Anesthesia and analgesia
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Anesthesia and analgesia · Apr 1999
Randomized Controlled Trial Comparative Study Clinical TrialUse of remifentanil during anesthetic induction: a comparison with fentanyl in the ambulatory setting.
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Anesthesia and analgesia · Apr 1999
Tracheal intubation of healthy pediatric patients without muscle relaxant: a survey of technique utilization and perceptions of safety.
We conducted a survey of Society for Pediatric Anesthesia anesthesiologists practicing within the United States to determine the frequency of tracheal intubation of healthy infants and children using an inhaled anesthetic without muscle relaxation (IAWMR). We also examined reasons for the use of this technique. Of all responders who listed their most often used technique for tracheal intubation of healthy infants and children, IAWMR was chosen over intubation with a muscle relaxant by 38.1% and 43.6%, respectively. Anesthesiologists who most often used IAWMR for tracheal intubation of healthy infants and children had over twice the odds (odds ratio [OR] 2.30 for infants, 95% confidence interval [CI] 1.18-4.50; P = 0.015) of classifying their own practice as nonacademic, and one-third the odds (OR 0.34 for infants, 95% CI 0.17-0.68; P = 0.002) of conducting more than half of their cases in a supervisory role. Anesthesiologists who use IAWMR to tracheally intubate healthy pediatric patients most commonly selected as their reasons the lack of need for a muscle relaxant and the desire to avoid both succinylcholine and the excessive duration of nondepolarizing muscle relaxants. ⋯ Inhaled anesthetic without muscle relaxation is the most often used method of intubation for more than one third of Society for Pediatric Anesthesia anesthesiologists when tracheally intubating healthy, fasted pediatric patients undergoing elective procedures. The frequency of this practice seems to be highest in nonacademic practices.
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Anesthesia and analgesia · Apr 1999
Comparative StudyTrabecular outflow facility and formation rate of aqueous humor during anesthesia with sevoflurane-nitrous oxide or sevoflurane-remifentanil in rabbits.
In the present study, we examined the effect of sevoflurane and remifentanil on intraocular pressure (IOP) and fluid dynamics. Twenty-eight rabbits were anesthetized with halothane, and IOP was measured via a 25-gauge needle in the anterior chamber. Rabbits were then assigned to one of four groups, and halothane was replaced with sevoflurane 1% (n = 7), 2% (n = 7), 3% (n = 7), or 1% + remifentanil 0.65 microg kg(-1) x min(-1) i.v. (n = 7). In all groups, a series of intraocular infusions was made into the anterior chamber, and IOP, trabecular outflow facility, the rate of aqueous humor formation, and intraocular compliance were determined. With sevoflurane only, intraocular compliance decreased (55 +/- 14, 39 +/- 22, 31 +/- 17 nL/mm Hg; P < 0.05) as the concentration of sevoflurane increased. With sevoflurane 1% + remifentanil, intraocular compliance was significantly increased (100.1 +/- 30.5 nL/mm Hg; P < 0.05) compared with sevoflurane 1%, 2%, or 3%. Trabecular outflow facility, rate of aqueous humor formation, and IOP did not differ among groups, and IOP was similar to values obtained during halothane anesthesia. ⋯ The dose-related effects of sevoflurane on intraocular compliance did not produce significant intraocular pressure differences. Adding remifentanil to sevoflurane increased intraocular compliance. Sevoflurane or sevoflurane + remifentanil causes a decrease in intraocular pressure compared with the average of previously reported values in awake rabbits, and the magnitude of the decrease is similar to that previously reported in rabbits anesthetized with ethyl urethane, pentobarbital, or halothane alone or in combination with propofol, cocaine, or lidocaine.
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Anesthesia and analgesia · Apr 1999
Isoflurane and sodium nitroprusside reduce the depressant effects of protamine sulfate on isolated ischemic rat hearts.
The administration of protamine sulfate (protamine) to reverse the action of heparin is associated with adverse reactions. We studied the effects of protamine and isoflurane on isolated, perfused rat hearts previously subjected to cardioplegic ischemia. Hearts were perfused with oxygenated Krebs-Henseleit (KH) solution for 30 min, then subjected to cardioplegic ischemia for 30 min (KCl 16 mEq/L at 31 degrees C) and 5 min reperfusion. Drug exposure lasted 15 min, and the recovery period was 60 min. Test groups were control, protamine (10 microg/mL), isoflurane (1.5%), protamine +/- isoflurane, sodium nitroprusside (SNP) (2.5 ng/mL), and SNP +/- protamine. Left ventricular developed pressure (LVP), coronary flow, and myocardial oxygen consumption were depressed by protamine to 30% +/- 4%, 47% +/- 4%, and 39% +/- 4% of baseline (P < 0.001 versus control), respectively. Isoflurane and SNP afforded partial protection from the effects of protamine: LVP was 57% +/- 5% and 51% +/- 3% of baseline, respectively (P < 0.05 versus protamine alone and control); coronary flow was 70% +/- 6% and 97% +/- 12% of baseline, respectively (P < 0.05 versus protamine alone; P < 0.05 for isoflurane versus control); and O2 consumption was 69% +/- 6% and 88% +/- 15% of baseline, respectively (P < 0.05 versus protamine; P < 0.05 for isoflurane versus control). In this model, protamine-induced myocardial depression and coronary vasoconstriction were less pronounced in the presence of either isoflurane or SNP. ⋯ We examined the interactions of isoflurane, sodium nitroprusside, and protamine in a rat heart model and found that both isoflurane and sodium nitroprusside partially protect the heart from the depressant effects of protamine. This finding is significant, as these drugs are often used in heart surgery.
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Anesthesia and analgesia · Apr 1999
Comment Letter Comparative StudyComparison of the laryngeal mask airway and cuffed oropharyngeal airway: alternative hypotheses.