Morphine pump-an ideal choice of analgesic treatment for cancer pain patients
A significant proportion of advanced cancer patients are suffering from severe pain all over the body, which seriously affects the patients’ life and confidence in fighting against tumors, depletes the patients’ physique and makes their immunity against tumor cells decrease rapidly. Internationally, analgesic treatment and anti-tumor treatment for patients with advanced cancer pain are in the same important position. A lot of studies have shown that good analgesia can significantly enhance patients’ physical fitness and immunity, improve patients’ confidence in treating tumors, multiply patients’ survival time, and let patients “survive with cancer” without pain. At present, the treatment of advanced cancer pain in China is mainly based on oral or intramuscular morphine, but the analgesic effect is poor and there are many side effects, so it cannot provide good analgesia for advanced cancer pain patients.
The intrathecal implantable drug infusion system, i.e. morphine pump, can provide strong analgesia with few side effects and does not even affect the patient’s daily life, which is currently recognized as the best solution for the treatment of advanced cancer pain internationally. Morphine pumps are divided into intrathecal morphine pumps and epidural morphine pumps, but the former is expensive and its large-scale application in China is obviously limited; while epidural morphine pumps are inexpensive and very suitable for China’s national conditions.
Morphine pump – the biggest advantages of this new pain relief method are high safety, small trauma, remarkable efficacy, simple operation, good patient tolerance and few complications, which is suitable for all patients with cancer pain and chronic intractable pain who are not treated by other traditional treatment methods and drug therapy, or cannot tolerate drug side effects.
People are not unfamiliar with analgesics such as painkillers and fenbid, but few people know about morphine pump – “central target-controlled infusion system implantation”. This new technique for the treatment of cancer pain and chronic intractable pain has been widely carried out in developed countries such as Europe and the United States, and has achieved satisfactory results. The World Health Organization (WHO) has listed opioids as the primary drug for the treatment of malignant pain. However, large amounts of oral or intravenous use of such drugs can rapidly produce drug resistance and drug dependence (i.e., addiction), and intolerable side effects, such as nausea, vomiting, abdominal distention, difficulty urinating, constipation, etc.
In the 1970s, scientists discovered that an opioid receptor exists in the brain and spinal cord of animals. This receptor has an affinity for opioids, and the combination of the two can block the transmission of pain information and play a pain-relieving role. So a small amount of morphine was injected into the cerebrospinal fluid in the vertebral canal, so that the drug binds directly to the receptor in the brain and spinal cord, producing a potent analgesic effect, and this method can also be repeatedly administered, and once the drug is stopped, neurological function can be fully restored. On this basis, the implantation of central target-controlled infusion system (morphine pump) began to be used in pain clinics in the late 1980s, providing a new way for the efficient application of morphine-based drugs for the treatment of chronic pain.
The so-called implantable epidural morphine pump is a catheter implanted under the skin, with one end leading to the spinal epidural cavity and the other end connected to a drug delivery pump buried under the skin, and the drug is fed into the spinal epidural through the drug delivery pump. Compared with traditional analgesic methods, the amount of drugs used in the implantable epidural infusion system is very small (only a few tens to a few hundredths of traditional drug delivery methods), but its analgesic effect is very strong, with few side effects, and patients can walk freely after treatment, and their daily life such as eating and living is not affected. This method is very traumatic and inexpensive, and patients can go home after 3-5 days of hospitalization and can take care of their daily lives. In contrast, the traditional analgesic methods such as intramuscular injection of morphine require long-term hospitalization because of many side effects, high cost and poor analgesic effect, which seriously affects the quality of life of patients and the ability of the body to resist tumors.
Small dosage of morphine with high analgesic effect
Central target-controlled infusion system implantation is a special catheter placed in the subarachnoid space (a gap in the spinal canal), and then a pain pump – a programmable morphine slow-release pump – is implanted under the patient’s skin (mostly placed in the lower abdomen), and the catheter is connected to the pump by means of a subcutaneous tunnel. The pump’s infusion system delivers the drug into the subarachnoid space at a continuous, slow, and uniform rate. It achieves analgesia with only 1/300th of the oral dose and does not create a dependence on morphine. In addition, the amount of morphine output can be remotely adjusted outside of the body according to the degree of pain and the pattern of attacks, so as to meet the analgesic needs of different patients to the maximum extent. The drug reservoir implanted under the skin can be repeatedly injected and the concentration of the drug can be changed.
Direct action with few side effects
When morphine is administered orally or intravenously for pain relief, most of the drug is dispersed throughout the body, while only a small amount of morphine that enters the blood circulation can enter the brain through the blood-brain barrier to exert pharmacological effects. On the contrary, subarachnoid application of morphine can directly act on the opioid receptors in the spinal cord to achieve the purpose of analgesia, and only a very small amount of the drug enters the systemic blood circulation. Therefore, subarachnoid injection of morphine has a much stronger analgesic effect compared with oral or intravenous morphine, while the drug dosage and side effects are much smaller.
Improve the quality of life of pain patients
The application of morphine pump can greatly improve the quality of life of patients, as shown by.
①The intensity of pain is reduced by 70% to 80%;
②According to statistics, 94% of the pain patients gave up or left social activities due to pain, while more than half of the patients rejoined social activities after treatment, and individual patients also resumed work;
③88% of the patients were in despair and depression before treatment, and 67% of the patients were satisfied with their current state after treatment;
④81% of the patients felt that their quality of life had improved after the treatment, and 92% were satisfied with the treatment;
⑤ About 36% of the patients stopped taking other pain medications after the operation.
Our department carries out implantable epidural morphine pump implantation for the treatment of advanced cancer pain, including advanced pancreatic cancer, rectal cancer bone metastasis, lung cancer bone metastasis, liver cancer abdominal metastasis and many other advanced cancer pains, so that many patients are free from the torture of cancer pain and live painlessly with cancer. The clinical application of our department shows that: implantable epidural morphine pump can provide strong analgesia and obviously enhance patients’ courage and confidence in life; patients can completely take care of themselves in daily life and their physical quality is obviously enhanced, and their survival period is several times longer than that of patients with advanced cancer pain who use traditional analgesic methods.
In China, most people are aware of the “three-step” treatment plan for advanced cancer pain. However, clinical facts show that the traditional “three-step” treatment plan is far from providing satisfactory analgesia to patients with advanced cancer pain. Patients with advanced cancer pain need a further “fourth-step” treatment plan, and implantable epidural morphine pump is undoubtedly one of the best options for “fourth-step” treatment plan.