Download painManagement

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
Hyperalgesia
And pain
Threshold in
humans
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 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
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 management
Algorithm
Head injury
patients
Clear mental
status
Unclear mental
status
Treat with any
modalities
Small doses of
opioids(codeine)
or/with Ketorolac
Trauma pain management
Algorithm
Extremity injury
Bone injury
Peripheral nerve or vascular
injury
Epidural analgesia
opioids or
local anesthetics
Nerve function
monitoring
yes
Epidural analgesia
Opioids only
No
PCA
Epidural opioids
with or without
local anesthetics
Peripheral
nerve block
Trauma pain management
Algorithm
Abdominal injury
Surgery required
Surgery not rquired
Epidural analgesia
PCA
Trauma Pain Management
Algorithm
Neurologic injuries
Spinal cord injury
Neuropathic
nerve injury
PCA
CRPS I
CRPS II
Epidural analgesia
with local anesthetics
(Very effective)
PO/IV Narcotics
Antidepressants
Anticonvulsants
Trauma pain management
Algorithm
Thoracic trauma
Intubated
patients
IV narcotics
PCA
Not Intubated
patients
Thoracic epidural
analgesia
Ready for
extubation
Thoracic epidural
analgesia
Intercostal
nerve block
PCA
Intercostal
nerve block
PCA
Pharmacokinatic model of Spinal injection of Hydrophilic Opioid
Referred Pain
PUBLICATIONS ON ACCELERATED OR MULTIMODAL POSTOPERATIVE
REHABILITATION PROGRAMS
Reference
Bardram et al: eight elderly highrisk patients, stress-free (i.e.,
laparoscopic) colonic resection
[8]
Moiniche et al: uncontrolled
pilot investigation, 17 patients,
open colonic resection
[111]
Liu et al: 54 patients, four groups,
partial colectomy
[95]
Collier: 186 patients, care
pathway for elective carotid
endarterectomy
[29]
Intervention
Findings
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
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
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
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; costsavings $3000 per patient
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
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
Liu et al: [95] 54 patients, four groups, partial
colectomy