Anesthetic techniques for the management of cancer pain.

This review focuses on available anesthetic techniques for cancer patients, the indications, and appropriate agents for these potent tools in a stepwise approach to cancer pain. Anesthetic procedures are desirable when they will not compromise bodily functions important to the patient, and when tumor-directed therapy and noninvasive or less-invasive, low-risk approaches (primarily pharmacologic tailoring of analgesic drugs) fail to control pain. Nondestructive techniques include the epidural/intrathecal use of opioids via an implanted catheter, and local anesthetic blocks of nerves and sympathetic ganglia. Chronic intrathecal or epidural opioid infusion seems ideal if the life expectancy is 2 to 3 months. Local anesthetic blocks can help prognosticate results of subsequent neurolytic blocks, including undesirable effects. Destructive anesthetic procedures comprise injections of neurolytic agents (most commonly phenol or alcohol), and insertion of freezing probes, into nerves and ganglia. The types of nerve blocks performed, their complications, and success rates, and limitations of commonly used neurolytic agents as well as their proper applications, are described. The importance of proper patient selection and knowledge of the pathophysiology of the pain being treated is stressed, as is the appropriate timing of anesthetic procedures in the course of the disease.