Cancer pain is a problem that is the main focus in the management of cancer patients and can develop from tumor invasion, musculoskeletal pain, visceral pain, the effects of radiation treatment, or neuropathy due to chemotherapy. The use of ketamine given primarily by continuous sub-cutaneous infusion (CSCI) has been used in cancer patients with palliative care as an opioid adjuvant with one or more secondary analgesics. Objective: I reported 3 cases of cancer pain that received intravenous ketamine and the pain improvements were evaluated using Ramsay score. Case: A 46-year-old woman, presented with complaints of pain in the middle abdomen since 1 year and this complaint has worsened in 1 week. The pain is getting worse and can be felt intermittently, especially in the middle of the abdomen and can spread throughout the stomach, and pain is dull in nature. The patient admitted that the frequency of pain felt more frequently since before he was admitted to the hospital. The patient had a history of morphine treatment for approximately 8 months and had received morphine 60 mg per day for approximately 3 months. The patient received a ketamine dose of 100 mg / 24 hours for 3 days and did not report any complaints of side effects. Evaluation of pain improvement occurred after 4 days with stable hemodynamics and a Ramsay score score of 0 (zero). This patient complained of back pain within 3 days. Male 70 years with Squamous Cell Carcinoma Region Hemithorax Dextra Post Wide & Deep Excition. Postoperative pain in the right chest experienced by the patient for about 2 weeks of SMRS. Initially the patient had a lump in the chest since 2 years ago. The lump appears as big as a corn kernels then the longer the lump gets bigger. The lump then became sores and bleeding since 1 year ago.The patient had a history of morphine treatment for approximately 6 months and had received morphine 60 mg per day for approximately 2 months. Patients received a ketamine dose of 100 mg / 24 hours for 1 day, a ketamine dose of 300 mg / 24 hours for 3 days and reported complaints of side effects such as hypersalivation, nausea and vomiting. Evaluation of pain improvement occurred after 2 days at a dose of 300 mg / 24 hours and was maintained for 3 days with stable hemodynamics and a Ramsay score of 0 (zero). This patient complained of back pain within 2 weeks. 52-year-old male with rabdomiosarcoma o / t (R) femur. Patients experienced right thigh pain for approximately 2 weeks of SMRS. Initially the patient complained of a lump on the right thigh since 1 year ago. The lump appears as big as a corn kernels then the longer the lump gets bigger. The lump then became sores and bleeding since 1 year ago. History of weight loss (+).The patient had a history of morphine treatment for approximately 1 year and had been receiving morphine 60 mg daily for approximately 4 months. Patients received ketamine doses of 100mg / 24 hours for 1 day, 300mg / 24 hours for 1 day and 500mg / 24 hours for 3 days and reported complaints of side effects such as nausea, vomiting, hypersalivation and having nightmares. Evaluation of pain improvement occurred after 3 days at a dose of 500 mg / 24 hours and was maintained for 3 days with stable hemodynamics and a Ramsay score score of 0 (zero). This patient complained of back pain within 4 weeks. Discussion: Ketamine as an opioid adjuvant is generally considered to be effective in good pain control and can reduce opioid dosage. Ketamine provides analgesic, antidepressant, and psychomimetic effects through a variety of routes. The main mechanism is as a noncompetitive antagonist to phencyclidine binding of the N-methyl-D-aspartate (NMDA) receptors located in the central nervous system (CNS), particularly in the prefrontal cortex and hippocampus which can decrease the frequency of channel opening and the duration of time spent active and open NMDA receptors are channels with ligand-gated channels that are agonists against major endogens such as glutamate, which is the main excitatory neurotransmitter in the CNS. The results of this case report are consistent with two other studies which found that ketamine can improve morphine analgesia. In patients with suspected opioid tolerance problems, ketamine may be a treatment option. Conclusion: This report shows that the continuous administration of ketamine provides good effectiveness as an alternative to cancer pain treatment that is not effective against morphine administration

Keywords : Cancer Pain, Ketamine, Ramsay Score.