Pain management in Nursing

1. PAIN MANAGEMENT IN
NURSING
PHYSIOLOGY OF PAIN
PREPARED BY;
SEIF SAID KHALFAN(BSc.N STUDENT)
UNDER SUPERVISION OF;
RN, BSc.N, MENTAL HEALTH SPECIALIST; SULTAN MUKKY

2. Introduction
Physiology of pain explains how pain is
transmitted and perceived. The mechanism of
pain physiology is still incompletely understood.
Whether the pain is perceived and to what
degree depend on the interaction between the
body’s analgesia system and the nervous
system’s transmission and interpretation of
stimuli

3. Key words
1. Nociceptors
The receptors that transmit pain sensation.
2. Neurotransmitters
are the chemicals which allow the transmission
of signals from one neuron to the next across
synapses.

4. 3. Substance P
a substance that functions as a neurotransmitter
and as a neuromodulator. To be specific,
substance P is an undecapeptide - a peptide
composed of a chain of 11 amino acid
residues.

5. Serotonin
•Serotonin is a chemical created by the human
body that works as a neurotransmitter. It is
regarded by some researchers as a chemical
that is responsible for maintaining mood
balance, and that a deficit of serotonin leads to
depression.

6. 1. Prostaglandin
The prostaglandins are a group of lipids made at
sites of tissue damage or infection that are
involved in dealing with injury and illness.
They control processes such as inflammation,
blood flow, the formation of blood clots and
the induction of labour. Mechanism of action
of the drug aspirin.

7. 5. Bradykinin
Peptide formed from the degradation of protein
enzymes. It is a powerful vasodilator that
also cause contraction of smooth muscle.
6. Histamine
An enzyme that cause local vasodilatation and
increase permeability of the blood vessel
walls.

8. Physiology of Pain
NOCICEPTION
The peripheral nervous system includes primary
sensory neurons specialized to detect tissue
damage and to evoke the sensation of touch,
heat, cold, pain and pressure.
The receptors that transmit pain sensation are
called Nociceptors.

9. The pain receptors or nociceptors can be
excited by mechanical, thermal, or chemical
stimuli.
The physiologic processes related to pain
perception are described as nociception. There
are four processes involved in nociception:
transduction, transmission, perception and
modulation.

10. i. Transduction:
• During the transduction phase, noxious
stimuli (tissue injury) triger the release of
biochemical mediators i.e. prostaglandins,
bradykinin, serotonin, histamine and
Substance P that sensitize receptors.
• The painful stimulation also cause
movement of movement of ions across cell
membranes, which excites nociceptors.

11. • Pain medications can work during this phase
by blocking the production of prostaglandin
(e.g. ibrufen) or by decreasing the movement
of ions across the cell membranes (e.g. local
anaesthetic).

12. ii. Transmission: The second phase of
nociception, transmission of pain, includes
three segments.
• The first segment the pain impulse travel
from the peripheral nerve fibres to the spinal
cord. Substance P serves as
neurotransmitter. Two types of nociceptors
cause this transmission to dorsal horn of the
spinal cord: C fibres transmit dull pain and A-
delta fibres which transmit sharp, localized
pain.

15. • The second segment is transmission from the
spinal cord to the brain stem and thalamus.
• The third segment involves transmission of
signals between the thalamus to the somatic
sensory cortex where pain perception occurs.
• Pain control can take place during this second
process of transmission. For example block of
release of neurotransmitters, particularly
substance P, which stops the pain at the spinal
level.

16. iii. Perception
It is the third process of nociception. It is when a
person becomes conscious of the pain. It is
believed that pain perception occurs in the
cortical structures, which allows for different
cognitive behavioural strategies to be
applied to reduce the sensory and affective
component of pain

17. • For example, non-pharmacological
interventions such as distraction, guided
imagery, and music can help direct the client’s
attention away from pain.

18. iv. Modulation
This is the fourth system, often describes as the
“descending system,”. This fourth system
occurs when neurons in the brainstem send
signals back down to the dorsal horn of the
spinal cord. These descending fibres release
substances such as endogenous opioids,
serotonin and norepinephrine which can
inhibit the ascending of noxious impulses in
the dorsal horn

19. GATE CONTROL THEORY
•Peripheral nerve fibres carrying pain to the
spinal cord can have their input modified at the
spinal cord level before transmission to the
brain.
•Synapses in the dorsal horn act as gates that
close to keep impulses from reaching the brain
or open to permit impulses to ascend to the
brain

20. • Small-diameter nerve fibres carry pain stimuli
through a gate, but large-diameter nerve
fibres going through the same gate can inhibit
the transmission of the pain impulses, that is,
close the gate.
• The gate mechanism is thought to be situated
in in the substantia gelatinosa cells in the
dorsal horn of the spinal cord.

21. • Because s limited amount of sensory
information can reach the brain at any given
time.
• The brain also appears to influence whether
the gate is open or closed. For example
previous experience with pain are known to
affect the way an individual response to pain.

22. RESPONSES TO PAIN
Body’s response to pain is a complex process
rather than a specific action. It has both
physiologic and psychological aspects. Initially
the sympathetic nervous system responds,
resulting in the fight-or-flight response. As pain
continues, the body adopts as the
parasympathetic nervous system takes over,

23. reversing many of the initial physiologic
responses.

24. References
1. Medical News Today:
www.medicalnewstoday.com/articles/23224
8.php
2. Kozier B, Erbs G, Berman A & Snyder S
(2004). Fundamentals of Nursing: Concepts,
Process and Practice (7th
edition). Pearson
Education, Inc., Upper Saddle River, New
Jersey 07458.