TY - JOUR
T1 - Analysis of peak magnitude and duration of analgesia produced by local anesthetics injected into sympathetic ganglia of complex regional pain syndrome patients
AU - Price, Donald D.
AU - Long, Stephen
AU - Wilsey, Barth
AU - Rafii, Amir
PY - 1998/9
Y1 - 1998/9
N2 - Objective: Pain-relieving effects of lidocaine/bupivicaine local anesthetic (LA) and saline (S) block of sympathetic ganglia (stellate block, 4 patients; lumbar sympathetic block, 3 patients) were compared in 7 complex regional pain syndrome (CRPS) patients on a double-blind crossover basis to evaluate the diagnostic and therapeutic value of local anesthetic sympathetic blocks. Design: Patients rated their pain on a visual analog scale before and after blocks and were tested for mechanical allodynia one-half hour after blocks. Thereafter, they rated their pain intensity in diaries four times a day for 7 days. Each patient received two blocks, S and LA, and served as his own control. Results: Both S and LA injections of sympathetic ganglia produced large reductions in pain intensity in 6 of 7 patients 30 minutes after block. These large reductions were accompanied by the reversal of mechanical allodynia in both S and LA. The mean difference between initial peak reduction in pain intensity produced by saline (68.7%) and active local anesthetic (74.4%) did not approach statistical significance. In striking contrast, the mean duration of pain relief was reliably longer in the case of LA (3 days, 18 hours) as compared with S (19.9 hours), a difference that occurred in all 7 patients. In a larger sample of 41 CRPS patients, signs of sympathetic efferent blockade, including Homer's syndrome or skin surface temperature change, were not predictive of initial peak magnitude of pain relief from sympathetic blockade but were predictive of duration of pain reduction. Conclusion: The combination of these results provides evidence that duration of pain relief is affected by injection of local anesthetics into sympathetic ganglia. These results indicate that both magnitude and duration of pain reduction should be closely monitored to provide optimal efficacy in procedures that use local anesthetics to treat CRPS.
AB - Objective: Pain-relieving effects of lidocaine/bupivicaine local anesthetic (LA) and saline (S) block of sympathetic ganglia (stellate block, 4 patients; lumbar sympathetic block, 3 patients) were compared in 7 complex regional pain syndrome (CRPS) patients on a double-blind crossover basis to evaluate the diagnostic and therapeutic value of local anesthetic sympathetic blocks. Design: Patients rated their pain on a visual analog scale before and after blocks and were tested for mechanical allodynia one-half hour after blocks. Thereafter, they rated their pain intensity in diaries four times a day for 7 days. Each patient received two blocks, S and LA, and served as his own control. Results: Both S and LA injections of sympathetic ganglia produced large reductions in pain intensity in 6 of 7 patients 30 minutes after block. These large reductions were accompanied by the reversal of mechanical allodynia in both S and LA. The mean difference between initial peak reduction in pain intensity produced by saline (68.7%) and active local anesthetic (74.4%) did not approach statistical significance. In striking contrast, the mean duration of pain relief was reliably longer in the case of LA (3 days, 18 hours) as compared with S (19.9 hours), a difference that occurred in all 7 patients. In a larger sample of 41 CRPS patients, signs of sympathetic efferent blockade, including Homer's syndrome or skin surface temperature change, were not predictive of initial peak magnitude of pain relief from sympathetic blockade but were predictive of duration of pain reduction. Conclusion: The combination of these results provides evidence that duration of pain relief is affected by injection of local anesthetics into sympathetic ganglia. These results indicate that both magnitude and duration of pain reduction should be closely monitored to provide optimal efficacy in procedures that use local anesthetics to treat CRPS.
KW - CRPS
KW - Local anesthetic
KW - Placebo
KW - Sympathetic block
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U2 - 10.1097/00002508-199809000-00008
DO - 10.1097/00002508-199809000-00008
M3 - Article
C2 - 9758071
AN - SCOPUS:0031722349
VL - 14
SP - 216
EP - 226
JO - Clinical Journal of Pain
JF - Clinical Journal of Pain
SN - 0749-8047
IS - 3
ER -