Chronic pain management - II . Dr Vitul Manhas Dr Girish Sharma Dr Gian Chauhan. Cancer-related pain syndromes. Acute pain syndromes Acute pain associated with diagnostic procedures Acute pain caused by therapeutic interventions Acute infection Acute pain due to cancer itself
Dr Girish Sharma
standard 21 G (gauge) green sharp bevelled injection needle, 22 G Huber side-holed needle used for intrathecal pump refills, 16 G Tuohyepidural needle marked in 1 cm graduations, 22 G short bevelled spinal needle, 24 G pencil point spinal needle, 22 G side-holed Sprotte spinal needle and
radiofrequency lesioning probe
Minimally invasive spinal procedures (e.g., vertebroplasty) may be used for the treatment of pain related to vertebral compression fractures.
Trigger point injections
These injections may be considered for treatment of myofascial pain
Nerve blocks right)
Some common sites for injection of right)myofascial trigger points
Trigeminal ganglion block right)
Unilateral facial pain such as perineural tumour invasion
Facial pain from multiple sclerosis
cardiac conduction problems (heart block) - arrhythmias during trigeminal ganglionolyis
Tumour invasion of the skull base distorts the anatomy
Patients who cannot lie still and co-operate fully with the procedure
Specific complications right)
● Haematoma in cheek
● Facial numbness
● Dysaesthetic facial pain (anaesthesia dolorosa)
● Loss of corneal sensation
● Motor deficit after mandibular lesioning
● Carotid artery puncture
● Intrathecal injection
● Retrobulbar haematoma
● Oculomotor weakness
● Cavernous sinus fistula
● Perioperative cardiac arrhythmias.
Specific complications right)
● Carotid puncture with haematoma
● Recurrent laryngeal nerve block occurs in 10% patients and produces hoarseness. Patients should eat or drink cautiously for several hours afterwards. Swallowing should be assessed with cool water first
● Brachial plexus block
● Phrenic nerve block
● Intravascular injection will produce a severe and rapid toxic reaction, as the vertebral artery will carry local anaesthetic directly to the brain
● Aspiration prior to injection cannot guarantee that the needle is not subarachnoid as the dura can act like a flap valve on the end of the needle. Injection into a dural sleeve will produce a ‘total spinal’
● Pleural puncture and pneumothorax are potential problems if the needle is either sited too low or directed caudad
● Osteitis and mediastinitis may occur after oesophageal puncture.
Sphenopalatine right) ganglion block – head and neck cancer pain
Lumbar psoas compartment block - Unilateral pain in the hip or leg, such as hip pain from fracture or Metastases
Paravertebral block - Nerve invasion from tumour, Radicular pain from spinal degeneration, Radicular pain from vertebral collapse
Intrapleuralblock - Unilateral chest wall pain over several levels such as due to malignancy, multiple rib fractures
Intercostal block - Rib fractures, Chest wall pain, Rib metastases
Brachial plexus block - Unilateral arm pain due to malignancy, radiation plexitis
Superior hypogastric plexus block - Pelvic pain due to gynaecological, distal gut, or urological malignancy
Presacral ganglion imparblock - Pelvic pain due to gynaecological, distal gut, or urological malignancy, Perineal pain.
Lumbar sympathetic block - Unilateral or bilateral ischaemic leg pain, Pain mediated via the sympathetic nervous system, Bilateral sympathectomy for rectal tenesmus
Epidural or caudal block right)- Back pain due to vertebral problems such as metastases, osteoporotic collapse, Coccydynia, Unilateral or bilateral leg pain such as radicular pain from degeneration or malignancy.
Intrathecalneurolytic injection of sacrococcygealnerve roots –
Pain affecting a limited number of dermatomes (sacral and coccygeal segments are the most appropriate), Perineal or rectal pain such as that from vulvaltumours or fungating rectal tumours, Patients who already have a urinary catheter and stoma do not risk incontinence
Chemical right)denervation – phenol
Phenol(6–12%) appears to coagulate proteins.
Phenol neurolytic mixture is a combination of carbolic acid, phenicacid,phenylicacid, phenyl hydroxide, hydroxybenzene, and oxybenzene. It is prepared in water or in glycerine.
Glycerine + phenol = slow diffusion , hyperbaric
Water + phenol = much more neurolytic
A concentration of at least 7–8% is needed for neurolysis.
It may take 24–48 hours after injection for the full effect to be
Larger systemic doses of phenol (>8.5 g) are toxic leading to seizures and cardiovascular and central nervous system depression.
Ethyl right)alcohol (50–100%) causes extraction of membrane phospholipids and precipitation of lipoproteins in axons and Schwann cells.
For peripheral nerve blocks, alcohol may be given undiluted, but for sympathetic blocks in which large volumes are injected, it is given in a 1:1 mixture with bupivacaine.
Glycerol is used for neurolysis of the trigeminal ganglion. It is considered a mild neurolytic; however, like all of these agents there is potential for adverse effects on motor function and sphincters
Cryoneurolysis right) or cryoablation
The temperature at the tip of a cryoprobe rapidly drops as gas (carbon dioxide or nitrous oxide) at a high pressure is allowed to expand.
The probe tip, which can achieve temperatures of –50 to –70°C, is introduced via a 16- to 12-gauge catheter.
Electrical stimulation (2–5 Hz for motor responses and 50–100 Hz for sensory responses) helps confirm correct positioning of the probe.
Cryoablation may be used in the care of selected patients (e.g., postthoracotomy pain syndrome, low back pain [medial branch], and peripheral nerve pain).
Botulinum toxin may be used as an adjunct for the treatment
of piriformis syndrome.