Acute pain relief at a teaching Hospital
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Transcript Acute pain relief at a teaching Hospital
Acute Pain Management
Dr Ashish Shetty
MBBS, MD(USA), FRCA, FFPMRCA
National Hospital for Neurology & Neurosurgery, UCLH
Honorary Consultant, Guys & St Thomas Hospital, London
Definition 1
Pain is an unpleasant sensory and emotional experience
associated with actual or potential tissue damage, or described
in terms of such damage.
IASP 1986
Acute Pain
1
Cause is known
2
Temporary (< 6 weeks)
3
Located in area of trauma
4
Resolves spontaneously
5
Trauma, Medical, Surgical
Clinical characteristics of
Acute Pain
Sudden, sharp, intense, localised
Usually self-limited
Consequences
Neuro-endocrine, Cardio-Respiratory, Gastrointestinal, Urinary
Musculoskeletal
Siddall PJ, et al. Neural Blockade in Clinical Anesthesia and Management of Pain; 1998:675–713.
Bonica JJ. The Management of Pain. Vol. 1; 1990.
24 yr old Jim
Writhing in Pain
Fracture of tibia
Waiting to go to OR
So do post-surgery patients still
have pain?
Main cause of concern of 57% of patients before surgery1
Of 3000 surgical and medical patients discharged from
UK hospitals:
87% had moderate-to-severe pain in hospital
33% had pain that was present all or most of the time2
1. Warfield CA and Kahn CH: . Anaesthesiology 1995, 83:1090-1094. 2. Bruster S et al: National survey of hospital patients. British
Medical Journal 1994, 309:1542-1546.
How effective is postoperative pain
therapy?
1973–1999:
‘significant (P<0.000l) reduction in the incidence of
moderate-severe pain of 1.9 (1.1–2.7)% per year.’
Severe pain
Hypoventilation
% (95% CI)
Hypotension
% Mean (95% CI)
Intramuscular
analgesia
PCA
29.1
0.8 (0.2-2.5)
3.8 (1.9-7.5)
10.4
1.2 (0.7-1.9)
0.4 (0.1-1.9)
Epidural
analgesia
7.8
1.1 (0.6-1.9)
5.6 (3.0-10.2)
Dolin SJ, Cashman JN, Bland JM. BJA. 2002; 89(3);409-423
Acute pain pathways
Nociceptioninhibiting neurons
Pain
Perception
Noxious
stimulus
Ascending
input
Descending
modulation
Dorsal
horn
Peripheral
nociceptors
Activation of the peripheral
nervous system
Transmission of the pain
signal to the brain
Dorsal root
ganglion
Spinothalamic
tract
Peripheral
nerve
Transmission
Modulation
Input
Activation of CNS
at spinal cord
Primary sensory neurone termination in the dorsal horn
A
A
C
I
II
III
IV
To
dorsal
columns
V
VI
Mechanism
Peripheral and central sensitisation
Wind-up
Recruitment of receptive fields
Longterm potentiation
Immediate early gene expression
Importance of Pain management
Reduce the Risk of Adverse Outcomes
Maintain the Patient’s Functional Ability, as well as
Psychological Well-being
Enhance the Quality of Life
Shortened Hospital Stay and Reduced Cost
Patient comfort and satisfaction
1. Eisenach JC, et al. Anesthesiology. 1988;68:444–448. 2. Harrison DM, et al. Anesthesiology.
1988;68:454–457. 3. Miaskowski C, et al. Pain. 1999;80:23–29.
4. Finley RJ, et al. Pain. 1984;2:S397.
Pain Assessment Tools
Pain Assessment Tools
In Adults: Self Report Measurement Scales, such as
Numerical Scales
In Pediatric Patients:
Physiologic and Behavioral Indicators of Pain ( Infants,
Toddlers, Nonverbal or Critically Ill Children)
Face Scale (Age 3-10 yrs)
Visual Analogue Scales (Age 10-18)
Management of Acute Pain
Pharmacologic
Interventional
Pharmacologic Management
Alter Nerve Conduction (Local Anesthetics
Modify Transmission in the Dorsal Horn (Opioids,
Antidepressants)
CNS modulation
Routes of Administration
PO
PR
IV
IM
Transdermal
Transmucosal
Epidural
Intrathecal
Principles Of Pain Management
WHO
Analgesic ladder
Acute Pain Analgesic Staircase
Stage 1: Immediately post-operative Strong
opioid eg morphine or epidural +/- non-opioid
analgesic
Stage 2: Oral opioid for moderate to strong
pain +/- non-opioid analgesic( NSAID)
Stage 3: Prior to discharge
opioid analgesic
Non-
What Endpoint Should Be
Achieved?
Patient awake and not nauseated
Ability to mobilise, cooperate with physiotherapy, eg
coughing, deep breathing
VAS of below 30mm on a scale of 0-100mm seen as
adequate
New developments: Delivery technology
Non-opioid Analgesics
Paracetamol: Acetaminophen
centrally acting 1g 6h or 1520mg/kg for children
Diclofenac sodium: 50mg TDS
orally
NSAIDs: Analgesic,
antipyretic,antiinflammato
ry
Opioid sparing
SE: Prostaglandin and
prostacyclin effect
Ibuprofen, diclofenac,
naproxen, piroxicam
COX 1 and COX 2
Non-Opioid Analgesics
Acetaminophen
NSAIDs ( Ibuprofen, Diclofenac)
COX-2 inhibitors
Lidocaine Patch
NSAIDs
Relieve of Mild to Moderate Pain
Complication:
GI Discomfort
GI Bleeding (Inhibition of COX-1)
Nephrotoxicity
Inhibition of Platelet Aggregation
Osteogenesis
IV NSAID: Ketorolac
Potent Analgesic
Parenteral (IV or IM)
15-30 mg Q 6hr
Patients Older than 16 yrs
Should not Exceed 5 days
Cox-2 Inhibitors
Drug
Dose
Celecoxib (Celebrex)
100-200mg PO Bid
Rofecoxib (Vioxx)
Valdecoxib (Bextra)
10-20mg PO Qd
Parecoxib
20-40mg IM
20-100mg IV
Compound Analgesics
Co-Proxamol: Paracetamol 325mg,
Dextropropoxyphene 32.5mg
Co-Dydramol: Paracetamol 500mg,
Dihydrocodeine 10mg
Co-Codamol: Paracetamol 500mg,
Codeine phosphate 8mg
Aspav:
Aspirin 500mg and opium
alkaloids
Weak opioids
Strong opioids
Dihydrocodeine 30mg 4 hrly po
Morphine
Tramadol weak iv,po agonist 50-
Fentanyl
Diamorphine
Pethidine: max 1.2g daily
100mg
Buprenorphine 200-400mcg sl 4-6h
Codeine phosphate 30-60mg 4h
Opioid Analgesics
Bind to Opioid Receptors
Morphine, Fentanyl, Codeine, Oxycodone,
Hydrocodone, Tramadol
Multimodal analgesia enhance Opioid Analgesic
Effect
Opioid Analgesics
Equianalgesic Conversion Charts are used when
Converting form one Opioid to Another, or Converting
from Parenteral to Oral Form
Respiratory Monitors may be Used Depending on the
Patients Age, Co-existing Medical Problems, or Route
of Opioid Administered
Conversions : Morphine
Oral
Parenteral
300
100
Epidural
10
Intrathecal
1
Patient controlled analgesia
Patient Controlled Analgesia
Small Doses of Analgesic Drug (Usually Opioids), are
Administered (IV) by Patient
Allows Basal Infusion and Demand Boluses
Over Dosage is Avoided
by Limiting the Amount
and Number of Boluses
in a Set Period of Time
Dose Regimens for PCA
Drug
Bolus Dose
(mg)
Lock-Out
(Minutes)
Morphine
1
5
Fentanyl
0.01-0.02
3
Patient Controlled Analgesia
Advantages
Safe, effective, good analgesia, reduces delay, saves
nursing time, high patient satisfaction, few complications
Disadvantages
Respiratory depression, nausea and vomiting,
programming errors, costs
PCA
120
100
80
intramuscular
PCA
60
40
20
0
0
1
2
3
4
5
6
7
8
Opioids
Drug
PO
mg
IV mg Starting Oral
Dose mg
Comments
Morphine
30
10
15-30
MS Contin, Release 8-12 hrs
MSIR for BTP
Methadone
20
10
5-10 Qd
Long Half-Life, 24-36 hrs
Accumulates on Days 2-3
Fentanyl
0.020.05
Fentanyl Patch, 12 hrs Delay
Onset and Offset
Opioids
Drug
PO mg
Comments
Precautions
Codeine
30-60
Combined With
Nonnarcotic Analgesics
Maximal Dose for
Acetaminophen
4gm/d
Oxycodone
5-10
Oxycodone 10-30mg Q 4h
Oxycontin 10mg Q 12h
Acetaminophen
or Aspirin toxicity
Tramodol
50-100 Q46hr
Central Acting, Affinity for
Mu Receptors
Maximal Dose
400 mg/d
Multimodal Analgesia
Reduced doses of
each analgesic
Morphine
Improved pain relief
Potentiation
Synergistic /
additive effects
NSAIDs,
paracetamol,
nerve blocks
Reduces severity of
side effects of each
drug
Kehlet H, Dahl JB. Anesth Analg. 1993;77:1048-1056.
Playford RJ, et al. Digestion. 1991;49:198-203.
Mean (SE) total pain relief for the
0.5- to 8-hour observation period
Diclofenac Paracetamol
Codeine
60
***
*p= 0.044; **p= 0.029; *** p= 0.002
*
50
**
40
30
20
10
0
D
P
P+C
D+P
D+P+C
D = 100 mg diclofenac alone;
P = 1 g paracetamol alone;
P+C = 1 g paracetamol plus 60 mg codeine;
D+P = single oral dose 100-mg enteric-coated diclofenac with 1 g paracetamol;
D+P+C = 100-mg enteric-coated diclofenac with 1 g paracetamol plus 60 mg codeine
Breivik et al, Clin Pharmacol Ther 1999;66:625-635
Adjuvant analgesics for opioid
sparing strategies
Established
NSAIDs and coxibs (safety and tolerability issues)
Paracetamol
Local anaesthetic techniques
Recent additional choices
Gabapentin
Low dose ketamine
Dexamethasone
Mr Jones will undergo a thoracotomy. What
would be your analgesia of choice?
Interventional Management
Epidural Analgesia (Continuous Lumbar or Thoracic
Epidural Catheter Placement, PCEA)
Spinal Analgesia
Peripheral Nerve Block ( Single Shot or Continuous)
Epidural Space
Surrounds the Dural
Sac
Anteriorly: Post.
Long. Ligament
Posteriorly:
Ligamentum Flavum
Laterally: Pedicles and
Intervertebral Foramina
Anatomy of Epidural Space
AP Dimension of the Epidural Space is Largest in the
Lumbar Region, 5-6 mm
In Thoracic Region the AP Dimension Decreases but
the Space is More Continuous
MIDLINE SAGITTAL VIEW OF THE LUMBAR SPINE
Epidural Anesthesia
Acts the emerging nerve roots from Spinal Cord
“dermatomal “band” of Anesthesia
Level of Anesthesia Depends on :
Volume of the Drug
Level of Injection
Epidural Anesthesia
Lumbar Epidural: Lower Extremity, Pelvic, and Lower
Abdominal Procedures
Thoracic Epidural: Upper Abdomen and Thoracic
Procedures
Caudal Injection: More Commonly Used for Pediatric
Patients (Genitourinary and Lower Abdominal
Procedures)
Advantages
Superior Pain Relief with
Lower Incidence of DVT and Pulmonary Emboli
Decrease Blood Loss Intraoperatively
More Rapid Recovery of Bowel Function
Earlier Ambulation
Better PFT
Suppression of Neuroendocrine Stress Res
Grass JA. The Role of Epidural Anesthesia and Analgesia in Postoperative
Outcome. Anesthesiol Clin North America 01-JUN-2000; 18(2): 407-28
Contraindications
Absolute
Relative
Patient Refusal
Uncooperative
Coagulopathy
Increased ICP
Skin Infection
Patient
Pre-existing Neurologic
Disorder
Anatomical Abnormalities
Drugs used in Epidural
Local Anesthetics
Lidocaine: 1-2% , 45-90 min.
Bupivacaine: 0.25-0.5% , 90-120 min.
Opioids : Diamorphine, Fentanyl
Others :Clonidine, Ketamine etc.
Opioids in Epidural Space
Drug
Dosage
Onset
(min)
Duration
(hrs)
Morphine
2-3 mg
30-90
6-24
Fentanyl
50-100 mcg
5-15
2-4
Diamorphine
Advantages
Disadvantages
Prolonged Single Dose
Delayed Onset of
Thoracic Analgesia with
Unpredictable Duration
Analgesia
Lumbar Administration
Minimal Dose Compared
with IV Administration
Analgesia
Delayed Respiratory
Depression
Local Anaesthetic Techniques
Local anaesthetics are either esters or amides
Influence action potential along the nerve
Local infiltration
Nerve block/ Plexus block
Caudal/ epidural/spinal analgesia
Epidural analgesia
Promises of epidural
analgesia
Mortality
Morbidity
Cardiovascular
Respiratory
Coagulation
Major infections
Quality of pain relief
Hospital costs
Problems
Dural puncture
Epidural haematoma
Epidural abscess
Failure of technique
Training
Resource restraint
Epidural complications
Failure of Block (Patchy or Unilateral Block)
Injury to Nerve
Infection
Epidural Hematoma or Abscess
Dural Puncture (Total Spinal or PDPH)
Epidural complications
- Hypotension Secondary to Sympathetic Blockade
- Intravascular Injection (Local Anesthetic Toxicity)
- Respiratory Depression
- Sedation
- Bladder Distention
- Difficulty in Ambulation
Spinal Anesthesia
Spinal Anesthesia : injecting small amount of local
anesthetic in the CSF
Results in Rapid Onset of Block
Rapid onset and requiring low dose of drugs
Spinal Anesthesia
CSE, Used in Labor
Preservative Free Morphine -Provides Pain Relief for
Abdominal, Pelvic, or Lower Extrimity Surgeries
Complications Similar to Epidural Technique Except
for Higher Risk of PDPH
Caudal Block
Single Injection or Continuous Infusion through a
Catheter
Excellent Intraoperative and Postoperative Pain Control
Easier to Perform in Children
Analgesia that Last About 12 hrs if Bupivacaine Used
Performed Following Induction of General Anesthesia
Indications for Caudal Block
Surgeries in Sacral Segments, (Circumcision and other
Urologic Surgeries, Rectal Dilation)
Combined with Light General Anesthesia Provides
Adequate Intraoperative Analgesia
Complications of Caudal Block
Infection
Dural Puncture and Spinal Anesthesia
Intravascular Injection of Local Anesthetics
Peripheral Nerve Block
Anesthetising the Nerve that is Innervating Surgical
or Painful Area
Single Shot or Continuous Infusion through Catheter
Upper Extrimity: Brachial Plexus, Median, Ulnar or
Radial Nerve
Peripheral Nerve Block
Lower Extrimity: Sciatic, Femoral, Posterior Tibial,
Sural, Saphenous, Deep and Superficial Peroneal
Nerve
Intercostal Nerve Block
Surgical Wound Infiltration of Local Anesthetic
Julie 4yrs old is scheduled for
a fixation of her fractured
femur.
Pain Management in Children
Consider Physiologic and Anatomic Differences
Assessment and Communication barriers
Pain and Anxiety Associated with Minor Procedures
or Unfamiliar Situations
Children
Opioid sensitive
PCA/NCA
Simple analgesics very useful
Regional analgesia
The Elderly patient
Slow circulation time
Associated diseases
Respiratory recovery
important
Early mobilisation
Elderly
Patient Population Older than 65 yrs of Age is
Growing
Age Related Physiologic Changes (Decreased
Muscle Strength): Decreased Cough
Decreased Mental Status (Dementia): Decreased
Narcotic Dose
Mr Jones
Your consultant has decided to discontinue
the epidural analgesia. What are the
appropriate next steps?
Step down analgesia
Aim: To discharge the patient on non-opioid analgesic
medication, often simple analgesics such as
paracetamol 1g QDS
If the patient is discharged on strong opioids the GP is
informed and a reduction plan advised.
Chronic
pain after
surgery:
Phantom
limb pain
Summary
Every patient has got individual needs.
Pain is best treated in a multimodal fashion
Balanced analgesia with opioids, reduced peripheral
stimulus (NSAID’s), interrupted pain pathways, eg
nerve block and alteration of emotional and behavioural
response
Careful monitoring of cardiovascular and respiratory
functions in the postoperative patient
Evidence that good pain relief will reduce the incidence
of ongoing pain
Multidisciplinary Approach
Surgeon
Pharmacist
Nurse
Acute Pain Team
Physiotherapist
Anaesthetist
Psychologist
My Philosophy
No Pain….
My Philosophy
No Pain….no Pain
Thank you