Epidural Association of Morphine and Ropivacaine for Cancer Pain Treatment

Change From Baseline in Pain Scores on the Visual Analog Scale (0 means no pain and 10 means worst pain) in patients in the control group and intervention group for up to 60 days.

Change of quality of life score by the European Organization for Research and Treatment of Cancer QLQ-C30 (EORTC QLQ-C30), which consists of a likert-type scale ranging from 1 to 4 for functions and symptoms, where 1= not at all, 2=slightly, 3= moderately, and 4 = very much. If the resulting score on the functional scale is high, this represents a healthy functional level, while a high score on the symptom scale represents a low level of symptom tolerance and treatment side effects. This scale also assesses overall health, ranging from 1 to 7, with 1=bad and 7 = very good

Change in the patient's functional status by the Karnofsky Performance Scale (KPS), which ranges from 100% to 0%, where 100% means no evidence of disease and 0% means death

Change in disease status using the Eastern Cooperative Oncology Group (ECOG) scale, ranging from 0 to 5, where 0 = completely active and 5 =dead

Change in clinical-functional status by the Palliative Performance Scale (PPS), which ranges from 100 to 0%, where 100% = good clinical-functional status and 0%= dead

Change in survival time by the Palliative Prognosis Scale (PPI), which assesses PPS, presence of delirium, dyspnea, oral intake and edema, where each factor presents a score and at the end the scores are summed and the patient is classified into group A (Total Score < 2.0): > 6 weeks survival, group B (Total Score between 2.0 - 4.0): 3 - 6 weeks survival and group C (Total Score > 4.0): < 3 weeks survival

For cost-effectiveness analysis, a direct cost analysis using the cost-effectiveness ratio will be used. The costs considered in this study will be the direct non-medical and direct medical costs. For direct cost analysis, the microcosting technique will be used.

For economic analysis, the incremental cost-effectiveness ratio (ICER) will be used. Once a CERI is obtained, the result is evaluated by defining a cost-effectiveness threshold, which aims to identify values that society considers feasible, from an economic point of view, to be incorporated as additional costs in society's spending on health (BRASIL, 2014).

Once the RCEI is obtained, the next step in a pharmacoeconomic analysis will be to perform a sensitivity analysis of the parameters involved during the research.

Patients will undergo blood draws to obtain plasma, 1:30h after taking morphine (oral or epidural) which will later be quantified for morphine by gas chromatography.

The amount of morphine found in plasma (outcome 8) will be correlated with the therapeutic effects (pain levels by Visual Analog Scale)

BDNF quantification will be done in the plasma of the patients, using the BDNF enzyme-linked immunosorbent assay (ELISA) kit from sigma and adverse effects