Necesidades asistenciales de la terapia de infusión intratecal en pacientes con dolor oncológico

Objectives: Intrathecal infusion is a widely accepted therapy for the treatment of refractory cancer pain, and is generally administered by partially externalised (PED) or totally internalised (ITD) devices. The objective of this work is to establish the pharmacological and healthcare needs of these two types of device, and to determine whether there are significant differences between them. Material and methods: Retrospective observational study of all patients in our pain unit, aged 18 years and older, who required intrathecal infusion therapy for cancer pain, with a fixed flow device, between 2009 and 2017. Four time points were established for follow-up: before device implantation and months 1, 3 and 6 after initiation of therapy. Data related to demographic and anthropometric information, oncological process, pain control, intrathecal dosing, modifications and number of intrathecal medication adjustments, and visits to the pain unit and emergency department were recorded. To detect possible differences between the pharmacological and health care needs of the two types of devices, a statistical analysis was performed and univariate and multivariate logistic regression models were established to predict which patients required an increase in morphine dose at month 1. Results: One hundred and thirty-two patients were included, with a mean VAS before implantation of 7.79 and a mean equipotent morphine dose of 257 mg. A PED was implanted in 60 cases and an ITD in 72 cases. After device implantation, intrathecal infusion therapy with morphine was started in all patients, with a mean dose of 1.13 mg/day, with no differences between the PED and ITD groups. At the end of the first month, the VAS score had decreased to 3.02, with a mean intrathecal morphine dose of 1.80 mg/day. At month 6, a mean VAS of 2.06 was observed, with no differences between groups, and with a mean daily dose of morphine of 2.86 mg of morphine per day. The univariate analysis detected six variables that predicted the need to increase the intrathecal morphine dose in the first month, but only a higher rescue dose of systemic morphine in the first 24 hours after device implantation remained predictive in the multivariate analysis. Forty-eight percent of the patients in the PED group did not make scheduled visits to the pain unit, compared to 14.7 % of those with an ITD, a highly significant difference. 72.7 % of our patients died in hospital. Conclusions: Intrathecal infusion therapy is e