1. Overview of palliative medicine
Significant changes in cure rates for patients with cancer and AIDS are not expected to occur in the next 10 years, and it is indisputable that many diseases that remain incurable cause intense suffering. Palliative medicine involves not only patients with advanced cancer, but also AIDS, neuropathic pain, and other lifelong intractable pain control. Because the infectious nature of AIDS and the singularity of symptoms of neuropathic pain differ greatly from those of patients with advanced cancer, the principles of medical care intervention are very different, and palliative medicine is usually referred to only for patients with advanced cancer.
It is now believed that the greatest needs of patients at the end of life are comfort, dignity, a sense of usefulness during their life and respect for their personality and reaffirmation of life. Therefore palliative medicine preserves life but does not delay the life course of the dying patient. Every patient with advanced cancer is considered to have somatic, spiritual-psychological, social and religious needs and needs of other problems, each of which should be given full and equal attention.
Tracheotomy, laser, etc. to relieve respiratory distress, i.e. to become palliative care for advanced bronchial obstruction, surgical stents to relieve biliary and ureteral obstruction, radiofrequency ablation, chemotherapy to necrotize or shrink symptom-causing cancer masses, radiotherapy to relieve bone metastatic pain or choking sensation in patients with superior vena cava obstruction, etc. are all elements of palliative care that have the potential to relieve suffering and improve the remaining quality of life, and are not motivated by They have the potential to relieve pain and improve the quality of remaining life, rather than being an attempt to force a longer or shorter life.
2. Pain profile of patients with advanced cancer
Most cancers occur in older patients, but those who die at age 35 and those who die at age 70 may have similar levels of pain. Of 218 patients with progressive cancer in southern Israel, 77% had real pain, of which 75% were treated with medication, but 81% were treated inappropriately, and 64% had moderate to severe limitations in their lives. The results also showed differences in the evaluation of patients’ pain by different investigators, e.g., internists usually evaluated pain levels more highly but underestimated the impact on daily life.
Complex pain must be evaluated in order to optimize treatment. A survey in Kentucky, USA, showed that 71% of 141 patients with advanced cancer complained of pain in the month before the survey, 158 significant pain points in 100, and 88% complained of up to 2 pain points. Pain caused by the tumor itself was the most common cause (68%). The nature of pain was 48% for continuous pain and 52% for intermittent pain. 75% of continuous pain had penetrating pain episodes, 30% of these people had frequent pain, 26% had occasional pain, 16% had continuous pain and 16% had pain only at the end of drug dose; 61% of patients with intermittent pain had penetrating pain.
3.The control method of cancer pain
Patients with advanced cancer pain have gradual organism failure, mostly accompanied by severe pain and anxiety, which aggravate loss of appetite and poor sleep, and form a vicious circle with other dysfunctions of the organism to accelerate death. Therefore, pain relief is the key to improve the quality of life. The problem of advanced cancer pain control is complex, and multi-drug therapy is used in treatment to alleviate side effects. Pharmacological pain relief has an important place in the comprehensive treatment of cancer pain patients, which can provide relief for 85% of cancer pain. Successful management is mainly based on the World Health Organization’s three-step medication guidelines.
Due to the side effects of various drugs, pharmacological pain relief has the same dual effect on quality of life as chemotherapy. Effective clinical adjustments include: timely administration of drugs, clinical pain intensification from 23:00 in the evening to 3:00 in the morning, and addition of drugs half an hour before the onset of pain is more effective; necessary suggestive therapy not only reduces pain, but also is necessary for terminal pain; active management of advanced cancer-related symptoms and symptoms of other concurrent diseases such as loss of appetite, nausea and vomiting, dyspnea, hoarseness, cough, difficulty in urination, constipation and other Symptoms; psychotherapy such as talking and soothing and comforting work can promote pharmacological pain relief.
Duke Dickerson surveyed 50 internists in 25 countries on five continents, and the approval rate was higher than 16%. These drugs are opioid analgesics: morphine (normal release), morphine extended-release, patch fentanyl, methadone, codeine; non-opioid analgesics: paracetamol, diclofenac, tramadol; antiemetics: antiemetic; phenylephrine anxiolytics: midazolam, valium; corticosteroids: dexamethasone; laxatives: lactulose, senna; antipsychotics: haloperidol; antidepressants: amitriptyline anticonvulsants: clonidine; antispasmodics: scopolamine butyrate; antifungals: mycoplasma; progestins: megestrol acetate; slightly less recognized drugs are H2 antagonists: ranitidine; antihistamines: secludine. The core medications thus recommended for pain control are extended-release morphine, methadone, amitriptyline, and diclofenac combination.
Many patients treated with opioids may still experience a state called “sudden onset pain”. Additional doses of 10-20% of the daily total can relieve this pain. Light laxatives are routinely used when prescribing opioid analgesics, and Valium is often used as an adjunct to morphine for skeletal muscle spasm pain. The development of different routes of morphine administration is also a clinical need, and excellent results have been reported for rectal administration of long-acting stable-release morphine tablets in a 72-year-old patient with prostate cancer.
Adverse effects of fentanyl transdermal patches mainly include nausea, vomiting, dizziness and constipation, most of which are relieved with time. Methotrexate can be given to prevent nausea and vomiting, and in severe cases, central antiemetics (e.g., Endanserone hydrochloride) are used with good results. Less severe constipation is usually improved by drinking more water, eating more fibrous food and being more active. In severe cases, the use of light laxatives (e.g. senna, fruit guide tablets) is effective. Methadone is considered a good alternative to mu-opioid agonists, with good oral and rectal absorption rates, high analgesic efficacy at low cost, no accumulation of active metabolites in patients with renal failure, and control potential for pain that does not respond to morphine, hydromorphone, and fentanyl.
Eighty to 90% of patients with advanced cancer have cachexia and anorexia, with most patients showing improvement with progesterone, dexamethasone, prednisone, dronabinol, and methotrexate. When end-stage disease has two or more symptoms, the most popular medications considered in terms of type of administration are antipsychotics, especially haloperidol, for prosopagnosia and antiemesis. Haloperidol is the drug of choice to control nausea and vomiting caused by opioids, radiation therapy, and most chemotherapy.
Non-steroidal anti-inflammatory drugs (NSAIDs) may be very useful when pain involves an inflammatory process, especially pain involving bones, muscles, and soft tissues. Patients with metastatic bone disease also require opioids in combination with NSAIDs for symptomatic relief.
Effective pain control requires a multidisciplinary approach to management. A Scottish survey of palliative medicine practitioners showed that the more socially underdeveloped the area, the less formal experience of managing cancer pain patients and the right attitude towards palliative medicine consultation. Approximately 8% of cancer patients have refractory pain and require anesthesia-related therapeutic techniques for pain management to achieve optimal outcomes. 72% of respondents felt that anesthesiologists provide the necessary skills and that more consultation with anesthesiologists would be beneficial. However, in practice, more than half of the respondents used anesthesia techniques to manage pain less than four times in a year, and one quarter of the respondents did not work with an anesthesiologist on pain management in a year.
Subarachnoid anhydrous ethanol, phenol glycerol block or epidural drug injection block are neurodestructive approaches that can effectively control most cancer pain. For limited-range cancer pain, nerve-destructive drugs can be applied to selectively block the nerve roots and nerve trunks associated with them to relieve cancer pain. All of these techniques can significantly reduce the amount of systemic opioid medication, but all require an experienced anesthesiologist to operate.
Abdominal plexus ethanol block is particularly effective for pancreatic cancer pain. Sympathetic ganglion block is effective for bone metastasis pain in the appropriate region. All of these operations need to be performed under X-ray fluoroscopy.
Permanently placed microcomputerized pumps for subarachnoid block with opioids are more costly but very effective and are especially valuable for intractable cancer pain where all conventional methods are unsatisfactory. Continuous epidural injection of drugs to control cancer pain is also becoming more and more widespread. The injection of morphine, fentanyl and tramadol into the epidural cavity by patient-controlled analgesia (PCA) pump or slow-release pump is rapidly and satisfactorily effective and can control cancer pain for a long time.
The pain relief rate of radiotherapy for common breast cancer, lung cancer, prostate cancer, thyroid cancer and bone metastases of bone marrow cancer can reach more than 80%. Chemotherapy can be considered for multi-site pain that cannot be relieved by local palliative radiotherapy. When tumor growth is sensitive to chemotherapy, tumor-induced pain can also be relieved by chemotherapy in general.
The growth of advanced breast cancer, prostate cancer and other cancerous tissues are significantly affected by hormones, and the same hormones are also effective for pain caused by cancerous tumors. Exogenous hormone levels must exceed endogenous hormone concentrations, which will certainly cause complex changes in endogenous hormone secretion in the body.
Neurorelaxation, percutaneous or open anterior lateral spinal column dissection, and stereotactic central nerve cautery, which are destructive procedures, are also effective in controlling some of the cancer pain.
The principles of palliative medicine in the future should be to achieve global standardization of understanding; deepen the application of the World Health Organization three-stage ladder analgesic therapy, and continuously introduce new advances in related disciplines. analgesia with SC salmon and eel calcitonin, new therapies in combination and rotation of opioids, advances in analgesia with neuropathology, the use of NSAIDs especially highly selective cyclooxygenase 2 (COX2) inhibitors, substance P receptor antagonists for antiemetic and antidepressant effects are among the most recent approaches that may be of value for clinical use. The use of gene transfection to obtain permanent chromophobic tissue for spinal cord transplantation for analgesia is expected to solve the problem of difficult access to autologous chromophobic tissue.
Morphine 300 mg orally, 100 mg intravenously, 10 mg epidurally, and 1 mg subarachnoid has the same analgesic effect, but the depressive effect on the mind and the effect on quality of life are apparently quite different. These differences show good prospects for regional analgesia in future cancer pain control. It is the unremitting pursuit of palliative medicine practitioners to enrich and improve the development of palliative medicine from different perspectives and to achieve the goal of making cancer patients pain-free worldwide as soon as possible and as early as possible.