Anesthesia and analgesia
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Anesthesia and analgesia · Feb 1997
Randomized Controlled Trial Clinical TrialThe direction of the Whitacre needle aperture affects the extent and duration of isobaric spinal anesthesia.
The use of Whitacre spinal needles results in directional flow out of the needle aperture, diverting local anesthetic from the longitudinal axis of the needle. Thus, a change in orientation of the needle aperture would be expected to result in a different local anesthetic distribution in the subarachnoid space. We studied 40 outpatients undergoing elective knee arthroscopy under spinal anesthesia with 60 mg plain lidocaine 2% in a prospective, double-blinded manner. ⋯ Group I had significantly shorter duration of lumbar sensory anesthesia (149.2 +/- 30.6 min vs 177.8 +/- 23.5 min, P < 0.01) and motor blockade (117.6 +/- 26.1 min vs 150.0 +/- 22.8 min, P < 0.001). Mean time to outpatient discharge was approximately 32 min shorter in Group I. The orientation of the Whitacre needle aperture exerts a major influence on sensory level, as well as the duration of isobaric lidocaine spinal anesthesia.
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Anesthesia and analgesia · Feb 1997
Randomized Controlled Trial Clinical TrialIntrathecal sufentanil for labor analgesia: do sensory changes predict better analgesia and greater hypotension?
Sensory changes and hypotension occur after intrathecal sufentanil (ITS) is given during labor. The goal of this study was to determine whether sensory changes are predictive of hemodynamic changes or duration of pain relief. We also examined whether sensory and hemodynamic changes relate to the concentration of ITS administered. ⋯ Systolic blood pressure decreased 23 +/- 2 mm Hg (P < 0.05) during the first 30 min after ITS, and six patients were given ephedrine. The magnitude of blood pressure change was not affected by the diluent volume or the presence of sensory changes. Because sensory changes were not predictive of the duration or quality of analgesia or the degree of hemodynamic change, we conclude that analgesia with ITS is predominantly mediated via spinal cord opioid receptors rather than by a local anesthetic-type conduction blockade.
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Anesthesia and analgesia · Feb 1997
Randomized Controlled Trial Clinical TrialUptake of desflurane and isoflurane during closed-circuit anesthesia with spontaneous and controlled mechanical ventilation.
Although theoretical models predict uptake of inhaled anesthetics during closed-circuit anesthesia (CCA), clinical data for most anesthetics are conflicting or non-existent. In addition, the effects of patient characteristics and mode of ventilation on anesthetic uptake are unclear. Forty-one ASA physical status I or II adult patients undergoing a variety of 1-1.5 h surgical procedures were randomly allocated to receive CCA with desflurane or isoflurane with ventilation being either spontaneous or controlled. ⋯ Patient characteristics (age, height, weight, weight3/4, and body surface area) were comparable between groups and did not correlate with uptake. The virtually constant uptake after wash-in of desflurane and isoflurane contrasts with the square root of time model of Lowe and Ernst. These findings may greatly simplify CCA.
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Anesthesia and analgesia · Feb 1997
Randomized Controlled Trial Clinical TrialParental desire for perioperative information and informed consent: a two-phase study.
The purpose of this investigation was to identify the perioperative anesthetic information parents want from the anesthesiologist, and to determine whether the provision of detailed anesthetic risk information is associated with increased parental anxiety. The investigation consisted of a cross-sectional study followed by a randomized controlled trial. In Phase 1, baseline and situational anxiety, coping strategy, and temperament were obtained from parents of children undergoing surgery (n = 334). ⋯ Also, the interaction between time and group assignment was not significant [F(3,135) = 1.66, P = 0.18]. We conclude that parents of children undergoing surgery desire comprehensive perioperative information. Moreover, when provided with highly detailed anesthetic risk information, the parental anxiety level did not increase.
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Anesthesia and analgesia · Feb 1997
Comparative StudyA comparison of the hemodynamic effects of amrinone and sodium nitroprusside in infants after cardiac surgery.
The phosphodiesterase inhibitor amrinone (AMR) increases cardiac output in children after cardiac surgery. In vitro, amrinone has both positive inotropic and vasodilatory effects. However the relative contribution of these effects to the increases in cardiac output observed clinically is unclear, and it has not been demonstrated that amrinone offers a hemodynamic advantage above that of pure vasodilators in infants. ⋯ Both SNP and AMR caused significant decreases in MBP and systemic vascular resistance index (SVRI). However, only AMR resulted in a significant increase in CI. The ratio of fractional increase in CI to fractional absolute decrease in MBP was significantly greater for AMR than SNP, indicating greater efficacy for AMR in the treatment of low cardiac output syndrome and suggesting that, in infants after cardiac surgery, AMR has clinically relevant positive inotropic effects.