There are two types of pain experienced after surgery: cutaneous and visceral pain. Cutaneous pain is fast, sharp pain caused by chemicals released after incision that activate nerve endings in the skin. This pain travels along A-delta fibers to the spinal cord. Visceral pain is slow, aching pain detected by nerves in internal organs that activates C fibers, carrying referred pain signals. Both types of pain signals travel up the spinal cord and midbrain to be processed and perceived as the pain sensation. The type of post-operative pain determines the appropriate analgesic treatment.

1. POST-OPERATIVE PAIN MANAGEMENT
Norma Cora Zavala

2.  The two types of pain which you may experience in
the post-operative setting are called cutaneous and
visceral pain.
 After a surgical incision, pain-causing substances
are released. These chemical substances cause
cutaneous nociceptors, or free nerve endings, to
detect the injury to the skin.

3.  This is known as “fast pain” and is sharp or acute. It
is also localised pain, meaning it is only felt in the
area of the injury.
 Nociceptors transmit impulses using afferent nerves
(nerves which carry impluses toward the central
nervous system) trough Type A-delta fibers.

4.  The fast, sharp pain impulses travel via peripheral
nerves to the dorsal horn at the back of the spinal
cord. Here they synapse, or connect, with the
second type of fibers, Type C fibers.
 Type C fibers detect visceral pain. Visceral
nociceptors are found in all the organs of the body
and detect pain impulses as slow, aching pain.

5.  Slow pain is also described as referred pain – that
is, pain which is felt in a different part of the body
from the original injury. In the dorsal horn, Type A-
delta and Type C fibers synapse with dendrites in
the spinal cord (extensions of the nerve cell body
that receive signals from other nerve cells) and
travel up the spine as neurons or nerve impulses.

6.  They then ascend to the midbrain where the nerve
impulses are processed and are transmitted back to
the body as a pain signal. The type of
pain, cutaneous or visceral, determines the choice
of analgesia, or pain relief, that you will be given for
your post-operative pain.