction whereby a solution of Lidocaine, Epinephrine,
and saline (salt water) is injected into the surgical
area. (The term tumescent, meaning swollen or puffy,
comes from the appearance of the area immediately
after injection, before the medicine is absorbed into
the surrounding tissues.) The saline helps to separate
the tissues, making the dissection less traumatic.
Epinephrine causes the tiny blood vessels in the area
to constrict, minimizing bleeding and bruising. Lidocaine
numbs the area to provide pain control. With this
technique, large volumes of anesthesia are used in
much lower concentrations. This means that a large
area can be anesthetized with significantly less anesthesia
than the traditional infiltrative method, and the
risk of Lidocaine toxicity is greatly reduced. (Read
more about Lidocaine toxicity under "local anesthesia"
above).
Ring Block
A ring block is a special technique whereby anesthetic
medication is injected in a circle surrounding the
surgical site. This will numb the area inside the
circle where the surgery will take place, without
actually having to inject into that specific area.
This is useful for smaller areas where it is important
to avoid the temporary distortion that can be caused
with direct injection, or to avoid rupturing a cyst
or tracking cancer cells into healthy tissue. It is
also commonly used when operating on the ear since
injection into the ear would cause significant distortion
in the thin tissues.
Regional Block
A nerve block or regional block involves injecting
the anesthetic medicine at the root of a particular
nerve so that sensation is blocked along the branches
of that nerve. Like the ring block, this is also useful
when the surgeon wants to prevent distorting the area
or has a large area to numb, but does not want to
use heavier sedation or general anesthesia. Regional
blocks require less anesthetic medicine reducing the
risk of toxicity, and reduce blood loss compared to
general anesthesia since the medicine used lowers
the blood pressure in that area. Regional techniques
can block or reduce pain anywhere from several hours
to several days, depending on the medicine and the
techniques, so some surgeons will perform a nerve
block at the end of surgery to reduce pain for the
first few days following surgery.
To Next Section
- IV Sedation / Monitored Anesthesia Care
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