Anesthesia and analgesia
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Anesthesia and analgesia · Jun 2002
Randomized Controlled Trial Comparative Study Clinical TrialLidocaine iontophoresis versus eutectic mixture of local anesthetics (EMLA) for IV placement in children.
Pain during venipuncture is a major source of concern to children and their caretakers. Iontophoresis is a novel technique that uses an electrical current to facilitate movement of solute ions (lidocaine) across the stratum corneum barrier to provide dermal analgesia. In this study, we compared dermal analgesia provided by lidocaine iontophoresis and eutectic mixture of local anesthetics (EMLA). After informed consent, 26 children, aged 7-16 yr, who required venous cannulation on multiple occasions, were enrolled in this prospective, randomized, crossover study to receive EMLA and iontophoresis on separate occasions. During a third session, each subject received his or her preferred treatment. Pain during venipuncture was assessed by the subject, parent, observer, and technician performing the procedure, by use of a 100-mm visual analog scale. The observer also used the Children's Hospital of Eastern Ontario Pain Scale to rate the subject's pain. Ratings of subject satisfaction were also assessed. There were no significant differences between the two groups in the subject-rated visual analog scale or the Children's Hospital of Eastern Ontario Pain Scale scores. Eleven (50%; 95% confidence interval [CI], 31%-69%) of the 22 subjects who completed both sessions preferred iontophoresis. Five subjects (23%; 95% CI, 10%-44%), including two who did not tolerate treatment with iontophoresis, preferred EMLA, and six (27%; 95% CI, 13%-48%) had no preference for the intervention to provide dermal analgesia. We conclude that lidocaine iontophoresis provides similar pain relief for insertion of IV catheters as EMLA and is a useful noninvasive alternative to establish dermal analgesia for venous cannulation. ⋯ Iontophoresis is a technique that uses an electrical current to facilitate movement of solute ions (lidocaine) across the stratum corneum barrier to provide dermal analgesia. Lidocaine iontophoresis provides similar pain relief for insertion of IV catheters as eutectic mixture of local anesthetics and is a useful noninvasive alternative to establish dermal analgesia for venous cannulation.
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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
Clinical TrialThe effects of systolic arterial blood pressure variations on postoperative nausea and vomiting.
In this clinical study, we tested the hypothesis that a marked systolic blood pressure decrease >35% (DeltaSBP >35%) from preanesthetic baseline during the induction and maintenance of anesthesia is associated with more postoperative nausea and vomiting (PONV). In 300 ASA physical status I and II women undergoing elective gynecological surgery with general anesthesia, the maximum DeltaSBP during the induction as well as maintenance of general anesthesia were calculated. Observers blinded to hemodynamic variables assessed the incidence of PONV. The overall incidence of nausea (visual analog scale >4) and vomiting within the immediate observation period (0-2 h) was 39% and 25%, respectively. Frequency of nausea and vomiting in the late observation period was 21% and 9%, respectively. Women with a DeltaSBP >35% during the induction of anesthesia suffered from a more frequent incidence of PONV within the immediate (57% versus 35% and 41% versus 22%, respectively; P < 0.01) and within the late observation period (33% versus 18% and 19% versus 7%, respectively; P < or = 0.01). In women with a DeltaSBP >35% during maintenance of anesthesia, a more frequent incidence of nausea within the immediate observation period (53% versus 36%; P < 0.05) was found. We conclude that a maximum DeltaSBP >35% during the anesthetic induction is associated with an increased incidence of PONV after gynecological surgery during general anesthesia. ⋯ A prospective clinical investigation revealed that a marked systolic blood pressure decrease >35% (DeltaSBP >35%) during the induction of general anesthesia is associated with an increased incidence of postoperative nausea and vomiting (PONV). The association between a DeltaSBP >35% during maintenance of general anesthesia and PONV is less pronounced.