Dextromethorphan Pretreatment Does not Reduce the Tourniquet Pain in Normal Volunteers / 대한마취과학회지

BACKGROUND: Dextromethorphan (DEX) is an NMDA receptor antagonist which has recently been introduced for the treatment of chronic pain mainly to reduce the central sensitization component of pain. It is also reported to reduce the pain from acute ischemia of an extremity in a rat model which has a similar mechanism as tourniquet pain. The purpose of this experiment was to see if dextromethorphan could reduce tourniquet pain in normal volunteers. METHODS: A double blind randomized cross-over test was done on ten healthy male volunteers. Each subject was orally administered with three different doses of DEX (placebo, 30, 60 mg) 1 h before the study according to a preallocated randomized table. The subject was not reallocated for the test within two weeks of the previous test. After a 10 minute acclimation period before each test, the degree of tourniquet pain measured by VAS, arterial blood pressure, heart rate, respiration rate, and pressure-evoked pain were measured before and every 5 minutes after inflation of the tourniquet until the subject felt unbearable pain. A mixed model for repeated measurement of data was used for statistical analysis (P 0.05). CONCLUSIONS: DEX is not effective in controlling tourniquet pain in normal awake subjects.

Efficacy of Intrathecal Fentanyl for Tourniquet Pain during Spinal Anesthesia with Hyperbaric Bupivacaine / 대한마취과학회지

BACKGROUND: Tourniquet pain is probably mediated by C-fiber. The ability of fentanyl to interrupt this nociceptive conduction was studied by administering either fentanyl or saline intrathecally along with hyperbaric bupivacaine for spinal anesthesia. METHOD: The incidence of tourniquet pain was evaluated in 60 patients having orthopedic surgery of the lower extremities during spinal anesthesia by administering either 30 mcg fentanyl (group 2) or saline (group 1) along with 0.5% hyperbaric bupivacaine 10 mg. We measured the maximal sensory spread of analgesia to pinprick, the incidence of tourniquet pain, and the sensory anesthesia to pinprick at the onset of tourniquet pain. RESULTS: The average maximal sensory spread of analgesia was the same in both groups (T9). The incidence of tourniquet pain was significantly greater in group 1 (33%) than in group 2 (10%). The sensory levels of anesthesia at the onset of tourniquet pain were not different in two groups. CONCLUSIONS: Intrathecal fentanyl was effective against tourniquet pain for 2 hours of the orthopedic surgery of the lower extremities.