Anesthesia and analgesia
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Anesthesia and analgesia · Sep 2002
Randomized Controlled Trial Clinical TrialIntrathecal magnesium prolongs fentanyl analgesia: a prospective, randomized, controlled trial.
Magnesium is a noncompetitive, N-methyl-D-aspartate receptor antagonist that does not effectively cross the blood-brain barrier when given IV. Intrathecal magnesium potentiates opioid antinociception in rats, and the safety of intrathecal magnesium has been demonstrated in animals. This is the first prospective human study evaluating whether intrathecal magnesium could prolong spinal opioid analgesia. Fifty-two patients requesting analgesia for labor were randomized to receive either intrathecal fentanyl 25 micro g plus saline or fentanyl 25 micro g plus magnesium sulfate 50 mg as part of a combined spinal-epidural technique. The duration of analgesia of the intrathecal drug combination was defined by the time of patient request for additional analgesia. There was significant prolongation in the median duration of analgesia (75 min) in the magnesium plus fentanyl group compared with the fentanyl alone group (60 min). There was no associated increase in adverse events in the group that received intrathecal magnesium. Larger doses of intrathecal magnesium were not studied in this group of patients because of the limitations on cephalad spread when hyperbaric solutions are injected in the sitting position. Our data indicate that intrathecal magnesium prolongs spinal opioid analgesia in humans and suggest that the availability of an intrathecal N-methyl-D-aspartate antagonist could be of clinical importance for pain management. ⋯ Magnesium occurs naturally in the spinal cord and blocks the NMDA glutamate channel. In animal studies, intrathecal magnesium sulfate improves spinal morphine analgesia. For patients receiving spinal analgesia for labor, the addition of magnesium sulfate to the opioid fentanyl prolonged analgesia with no increase of side effects.
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Anesthesia and analgesia · Sep 2002
Randomized Controlled Trial Clinical TrialThe dose-sparing effect of clonidine added to ropivacaine for labor epidural analgesia.
To determine the effects of clonidine with ropivacaine during epidural labor analgesia, we studied 66 nulliparous women in early active labor. Women were randomized to receive ropivacaine 0.1% 8 mL plus 75 microg of clonidine (Group 1), ropivacaine 0.2% 8 mL plus 0.5 mL of NaCl 0.9% (Group 2), or ropivacaine 0.2% 8 mL plus 75 microg of clonidine (Group 3) 5 min after a bupivacaine 7.5 mg with epinephrine 15 microg test dose. Upon request, additional analgesia with ropivacaine 0.1% 8 mL followed by ropivacaine 0.2% 8 mL/h was administered. With clonidine, duration of analgesia was increased (132 +/- 48 min [Group 1] and 154 +/- 42 min [Group 3] versus 91 +/- 44 min [Group 2]; P < 0.05), and total ropivacaine dose over the first 4 h was significantly reduced (40.5 +/- 15 mg [Group 1] and 47.0 +/- 16 mg [Group 3] versus 72.5 +/- 18 mg [Group 2]; P < 0.01). The incidence of more profound motor block was more frequent in Group 2 (P < 0.05). Although there was a trend for more women receiving clonidine to require ephedrine for treatment of hypotension, this did not seem to have an impact on fetal outcome or incidence of cesarean deliveries for nonreassuring fetal heart rate tracings. This study demonstrates the dose-sparing effect of clonidine when added to ropivacaine. ⋯ The effect of adding 75 microg of clonidine to ropivacaine for epidural labor analgesia was studied. Clonidine increased analgesia duration and produced dose sparing compared with ropivacaine alone. Despite a tendency for hypotension in women receiving clonidine, there was no apparent effect on delivery mode or neonatal outcome.
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Anesthesia and analgesia · Sep 2002
Randomized Controlled Trial Clinical TrialPrehospital analgesia with acupressure in victims of minor trauma: a prospective, randomized, double-blinded trial.
Untreated pain during the transportation of patients after minor trauma is a common problem in emergency medicine. Because paramedics usually are not allowed to perform invasive procedures or to give drugs for pain treatment, a noninvasive, nondrug-based method would be helpful. Acupressure is a traditional Chinese treatment for pain that is based on pain relief followed by a short mechanical stimulation of specific points. Consequently, we tested the hypothesis that effective pain therapy is possible by paramedics who are trained in acupressure. In a double-blinded trial we included 60 trauma patients. We randomly assigned them into three groups ("true points," "sham-points," and "no acupressure"). An independent observer, blinded to the treatment assignment, recorded vital variables and visual analog scales for pain and anxiety before and after treatment. At the end of transport, we asked for ratings of overall satisfaction. For statistical evaluation, one-way analysis of variance and the Scheffé F test were used. P < 0.05 was considered statistically significant. Morphometric and demographic data and potential confounding factors such as age, sex, pain, anxiety, blood pressure, and heart rate before treatment did not differ among the groups. At the end of transport we found significantly less pain, anxiety, and heart rate and a greater satisfaction in the "true points" groups (P < 0.01). Our results show that acupressure is an effective and simple-to-learn treatment of pain in emergency trauma care and leads to an improvement of the quality of care in emergency transport. We suggest that this technique is easy to learn and risk free and may improve paramedic-based rescue systems. ⋯ We tested, in a double-blinded manner, the hypothesis that acupressure could be an effective pain therapy in minor-trauma patients. Our results show that acupressure is an effective and simple-to-learn treatment of pain in emergency medical care and can improve the quality of care.
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Anesthesia and analgesia · Sep 2002
Randomized Controlled Trial Comparative Study Clinical TrialBispectral index in patients with target-controlled or manually-controlled infusion of propofol.
In this prospective, randomized study we compared bispectral index (BIS), hemodynamics, time to extubation, and the costs of target-controlled infusion (TCI) and manually-controlled infusion (MCI) of propofol. Forty patients undergoing first-time implantation of a cardioverter-defibrillator were included. Anesthesia was performed with remifentanil (0.2-0.3 micro g. kg(-1). min(-1)) and propofol. Propofol was used as TCI (plasma target concentration, 2.5-3.5 micro g/mL; n = 20) or MCI (3.0-4.0 mg. kg(-1). h(-1); n = 20). BIS, heart rate, and arterial blood pressure were measured at six data points: T1, before anesthesia; T2, after intubation; T3, after skin incision; T4, after first defibrillation; T5, after third defibrillation; and T6, after extubation. There were no significant hemodynamic differences between the two groups. BIS was significantly lower at T3 and T4 in the TCI group than in the MCI group. The mean dose of propofol was larger in TCI patients (5.8 +/- 1.4 mg. kg(-1). h(-1)) than in the MCI patients (3.7 +/- 0.6 mg. kg(-1). h(-1)) (P < 0.05), whereas doses of remifentanil did not differ. Time to extubation did not differ between the two groups (TCI, 13.7 +/- 5.3 min; MCI, 12.3 +/- 3.5 min). One patient in the MCI group had signs of intraoperative awareness without explicit memory after first defibrillation (BIS before shock, 49; after shock, 83). Costs were significantly less in the MCI group (34.83 US dollars) than in the TCI group (39.73 US dollars). BIS failed to predict the adequacy of anesthesia for the next painful stimulus. ⋯ In this prospective, randomized study, bispectral index (BIS), hemodynamics, time to extubation, and costs of target-controlled infusion (TCI) and manually-controlled infusion of propofol were compared. TCI increased the amount of propofol used. BIS failed to predict the adequacy of anesthesia for the next painful stimulus.
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Anesthesia and analgesia · Sep 2002
Clinical TrialPain as a factor complicating recovery and discharge after ambulatory surgery.
Pain complicates the recovery process after ambulatory surgery. We surveyed 175 ambulatory surgery patients to determine pain severity, analgesic use, relationship of pain to duration of recovery, and the relative importance of various factors to predicting these outcomes. Multivariate regression analysis was used to determine unique contributions of predictor variables to outcome. Surgical procedures included knee arthroscopy (n = 50), hernia surgery (n = 25), pelvic laparoscopy (n = 25), transvaginal uterine surgery (n = 25), surgery for breast disease (n = 25), and plastic surgery (n = 25). Maximum pain (on a scale of 0-10) varied from 2.3 +/- 0.5 to 5.1 +/- 0.5 (mean +/- SE), depending on surgical procedure; 24% of patients had pain scores of > or =7, and 24% were delayed in Phase 1 recovery by pain. Pain scores were lower if local anesthetic or ketorolac was administered intraoperatively (22% and 26% respectively). Fentanyl dose during recovery correlated with maximum pain scores; fentanyl dose was 42% less if ketorolac was administered intraoperatively. In females, the recovery fentanyl dose increased in proportion to the intraoperative fentanyl dose. The maximum pain score was predictive of total recovery time (135, 172, and 212 min of recovery for maximum pain scores of 0-3, 4-6, and 7-10, respectively; P < 0.001). We conclude that improvements in pain therapy are warranted to improve patient comfort and to expedite recovery. ⋯ Moderate to severe pain is common after ambulatory surgery and is a frequent cause of delayed discharge. Postoperative pain, opioid-related side effects, and time to discharge were less when nonsteroidal antiinflammatory drugs or local anesthetics were used intraoperatively to prevent pain before patient awakening.