The modern pain clinic

Canadian Journal of Anesthesia/Journal canadien d'anesthésie -     

The care of patients with phantom limb pain in a pain clinic

Patients referred to the Pain Clinic at the University of Virginia Medical Center with genuine phantom pain rather than stump pain have been treated by a variety of technics. Simple revision of drug therapy has proved helpful in some instances, as has repeated injection of trigger areas or neuromata, though surgical excision has proved necessary in some patients. Mechanical stimulation by stump tapping, prosthetic application, or electrical transcutaneous stimulation also may be useful. Sympathetic nerve block is occasionally very rewarding. Most patients need some form of psychological therapy. Rarely is cordotomy or higher central nervous system surgery required. There is no single best mode of therapy for phantom limb pain, nor can patients be guaranteed a permanent cure.     

Remarks on some analgesics used in the pain clinic

The mechanism of action of aspirin as an analgesic is an inhibition of biosynthesis of prostaglandins. Thus the site of action has been believed to be peripheral. However, when aspirin is injected intra- thecally, it produces an analgesic effect. Aspirin has a membrane-stabilizing effect and it is used locally for the treatment of post- herpetic neuralgia. Epidural opioids are frequently used for the management of post-operative pain or cancer pain. Pharmacokinetic studies have shown that delayed respiratory depression results from migration of morphine in the cerebrospinal fluid to the brain. Peak concentrations of morphine near the brain stem occur about 3 hours after lumbar epidural injection, whereas lipophilic opioids such as meperidine, peak concentration occur within 30 to 60 minutes. The clearance from cerebrospinal fluid of lipophilic opioids is more rapid than that of morphine. Besides opioids, alpha 2 receptor agonists such as clonidine also have analgesic action when administered into the epidural space. Somatostatin is one of many neuropeptides found in the spinal cord. It has dual action: a mediation of thermal nociception and a general antinociceptive action. When somatostatin is administered intrathecally or epidurally, it produces analgesic effect and its efficacy appears to be equal to that of morphine.     

Ultrasound-guided puncture: applications in a chronic pain clinic

Ultrasonography provides an excellent tool for the real-time visualization of peripheral nerve structures in regional anesthesia. Techniques are enhanced further when the progress of the needle and diffusion of the anesthetic can be observed. In a chronic pain clinic, ultrasound-guided puncture offers the advantages of accurate images of structures where pain arises: muscles, fascias, tendons, periostea, and joint structures. Visualization also helps the anesthetist to keep the needle away from structures (eg, the esophagus, pleura, vessels or peritoneum) that might lie near the target site. Unlike fluoroscopy, which produces radiation that is potentially dangerous for both patient and health care staff, ultrasound imaging is not harmful. Disadvantages are poor quality images of structures at a certain depth, acoustic shadows from bone structures that block the view of underlying tissues, and poor transport of ultrasound waves by air. Our aim is to describe a series of techniques for ultrasound-guided puncture and the results obtained on applying them weekly for 12 months in a chronic pain clinic.     

The paediatric pain clinic in Reims (France)

The activity of a paediatric chronic pain clinic is described. The author highlight the importance of the first visit of the child with its parents, and of a multidisciplinary approach adapted to the child's individual needs.     

Attendance at a pain clinic with severe chronic pain after open and laparoscopic inguinal hernia repairs

BACKGROUND: The aim was to compare the frequency of severe chronic pain that required attendance at a pain clinic after open and laparoscopic inguinal hernia repairs. METHODS: This was a retrospective analysis of 7999 patients who underwent inguinal hernia repair between January 1994 and December 2001. The definition of severe chronic pain was pain related to inguinal hernia surgery that was bad enough for the patient to seek further medical help and be referred to the specialist pain clinic after exclusion of surgically correctable pathology such as hernia recurrence. RESULTS: During the study there were 7153 open repairs and 846 laparoscopic repairs. Sixty-nine patients (1.0 per cent) were referred to the pain clinic a median of 16.9 (range 5.1-69.4) months after open hernia repair. Three patients (0.4 per cent) were referred a median of 16.5 (range 7.3-21.5) months after laparoscopic hernia repair (P = 0.045). CONCLUSION: Laparoscopic inguinal hernia repair was associated with a significantly lower frequency of attendance at the pain clinic with severe chronic pain.