Movement-evoked breakthrough cancer pain despite intrathecal analgesia: a prospective series

Intrathecal analgesia (ITA) is a valuable treatment option for intractable cancer-related pain. However, the issue of movement-evoked breakthrough pain (BTP) has not been specifically investigated in the ITA setting. The aim of the study was to evaluate the effect of ITA on spontaneous resting pain intensity (SRPI), doses of non-ITA opioids, and specifically on movement-evoked pain intensity (MEPI).

We prospectively studied 28 consecutive patients who graded SRPI and MEPI on a 0-10 numerical rating scale (NRS) at the time of ITA procedure, after 1 week, and after 1 month. Mild pain was defined as NRS ≤ 3 and severe pain as NRS ≥ 7. Concomitant doses of opioids were registered.

After 1 week, no patient had severe SRPI compared with 31% before ITA, and the proportion of patients with mild SRPI had increased from 27% to 76%. Meanwhile, the median daily dose of non-ITA opioids decreased from 575 to 120 mg of oral morphine equivalents. The effect on SRPI and on doses of non-ITA opioids remained essentially unchanged during the study month, but the proportion of patients having severe MEPI did not change significantly: 44% still had severe MEPI after 1 week and 40% after 1 month.

Movement-evoked BTP was a major clinical problem throughout the study month despite otherwise successful ITA. Improving the quality of life of patients with intractable cancer-related pain should include developing strategies to better deal with movement-evoked BTP.