1) The document discusses the history and modern understanding of pain physiology and management of postoperative pain. It describes how pain was originally thought to be outside the body but is now understood as a physical sensation processed in the nervous system. 2) Postoperative pain has acute causes from incisions and procedures as well as referred pain, and poorly managed pain can impair recovery. A multimodal approach using combinations of analgesics like paracetamol, NSAIDs, and opioids along with local anesthetics and nerve blocks is recommended. 3) Patient-controlled analgesia allows patients to self-administer opioids within safe limits and provides effective pain relief. Preemptive analgesia aims to prevent central sensitization by treating pain before and

1. Post Operative
Pain Management
Dr. Golam Mursalin
Phase A CVTS
Dr. Rushdah Mariam
Phase A Paediatric Surgery

2. Content
◦ Definition of Pain
◦ Physiology
◦ Causes of PostOp Pain
◦ Effects of Pain
◦ Treatment Options
◦ Modalities of Treatment
◦ Related Thesis in BSMMU

3. HISTORY1

4. DURING ANCIENT TIMES
Aristotle did not include a sense of pain
when he enumerated the five senses.
Hippocrates believed that pain was
caused by an imbalance in the vital
fluids of a human.

5. BEFORE THE RENAISSANCE
Even just prior to the scientific
Renaissance in Europe, pain was not
well understood and it was theorized
that pain existed outside of the body,
perhaps as a punishment from God,
with the only treatment being prayer.

6. DURING THE RENAISSANCE
In his 1664 Treatise of Man, René
Descartes theorized that the body was
more similar to a machine, and that pain
was a disturbance that passed down
along nerve fibers until the disturbance
reached the brain. This theory
transformed the perception of pain from a
spiritual, mystical experience to a
physical, mechanical sensation.

7. MODERN THEORY
In 1975, well after the time of Descartes,
the International Association for the Study
of Pain sought a consensus definition for
pain, finalizing “an unpleasant sensory and
emotional experience associated with
actual or potential tissue damage” as the
final definition.

8. PHYSIOLOGY OF PAIN2

9. Pain involves four physiological
processes:
◦ Transduction
◦ Transmission
◦ Perception
◦ Modulation

13. Acute Pain
Acute pain typically
has a sudden onset
and recedes during
the healing process.
it can be regarded as
“good pain” as it
serves an important
protective
mechanism.
TYPES OF PAIN
Chronic Pain
It persists long after
recovery from an
injury and is often
refractory
to common
analgesic agents.
Results from nerve
injury (neuropathic
pain) and ischemia.

14. REFERRED PAIN
Irritation of a visceral organ frequently
produces pain that is felt not at that site
but in a somatic structure that may be
some distance away.
When pain is referred, it is usually to a
structure that developed from the same
embryonic segment or dermatome as the
structure in which the pain originates.

16. POST OPERATIVE PAIN3

17. CAUSES OF POST OPERATIVE PAIN
Incisional
◦ Skin
◦ Subcutaneous
tissue
Deep
◦ cutting
◦ coagulation
I/V site
◦ Needle trauma
◦ Extravasation
◦ Irritation
Tube
◦ Drain
◦ Nasogastric
◦ Endotrachial
tube
Operative site
◦ Cast
◦ Tight dressing
Others
◦ Urinary retention
◦ Ambulation

18. CONSEQUENCES OF POORLY MANAGED POST OPERATIVE
PAIN
Respiratory effects
Surgery involving the upper abdomen or chest
reduces vital capacity, functional residual
capacity and the ability to cough and deep
breathe. This in turn can lead to retention of
secretions, atelectasis and pneumonia.
Cardiovascular effects
Pain causes an increase in sympathetic output
(tachycardia, hypertension and increasing blood
catecholamines), which leads to increasing
myocardial oxygen demand.

19. CONSEQUENCES OF POORLY MANAGED POST OPERATIVE
PAIN
Neuroendocrine effects
The stress response to surgery and pain includes
the secretion of catecholamines and catabolic
hormones. This increases metabolism and
oxygen consumption and promotes sodium and
water retention.
Effects on mobilization
Mobilization may be delayed if the patient is
experiencing pain. This may increase the risk of
deep vein thrombosis and also prolong hospital
stay.

22. POST OPERATIVE PAIN
MANAGEMENT
4

23. Non Pharmacological
◦ PreOp Counselling
◦ TENS
◦ Acupuncture
◦ Massage
◦ Hypnosis
METHODS AVAILABLE TO TREAT PAIN
Parmacological
◦ Paracetamol
◦ NSAIDs
◦ Opoids
◦ Local Anaesthetics
◦ Spinal analgesia
◦ Epidural analgesia

25. PARACETAMOL & NSAIDs
◦ Paracetamol & NSAIDs block the synthesis of
prostaglandins by inhibiting the enzyme cyclo-
oxygenase.
◦ They do not relieve severe pain when used
alone, but they are valuable in multimodal
analgesia because they decrease opioid
requirement and thus its side effects.
◦ Adverse effects include: Gastrointestinal
disturbance, impaired hemostasis,
nephrotoxicity, aggrevation of asthma etc.

28. OPIOIDS
◦ Opioids mimic endogenous opioid peptides at
3 opioid receptors, causing their activation
within the central nervous system. This
decreases the activity of the dorsal horn relay
neurons that transmit painful stimuli, thereby
reducing their transmission to higher centers
and producing analgesia.
◦ Side effects include itching, sedation,
respiratory depression, nausea and vomiting,
euphoria or dysphoria and bladder
dysfunction.

29. LOCAL ANAESTHETICS
◦ Local anaesthetic drugs (e.g. bupivacaine and
lidocaine) are sodium channel blockers and
prevent the propagation of nerve impulses when
applied to peripheral nerves or nerve roots.
Sensory and sympathetic nerve fibers are also
blocked as are motor nerves.
◦ In the treatment of postoperative pain, LA drugs
can be used in many ways: Local wound
infiltration (e.g. after an inguinal hernia repair),
Injection close to a peripheral nerve, Injection
close to a plexus of nerves, central neural
blockade (e.g. a spinal or epidural).

31. LOCAL ANAESTHETICS
All local anaesthetic drugs can cause toxic
effects if given in large doses or if accidental
intravascular injection occurs. Central nervous
system and cardiovascular toxicity can result in
restlessness, hypotension, convulsions, cardiac
arrhythmias and even cardiorespiratory arrest.
Drug Safe Dose
Bupivacaine 2 mg/kg
Lignocaine 3 mg/kg
Lignocaine (with adrenaline) 7 mg/kg

33. SPINAL ANALGESIA
◦ Local anaesthetic drugs with or without an
opioid may be administered intrathecally as a
'single shot' spinal injection.
◦ An opioid such as morphine or diamorphine
may provide useful postoperative analgesia for
up to 12-24 h.
◦ Side effects include: hypotension, reduced
cardiac output, respiratory depression,
postdural puncture headache, spinal
hematoma, infection.

34. EPIDURAL ANALGESIA
◦ The epidural space is a fat-filled space within
the spinal canal. Anaesthetists inject local
anaesthetics into this space, and, by doing so,
block nerve root transmission of pain. Epidural
opioids can also modulate pain pathways once
within the epidural space by diffusion through
the dura mater into the cerebrospinal fluid
(CSF) and so to the opioid receptors of the
spinal cord.
◦ Side effects are similar to spinal analgesia.

35. MODALITIES OF PAIN MANAGEMENT5

36. ◦ Multimodal (Balanced) Analgesia
◦ Patient Controlled Analgesia
◦ Preemptive Analgesia

37. MULTIMODAL (BALANCED) ANALGESIA
◦ Using more than one drug for pain control
◦ Drugs : Opioids with Paracetamol / NSAIDs
/ LAs
◦ Each with a lower dose than if used alone
◦ Can provide additive or synergistic effects
◦ Provides better analgesia with less side
effects

38. THE WHO ANALGESIC LADDER
The basic principle of the WHO ladder
is that analgesia which is appropriate
for the degree of pain should be
prescribed. If pain is severe or remains
poorly controlled, strong opioids should
be prescribed and increased as
indicated by the patient’s need for
additional analgesia (opioid titration).

40. PATIENT CONTROL ANALGESIA (PCA)
◦ Procedure where patient controls the
frequency of analgesic
administration but within safe limits.
◦ First PCA machine demonstrated in
1976 was “The Cardiff Palliator”.

42. PATIENT CONTROL ANALGESIA (PCA)
Settings of PCA machine :
◦ A microprocessor controlled pump
◦ A button to trigger the pump
◦ Computer for controlling the strength,
frequency and total dose in a specific time
Routes :
◦ Usually intravenous
◦ Patient controlled epidural analgesia (PCEA)

43. PRE-EMPTIVE ANALGESIA
A hypothesis exists that surgery, which produces
a barrage of pain signals to the spinal cord, is a
'priming‘ mechanism which sensitizes the central
nervous system. This is said to lead to enhanced
postoperative pain. The rationale behind several
studies is that, by providing presurgery, or pre-
emptive, analgesia using parenteral opioids,
regional blocks or NSAIDs, either individually or
in combination, these sensitizing neuroplastic
changes can be prevented within the spinal cord,
leading to diminished postoperative analgesic
requirements.

44. SPECIAL CONSIDERATION FOR CHILDREN
◦ Psychological support may decrease anxiety
and fear of surgical procedure
◦ Presence of parent in the anesthetic room
decreases post operative pain and reduces
risk of psychological sequelae
◦ Dosage selection must be guided by
calculation based on patient weight

45. Good Analgesia
Results in:
◦ Improved patient satisfaction and
Doctor-Patient relationship
◦ Better rehabilitation
◦ Earlier discharge from hospital & return
to function
◦ Decrease likelihood of chronic pain
◦ Reduced health care costs

46. Honorable Mentions
Assessment of the effect of paracetamol as a
centrally acting adjunct with diclofenac in
preemptive analgesia of children.
Prof. M. Saiful Islam, Dr. Md. Nooruzzaman
Comparison of degree of pain centered between
protocol based and randomly administered
postoperative pain intervention in children.
Prof. M. Saiful Islam, Dr. Ramana Rajkarnikar

47. “
Patient has every right to remain pain
free during and after operation. This can
be achieved by appropriate counselling,
gentle tissue handling and proper
analgesia.

48. Thanks!
ANY QUESTIONS?