Longnecker's Anesthesiology > Part 8. Care of the Chronic Pain Patient > Chapter 94. Palliative and Cancer Pain Care Phillip C. Phan, MD, and Allen W. Burton, MD

Key Points

"1. Cancer pain remains a significant problem. Studies show approximately 30% of ambulatory cancer patients suffer moderate-to-severe pain. With progressive disease, the incidence is far higher. Breakthrough pain or episodic severe pain often is problematic for cancer patients.

2. Elucidation of the painful syndrome will help guide effective treatment. In most cases, cancer pain stems from the tumor itself. Tumors cause pain due to invasion of bone, soft tissues, muscle, and nervous structures. A less frequent cause of cancer pain is treatment-related pain, including postchemotherapy neuropathic pain, postsurgical pain syndromes, and postradiation pain syndromes.

3. Neuropathic pain states usually are more difficult to treat. Neuropathic pain is seen with chemotherapy-induced painful peripheral neuropathies, postherpetic neuralgias, phantom limb pain, and others. Nociceptive pain syndromes typically are opioid responsive, whereas in neuropathic pain states, adjuvant analgesics may be needed to obtain adequate analgesia.

4. Treat opioid-related side effects aggressively. In some patients, opioid doses are limited by intolerable side effects, including sedation, confusion, constipation, nausea, and pruritus. These side effects are best managed by changing opioids, adding agents to treat the side effect, or using neuraxial, neural blockade, or other interventional pain techniques to lower systemic opioid doses.