Prospective Observational Study of Patient-Controlled Intrathecal Analgesia

Background and Objectives

Although data exist for the efficacy of intrathecal therapy (ITT), there are no prospective data on patient-controlled intrathecal analgesia (PCIA) in refractory cancer pain. This study examines the effect of PCIA on cancer symptom scores, patient satisfaction, and analgesic efficacy with an emphasis on breakthrough pain (BTP).

Methods

Ninety-eight patients with refractory cancer pain prospectively completed questionnaires including the MD Anderson Symptom Inventory and a BTP survey before and after the implantation of an intrathecal pump.

Results

Fifty-eight patients were included in the study group. Average "worst" pain scores decreased from 8.32 (SD, 1.73) pre-ITT to 4.98 (SD, 2.92) post-ITT, P < 0.001. Severe pain (numerical rating score ≥7) decreased from 84.2% to 35.2% (P < 0.001). Mean daily morphine equivalent dosing decreased from 805.3 mg/d to 128.2 mg/d, with 65.5% of patients discontinuing all nonintrathecal opioids. The mean MD Anderson Symptom Inventory symptom severity score decreased from 4.98 to 3.72 (P < 0.0001), and the symptom interference score from 6.53 to 4.37 (P < 0.001). Pain reduction was 46.8% with pre-ITT breakthrough medications and 65.2% with PCIA (P < 0.001). Median time to onset was 30 minutes with pre-ITT breakthrough medications and 10 minutes with PCIA (P < 0.001). Patient-controlled intrathecal analgesia, compared with conventional BTP medications, was "a lot better" in 60.7% and "a little better" in 28.6%. Overall pain control satisfaction was also improved, with 78.2% "a lot better" and 10.9% "I have no pain."

Conclusions

In patients with poorly controlled cancer pain, PCIA is associated with improved pain control, improved cancer-related symptoms, and high satisfaction. Compared with conventional BTP regimens, PCIA provides superior analgesia and a 3-fold faster onset of action.