Post on 27-Dec-2015
transcript
What’s the definition of pain?
Pain is a Sensory and Emotional experience associated with tissue damage or described in terms of such damage
(I.A.S.P.)
The Pain Pathways and Mechanisms
Pain Pathways
Frenchman Rene Descartes, De humine textbook
Aß Fibers C Fibers
Axon Reflex
Np : Neuro-peptides, BV : Blood Vessels
Physiology of the dorsal horn of the spinal cord
HyperalgesiaAnd pain Threshold inhumans
Pain Management in the late 18th century
Barker M.D.
Different Pain management Modalities
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
Patient Controlled AnalgesiaPCA
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 Elderly6. PCA Flowsheets
Regional analgesia
Isolated Extremity Injury
Brachial plexus Anatomy
Infraclavicular Approach
Infraclavicular Approach
Lower Extremity Injury
Paravertebral Lumbar Somatic Nerve Block
Femoral Nerve Block
Sciatic Nerve Block
Neuroaxial Blocks
Opioid Spread after Epidural injection
CSF Circulation
Each of the four ventricles of the brain has a choroid plexus and CSF normally circulates between them:
1. The foramen of Monro is an opening from the lateral ventricle into the third ventricle
2. The aqueduct of Sylvius is the pathway of CSF flow between the third and fourth ventricles
3. The foramina (plural of "foramen") of Magendie and Luschka are openings from the fourth ventricle into the subarachnoid space around the base of the brain and upper spinal cord
4. The daily production is around 400-600 ml/ day
5. The reabsorption occurs over the surface of the brain and into the venous dural sinus drainage channels
Spread of Opioids in CSF
Pharmacokinatics of Epidural injection of Hydrophilic Drug
Pharmacokinatics of Epidural Lipophilic Opioid
Effects of Increased Pressure on Venous drainage“Pregnancy, Morbid obesity”
Complications of Epidural Morphine
Morphine concentration in Cervical CSF after lumbar Epidural injection
Epidural Homodynamic Facts
• Local anesthetics may cause vasodilatation and hypotension (Sympathectomy)
• Narcotics dose not cause Hypotension• Not every post-op hypotension is related to
Epidural analgesia.• Epidural analgesia promotes early mobilization• Nausea & vomiting response to small doses of
Narcan or Zofran. Avoid Phenergan
Tunneling Technique
Adjuvant Therapy
Nonsteroidals
Conformational structure of COX-1 and COX-2 isozymes
COX-1 (A) COX-2 (B)
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
Practical guide for NSAID’s Usage
• Pre-op administration significantly decreases post-op pain and cramps
• Toradol 30mg, IV or Celebrex 400mg, P.O. pre-op• 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 function
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 ?
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
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
Coanalgesic Agents
• Anxiolytic drugs
• Anticonvulsants
• Antidepressants
• Ketamine
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
Mechanisms of Anti-Epileptic Drugs in Pain
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
Non Chemical Techniques
• Psychological treatments: Relaxation, hypnosis Cognitive therapy etc..
• TENS Units
• Physiotherapy
Pain Management Algorithm
Trauma pain managementAlgorithm
Trea t w ith an ym od a lit ies
C lear m en ta ls ta tu s
S m all d oses o fop io id s (cod e in e)o r/w ith K e to ro lac
U n c lear m en ta ls ta tu s
H ead in ju ryp a tien ts
Trauma pain managementAlgorithm
E p id u ra l an a lg es iaop io id s o r
loca l an es th e tic s
B on e in ju ry
E p id u ra l an a lg es iaO p io id s on ly
P C A
yes
E p id u ra l op io id sw ith o r w ith ou t
loca l an es th e tic s
P erip h era ln e rve b lock
N o
N erve fu n c tionm on ito rin g
P erip h era l n e rve o r vascu la rin ju ry
E xtrem ity in ju ry
Trauma pain managementAlgorithm
E p id u ra l an a lg es ia
S u rg ery req u ired
P C A
S u rg ery n o t rq u ired
A b d om in a l in ju ry
Trauma Pain Management Algorithm
P C A
S p in a l co rd in ju ry
E p id u ra l an a lg es iaw ith loca l an es th e tic s
(V ery e ffec tive )
P O /IV N arco tic sA n tid ep ressan tsA n ticon vu lsan ts
C R P S IC R P S II
N eu rop a th icn erve in ju ry
N eu ro log ic in ju ries
Trauma pain managementAlgorithm
Th orac ic ep id u ra lan a lg es ia
In te rcos ta ln erve b lock
P C A
R ead y fo rextu b a tion
IV n arco tic sP C A
In tu b a tedp a tien ts
Th orac ic ep id u ra lan a lg es ia
In te rcos ta ln erve b lock
P C A
N ot In tu b a tedp a tien ts
Th orac ic trau m a
Pharmacokinatic model of Spinal injection of Hydrophilic Opioid
Referred Pain
Bardram et al: [8] eight elderly high-risk patients, stress-free (i.e., laparoscopic) colonic resection
Combination of laparoscopic surgery, epidural analgesia, early
oral nutrition, and early mobilization
Pain relief → early mobilization in elderly patients → accelerated
recovery; hospital stay: 2 d
Moiniche et al: [111] uncontrolled pilot investigation, 17 patients, open colonic resection
Combined epidural–general anesthesia, epidural analgesia, no
nasogastric tube, oral feeding in 24 h, early mobilization
VAS 0 at rest, minimal with mobilization; normal defecation in
12 patients within 48 h; median hospital stay: 5 d
Liu et al: [95] 54 patients, four groups, partial colectomy
Multimodal recovery program Epidural analgesia: superior; earlier recovery of gastrointestinal function
but more orthostatic hypotension; epidural bupivacaine combined with morphine: best balance of analgesia
and side effects
Collier: [29] 186 patients, care pathway for elective carotid endarterectomy
Preoperative education, same-day admission, regional anesthesia,
selective use of ICU
10% ICU admission; 157 patients discharged on first postoperative day; average stay: 1.27 d; cost-
savings $3000 per patient
Reference Intervention Findings
PUBLICATIONS ON ACCELERATED OR MULTIMODAL POSTOPERATIVE REHABILITATION PROGRAMS
References Intervention Findings
Moiniche et al: [112] 13 patients, hip replacement pilot investigation
Epidural analgesia (bupivacaine-morphine), ibuprofen, intensive mobilization regime
11 patients ready for discharge on day 6, 2 patients discharged on day 9 (usual
hospitalization was 13 d)
Pedersen et al: [126] prospective study, breast surgery, questionnaires from 373 patients
Standardized clinical protocols, support from senior management, expanded educational
resources for patients
Length of stay: 39% decrease; patient volume: up 22%; low incidence of surgical
complications, high patient acceptance
Weingarten et al: [173] retrospective study, 230 patients, total hip replacement
Practice guideline: 5-d postoperative stay in low-risk patients
Practice guideline can reduce hospital length of stay from 8.4 to 5.9 d
Bardram et al: [8] eight elderly high-risk patients, stress-free (i.e., laparoscopic) colonic resection
Combination of laparoscopic surgery, epidural analgesia, early oral nutrition, and
early mobilization
Pain relief → early mobilization in elderly patients → accelerated recovery; hospital
stay: 2 d
Moiniche et al: [111] uncontrolled pilot investigation, 17 patients, open colonic resection
Combined epidural–general anesthesia, epidural analgesia, no nasogastric tube, oral
feeding in 24 h, early mobilization
VAS 0 at rest, minimal with mobilization; normal defecation in 12 patients within 48 h;
median hospital stay: 5 d
Liu et al: [95] 54 patients, four groups, partial colectomy
Multimodal recovery program Epidural analgesia: superior; earlier recovery of gastrointestinal function but more
orthostatic hypotension; epidural bupivacaine combined with morphine: best balance of
analgesia and side effects
PUBLICATIONS ON ACCELERATED OR MULTIMODAL POSTOPERATIVE REHABILITATION PROGRAMS