Pain in the Older Patient. Dr. Christopher A. Jenner Consultant in Anaesthesia and Pain Medicine, SMH 20 th June 2005
Dec 02, 2014
Pain in the Older Patient.
Dr. Christopher A. JennerConsultant in Anaesthesia and Pain Medicine, SMH
20th June 2005
Agenda
• Definition
• Physiology
• Acute
• Chronic
• Neuropathic
• Differences
• NSAID/ COX 2 controversy
Definitions
• Pain. ‘An unpleasant sensory and emotional experience which we primarily associate with tissue damage or describe in terms of tissue damage, or both.’ (IASP 2001)
• Time-course: acute/ chronic
• Type: nociceptive/ neuropathic
Pain Physiology (boring)
Pain Physiology (funky)
Prevalence
• Acute pain • SMH 13,213 operations p.a. (Nov 03-04, DSU 41%)
• SMH 484 operations p.m. (Sep 04, Main, 15% PCA/ epi)
• Chronic pain
• 7-14% UK population
• ‘1 in 7’ figure
The Challenges of Acute Pain
• Primary Care
• ↑ healthcare utilisation
• Secondary Care
• ↑ length stay/ complications • 10-15% post-op chronic pain (Macrae)
The Challenges of Chronic Pain
• Bio-psycho-social model
• Individual and societal costs
• Biological- pain/ suffering/ disability
• Psychological- anxiety/ depression
• Social- work/ relationship/ family/ benefits
Acute Pain Management
• Non-pharmacological • RICE
• Pharmacological • WHO ladder (amended from cancer)
Step 1 paracetamol/ NSAID/ COX 2
Step 2 + weak opioids
Step 3 + strong opioids
Massive Financial Burden
• NHS/ DWP/ tax-payers
• Lower back pain (CSAG 1994)
• NHS £481 million
• The Exchequer £1.4 billion
Chronic Pain Management
• Non-pharmacological • Physical- heat/ cold/ TENS/ hydro/ supports/ US/ IR
• Manipulation- PxTx/ chiropracter/ osteopathy/ deep tissue massage
• Alternative- acupuncture
Headache!
5. (a) Veterinary practitioners?
Chronic Pain Management
• Nerve block techniques: epidurals
facets
tenoperiostial
ON
SSN
Occipital N
Ilioinguinal
Chronic Pain Management
• Nerve stimulation- spinal cord stimulation
peripheral nerve stimulation
• Pumps-
Intrathecal pump delivery systems
Chronic Pain Management
• Pharmacological
• WHO analgesic ladder (abridged)
• + tramadol • + opioids- buprenorphine TDD/ oxycontin/ fentanyl TDD
• (New: sufentanyl TDD/ product X)
Neuropathic Pain Management
• Non-pharmacological •Nerve blockade- lumbar sympathectomy/ stellate/
guanethidine
Neuropathic Pain Management
• Antidepressants- Amitryptilline
• Anticonvulsants- Gabapentin/ Pregabalin/ Carbamazepine/ Valproate
• Opiods• Local Anaesthetics- Lignocaine/ EMLA
• NMDA antagonists• Sympatholytics• GABA ergics• Capsaicin
Future Agents in Neuropathic Pain
• Ziconotide (sea snail, conus magnus)
• P2X3- (purine) receptor antagonists (ATP) (knockout mice)
• Epibatidine (Equadorian poison dart frog)
• Morphine and ketamine
• Regular gabapentin
• Dexmetomidine
Differences
• ‘Intense pain which interferes with functioning is not a normal part of ageing and should never be accepted as such.’ Textbook of Pain. Melzack and Wall 1984
Physiological Differences
• ↑ pain threshold/ tolerance
• ↓ discrim. to suprathreshold noxious• CVS- ↑ ihd/ ↓ compliance/ ↓ CO/ ↓ bf organs/ HT/ DVT
• RS- ↑ close capacity/ ↓ response hypercapnia/ hypoxia/ ↑ atelectasis/ ↑ chest infections
Physiological Differences
• Metabolic- ↓ BMR/ ↓ renal function/ ↓ rbf/ dehydration/ heat loss
• CNS- cerebrovascular disease/ confusion (hypoxia/ drugs/ hospital/ illness)/ ↓ hearing n memory
• ↑ systemic disease
• Biological age versus Chronological age
Pharmacological Differences
• ↓ TBW so ↑ proportion body wt. fat
• ↑ sensitivity many drugs esp. CNS depressants
• ↓ plasma proteins- binding/ ↑ free unbound
• ↑ t ½ many drugs
• ↑ multiple drug treatments (Bdz n LBP patient)
• Start low, go slow!
Psychological Differences
• Stoical
• Afraid of diagnosis
• Take me home/ kept in
• Not seen as capable
• Adverse effects• Concern over drugs- newspaper cuttings
Clinical Differences
• Less reporting
• ↓ post-op
• undertreated
• MDT
• non-pharmacological
• Pain- the 5th vital sign!
Clinical Differences
• Beware- no complaints/ pain on movement or resisting movement/ lying quietly/ ask, don’t assume/ pain scores/ friends and relatives/ prejudices
The NSAID/ COX 2 controversy
The NSAID/ COX 2 controversy
• COX 1/ 2/ 3
• Asthma/ GI/ renal/ platelets/ bone healing
The NSAID/ COX 2 controversy
• VIGOR (Vioxx- Rofecoxib)- ↑ CVS/ change labelling
• APPROVE (Vioxx)- Colonic polyps/ 18/12 ↑ CVS ↑ stroke
• 23/12/04 FDA warning- celecoxib/ valdecoxib/ naproxen
• 7/4/04 FDA Pfizer Valdecoxib withdrawal/ celecoxib box warning
The NSAID/ COX 2 controversy
• 4/05 FDA
‘ Long-term controlled clinical trials have not been conducted on most NSAIDs. However, available data suggests that use of COX 2 may increase cardiovascular risk. Difficult to draw conclusions about relative cardiovascular risk of COX 2 and NSAIDs with the data available.’
The NSAID/ COX 2 controversy
• FDA- no rank for valdecoxib/ rofecoxib/ celecoxib
• BMJ 2005; 330; 1366 ↑ MI
NNH
ibuprofen 1005
rofecoxib 695
diclofenac 521
The NSAID/ COX 2 controversy
• S/T L/T- risk- benefit
The Future?
The Future?
• Demographics
• Healthcare advances
• ↑ Patient expectations and involvement
Summary
• Very common
• Time course- acute n chronic
• Nociceptive and neuropathic
• Differences
• Start low, go slow!
• NSAID/ COX2 controversy
Any Questions