For MBBS students

1. REGIONAL ANESTHESIA & PAIN
MEDICINE
DR.G.UMA
DEPT OF ANESTHESIOLOGY
KIMS&RC

2.  Anesthesia for the area to be operated
 Spinal, Epidural, Caudal
 Plexus Blocks(e.g.) - Brachial plexus block
 Peripheral Nerve blocks
What is Regional Anesthesia?

3.  Instructions
 Equipment
 Choice of anesthetic
 Positioning the patient
 Preparation of area to be blocked
 Choosing the nerves to block
Preparation

4.  Suitability for the type of surgery being performed
 Surgeon’s preference
 Experience in performing the block
 Physiological/mental state of the patient
General Considerations

5.  Improved patient satisfaction
 Less immunosuppression
 Less nausea and vomiting
 Non-general anesthetic option for patient with
malignant hyperthermia
 Patient who is hemodynamically unstable or too ill to
tolerate a general anesthetic
Advantages of Peripheral Nerve Blocks

6.  Neuraxial Techniques
 Spinal (subarachnoid) anesthesia
 Epidural anesthesia (lumbar and thoracic)
Regional Anesthesia

7.  In addition to some of the peripheral nerve block
indications…
 Patient mentally prepared to accept neuraxial
blockade
 No contraindications
 No need for routine labs unless meds or conditions
dictate this
Indications for Neuraxial Blockade

8.  Patient refusal
 Infection at the site of injection
 Coagulopathy
 Severe hypovolemia
 Increased Intracranial pressure
 Severe Aortic Stenosis
 Severe Mitral Stenosis
 Ischemic Hypertrophic Sub-aortic Stenosis
Absolute Contraindications for Neuraxial
Blockade

9.  Sepsis
 Uncooperative patients
 Pre-existing neuro deficits/neurological deficits
 Demylenating lesions
 Stenotic valvular heart lesions (mild to moderate
Aortic Stenosis/Ischemic Hypertrophic Sub-aortic
Stenosis)
 Severe spinal deformities
Relative Contraindications

10.  Superior analgesia to IV PCA in open abdominal procedures &
specifically in colorectal surgery
 Reduce incidence of paralytic ileus
 Blunt surgical stress response
 Improves dynamic pain relief
 Reduces systemic opiate requirements
 Facilitates early oral intake, mobilization and return of bowel fx
when part of fast track protocols
Benefits of
Epidural Analgesia

11.  Involves blockade of nerve impulses using local
anesthetics (LA)
 LA bind sodium channels preventing propagation of
action potentials along nerves
 Wide variety of LA with different characteristics:
 ie. Lidocaine – fast onset, short duration of action
 ie. Bupivacaine (Marcaine) – slow onset, longer duration
Regional Anesthesia

12.  Peripheral Nerve Blocks
 Upper Limb: Brachial plexus
 Lower Limb: Femoral, sciatic, popliteal, ankle
 Abdomen: TAP blocks
 Thoracic: Paravertebral, intercostal blocks
 Use of Ultrasound Imaging has revolutionized
peripheral nerve blockade
 Safety?
 Accuracy / Improved Success
 Efficiency
Regional Anesthesia

13.  Distortion from local
infiltration
 Large area
 Most efficacious
 Extensive
manipulation

14. Pain is the fifth vital sign

15. Pain is perfect miserie,
The worst of all Evils,
And if excessive,
Overturns all patience!
Milton

16. “It is important what you have,
What is more important is what you do
With what you have”

17.  Multi modal analgesia
 Individualized therapy
New modalities----
 Transdermal patches of opioids,NSAIDS etc
analgesia in low dose & less side-effects
 Sustained-release epidural morphine ‘Depodur’- microcapsules
epidurally --single-dose extended-release epidural morphine
 Tapentadol -an interesting new molecule that activates opioid receptors
and inhibits norepinephrine uptake
 Basic research is in the inhibition of breakdown of endogenous opioids
with opiorphin, targeting of the endocannabinoid system, and the use of
ampakines to obtund opioid-induced side-effects
 Availability of infusion pumps and syringe pumps-for continuous
infusions
Acute pain

18. “Pain is all in the mind”
“Surgery will be associated with pain”
Does it have to???

19. ROLE OF PAIN
1. Focus attention and empathy
2. Protect body from further damage
3. Gives rest to the part - helps healing
4. Immediate benefit to patient/caregiver
5. Disposition to care for people in pain

20.  “Unpleasant sensory or emotional experience associated
with actual or potential damage
or described in terms of such damage!”
IASP definition of PAIN

21.  Most common annoying complaint
 Most inadequately assessed & treated symptom
 Most difficult sensation to define - protopathic
 Subjective, but not personal & is of vital importance
 Most important person is the observer
- hears beyond the words
- sees behind the picture
PAIN

22.  Post - operative
 Trauma
 Burns
 Medical procedures
 Signals organic disease,easy to diagnose
 Disappears with Rx
 Opioids are specifically effective
WHAT IS ACUTE PAIN?

23.  Lack of awareness - surgery is assoc. with pain
 “Pain not visible”- not assessed
 Understaffed anaesthesia dept.( freelancing)
 Myths & fears assoc. with opiates/ underprescription,
 Unavailability of opiates and preservative free drugs
 Patient expenditure when using sophisticated equip
WHY IS ACUTE PAIN BADLY MANAGED?

24. • Surgery--> tissue damage/ release of mediators
• CNS stimulation and pain perception
• CVS - Increase BP, HR, Workload
• RS - Increase work of breathing
• Renal /GIT - decreased function
• Inadequate --- cause of 30% chronic pain
WHY TREAT ACUTE PAIN?

25. Stress hormone release, catabolism, lipolysis
Hyperglycaemia & glucose intolerance
Retention of Na+ & H2O, excretion of K+
Impaired wound healing–reflex vasoconstriction
Reflex skeletal muscle spasm-hypoventilation
Recovery & Rehabilitation delayed
NEURO – ENDOCRINE RESPONSES

26.  Pain atleast 2 months duration after surgery
 Other causes excluded - malignancy, c/c inf
 Mastectomy, cholecystectomy, thoracotomy
 Inguinal hernia, laminectomy, amputations
 Phantom sensations with / without pain
 Neuroplasticity / continuation of pre-op pain
CHRONIC PAIN AFTER SURGERY

27. “Patient is the best sensor of his
pain,
Believe his pain”

28.  Pain receptors – free nerve endings
 Nerve fibres - A delta (a/c) & C fibres(c/c)
 Neurotransmitters – excitatory / inhibitory
 Algogenic substances -leucotrienes
-serotonin
-substance P
-histamine
-Prostaglandins
PAIN MECHANISMS

29.  Pain receptors
 Spinal cord - dorsal horn cells
 Spinal cord tracts
 Reticular formation - HR, BP, resp changes
 Thalamus, Cortex- conscious awareness
 WIND–UP of pain, PRE-EMPTING pain
PAIN PATHWAY

30.  Nociceptors – activated by tissue damage
 Pain – perception of noxious stimulus
 Suffering - negative affective response
 Pain behaviours - linked to suffering
 Subjective - emotional, psychological
CLINICAL PHENOMENA

31.  Every patient different, Multimodal therapy
 All pain protocols not suitable for all patients
 If one protocol fails, choose another
 Rescue analgesics mandatory
 No IM opiates when already on other opiates
 Discuss with the surgeons / assure safety
EMPHASISE AND STRESS

32. Medical Reasons:
Improved respiratory function
Earlier ambulation --> DVT
Shorter post - op hospitalisation
Cost to patient and hospital less
Comfortable and pain- free patient
NEED FOR ADEQUATE PAIN RELIEF

33. • Traditional I/M route disliked by all
• Big prn doses ---> sedation, analgesia, pain
• Underprescription due to myths & fears
• Relies on another person for pain relief
• Multiple needle sticks --> infection
• Variability in absorption ---- peak time & conc:
NEED FOR NEWER METHODS

35. ANY PAIN THERAPY
not
“One size fits all
or
Set and forget therapy.
Is essentially a
maintenance therapy”

36. GOALS OF ACUTE PAIN SERVICES
“NO MAGIC BULLETS”
Ensure all patients pain-free at rest, on movt.
Discourage IM analgesics and prn orders
Switch to S/C routes wherever possible
Standard protocols to avoid confusion
Prevent pain – round the clock drugs

37. Posters
Make “PAIN” visible
APS Sheets
Free services initially and contactable any time
Equipment technician-maintenance/record of equip.
Anaesthesia technician –adequate supply of epi.cocktail
IMMEDIATE back up and advice whenever required.
Encouragement / acknowledgement in plenty

38. “Any drug is valueless if it remains in the ampoule, bottle
on infusion pump.”
It has to be give in adequate doses at adequate time
intervals to be effective, whatever technique you use.

39. MODALITIES AVAILABLE
1.Intravenous 8. Oral
2. Subcutaneous 9. Rectal
3. Intrathecal 10. Transmucosal
4. Epidural 11. Transdermal
5. Via peripheral nerves 12. Sublingual
6. Direct wound infiltration 13. Intranasal
7. Interpleural 14. Intra- articular

40. Multimodal pain therapy
NSAIDs,
Opiods
Spinal &
Systemic
Opiods
Regional

41.  Subcutaneous opiates
 Continuous opiate infusions - I/V, S/c
 Epidural / intrathecal LA + opiates / infusion
 PCA via I/V, S/C, epidural routes
 Nerve blocks /Interpleural / intra-articular/ PV
 Oral / rectal / parenteral NSAIDs

42. • .
 Improves controllability through any route
 Prevents fluctuating analgesic concs:
 Does not have to rely on others
 Rate adjustments may be required
 Post-op pain intensity not the same thru
CONTINUOUS INFUSIONS

43.  Continuous I/V, S/C, epidurally
 Morphine-1mg/ml: pethidine10mg/ml:
 Initially 1 ml/hr with naloxone I/V or S/C
 Ensure pumps functioning well
 Most common causes of patient mishaps
- pump
dysfunction
- errors in programming
OPIATE INFUSIONS

44.  Infusions set at 5-10 ml / hr for 72 hrs
 0.1%bupivacaine + 2-5ug/ml fentanyl
 Monitor pulse, BP, respiration closely
 PCEA - bolus 5-8ml: LOI-15-20 mins
 Catheter migration - I/V or dural space
 Premixed syringes - LA + opioids
EPIDURAL INFUSIONS

46. Fig.2.
ELECTRONIC PCA PUMP MEAC

47. •Analgesia on demand
• Patients can regulate analgesic to MEAC
•Sense of control over his pain
• High acceptance and popular
•Decreased drug usage via any route
•Trained staff, back up, education
PATIENT - CONTROLLED ANALGESIA
(PCA)

48.  Must understand the concept of PCA
 Must be willing to use it
 Must be able to perceive pain intensity
 Must be able to respond
 Must be relieved of all doubts
 Must not be an `Opiate-abuser’
THE PATIENT IN PCA

49.  Pumps with patient demand button
 Ensure pump is locked, key kept safe
 Set 1 ml boluses, no background infusion
 Lockout interval - 5-10 mins 1/V, S/C
 Disposable PCA pumps available
 Note total dose consumed by the patients
PCA PUMPS

51.  Demand made only by the patient
 Lock- out interval for full effect of drug
 Negative feed- back and dose limits
 Demand/infusion modes/computer integrated PCEA
 Fail-proof designing of pumps (max.dose limits)
 Lockable, monitor incorporated pumps (O2,BP)
SAFETY ASPECTS OF PCA

57. Fig.1.DISPOSABLE PCA PUMPS

58.  Intrathecal Analgesia
 Spinalcord stimulation
 Radiofrequency ablation
 Ultrasound guided/Nerve stimulator guided specific nerve
blocks
Chronic pain

59.  Resp depression/ sedation/ pruritis
 Hypotension/ bradycardia/ urine retention
 Have mephentine & naloxone in the ward
 Call the Pain physician
 Meanwhile treat with O2,vasopressors & fluids
 Instructions on the APS sheets
COMPLICATIONS WITH OPIATES

62. “ACUTE PAIN SERVICES
Looks good from far,
Actually Far from good!”
RAWAL

63.  All patients pain-free entire post-op period
 Standard protocols to avoid confusion
 Discourage IM analgesics/ use other techniques
 Switch to other routes whenever one fails
 Routine patient observation charts/ audits
 Create Awareness among Surgeons/ Nurses
 Better relationship between Nursing staff & pts
APS IS TO ENSURE

64. Origin of Pain
 Acute Pain
 ie. Incisional pain, acute appendicitis
 Chronic Pain
 ie. Chronic back pain
 Acute on Chronic Pain
 Acute and chronic causes may or may not be related to each
other
Pain Assessment

65. Pain Assessment
Visual Analogue Scale

66. Current Pain Medications
 Accuracy and detail are very important!
 Name, dose, frequency, route
 ie. Oxycontin 10mg PO TID
 Don’t forget to re-order or factor in patient’s pre-existing
pain Rx usage when writing orders
Conflicts with HPI / PMH
 Renal disease → avoid morphine, NSAID’s
 Vomiting → avoid oral forms of medication
 Short gut/high output stomas → avoid CR formulations
Pain Assessment

67. Allergies / Intolerances
 Drug allergies
 Document drug, adverse reaction and severity
 Intolerances
 Nausea / vomiting, hallucinations, disorientation, etc.
Very important to differentiate between an allergy and an
intolerance!
Pain Assessment

68.  Pharmacologic
 Medications (po, iv, im, sc, pr, transdermal)
 Acetaminophen
 NSAIDs
 Opioids
 Gabapentin
 NMDA antagonists
 Alpha-2 agonists
 Procedures
 Regional Anesthesia
 LA infiltration at incision site
 Surgical Intervention
 Non-Pharmacologic / Non-Surgical
Methods to Treat Pain

69. WHO Analgesic Ladder

70. Using more than one drug for pain control
 Different drugs with different mechanisms/sites of action
along pain pathway
 Each with a lower dose than if used alone
 Can provide additive or synergistic effects
 Provides better analgesia with less side effects (mainly
opiate related S/E)
Always consider multimodal analgesia when treating pain
Multimodal Analgesia

71.  First-line treatment if no contraindication
 Mechanism: thought to inhibit prostaglandin
synthesis in CNS → analgesia, antipyretic
 Only available in po form in Canada
 Typical dose: 650 to 1000 mg PO Q6H
 Max dose: 4 g / 24 hrs from all sources
 Warning: ↓ dose / avoid in those with liver damage
Acetaminophen

72.  Also, first-line treatment
 Mechanism
 Block cyclooxygenase (COX) enzyme → ↓ prostaglandin
synthesis
 COX-2 → Prostaglandins → pain, inflammation, fever
 COX-1 → Prostaglandins → gastric protection, hemostasis
NSAIDs

73.  Warnings: ↓dose / avoid if
 GI ulceration
 Bleeding disorders / Coagulopathy
 Renal dysfunction
 High cardiac risk – COXII inhibitors
 Asthma
 Allergy
 ?Avoid celecoxib if allergic to Sulpha
Concern for anastomotic leaks?
NSAIDs

74. Dilaudid 1-4mg PO/IM/IV/SC Q3H PRN
Any concerns?
Opioids

75. Key Points:
 Centrally acting on opioid receptors
 No ceiling effect
 High dose/response variability in non-opiate users
 Previous dependence creates a challenge in acute on chronic pain
management cases
 Balancing safety and efficacy can be difficult (OSA patients)
 Side effects may limit reaching effective dose
Opioids

76. Side Effects
 Nausea / Vomiting
 Sedation
 Respiratory Depression
 Pruritus
 Constipation
 Urinary Retention
 Ileus
 Tolerance
Opioids

77.  Morphine
 Most commonly prescribed opioid in hospital
 Metabolism:
 Conjugation with glucuronic acid in liver and kidney
 Morphine-3-glucuronide (inactive)
 Morphine-6-glucuronide (active)
 Impaired morphine glucuronide elimination in renal failure
 Prolonged respiratory depression with small doses
 Due to metabolite build-up (morphine-6-glucuronide)
Opioids

78.  Hydromorphone (Dilaudid)
 Better tolerated by elderly, better S/E profile
 Preferred over morphine for renal disease patients
 Low cost, IV and PO forms available
 Oxycodone
 Good S/E profile, but $$
 PO form only
 Percocet (oxycodone + acetaminophen)
Opioids

79.  Codeine
 1/10th Potency of morphine
 Metabolized into morphine by body
 Ineffective in 10% of Caucasian patents
 Challenge with combination formulations
 Meperidine (Demerol)
 Not very potent
 Decreases seizure threshold, dystonic reactions
 Neurotoxic metabolite (normeperidine)
 Avoid in renal disease
Opioids

80.  Short acting forms
 Need to be dosed frequently to maintain consistent analgesia
 Controlled Release forms
 Provides more consistent steady state level
 Helpful for severe pain or chronic pain situations
 Never crush / split / chew controlled release pills
Opioids - Formulations

81. Drug Equianalgesic Dose Initial Adult Dose (>50kg)
IV/SC/IM Oral IV/SC/IM Oral
Morphine 10 mg 20-30 mg 2-10 mg q4h 5-20 mg q4h
Hydromorphon
e
1.5 mg 4-7.5 mg 0.5-2 mg q4h 1-4 mg q4h
Oxycodone N/A 10-20 mg N/A 5-10 mg q4h
Opioid Equianalgesic Table

82. Opioids – PCA

83.  Allows patient to reach their own minimum effective
analgesic concentration (MEAC)
 Rapid titration (Morphine 1mg IV every 5 min)
 Better analgesia and less side effects than IM prn
Opioids – PCA

84.  Anti-epileptic drug, also useful in:
 Neuropathic pain, Postherpetic neuralgia, CRPS
 Blocks voltage-gated Ca channels in CNS
 Additive effect with NSAIDs
 Reduces opioid consumption by 16-67%
 Reduces opioid related side effects
 Drowsiness if dose increased too fast
Gabapentin

85.  Nausea / Vomiting
 Ondansetron (Zofran)
 Dimenhydrinate (Gravol)
 Metoclopramide (Maxeran)
 Changing medication(s) / ↓ dose
 Pruritus
 Diphenhydramine (Benadryl)
 Changing medication(s) / ↓ dose
Management of Side Effects

86. Radiofrequency ablation

87.  Accurate pain assessment
 Make sure to continue or account for patient’s pre-
hospital pain regimen
 Use Multimodal pain management
 Discharge pain management plan
 Acute Pain Service available 24 hrs/day
Summary

88.  Superior analgesia, ↓ side effects means:
 Improved patient satisfaction
 Better rehabilitation
 Earlier functional return
 Earlier discharge from hospital
 ↓ likelihood of chronic pain
 Reduced health care costs
Summary

89. Nerve Blocks of the Digits
 Anatomy
 Technique
 Dorsal approach

90. Nerve Blocks of the Digits
 Anatomy
 Technique
 Dorsal approach
 Ring block
 Palm approach

91. Nerve Blocks of the Lower
Extremity

92.  Ankle
 Metatarsals
 Toes
Nerve Blocks of the Lower Extremity

93. Nerve Blocks of the Ankle

94. IVRA-BIER’S BLOCK