Anesthesia and analgesia
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Anesthesia and analgesia · Sep 2002
Randomized Controlled Trial Clinical TrialThe analgesic efficacy of bilateral combined superficial and deep cervical plexus block administered before thyroid surgery under general anesthesia.
In this study we evaluated the analgesic efficacy of combined deep and superficial cervical plexus block in patients undergoing thyroidectomy under general anesthesia. For this purpose, 39 patients undergoing elective thyroid surgery were randomized to receive a bilateral combined deep and superficial cervical block (14 mL per side) with saline (Group 1; n = 13), ropivacaine 0.5% (Group 2; n = 13), or ropivacaine 0.5% plus clonidine 7.5 microg/mL (Group 3; n = 13). Deep cervical plexus block was performed with a single injection (8 mL) at the C3 level. Superficial cervical plexus block consisted of a subcutaneous injection (6 mL) behind the lateral border of the sternocleidomastoid muscle. During surgery, the number of additional alfentanil boluses was significantly reduced in Groups 2 and 3 compared with Group 1 (1.3 +/- 1.0 and 1.1 +/- 1.0 vs 2.6 +/- 1.0; P < 0.05). After surgery, the opioid and non-opioid analgesic requirements were also significantly reduced in Groups 2 and 3 (P < 0.05) during the first 24 h. Except for one patient in Group 3, who experienced transient anesthesia of the brachial plexus, no side effect was noted in any group. We conclude that combined deep and superficial cervical plexus block is an effective technique to alleviate pain during and immediately after thyroidectomy. ⋯ Combined deep and superficial cervical plexus block is an effective technique to reduce opioid requirements during and after thyroid surgery.
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Anesthesia and analgesia · Sep 2002
Randomized Controlled Trial Clinical TrialPropofol-sufentanil anesthesia for thyroid surgery: optimal concentrations for hemodynamic and electroencephalogram stability, and recovery features.
Hypnotics and opioids interact synergistically to block responses to surgery and different dose combinations may be used to provide adequate anesthesia. In this study, we sought to determine the optimal concentrations of propofol and sufentanil, given by target-controlled infusions, to ensure hemodynamic stability, adequate hypnosis (assessed by electroencephalogram bispectral index), and fast recovery for a moderately painful operation. Forty-five patients, ASA physical status I or II, undergoing thyroidectomy, were randomly assigned to a sufentanil target concentration (STC) that was maintained throughout surgery (0.1, 0.2, or 0.3 ng/mL). The propofol target concentration was adjusted to keep mean arterial blood pressure within 30% of a reference value, and bispectral index between 40 and 60. Adequate anesthesia was obtained in all groups. Hypertension and clinically dangerous movements were more frequent with the small STC, and hypotension requiring treatment was more frequent with the large STC. Propofol target concentration during surgery decreased significantly with increasing STC (median at thyroid removal 5.0, 4.0, and 2.5 microg/mL, respectively) as well as the propofol consumption (740, 668, 474 mg/h). The 0.3 ng/mL STC significantly delayed the return of spontaneous breathing. ⋯ Given as a target-controlled infusion for thyroid surgery, sufentanil 0.3 ng/mL for intubation and 0.2 ng/mL during surgery, combined with propofol 4 microg/mL (corresponding to a maintenance infusion rate of approximately 7-10 mg. kg(-1). h(-1)), is recommended to ensure both optimal intraoperative stability and fast recovery.
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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 TrialThe use of magnesium sulfate to prevent pain on injection of propofol.
Magnesium sulfate, 2.48 mmol, injected 20 s before the administration of propofol significantly reduced the incidence of pain caused by a propofol injection and may be useful in minimizing this common side effect.
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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.