Anesthesia and analgesia
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Anesthesia and analgesia · Jan 2006
Comparative StudyThe efficacy and safety of intravenous emulsified isoflurane in rats.
Although direct IV injection of liquid volatile anesthetics is usually lethal, anesthesia using emulsified halothane and isoflurane without adverse effects has been safely induced in animals. We identified the safe concentration of emulsified volatile anesthetic preparations and determined the dose-response relationship of IV emulsified isoflurane and propofol in rats. Liquid/gas partition coefficients of desflurane, sevoflurane, isoflurane, enflurane, and halothane in 20% and 30% Intralipid were measured and used to calculate their saturated concentrations. ⋯ Time to return of forepaw righting reflex after injection of emulsified isoflurane (38 +/- 18 s) was significantly shorter than with propofol (101 +/- 62 s; P < 0.05). Anesthesia was successfully induced in rats by IV emulsified isoflurane with a comparable safety index and certain safety factor as propofol. Recovery of anesthesia after IV emulsified isoflurane was faster than with propofol.
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Anesthesia and analgesia · Oct 2006
Randomized Controlled Trial Comparative StudyA comparison of intrathecal morphine/fentanyl and patient-controlled analgesia with patient-controlled analgesia alone for analgesia after liver resection.
Continuous epidural anesthesia and analgesia may be considered in liver resection, but is often avoided because of the potential development of coagulopathies and the risk of epidural hematoma. In this prospective, randomized, double-blind study we compared postoperative morphine consumption via patient-controlled analgesia after liver surgery between two groups of patients: patients receiving a preoperative dose of intrathecal morphine (0.5 mg) and fentanyl (15 microg) (treatment group) and patients receiving a sham intrathecal injection (placebo group). Forty patients scheduled for major liver resection (> or = two segments) were enrolled. ⋯ Pain evaluation on the visual analog scale was lower for the first 18 h in the treatment group. There was no difference in the incidence of side effects in both groups. Intrathecal morphine (0.5 mg) and fentanyl (15 microg) given before liver surgery significantly decreased postoperative morphine consumption compared to placebo without any increase in side effects.
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Anesthesia and analgesia · Mar 2006
Randomized Controlled Trial Comparative StudyUpper airway collapsibility in anesthetized children.
We sought to establish the feasibility of measuring upper airway narrowing in spontaneously breathing, anesthetized children using dynamic application of negative airway pressure. A secondary aim was to compare differences in upper airway collapsibility after the administration of sevoflurane or halothane. Subjects were randomized to either drug for inhaled anesthetic induction. ⋯ Pcrit for sevoflurane ranged from -6.7 to -11.6 (mean +/- sd, -9.8 +/- 1.9) cm H2O. Pcrit for halothane ranged from -8.1 to -33 (mean +/- sd, -19.4 +/- 9.3) cm H2O (sevoflurane versus halothane, P = 0.048). We conclude that when using dynamic application of negative airway pressure, halothane appears to cause less upper airway obstruction than sevoflurane at equipotent concentrations.
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Anesthesia and analgesia · Dec 2006
Randomized Controlled Trial Comparative StudyThe posterior approach to the sciatic nerve in the popliteal fossa: a comparison of single- versus double-injection technique.
We compared single-injection and double-injection of the sciatic nerve with nerve stimulation in the posterior popliteal approach using mepivacaine 1% in a prospective, randomized and single-blind study to evaluate effectiveness, delay of onset, and complications in patients undergoing foot and ankle surgery. In the single-injection group (Group S, n = 30), 25 mL of mepivacaine 1% was administered after eliciting foot inversion or plantar flexion. In the double-injection group (Group D, n = 30), 12.5 mL of the solution was injected after eversion or dorsiflexion and 12.5 mL after plantar flexion of the foot. ⋯ Complete analgesia of the deep peroneal nerve was achieved in 80% and 97% in Group S and D, respectively; P < 0.05. There were more paresthesias during block procedure in Group D (17% vs 40%) (P < 0.05). We conclude that double-nerve stimulation of the sciatic nerve gives similar complete onset times and overall success rate to single-nerve stimulation and more paresthesias during block performance.
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Anesthesia and analgesia · Sep 2006
Randomized Controlled TrialThe pharmacodynamics of ropivacaine and bupivacaine in combined sciatic and femoral nerve blocks for total knee arthroplasty.
The potency of ropivacaine compared with bupivacaine in regional anesthesia remains controversial. Therefore, we compared the pharmacodynamics of equal concentrations of bupivacaine and ropivacaine in combined sciatic and femoral nerve blocks for patients undergoing knee arthroplasty. Fifty patients received 40 mL of either 0.5% bupivacaine (n = 25) or 0.5% ropivacaine (n = 25) divided between the sciatic (15 mL) and the femoral (25 mL) nerves before induction of anesthesia. ⋯ Overall, pain scores and morphine consumption were similar. In conclusion, we showed that block resolution is different between bupivacaine and ropivacaine when administered for combined sciatic and femoral nerve blocks. A new systematic method to assess sciatic and femoral nerve blockade is proposed.