Under-treated cancer pain is widespread, causing at least 5 million cancer patients worldwide to suffer from pain every day. Each year, 50% of adults and children treated for cancer worldwide have pain, and 50% of those with cancer pain have moderate to severe pain and 30% have unbearable severe pain. Seventy percent of patients with advanced cancer have pain. There are more than 2.2 million new cancer patients in China every year, more than 6 million patients under treatment every year, and 1.6 million cancer deaths. 50%-61% of these patients have different degrees of pain, and there are more than 1 million people who endure cancer pain every day, and the pain caused by cancer and the accompanying depression have reduced the quality of life, so cancer pain treatment is a global problem.
Cancer pain
The pain of cancer patients is complicated and WHO classifies it as follows
1. directly caused by tumor development and invasion
2. related to tumor but not directly caused by it.
3. caused by tumor treatment.
4.Pain not related to tumor. The survey results show that the above categories account for 78.2%, 6%, 8.2% and 7.2% respectively, and 6.7% of the patients are caused by more than two causes. It is self-evident that for pain caused by 1 and 2, anti-tumor treatment can relieve the pain to a certain extent, so it should be anti-tumor plus analgesic treatment; while for pain caused by 3 and 4, analgesic and other related adjuvant treatments are needed. Here, we should not ignore that some patients’ own factors may also be the cause or aggravation of pain. For example, patient sensitivity, anxiety and fear of disappointment before the end of life can lead to a lower pain threshold.
Definition of pain and assessment of pain level
The International Association for the Study of Pain defines pain as an unpleasant sensory and emotional sensation accompanied by existing or potential tissue damage. Pain is often subjective, and each person learns the exact words to express pain early in life through the experience of injury. It is undoubtedly a local or global sensation in the body, and it is also an unpleasant emotional sensation.
Although pain is subjective, it is important to assess pain intensity quantitatively. 2005 National Comprehensive Cancer Network guidelines classify pain according to pain intensity as 1 to 3, 4 to 6, and ≥ 7. Pain level evaluation can also be done using VRS criteria, which are classified into 4 levels according to the patient’s complaints of pain. level 0: no pain.
Grade Ⅰ (mild): mild pain, tolerable, generally does not affect sleep, basically can live normally.
Grade Ⅱ(moderate): significant pain, not tolerable, request for painkillers, sleep disturbed.
Grade III (severe): severe pain, unbearable, requiring narcotic analgesic drugs, sleep is seriously disturbed, may be accompanied by irritability, irritability and other plant nervous disorders or passive body position.
Standardized pain treatment
WHO three-step pain relief program for cancer. The use of analgesic drugs alone, if applied correctly, can result in satisfactory pain control in 90% of cancer patients. The principles of standardized pain treatment include: effectively eliminating pain; limiting the occurrence of adverse drug reactions; minimizing the psychological burden caused by pain and treatment; and comprehensively improving the quality of life of patients. The key to standardized treatment is to follow the three-step treatment principle.
1, oral administration: the advantages of the oral route of drug administration are simple, convenient, economic, not dependent on others, and unrestricted activity. Especially for opioids, proper oral administration rarely produces mental dependence (addiction) or physical dependence (<1%). This is because what cancer patients require is analgesic effect rather than mental enjoyment. Meanwhile, oral morphine does not meet the needs and effects of drug addicts.
2.Dosing according to the ladder: It means that after the correct evaluation of the nature and causes of cancer pain, the corresponding analgesic should be selected appropriately according to the patient’s pain degree and causes, i.e. for patients with mild pain, analgesics of antipyretic class such as anti-inflammatory pain, fenbid, aspirin, prednisolone, paracetamol, aminoglutethimide, danine, etc. should be mainly used; for moderate pain, weak opioids such as codeine, Diclofenac sodium, Tramadol, Crotal tablet (the main ingredients are cobra toxin, tramadol hydrochloride and ibuprofen), Xinhuang tablet (composed of swelling wind, panax ginseng, niuhuang, pearl powder, etc.), etc.
If the pain is severe, strong opioid drugs such as mescaline, oxycontin, fentanyl transdermal preparation, mefecam, methadone, etc. should be used. Currently, cancer pain treatment includes surgical treatment, pharmacotherapy and psychotherapy, and since pharmacotherapy is the most commonly used in clinical practice, it is called the “mainstream of pain treatment”. Using the right drug, the right dosage and the right time can make most patients achieve effective analgesia. The three-step treatment principle for cancer pain is not only applicable to patients with terminal cancer, but also to every stage of the cancer pain process, making it possible to apply strong opioids to relatively early cancer pain.
Frequently selected adjuvant drugs include: antidepressants (commonly used are tricyclics such as amitriptyline, desipramine and nortriptyline, etc.). Available options are.
1. Xipomol 20mg once daily.
2. Celete 20mg, 1 time daily.
3. fluoxetine 20 mg once daily.
4. Boloxin 25 mg twice daily.
5.Amitriptyline 25-50 mg once a night. The improvement of depressed mood will help the treatment and recovery of somatic diseases; anticonvulsants (carbamazepine, phenytoin sodium and the new anticonvulsant gabapentin), which are effective in the treatment of nerve injury pain.
In short, the current domestic dozens of new analgesics, each with its own characteristics, can basically meet the needs of various patients.
Mild pain: non-opioid analgesics ± adjuvant drugs
Moderate pain: weak opioids ± non-opioid analgesics ± adjuvant drugs
Severe pain: strong opioids ± non-opioid analgesics ± adjuvant drugs
3. Timely dosing: painkillers should be given regularly (once every 3-6 hours), rather than on demand, i.e. only when the pain is present. If the patient’s pain is not relieved or even worsens during treatment, the dose of a single dose should be increased, not the number of doses. It is safer and more effective to use painkillers in time, and the strength and dose of drugs required are also the lowest.
4.Individualization of medication: that is, attention should be paid to the actual efficacy of specific patients. The dose of painkillers should be from small to large according to the patient’s needs until the pain disappears. And the dosage should not be controlled too strictly, resulting in underdosing.
During the treatment process, the treatment of psychological and mental problems should not be neglected. The research results show that depression of advanced patients is significantly and positively correlated with the degree of pain, indicating that the more severe the pain is, the more severe the psychosomatic symptoms tend to be. It can be seen that pain experience is a mind-body complex product. When dealing with pain in advanced cancer patients, in addition to therapeutic measures such as drugs, psychological factors intervention and antidepressant anxiety treatment should also be emphasized, which can increase the analgesic effect. For advanced cancer patients with refractory pain, the use of implantable self-administered drug infusion pump for pain management is effective, and the patient’s quality of life is improved significantly. Some patients can have pain relief by nerve block, which is mainly applied to localized pain.
Nerve block is the injection of drugs in or near the terminal cerebrospinal ganglia, cerebrospinal nerves, sympathetic ganglia and other nerves. Commonly used are local anesthetics and nerve destruction drugs, such as lidocaine, ethanol, phenol and hypertonic saline, etc. to cause certain nerve destruction for pain relief. In recent years, radiofrequency neurodesis has been used for cancer pain treatment to obtain good results, providing a new option for a few patients with refractory cancer pain.
In general, the “three-step protocol” for cancer pain treatment can relieve most of cancer pain, but for pain that is not effectively treated according to the “three-step protocol”, other invasive treatments can be used, such as neurodestructive treatment, patient-controlled analgesia, intracerebroventricular analgesia, and nerve disruption. Patient-controlled analgesia, intracerebroventricular drug delivery, etc. Self-controlled analgesia can be administered via epidural, intravenous, subcutaneous, or nerve trunk routes, with the first three commonly used. Intracerebroventricular administration is an emerging method for treating cancer pain in recent years, which is characterized by certain efficacy, small amount of medication and long duration of pain relief, and has ideal effects. It is well known that there are abundant morphine receptors around the third ventricle of human brain, which can produce obvious analgesic effect when combined with morphine.
Who are suitable for ventricular administration.
1.People with advanced cancer and ineffective third-step pain relief.
2.Extensive metastatic cancer.
3.People with head and neck tumors invading the skull base.
4.Patients with intractable cancer pain caused by chest tumors and abdominal tumors.
The dose of intracerebroventricular injection of morphine can start with the smallest dose, and the amount of pain medication will gradually increase as the patient needs, but it is best not to exceed 60mg/day. The concentration of morphine sulfate should also be gradually increased. During the patient’s daytime activities, one injection per day is usually sufficient to achieve efficacy.
Pay attention to pain and care for patients
It is believed that with the progress of human civilization and the development of society, people generally recognize that pain must be effectively relieved, and people have brought pain to the height of human rights, and medical workers should raise pain treatment to the same level as disease treatment. In 2001, the Second Asia-Pacific Pain Management Symposium in Sydney issued the call for “eliminating pain as a basic human right”. In 2000, the World Health Organization (WHO) clearly stated that “chronic pain is a category of disease”. In the 9th World Congress on Pain, the new concept of “pain is a disease, not just a symptom” was proposed. At the same time, he pointed out that pain is the fifth vital sign of the human body, equal to pulse, respiration, blood pressure and body temperature. The significance of pain and cancer pain treatment goes far beyond pain relief itself, it can improve patients’ quality of life, ability to work, enjoy recreation, and enable them to function normally in family and society.
Therefore, according to the recommendation of experts, “Pain Awareness Day, Care for Pain Patients” was established. The International Pain Society decided to designate October 11 every year as “World Analgesia Day” from 2004 onwards, in order to better popularize pain knowledge. The Chinese Pain Society designated October 11-17, 2004 as the first “Chinese Analgesia Week”, with the theme of “Pain Relief is the Basic Right of Patients”, in order to accelerate the improvement of pain treatment in China.
Pain control is the sacred duty of medical personnel, who should be highly responsible for relieving pain for patients; pain control is a noble cause, and in order to truly achieve the WHO’s strategic goal of “making cancer patients pain-free by the year 2000” and “making patients pain-free” in China, there is a big difference. Pain control is a noble cause, and in order to truly achieve the strategic goal of “pain-free cancer patients by 2000” and “pain-free patients” proposed by WHO, medical workers have a long way to go and need to make unremitting efforts.