Anesthesia and analgesia
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Anesthesia and analgesia · Jun 2002
Randomized Controlled Trial Clinical TrialEpidural morphine delays the onset of tourniquet pain during epidural lidocaine anesthesia.
We conducted a randomized, double-blinded study to examine the onset time of tourniquet pain during epidural lidocaine anesthesia either with or without morphine in the epidural solution. Forty-five patients undergoing knee surgery with a thigh tourniquet were randomly allocated into 3 groups of 15 patients each: epidural morphine (EM; epidural administration of 17 mL of 2% lidocaine plus 2 mg of morphine, followed by IV injection of 0.2 mL of normal saline), IV morphine (IVM; 17 mL of 2% lidocaine plus 0.2 mL of normal saline, followed by IVM 2 mg IV), and control (17 mL of 2% lidocaine plus 0.2 mL of normal saline, followed by 0.2 mL of normal saline IV). The onset time of tourniquet pain was recorded. The level of sensory block was determined by the pinprick method at the occurrence of tourniquet pain. Hemodynamic changes and side effects of EM were also recorded. The onset time of tourniquet pain from both the epidural injection and the tourniquet inflation were significantly longer in the EM group (103 +/- 15 min and 80 +/- 15 min, respectively) compared with the IVM group (74 +/- 12 min and 50 +/- 12 min, respectively; P < 0.05) and the Control group (67 +/- 9 min and 45 +/- 9 min, respectively; P < 0.05). The level of sensory block at the onset of tourniquet pain and hemodynamic changes were not different among the three groups. Only two and three patients in the EM group complained of nausea/vomiting and pruritus, respectively. Respiratory depression was not observed in any patient. We conclude that epidural injection of the mixture of 2 mg of morphine and 2% lidocaine solution delayed the onset of tourniquet pain during epidural lidocaine anesthesia without significant morphine-related side effects. ⋯ We examined the effect of epidural morphine on the onset of tourniquet pain during epidural lidocaine anesthesia. We found that the addition of 2 mg of morphine to epidural 2% lidocaine significantly delayed the onset of tourniquet pain without increasing morphine-related side effects.
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Anesthesia and analgesia · Jun 2002
Randomized Controlled Trial Comparative Study Clinical TrialDextromethorphan reduces immediate and late postoperative analgesic requirements and improves patients' subjective scorings after epidural lidocaine and general anesthesia.
Central N-methyl-D-aspartate receptors modulate postoperative pain. We compared the effects of preincision oral dextromethorphan (DM), an N-methyl-D-aspartate receptor antagonist, on postoperative IV patient-controlled analgesia morphine demand and on subjective variables in 80 patients undergoing lower-body procedures who were randomly assigned to epidural lidocaine (LA; 16 mL, 1.6%) or general anesthesia (GA). The patients were premedicated 90 min before surgery with placebo or DM 90 mg (20 patients per group) in a double-blinded manner. ⋯ All DM patients experienced significantly (P < 0.001) less pain, were less sedated, and felt better than their placebo counterparts; however, compared with placebo, DM improved subjective scorings in the GA patients more significantly (P < 0.05) than in the LA patients. We conclude that oral DM 90 mg in patients undergoing surgery under LA or GA reduces morphine and diclofenac use by approximately 50% in the immediate and late postoperative period compared with placebo. Subjectively scored levels of pain, sedation, and well-being were better as well.
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Anesthesia and analgesia · Jun 2002
Randomized Controlled Trial Clinical TrialThe hypnotic and analgesic effects of oral clonidine during sevoflurane anesthesia in children: a dose-response study.
Although clonidine has both hypnotic and analgesic actions, the dose relationship for each actions is still unknown in a clinical setting when clonidine is used as a premedication in children. We studied 80 ASA physical status I children (age range, 3-8 yr). Subjects were randomly divided into two groups (minimum alveolar anesthetic concentration [MAC]-Awake group, n = 40; MAC-Tetanus group, n = 40). Each patient received one dose of clonidine from 1 to 5 microg/kg orally, 100 min before arrival at the operating room. Anesthesia was induced and maintained with sevoflurane in oxygen and air. Before tracheal intubation, end-tidal sevoflurane was decreased stepwise by 0.2% at the start of 1.2%, a verbal command was given to the patients, and MAC-awake was determined in each patient. We also investigated MAC-tetanus, determined with transcutaneous electric tetanic stimulations, after tracheal intubation in each patient by observing the motor response to a transcutaneous electric tetanic stimulus to the ulnar nerve at a sevoflurane concentration decreased stepwise by 0.25% at the start of 2.75%. The initial reduction in MAC-tetanus was not as steep as that in MAC-awake. Clonidine reduced MAC-tetanus by 40% at the maximal dose of 5 microg/kg, whereas MAC-awake was already reduced by 50% at 2 microg/kg. We conclude that separate dose-response relationships for oral clonidine are present regarding the hypnotic and analgesic effects in children undergoing sevoflurane anesthesia. ⋯ Separate dose-response relationships for oral clonidine were found regarding the hypnotic and analgesic effects in children undergoing sevoflurane anesthesia.
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Anesthesia and analgesia · Jun 2002
Clinical TrialRemifentanil dose/electroencephalogram bispectral response during combined propofol/regional anesthesia.
The effect of opioid administration on the bispectral index (BIS) during general anesthesia is controversial. Several investigators have reported BIS to be insensitive to opioid addition, whereas others have found a hypnotic response. We designed this study to examine the effect of remifentanil on BIS during combined regional/general propofol anesthesia under steady-state conditions. After Human Investigations Committee approval, 19 healthy ASA physical status I or II patients were enrolled in a prospective experimental design. Regional anesthesia was initiated and general anesthesia induced by using computer-assisted continuous infusion of propofol. Propofol was incrementally adjusted to a BIS of approximately 60. After 20 min at a stable propofol infusion rate, a remifentanil computer-assisted continuous infusion (effect-site target concentration of 0.5, 2.5, and then 10 ng/mL) was sequentially administered at stepped 15-min intervals. BIS decreased from 56 +/- 2 to 44 +/- 1, 95% spectral edge frequency from 17.9 +/- 0.5 Hz to 15.0 +/- 0.4 Hz, heart rate from 84 +/- 5 bpm to 62 +/- 4 bpm, and mean arterial blood pressure from 93 +/- 4 mm Hg to 69 +/- 3 mm Hg with increasing remifentanil concentration. A significant linear correlation between BIS, 95% spectral edge frequency, heart rate, and log (remifentanil effect-site) concentration was found. The change in baseline BIS was relatively modest but significant, suggesting that remifentanil has some sedative/hypnotic properties, or that it potentiates the hypnotic effect of propofol. ⋯ This experiment identified a significant, dose-dependent decrease in bispectral index (BIS), 95% spectral edge frequency, heart rate, and mean arterial blood pressure with increasing remifentanil dose. The change in baseline BIS was relatively modest but significant, suggesting that remifentanil has some sedative/hypnotic properties, or that it potentiates the hypnotic effect of propofol.
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Anesthesia and analgesia · Jun 2002
Case ReportsOral ketamine: a promising treatment for restless legs syndrome.
Oral Ketamine, an NMDA receptor antagonist, can be used to treat restless legs syndrome. A mechanism for the efficacy of this treatment is discussed.