Evidence of peripheral nerve blocks for cancer-related pain: a systematic review.

The European Association for Palliative Care has initiated a comprehensive program to achieve an over-all review of the evidence of multiple cancer pain management strategies in order to extend the current guideline for treatment of cancer pain. The present systematic review analyzed the existing evidence of analgesic efficacy for peripheral nerve blocks in adult patients with cancer. A search strategy was elaborated with words related to cancer, pain, peripheral nerve and block. The search was performed in PubMed, EMBASE, and Cochrane for the period until February 2014. The number of abstracts retrieved was 155. No controlled studies were identified. Sixteen papers presented a total of 79 cases. The blocks applied were paravertebral blocks (10 cases), blocks in the head region (2 cases), plexus blocks (13 cases), intercostal blocks (43 cases) and others (11 cases). In general, most cases reported good pain relief and no side effects. The use of peripheral blocks is based upon anecdotal evidence. However, this review only demonstrates the lack of studies, which does not equal a lack of effectiveness.