Chronic pain - Anesthesia

Chronic pain

Anesthesiologists have assumed an ever-increasing role in the treatment of patients with pain that ranges from the acute pain in the PACU, to the persist-ing (days rather than hours) post-operative pain, to the truly chronic (weeks and months rather than days) pain. The latter often does not arise from a surgical trauma but instead from tumors and degenerative diseases. The armamentarium of the chronic pain physician also differs from that of the acute care anesthesiol-ogist. Gone are invasive monitors and moment-to-moment control of vital signs. Still very much in evidence are regional anesthesia procedures and a vast array of medications, most of them to be taken by mouth. Many patients with chronic pain suffer greatly from conditions for which we cannot find an anatomic explan-ation, conditions the treatment of which require as much skill and compassion as should be expected by a patient with traumatic pain. Thus, for all patients with chronic pain, we emphasize a dual approach: pharmacologic treatment and non-pharmacologic treatment that includes therapeutic exercises and distraction techniques and massage, which calls for the skills of nurses, physical therapists, and psychologists.

In the management of chronic pain, a number of different nerve blocks have been used. More common among them are stellate ganglion and paravertebral sympathetic blocks, e.g., for complex regional pain syndrome (CRPS), formerly called reflex sympathetic dystrophy (RSD), and celiac plexus block, e.g., for pain from pancreatic cancer. Nerve blocks are often repeated to tide the patient over a condition that can be expected to improve. If that is not the case, neurolytic (destructive) nerve blocks can be considered. For these, alcohol or phenol have been used. Such blocks are usually employed only for terminally ill cancer patients, not only because of the potential for serious side effects but also because axons often regrow with recurrence of pain in two or three months, and some patients develop a central denervation dysesthesia, which is very difficult to treat.

The first step will always be to assess the severity of pain, if for no other reason than to gauge the effectiveness of the treatment. A guideline for treatment might suggest the following:

·           For mild pain (VAS 4 or below) Oral medication with acetaminophen such astramadol/acetaminophen (Ultracet ®) is often sufficient. If necessary, we might consider low dose narcotics, such as oxycodone or hydrocodone.

·           For moderate to severe pain (VAS up to 7) We would rely more on nar-cotics such as morphine or hydromorphone (Dilaudid®). Depending on the circumstances, centrally acting muscle relaxants, anti-depressants, and anxi-olytics can be added.

·           For the most severe pain Higher doses of narcotics, continuous infusions throughimplanted catheters, e.g., intrathecal or epidural pumps, and in terminally ill

·           patients, neurolytic nerve blocks will come into consideration.

In the past, many patients suffered greatly because physicians feared that opiate medication would lead to addiction. Such concerns must be tempered by the obligation to alleviate pain and will be abandoned when dealing with a terminally ill patient.