British Journal of Anaesthesia, 2003, Vol. 90, No. 4 467-473
© 2003 The Board of Management and Trustees of the British Journal of Anaesthesia
Clinical Investigations |
Lumbar epidural fentanyl: segmental spread and effect on temporal summation and muscle pain
1 Department of Anaesthesiology, Division of Pain Therapy, University of Bern, Inselspital, CH-3010 Bern, Switzerland. 2 Laboratory for Experimental Pain Research, Center for Sensory-Motor Interaction, University of Aalborg, Aalborg, Denmark
Corresponding author. E-mail: urs.eichenberger@insel.ch
Background. Despite extensive use, different aspects of the pharmacological action of epidural fentanyl have not been clarified. We applied a multi-modal sensory test procedure to investigate the effect of epidural fentanyl on segmental spread, temporal summation (as a measure for short-lasting central hyperexcitability) and muscle pain.
Methods. Thirty patients received either placebo, 50 or 100 µg single dose of fentanyl epidurally (L2–3), in a randomized, double-blind fashion. Heat pain tolerance thresholds at eight dermatomes from S1 to fifth cranial nerve (assessment of segmental spread), pain threshold to transcutaneous repeated electrical stimulation of the sural nerve (assessment of temporal summation) and pain intensity after injection of hypertonic saline into the tibialis anterior muscle (assessment of muscle pain) were recorded.
Results. Fentanyl 100 µg, but not 50 µg, produced analgesia to heat stimulation only at L2. Surprisingly, no effect at S1 was detected. Both fentanyl doses significantly increased temporal summation threshold and decreased muscle pain intensity.
Conclusions. The findings suggest that a single lumbar epidural dose of fentanyl should be injected at the spinal interspace corresponding to the dermatomal site of pain. Increased effect on L2 compared with S1 suggests that drug effect on spinal nerve roots and binding to opioid receptors on the dorsal root ganglia may be more important than traditionally believed for the segmental effect of epidurally injected fentanyl. Epidural fentanyl increases temporal summation threshold and could therefore contribute to prevention and treatment of central hypersensitivity states. I.M. injection of hypertonic saline is a sensitive technique for detecting the analgesic action of epidural opioids.
Br J Anaesth 2003; 90: 467–73
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  M. Curatolo, S. Petersen-Felix, and L. Arendt-Nielsen Assessment of regional analgesia in clinical practice and research Br. Med. Bull., January 31, 2005; 71(1): 61 - 76. [Abstract] [Full Text] [PDF]
|
|