Post operative pain management has no specific criteria. Lots of methods and procedures are suggested with various types of drugs. It is just a guideline for management of pain after surgery.

1. Postoperative Pain
Management
Dr. Hriday Ranjan Roy
Assistant Professor,
Surgery,
Rangpur Medical
College, Rangpur,
Bangladesh

2. What’s the definition of pain?

3. Pain is a Sensory and Emotional experience
associated with tissue damage or described
in terms of such damage
(I.A.S.P)
(The International Association for the
Study of Pain)

6. Pain is
Always
Subjective
and Can
Never be
Proved or
TOTAL RECALL

7. The Pain Pathways and
Mechanisms

8. How Pain Occurs
Tissue damage
prostaglandins,
releases bradykinin and
which activate or sensitize
nociceptors.
Activation of nociceptors
leads to the release of
substance P and calcitonin gene related peptide
(CGRP).
Substance P
acts on mast cells in the vicinity of
sensory endings and release of histamine, which
directly excites nociceptors.
Substance P and CGRP produces dilation of
peripheral blood vessels. The resultant edema causes
additional liberation of bradykinin.
Thus Nociceptors activate and cause pain.

9. Pain Pathways
Frenchman Rene Descartes, De humine textbook

11. Axon Reflex
Np : Neuro-peptides, BV : Blood Vessels

12. Pathophysiology
• The generation of pain
involves interaction
between all parts of the
nervous system.
Pain ultimately transmitted to:
• Thalamus
• Medulla oblongata
• Cerebral cortex.

13. Types of Pain
Fast Pain: Felt within 0.1 second after
painful stimulus.
Also called: sharp pain, pricking pain,
electric pain and acute pain.
Slow Pain: Felt within 1.0 second or
more after painful stimulus.
Also called: dull pain and chronic pain.

14. Types of Pain
1. Nociceptive pain- Direct stimulation of intact
nociceptors
• Transmission along normal nerves
• Sharp, aching, throbbing
– somatic
• easy to describe, localize
– visceral
• difficult to describe, localize

15. 2. Neuropathic pain . . .
• Disordered peripheral or central nerves
• Compression, transection, infiltration,
ischemia, metabolic injury
• Varied types
– peripheral, deafferentation, complex regional
syndromes
• Pain may exceed observable injury
• Described as burning, tingling, shooting, stabbing,
electrical
• Mx: opioids, adjuvant / coanalgesics often req.

16. Assessment of Pain
How do
You
Quantify
pain?

17. Pain rating scales
Categorical scale
1
Mild
0
No pain
2
3
Discomforting Distressing
4
Intense
5
Excruciating
Visual analogue scale (VAS)
No pain
Most pain
Numeric rating scale
0
1
2
3
4
5
6
7
( 0 = No pain, 10 = Worst pain imaginable )
“Ten Scale” most common: 11 point scale
– 0 = No pain
– 10 = Worst pain imaginable
8
9
10

18. •PAIN
MANAGEMENT

19. Pain Management in the late 18 th
century
Barker M.D.

20. Pain Management

24. Different Pain management
Modalities

25. Pre-emptive Analgesia
•
•
•
•
•
Pre-emptive analgesia can be achieved
by:
local anesthetic infiltration of the skin
Effective dose of systemic opioids
Systemic nonsteroidal anti-inflammatory
drugs (NSAIDs)
Neuroaxial opioids or local anesthetic
Peripheral nerve blocks

26. Patient Controlled Analgesia
PCA
1. Increase patient satisfaction
2. Decrease side effects and
complications
3. Decrease sedation
4. Decrease total amount of daily
opioids
5. Avoid Basal rate in the Elderly
6. PCA Flowsheets

27. Regional analgesia

28. Isolated Extremity Injury

29. Brachial plexus Anatomy

30. Infraclavicular Approach

31. Infraclavicular Approach

32. Lower Extremity Injury

33. Paravertebral Lumbar Somatic Nerve Block

34. Femoral Nerve Block

35. Sciatic Nerve Block

36. Neuroaxial Blocks

37. Opioid Spread after Epidural injection

38. Adjuvant Therapy

39. Nonsteroidals

40. Conformational structure of COX-1
and COX-2 isozymes
COX-1 (A)
COX-2 (B)

41. NSAID's
• Blocks the production of
Prostaglandin
• Very effective in pain control, Alone
or in Combination with Narcotics
• Ketorolac is My drug of choice as
an adjunct therapy in acute pain
• Use p.o. forms “Cox2 inhibitors”
when possible in combination with
Epidural,
IV,or oral narcotics

42. Practical guide for NSAID’s
Usage
• Pre-op administration significantly decreases
•
•
•
•
•
post-op pain and cramps
Toradol 30mg, IV or Celebrex 400mg, P.O. preop
For sever acute pain Celebrex 400mg, P.O. bid
X one week the 200 P.O., bid. Bextra 20mg,
bid X one week the 20mg, QD
PPI are the drugs of choice to treat gastric
complications. H2 blockers only mask the
disease
Please check the patient renal function
routinely prior to administration
COX2 inhibitors doesn’t affect the platelet

43. Practical guide for NSAID’s
Usage
(Continuum)
All specific or non-specific NSAID’s may
cause:
• water retention and edema
• Hypertension
• Renal dysfunction
• May delay bony fusion in chronic usage ?

44. Clonidine
• Alpha2 agonist with outstanding
•
•
•
•
•
properties when administered
intrathecally:
Pain control properties by itself
Decrease the requirement of narcotics
Decrease tolerance
Great for neuropathic pain control
Adding 1mcg/kg for children caudal
block will extend pain relief up to 24h

45. Clonidine
Oral or transdermal Clonidine:
 Enhance the effect of narcotics
 Decreases the daily narcotic requirement
 Excellent Adjuvant therapy for narcotic
dependent patients
 Effective for neuropathic pain

46. Coanalgesic Agents
•
•
•
•
Anxiolytic drugs
Anticonvulsants
Antidepressants
Ketamine

47. Ketamine
• NMDA receptors antagonist →
Neuropathic pain
• Potent analgesic effect
• Small doses in combination of opioids
substantially improve pain control
• Bolus dose of 100 mcg/kg followed by a
continuous drip of 1-3 mcg/kg/min is ideal
for chronic opioid users postoperatively

48. Mechanisms of Anti-Epileptic
Drugs in Pain

49. Usage of Anti-Epileptic Drugs in
Acute Pain
• Every surgical incisional pain has Neuropathic
•
•
•
component
Studies showed giving 1200 mg of Gabapentin
1 h prior to surgery decreases the opioids
requirement post-op and results in better pain
control without increased sedation
Combining Gabapentin with opioids is ideal for
re-do back surgery cases with chronic opioids
usage
These class of drugs are also mode stabilizers

50. Non Chemical Techniques
• Psychological treatments:
Relaxation, hypnosis Cognitive
therapy etc..
• TENS Units
• Physiotherapy

51. The W.H.O 3-step Pain “Ladder”
• Step 1 (mild):
– non opioid + adjuvant
• Step 2 (moderate):
ASA
Acetaminophen
NSAIDs
± Adjuvants
• Step 3 (severe) :
– ‘strong’ opioid+step 1 meds
Hydrocodone
Oxycodone
Dihydrocodeine
Tramadol
– “weak” opioid + step 1 meds
Codeine
± Adjuvants
Nalbuphine
Morphine
Hydromorphone
Methadone
Levorphanol
Fentanyl
Oxycodone
± Adjuvants

52. Physiological vs clinical pain
• Physiological pain has a biological
function
• Pathological pain has no biological
function
Woolf

53. Multidisciplinary Approach
Surgeon
Pharmacist
Nurse
Acute Pain Team
Physiotherapist
Anaesthetist
Psychologist

54. Pain after surgery
Inflammatory pain
•
•
•
Inflammatory pain
Nociceptive painpain
Nociceptive
Neuropathic pain
Neuropathic pain

55. Chronic post surgical pain
•
•
•
Pain developed after a surgical procedure
At least 2 month duration
Other causes excluded (malignancy, chronic
infection)
• Possibility of continuous pain of pre-existing
problem
Macrae 2001

56. Principles of analgesic Plan
•
•
•
•
•
Balanced analgesia
Opioids: First line morphine
Regional analgesia
Actual dose of analgesics will not be discussed
Regular and breakthrough prescription including
night-time

57. Analgesic ladder

58. Non-opioid Analgesics
• Paracetamol:
Acetaminophen
centrally acting
500mg-1g 6h or 1520mg/kg for children
• Diclofenac sodium:
50mg TDS orally
• Aspirin: 300-900mg
4h
• NSAIDs: Analgesic,
antipyretic,antiinflam
matory
• Opioid sparing
• SE: Prostaglandin and
prostacyclin effect
• Ibuprofen, diclofenac,
naproxen, piroxicam

59. Opioid Analgesics
• Weak opioids
Codeine phosphate 3060mg 4h
Dihydrocodeine 30mg 4-6h
po or 50mg 4-6h im
Buprenorphine 200400mcg sl 4-6h
Tramadol weak agonist 50100mg 4h
• Strong opioids
Nalbuphine
Morphine
Diamorphine
Pethidine: max
1.2g daily

60. Prevalence of chronic pain following surgery
Surgery
Perkins & Kehlet
Macrae
Breast
11-49%
23-49%
Thoracotomy
22-67%
5-67%
Cholecystectomy
3-56%
3.4-27%
Inguinal Hernia
0-37%
15-63%
N/A
0-37%
Vasectomy

61. Neuropathic pain can become
established extremely quickly after
trauma and surgery and remain
unchanged after 6 months