Pain Management

         ACUTE PAIN MANAGEMENT

1. Pain is the fifth vital sign.
2. Good pain control may decrease postoperative complications.
3. Adjuvant drugs can be helpful.
4. Continuous femoral infusions are as good as epidural infusions for postoperative pain control after knee procedures.
5. Doses of morphine differ by a factor of 10 between intravenous, epidural, and intrathecal routes.

·         CHRONIC PAIN MANAGEMENT

1. Chronic pain is best treated using multiple therapeutic modalities. These include physical therapy, psychological support, pharmacological management, and the rational use of more invasive procedures such as nerve blocks and implantable technologies.
2. Patients suffering from cancer pain often exhibit complex symptomatology that includes various forms of nociceptive and neuropathic pain.
3. In patients suffering from chronic pain underlying psychological/psychiatric conditions should be addressed if any meaningful recovery is to be achieved.
4. Neuropathic pain is usually less responsive to opioids than pain originating from nociceptors.

·         CRPS stands for complex regional pain syndrome. It is a painful condition usually centered in an extremity in which different degrees of sympathetic dysfunction can be identified. CRPS usually presents with spontaneous pain, hyperalgesia, hyperpathia, and allodynia that is not restricted to the territory of a single nerve. Sympathetic dysfunction presents as variations in regional blood flow that can cause edema and cyanosis. Localized sweating and trophic changes in the skin and nails of the affected part of the body can be seen as the disease progresses. CRPS I (formerly known as RSD) can follow minor trauma, venipuncture, or carpal tunnel surgery; sometimes no identifiable cause can be found. CRPS II (formerly causalgia) follows damage to a peripheral nerve. Sympathetic blocks are very useful since they can facilitate physical therapy and help the patient regain some function in the affected extremity. Upper extremity sympathetic denervation is accomplished by blocking the stellate ganglion; for lower extremity sympathetic block a lumbar sympathetic block is performed.

·         Myofascial pain syndrome is a group of muscle disorders characterized by hypersensitive areas called trigger points that can occur in more than one muscle group. Trigger points when mechanically stimulated will be painful and will refer pain to an area called the reference zone. This reference zone does not correlate with any dermatome or peripheral nerve innervation area.

·         Fibromyalgia is a chronic pain condition characterized by widespread musculoskeletal pain, aches, and stiffness, soft tissue tenderness, general fatigue, and sleep disturbances. The most common sites of pain include the neck, back, shoulders, pelvic girdle, and hands, but any body part can be involved. Fibromyalgia patients experience a range of symptoms of varying intensities that wax and wane over time.

·         Melzack and Wall in 1965 proposed that the substantia gelatinosa in the spinal cord was the primary gate in the transmission of noxious and non noxious stimulus to the central nervous system. The pain gate is opened by information coming from slow unmyelinated C fibers and closed by the impulses from faster myelinated fibers such as A-ß. Since pain is transmitted by slow A-d and C fibers they reason that by activating faster fibers such as the ones that transmit proprioception the gate will be closed and the pain symptoms will improve. A practical application is the use of TENS units as well as spinal and peripheral nerve stimulators for the treatment of pain.

·         The most common indication for use of spinal cord stimulation in the United States is in the treatment of postlaminectomy pain syndromes. In Europe the most common indication is in the treatment of peripheral vascular disease. Among other uses are CRPS I and II, arachnoiditis, and intractable angina pectoris.