Anesthesia and analgesia
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Anesthesia and analgesia · Apr 2003
Randomized Controlled Trial Clinical TrialThe effect of remifentanil on seizure duration and acute hemodynamic responses to electroconvulsive therapy.
We designed this prospective, randomized, double-blinded, placebo-controlled, crossover study to evaluate the effect of different doses of remifentanil on the acute hemodynamic response and duration of seizure activity after a standardized electroconvulsive therapy (ECT) stimulus. Twenty consenting patients with major depressive disorders receiving maintenance ECT participated in this study. Eighty ECT treatments were evaluated. All patients were premedicated with glycopyrrolate 0.2 mg IV, unconsciousness was induced with methohexital 1 mg/kg IV, and muscle paralysis was produced with succinylcholine 1.2 mg/kg IV. Subsequently, patients received 1 of 3 different doses of remifentanil 25, 50, and 100 microg or saline (control) in a random sequence immediately after methohexital at 4 consecutive ECT treatments. Labetalol, in 5-mg IV boluses, was used as a rescue antihypertensive medication. A fixed suprathreshold electrical stimulus was administered to elicit a seizure, and the times from the stimulus to the cessation of the motor and electroencephalographic (EEG) seizure activity were noted. Pre- and post-ECT blood pressure values were significantly decreased in the 100- microg remifentanil group compared with the control group. The durations of motor (38 +/- 9 s to 43 +/- 15 s) and EEG (55 +/- 29 s to 60 +/- 21 s) seizure activity were not significantly different among the four groups. Similarly, recovery times to eye opening, obeying commands, and discharge from the recovery room did not differ among the four study groups. The requirement for labetalol after ECT was nonsignificantly decreased in the remifentanil groups. In conclusion, remifentanil 100 microg IV attenuated the acute hemodynamic response to ECT. Furthermore, remifentanil had no adverse effect on the duration of ECT-induced seizure activity. Finally, adjunctive use of remifentanil did not prolong recovery times or increase post-ECT side effects. ⋯ Remifentanil (100 microg IV) attenuated the acute hemodynamic response after electroconvulsive therapy (ECT) without adversely affecting the length of the ECT-induced seizure activity or prolonging recovery times.
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Anesthesia and analgesia · Apr 2003
Randomized Controlled Trial Comparative Study Clinical TrialRopivacaine 0.15% plus sufentanil 0.5 microg/mL and ropivacaine 0.10% plus sufentanil 0.5 microg/mL are equivalent for patient-controlled epidural analgesia during labor.
We compared the administration of 0.15% ropivacaine plus 0.5 microg/mL of sufentanil with that of 0.10% ropivacaine plus 0.5 microg/mL of sufentanil for labor analgesia with patient-controlled epidural analgesia (PCEA) to determine whether a decreased concentration of ropivacaine could produce equally effective analgesia. One-hundred-thirty healthy pregnant women at term were randomized in a double-blinded fashion. The PCEA settings were as follows: 12-mL initial bolus, 5-mL bolus dose, 5-min lockout interval, and 10 mL/h basal infusion. Patient demographics and labor characteristics were comparable in both groups. No differences were observed for pain scores, maternal satisfaction, volume of anesthetic solution administered, number of boluses requested and delivered, need for supplemental boluses, mode of delivery, motor block, side effects, or Apgar scores. Patients in the 0.10% ropivacaine group used significantly less drug than those in the 0.15% group (mean, 57 mg; 95% confidence interval, 50.5-63.5 mg; versus mean, 88.0 mg; 95% confidence interval, 74.4-93.3 mg, respectively; P < 0.0001). Ropivacaine 0.10% plus 0.5 microg/mL of sufentanil administered via PCEA for labor analgesia is equally effective as ropivacaine 0.15% plus 0.5 microg/mL of sufentanil, with a 30% local anesthetic-sparing effect and a 40% reduction in cost. However, this reduction in local anesthetic is not associated with a decrease in the incidence of motor block, side effects, or instrumental deliveries. ⋯ Ropivacaine 0.10% plus 0.5 microg/mL of sufentanil given via patient-controlled epidural anesthesia for labor analgesia is equally as effective as ropivacaine 0.15% plus 0.5 microg/mL of sufentanil, with a 30% local anesthetic-sparing effect and a 40% reduction in cost. This reduction in ropivacaine concentration is not associated with a decrease in the incidence of motor block, side effects, or instrumental deliveries.
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Anesthesia and analgesia · Apr 2003
Randomized Controlled Trial Clinical TrialA liberalized fasting guideline for formula-fed infants does not increase average gastric fluid volume before elective surgery.
Recommended preoperative fasting intervals for infant formula vary from 4 to 8 h. We conducted a prospective, randomized, observer-blinded trial of 97 ASA physical status I and II infants scheduled for elective surgery to determine whether average gastric fluid volume (GFV) recovered from infants formula-fasted for 4 h (liberalized fast, Group L) differed from that recovered from infants allowed clear liquids up until 2 h, but fasted 8 h for formula and solids (traditional fast, Group T). In Group L, 31 of 39 subjects followed protocol and ingested formula 4-6 h before surgery. In Group T, 36 of 58 subjects followed protocol, taking clear liquids 2-5 h before the induction of anesthesia. Thirty subjects had prolonged fasts and were included only in a secondary intent-to-treat analysis. Respective mean age (5.7 +/- 2.3 versus 6.4 +/- 2.4 mo; range, 0.7-10.5 mo), weight (7.5 +/- 1.8 versus 7.5 +/- 1.1 kg), and volume of last feed (4.9 +/- 2.2 versus 4.0 +/- 2.3 oz.) did not vary between Groups L and T. GFV (L: 0.19 +/- 0.38 versus T: 0.16 +/- 0.30 mL/kg) and gastric fluid pH (L: 2.5 +/- 0.5 versus T: 2.9 +/- 1.3) did not vary. For all subjects, GFV (mL/kg) increased with age (Spearman correlation coefficient = +0.23, P = 0.03). Infant irritability and hunger and parent satisfaction were similar between groups. We conclude that average GFV after either a 4- to 6-h fast for infant formula or 2-h fast after clear liquids is small and not significantly different between groups. On the basis of these findings, clinicians may consider liberalizing formula feedings to 4 h before surgery in selected infants. ⋯ Healthy infants aged < or =10.5 mo may drink formula up to 4 h before surgery without increasing gastric fluid volume compared with infants allowed clear liquids up to 2 h and formula 8 h before surgery.
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Anesthesia and analgesia · Apr 2003
Randomized Controlled Trial Clinical TrialMinimum analgesic doses of fentanyl and sufentanil for epidural analgesia in the first stage of labor.
In this study, we sought to determine the minimum analgesic doses and relative potencies of fentanyl and sufentanil when they are used as the sole epidural analgesic during the first stage of labor. Nulliparous parturients (n = 66) in spontaneous labor at term gestation and requesting epidural analgesia were enrolled into this prospective, double-blinded, randomized, sequential-allocation study. Each woman received fentanyl or sufentanil diluted with 0.9% wt/vol saline to a volume of 10 mL. The initial dose was arbitrarily chosen to be 125 microg for fentanyl and 25 microg for sufentanil, with subsequent doses being determined by the response of the previous patient (testing interval, 5 microg for fentanyl and 1 microg for sufentanil). Efficacy was accepted if the visual analog score decreased to < or =10 mm on a 100-mm scale within 30 min. The minimum analgesic dose or median effective dose was 21.1 microg (95% confidence interval [CI], 20.2-21.9 microg) for sufentanil and 124.2 microg (95% CI, 118.1-130.6 microg) for fentanyl (P < 0.0001). The sufentanil/fentanyl potency ratio was 5.9 (95% CI, 5.6-6.3). In conclusion, we have established the equivalent doses and relative potencies of fentanyl and sufentanil for epidural analgesia in the first stage of labor. ⋯ This study determined the minimum analgesic doses of fentanyl and sufentanil for epidural anesthesia in the first stage of labor. The sufentanil/fentanyl potency ratio was 5.9. This ratio may be used to establish the equivalent doses for fentanyl and sufentanil for epidural analgesia in labor.
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Anesthesia and analgesia · Apr 2003
Randomized Controlled Trial Clinical TrialSuprascapular nerve block prolongs analgesia after nonarthroscopic shoulder surgery but does not improve outcome.
Suprascapular nerve block (SSNB) reportedly improves analgesia and 24-h outcomes after arthroscopic shoulder surgery performed under general anesthesia. In this study, we assessed the analgesic and clinical outcome efficacy of SSNB as an adjunct to interscalene brachial plexus block (ISB) for ambulatory nonarthroscopic shoulder surgery. Fifty patients were randomized to receive either a SSNB or sham injection as part of a standardized ISB-general anesthesia regimen. Time to first significant pain (the primary outcome measure) was significantly delayed in the SSNB group (594 +/- 369 min versus 375 +/- 273 min, respectively; P = 0.02). There were no other differences between groups with regard to postanesthesia recovery unit measures, 24-h assessment of pain, supplemental analgesic use, or quality of life outcomes. We conclude that adjunctive SSNB adds minimal value to a primary ISB anesthetic for nonarthroscopic shoulder surgery. ⋯ When used as an adjunct to an interscalene block combined with general anesthesia, suprascapular nerve block with bupivacaine moderately prolongs analgesia without improving other outcome measures after ambulatory nonarthroscopic shoulder surgery.