Cancer Pain Management: Nerve Blocks, Pumps and Opioids

Cancer pain management, in the practice of Dr. Ashu Kumar Jain, Chief – Pain Medicine & Palliative Care, Artemis Hospitals, Gurugram, India, follows a set order: sympathetic nerve blocks or ablation where a target exists, opioids with paracetamol and a neuropathic agent where it does not, and intrathecal pumps or spinal cord stimulation when drugs and blocks fall short. The same tools serve pelvic, visceral and sickle cell pain.

Pain from cancer, from the pelvic organs and from damaged nerves often outruns what tablets can control. It is also where the choice of drug carries real risk: too little leaves a patient in distress, the wrong drug for the wrong pain creates dependence. Each tool has a defined place, and the order in which Dr. Jain reaches for them matters as much as the tools themselves.

Sympathetic nerve blocks for cancer pain

Sympathetic nerve blocks interrupt the nerves that carry pain from the internal organs. Cancer pain management is a large part of Dr. Jain's practice, and sympathetic procedures are central to it, particularly for international patients. Three levels of the sympathetic chain are used:

• [T2-T3 sympathectomy](/articles/trigeminal-neuralgia-radiofrequency-ablation-vs-surgery) for cancer-related pain in the upper limb.
• Splanchnic nerve RFA for upper abdominal cancers such as gallbladder and pancreatic cancer.
• Lumbar sympathectomy for pain in the lower limb.

Splanchnic nerve ablation for pancreatic and upper abdominal cancer pain

For upper gastrointestinal cancers, Dr. Jain places two electrodes and performs radiofrequency ablation of the splanchnic nerves. In his experience it gives, on average, more than a year of pain relief. The same procedure helps patients with chronic pancreatitis that is not settling, and survivors of pancreatic cancer who continue to have pain after their cancer has been treated.

Its key technical advantage is visible on the lateral view: the needles never enter the abdomen. They run along the vertebral body, in the retrocrural space. That matters when the abdomen itself is hostile. In patients with ascites or multiple abdominal metastases, where a coeliac plexus block (an injection into the nerve network in front of the aorta) cannot be performed, a splanchnic nerve block or RFA still gives good results.

Pelvic pain treatment: superior hypogastric plexus block

For pain from the pelvic organs, whether from pelvic cancer, endometriosis, irritable bowel syndrome or interstitial cystitis, Dr. Jain uses a superior hypogastric plexus block followed by neurolysis. Long spinal needles (15 cm) are placed to reach the plexus.

Two cases show how severe these presentations can be:

• A young woman had such severe pain after each bowel movement that she had stopped going to the toilet, and had been advised to have an ileostomy. After a superior hypogastric plexus procedure she recovered fully.
• Days before the session, Dr. Jain's team treated a patient who had suffered severe rectal pain after defecation for many years. A superior hypogastric plexus block followed by neurolysis relieved it completely.

In his experience, gynaecological pain, including endometriosis, responds in the same way.

Coccydynia and perineal pain treatment

Ganglion impar RFA for tailbone pain

Coccydynia, or tailbone pain, is common, and its sufferers move from hospital to hospital. In Dr. Jain's experience, surgeons are reluctant to operate because the infection risk in that area is high. He uses radiofrequency ablation (RFA) of the ganglion impar, a small nerve cluster in front of the coccyx, and puts its success rate at 90 to 95 per cent.

• In 80 per cent of patients, a single treatment gives 18 to 24 months of relief.
• Around 20 per cent may need a repeat procedure, which is straightforward to perform.
• Dr. Jain demonstrated the block in a patient with a displaced coccyx.

The ganglion impar block can also work for perianal, vaginal and rectal pain, and neuropathic tenesmus.

Pudendal neuralgia and other perineal nerve pain

Testicular, penile, vaginal and perineal pain in both men and women can have a neuralgic cause. Anteriorly it may come from the ilioinguinal or genitofemoral nerve; posteriorly from the pudendal nerve or the ganglion impar. Each can be blocked or treated with pulsed radiofrequency (PRF), a form of radiofrequency treatment that modulates the nerve rather than burning it.

One of Dr. Jain's patients had penile pain so severe and so damaging to his marriage that he asked for his penis to be amputated. Bilateral pudendal nerve PRF relieved the pain. During the procedure, the patient jumped the moment sensory stimulation was switched on, because it reproduced his pain exactly: confirmation that the electrode was on target.

Intrathecal pumps and spinal cord stimulation for refractory pain

When drugs and blocks fall short, Dr. Jain uses two implantable devices: intrathecal pumps for spasticity and pain, and spinal cord stimulation for neuropathic pain.

Intrathecal pumps

An intrathecal pump is implanted in a pocket in the abdominal wall and connected to a catheter placed in the intrathecal space. Dr. Jain uses it for two problems:

• Spasticity. Shortly before the session, his team implanted a pump for a patient with severe spasticity after a spinal cord injury. With intrathecal baclofen, the patient settled on a stable dose and the rigidity resolved. Because intrathecal baclofen acts directly on the spinal cord, it works at microgram doses, a small fraction of the oral dose.
• Pain with spasticity. A woman with an intramedullary tumour at T6 developed gross spasticity and severe pain after surgery. A pump delivering morphine and baclofen combined was implanted. Within 24 hours she was free of pain and spasticity and comfortable.

Pumps delivering morphine, alone or in combination, are also used for pain such as failed back surgery syndrome.

Spinal cord stimulation

Spinal cord stimulation, which delivers mild electrical current to the spinal cord through an implanted lead, is used for neuropathic pain, ischaemic pain, complex regional pain syndrome and phantom limb pain. Dr. Jain showed a patient with brachial plexus injury who obtained very good pain relief, and a young patient who had become dependent on drugs because of his pain and was relieved of it after a paddle lead was placed surgically.

Opioids for cancer and sickle cell pain

Why NSAIDs are not enough

Visceral pain, which includes much cancer pain, travels with the sympathetic nervous system. Conventional painkillers such as diclofenac are rarely enough on their own for severe cancer or sickle cell pain, and high doses of NSAIDs can damage the kidneys. In Dr. Jain's teaching, sickle cell pain is managed on the same lines as cancer pain: with opioids, in combination with a neuropathic agent and paracetamol. Strong opioids sit at the top of the WHO analgesic ladder, and he regards them as potent and safe for these patients. Tolerance and dependence can still develop with any long-term opioid use, so treatment needs regular review.

The options

Where a specific target exists, such as a nerve involved in the pain, he treats it with an intervention. Otherwise management is opioid-based, with a choice of:

• tramadol;
• tapentadol;
• buprenorphine, as patches or sublingual tablets;
• morphine;
• fentanyl patches.

Each is combined with paracetamol and a neuropathic medicine.

How pain in a sickle cell crisis is managed

A patient in sickle cell crisis needs hospital admission. Management covers hydration, oxygen if saturation is low and monitoring for acute chest syndrome, with intravenous opioids given promptly for pain, since NSAIDs such as diclofenac are not enough on their own in a crisis. Dr. Jain uses patient-controlled analgesia (PCA) with opioids during the crisis, then switches to patches or oral medication once the patient has stabilised.

Should opioids be used for chronic back or knee pain?

Not in Dr. Jain's practice. For chronic low back pain, knee pain and similar non-cancer musculoskeletal pain, opioids are habit-forming and he never prescribes them. Doctors asked him why, if the receptors work the same way, opioids should be treated differently in sickle cell disease; his answer is in the live discussion from the masterclass. He points to the experience of the United States and several European countries, where routine opioid prescribing for back pain has caused serious harm. For chronic non-cancer pain, long-term opioid therapy offers limited benefit relative to its risks of dependence and overdose, and current guidelines favour non-opioid treatment first.

Cannabis-based medicine is a different case. He regards it as safer than typical opioids and among the safest options for chronic non-cancer pain, including musculoskeletal pain, but, as he noted, it is not approved in India. Evidence for cannabinoids in chronic non-cancer pain remains limited.

Who can prescribe opioids, and how supply is controlled

Supply of controlled analgesics is a practical problem in some countries, Zambia among them, and access rules differ widely: some countries do not even allow patients to carry pregabalin or gabapentin across their borders. In India, opioids are scheduled drugs. As Dr. Jain described the controls in his practice, the system has three layers:

• Who can prescribe. In his hospital, prescriptions come from a pain physician, an anaesthesiologist or a neurologist rather than a general physician, ENT specialist or general surgeon; under the 2015 NDPS rules, essential narcotic drugs are prescribed by registered medical practitioners at Recognised Medical Institutions.
• Morphine and fentanyl. The hospital must hold a government licence to keep a defined quantity in stock. Prescriptions are written and stamped on a special designated form, and patients bring back a chart of their consumption, which the hospital submits to the drug controller.
• Tramadol, tapentadol and buprenorphine. No special licence is required, but a valid, stamped prescription from a competent doctor is.

Under the Narcotic Drugs and Psychotropic Substances (Amendment) Act 2014, access to essential narcotic drugs such as morphine runs through Recognised Medical Institutions.

Cancer pain management: matching the tool to the pain

Taken together, Dr. Jain's approach to the hardest pain follows a clear order of preference:

• Find a target if one exists. A sympathetic plexus, the ganglion impar, the pudendal nerve or the nerves of a joint can each be blocked or ablated, often giving relief measured in months or years rather than hours.
• Use opioids where they belong. Cancer pain and sickle cell pain are managed with opioids alongside paracetamol and a neuropathic agent, with intravenous PCA in a crisis.
• Keep them away from where they do not. Routine back, knee and other musculoskeletal pain should not be treated with opioids.
• Escalate to devices when drugs and blocks fall short. Intrathecal pumps and spinal cord stimulators address spasticity and neuropathic pain that nothing else controls.

Palliative care in Dr. Jain's service also extends to end-of-life symptom management in the patient's home. The wider framework, including the two-week limit on NSAIDs and the criteria for surgical referral, is set out in Advances in Chronic Pain Treatment: A Complete Guide.