Invasive options in palliative care

Tim Bushnell

So: what do you want?Various models: tradesman?, superhero,? team member?Not all pain specialists are anaesthetists, and not all pain medicine involves anaesthetic techniques.

• Coeliac Plexus Block

• Saddle block

• Epidural/spinal infusions.

• Superior Hypogastric Block

• Cordotomy

• Tender point injections.

General comments

Coeliac plexus blockade.• Sympathetics provide both afferent and efferent supply to

and from abdominal viscera (?).

• Abdominal contents from low stomach to splenic flexure supplied by coeliac plexus.

• Plexus easily (?) located at L1, around the aorta, using image intensification or CT.

• Technique usually performed is actually a splancnic nerve block due to crus of diaphragm

Surface anatomy:Coeliac Plexus Block

Needle insertion points

12th ribL1

L3

Coeliac Block

Coeliac ganglion

aorta

ivc

liverCrura diaphragm

7cm

Coeliac axis on AP Xray

Coeliac block: practical considerations.

• Contra-indicated if poor clotting or unable to withstand procedure.

• Significant risks- a second line option.

• Impossible to perform and ineffective if abdominal lesion invading posterior abdominal wall- do early if possible.

• Significant aftercare- perform as i/p.

Coeliac block: Advantages.• Can be dramatically effective.

• One off procedure, should last months or even years.

• Increased gut transit can be advantageous.

• Effective in pancreatic and liver tumour pain: 75% Good to excellent response.

• Genuine evidence base: multiple studies. Eisenberg E, Carr DB, Chalmers TC. Neurolytic coeliac plexus block for treatment of cancer pain: a meta-analysis. Anesth Analg. 1995; 80: 290-5

Coeliac block: Disadvantages.• Difficult, anatomy can be disrupted by tumour.

• Side effects: postural hypotension, shoulder pain, diarrhoea, sexual dysfunction, haemorrhage, paralysis (1:200-1:600) etc.

• Usually “incomplete” effect : patients still require opioids in majority of cases

• Only effective if pain still mediated by sympathetics: ineffective if involving posterior abdominal wall.

• May wear off and need to be repeated.

Newer approaches to the coeliac plexus

• CT guided: Good when there is significant anatomical disturbance: however availability issues and involves much more movement for patient.

• CT guided Anterior approach. Good if patient can’t lie prone. Otherwise no particular advantage though as performed under CT less skill needed (radiologist does most of the work)

• Peri-operative. Useful if having “staging” surgery.

CT guided anterior Coeliac Plexus block

Needle

Subarachnoid and Epidural Phenol.

• Thoracic rarely performed. Requires great skill.

• Pelvic pain mainly.

• Highly destructive: potential for disaster.

• One off, effective even in somatic pain.

• Saddle block: 10-50% require urinary catheter, 50%+ Loss anal tone. >10% some motor weakness, usually reversible. Some evidence.

Subarachnoid block:To obtain a localised effect position andgravity is used.

Subarachnoid block:Injection can be performed with patient angled to one side.

Neurolytic Subarachnoid Block• Phenol 6-10%

• Usually at level of cauda equina (L2) or below: occasionally higher.

• Difficult to predict effect therefore Perform first with LA (eg reversible!). Allow patient to feel the numbness: some would prefer the pain.

Side effects

• One off/LA

– Difficult to do

– Bruising

– Hypotension: sympathetic block

– SA bleed: disastrous

– Infection: disastrous

– “Total spinal”

– Spinal cord trauma

– Post spinal headache

• Neurolytic

– All above plus….

– Indiscriminate: blocks motor, autonomic and sensory nerves. Therefore….

– 30% chance doubly incontinent

– 10% unable to walk

– Replaces pain with numbness

– Therefore: perform temporary block first

Spinal Medication in cancer pain.• “one off epidural”- limited applications now.

• Externalised (eg pump on outside)- if life expectancy <6/12.

• Fully implanted (eg like a pacemaker- Life expectancy >6/12.

• Remember, a delivery system only. However, local anaesthetics, opioids, clonidine, baclofen all suitable.

• Epidural vs Subarachnoid: SA smaller volume, less refilling, more leaking, much newer, infection more calamitous.

Epidural space

Subarachnoid space

Spinal infusions: How often needed?

• Relevant to 16/1205 patients: 1.3% Abram et al . Pain 1991 46:271-279

• Local audit: 2 uses in 2 years, only used at one pain clinic out of ten, covered by 6 hospices.

Intrathecal opioids in Palliative care: Criteria for use.

• Appropriate trial of strong opioids• Intolerable side effects from systemic opioids.• Life expectancy >3mnths• Exclude tumour encroachment on theca/

Interrupted cns circulation.Krames Schuchard Pain reviews 1995

Deer, Winkelmuller et all, Neuromodulation 1999

• Very “In” in USA: some good trials showing better pain improvement than “medical” approach alone.

• Maintenance/down time real issues• Side effects: Catheter problems 22%, N&V

25%, pruritis 13%, constipation 50%, Infection ?

Intrathecal opioids in Palliative care: Continued

Advantages of spinal infusions.

• Use of local anaesthetic possible: can be wonderfully effective in poorly opioid sensitive pain eg incident pain, pelvic pain, thoracic wall involvement.

• Opioid side effects MAY be reduced, but no evidence that efficacy is greater.

• Continuous delivery with bolus doses available.

Disadvantages of spinal.• Complicated, difficult to do and maintain.

• Continuous link required for reservoir filling etc.

• Calamitous side effects possible: postural hypotension, infection etc, etc.

• LAs may lead to muscular weakness.

• What is the “down time” of the system? Eg waiting for refills, consultant review etc etc.

• Huge demands place on support teams.

• Expensive.

Superior Hypogastric Plexus Blockade.

• Relatively recent introduction. • Similar to coeliac but lower: ?

ideal for pelvic invasion.• Seems to have fewer side effects.

Xray of patient prone with contrast at level of superior hypogastric plexus

Superior hypogastric block

L5/S1

Line of psoas

Contrast in retroperitoneal space

Front view Lateral view

The trigger point• Exquisitely tender point within muscle, tendon or

associated fascia.

• Firm nodule or band. Gritty feel and grips needle.

• Anatomical consistancy

• Referred pain: myotomal pattern.

The Trigger point

Injury/overload

Ruptured sacoplasmicreticulum

Release Ca : sustainedcontraction

ATP depletion results in localcontraction and electrical silence

Local hypoxia/ischaemia

Release Kinins,prostaglandins

Sensitized nociceptors

The Vicious circle

Local Ischaemia

Release algogens

Sensitized nociceptors

Nociceptor firing

CNS activation/sensitization

Increased muscle tension, sympathetic activity

Myotomal referral

Pattern of referred pain from trigger points

Trigger point

Trigger point treatments

• Heat/cold

• Stimulation

• Physical therapy: spray and stretch

• Trigger point injections

– Dry needling/LA/Depot-steroid

– Botulinum toxin.

All treatments aimed at breaking vicious cycle

Caution

Tender points can be found in many conditions and can be an indicator of degree depression for instance.

“Trigger points” as found in fibromyalgia are thought to represent a completely different causation

Anterolateral Cordotomy

Thorax. 1999 Mar;54(3):238-41 Percutaneous cervical cordotomy for the control of pain in patients with pleural mesothelioma.

Interruption of spinothalamic tract within the spinal cord, usually performed as radiofrequency coagulation at C2

Cordotomy• Only treats pain on one side of the body. Bilateral cordotomy

can be performed, but although this will stop pain on both sides of the body it does not affect midline pain and is generally associated with a higher incidence of side effects. Evidence level IV

• Percutaneous procedure is more commonly used, and is performed in the cervical region at C1-2. The highest level of analgesia obtainable is about C4 which corresponds to the shoulder. Neck pain does not normally respond. Special care is needed in patients with impaired lung function, as percutaneous cervical cordotomy may cause some reduction in the expansion of the lung on the side of the procedure. This is obviously important in patients with lung tumours.

• Cordotomy can provide complete analgesia in about 2/3 of patients. If a patient has widespread pain, but one location where it is not controlled by simple measures, then cordotomy may be useful in controlling that pain. The pain relief is not permanent, and the duration is variable. Pain relief will seldom last longer than one year in most patients. Evidence level IV

Image intensifier showing C1/2 placement or thermocouple for percutaneous cordotomy

Evidence Based Care:• Evidence base very confused

• Background schism in chronic pain management: psychologists vs cutters and burners

• Cancer pain main justification for implanted techniques in chronic pain.

• What is asked for? Specialist pain management or a specific technique.

Evidence Based Care: Invasive procedures continued

• What does evidence based medicine mean in individual cases? What is the best evidence base for a biopsychosocial model?

• If all you’ve got is a hammer than everything begins to look like a nail. Chronic pain teams do best what they are good at: whatever the evidence base.

Summary• Do you need a different approach (alternative opioids,

alternative routes, alternative adjuncts unhelpful?)

• Would invasive option be feasible?

• Would invasive option help (33% patients>= 3 different pains, is this “Total pain”?)

• Can you support and maintain the new option?

• Is this the right time? Is this what the patient wants?

If so: go for it!

Case history. Mrs H. aged 64yr.

• Upper abdominal pain: “boaring”. Also mid thoracic back pain. Difficult to get comfortable. Not jaundiced.

• Diagnosis uncertain: ?Ca Ampulla/Ca Pancreas.

• Very poor pain control with midpotency opioids, sleep disturbed.