Patient-Controlled Intrathecal Analgesia for the Management of Breakthrough Cancer Pain: A Retrospective Review and Commentary

Abstract

Intrathecal therapy (ITT) via an implanted pump has become an accepted practice for the treatment of refractory cancer pain by infusing opioids and adjuncts directly to the neuraxis. Until recently, only a programmed basal rate of infusion could be delivered, and therefore, breakthrough pain required ongoing use of oral or transmucosal opioids. Recently, an implanted pump manufacturer has introduced a handheld device to bolus additional medication for breakthrough pain. We hypothesize that patient-controlled intrathecal analgesia (PCIA) for the treatment of breakthrough cancer pain reduces the need for breakthrough opioids and improves the patient perception of pain. A retrospective chart review was done on all patients who underwent ITT for cancer pain between January 2009 and February 2011. Clinical outcomes of interest were reduction in nonintrathecal opioid use and reduction in numerical rating score (NRS) for pain. The data was collected prior to ITT and at a 4-6 week postimplant visit. After initiation of ITT with PCIA, 50% of patients had discontinued all nonintrathecal opioids at follow-up, and 46% of the patients on breakthrough medications no longer required their use. At follow-up, there was a significant reduction in total nonintrathecal opioid use, with an average of 796 mg pre-ITT vs 64 mg post-ITT of daily oral morphine equivalent dosing (P = <0.001). There was a significant difference between mean NRS pain score at follow-up-6.5 vs 3.1 pre-ITT (P<0.001). 65% of patients reported their pain as severe (NRS of 7 or greater) prior to ITT; this decreased to 3% at follow-up. In patients with refractory cancer pain, intrathecal drug therapy with PCIA is associated with improved pain reporting, reduced nonintrathecal around-the-clock, and breakthrough opioid requirements.