Pain in oncology

Etiology of cancer pain[edit | edit source]

Direct tumor invasion (70%) - skeletal involvement, invasion or compression of nerve structures, obstruction of hollow organs or outlets, invasion of blood vessels or obstruction of blood vessels, ulceration, mucosal infiltration.
In connection with treatment (20%) - diagnostic and staging examinations, postoperative pain, radiation pain (stomatitis, esophagitis, spinal cord injury), after chemotherapy (neuropathic, stomatitis, hemorrhagic cystitis, ...).
In a more distant context (below 10%) - paraneoplastic pain (hypertrophic osteoarthropathy), pain associated with low performance and self-sufficiency (bedsores, constipation), ...
Esophageal cancer, CT scan with contrast, coronal image
Pain of non-tumor origin (10%).

We determine the location, character, propagation, and changes in intensity over time.
Intensity:
- visually analog curve - a line 10 cm long, its left end indicates "no pain" and the right "worst imaginable pain", the patient marks the value on the curve that corresponds to his pain;
- Melzack scale - the patient classifies pain as mild, uncomfortable, strong, cruel, unbearable.

The procedure varies according to the type and intensity.
In the first place, it is necessary to treat the cause of the pain.
Palliation leads to a reduction in analgesic consumption in many tumors (we gain temporary control over the tumor).
We achieve symptomatic relief in 80% orally, in 10% the intervention of an anesthesiologist or surgeon is necessary, in about 10% it is not possible to achieve optimal relief.
The optimal pain relief is a reduction in the intensity of approximately 90%.
Analgesics
Complete removal is usually only possible at the cost of significant patient sedation.

First grade - NSAIDs (Non-steroidal anti-inflammatory drugs) and analgesics-antipyretics.
Second grade - weak opiates (codeine, dihydrocodeine, propoxyphene, oxycodone, tramadol).
Third grade - strong opiates (morphine, fentanyl, buprenorphine).
- Anticonvulsants and muscle relaxants are effective in neuropathic pain.
- Neuroleptics increase the pain threshold.
- Antidepressants eliminate painful psychosyndrome, fear, paraesthesia, improve sleep.
- The combination of opiates and NSAIDs has an additive effect.
- The antiedematous effect of corticoids, also bisphosphonates, is used for bone metastases.
- Analgesics are given at fixed intervals, the next dose is given before the effects of the previous one subside.
- We preferably use p.o. treatment.
- External analgesic radiation can also be used for bone metastases, and brain meta can also be affected.
- Use of 89Sr (strontium) - useful in multiple skeletal metastases, in functional marrow (the main emergency is thrombocytopenia).
- Pharmacologically uncontrollable pain - epidural or subarachnoid anesthesia, neurolysis, or neurosurgery.

BENEŠ, Jiří. Studijní materiály [online]. ©2012. [cit. 25. 4. 2012]. <http://jirben2.chytrak.cz/materialy/onko_JB.doc>.