Implantable intrathecal pumps for the treatment of noncancer chronic pain in elderly population: drug dose and clinical efficacy.

Objective.   This study aims to assess long-term follow-up of efficacy and quality of life for 34 geriatric patients (10 men, 24 women, mean age 72.3 ± 11.6 years) with intrathecal (IT) drug delivery systems (IDDS), implanted between 1994 and 2002, for the treatment of severe noncancer chronic pain. Methods.   Patients equal to or older than 64 years, who had no pain relief after administration of a placebo injection (subcutaneous saline), and who responded positively to an IT trial (morphine and bupivacaine at low doses) with pain relief greater 70% without intolerable adverse effects were included into our study. Clinical assessment forms and questionnaires assessing pain intensity, adverse events, complications, concommitent use of analgesics, and doses of IT drugs administered were filled out by our patients prior to and after IT drug delivery implantation. Results.   Pain intensity was substantially reduced (60%) at three-month follow-up after commencing IT therapy and was consistently reduced at 48-month follow-up. The mean visual analog scale (VAS) value decreased from 8.09 (± 1.25) before implantation to 1.68 (± 0.63) after implantation at 48-month follow-up. This benefit, at 48 months, was achieved using mean low doses of IT morphine and bupivacaine, 1.03 ± 0.61 mg and 1.15 ± 0.58 mg, respectively. Only two out of 34 patients (5.9%) had complications related to the implantation procedure, itself. Side-effects of therapy were reported by 50% of the patients, the most frequent being constipation (34.4%), drowsiness (21.9%), nausea (21.9%), and urinary retention (18.8%). No side-effects of therapy resulted in removal of the IDDS. Conclusion.   The use of IT drug delivery through IDDS for the treatment of non-cancer- and cancer-related pain in geriatric patients is successful.