Anesthesia and analgesia
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Anesthesia and analgesia · Aug 1997
Randomized Controlled Trial Comparative Study Clinical TrialImmediate 8% sevoflurane induction in children: a comparison with incremental sevoflurane and incremental halothane.
We compared the efficacy and tolerance of pediatric inductions with immediate 8% sevoflurane in 70% nitrous oxide with either incremental sevoflurane or incremental halothane in 70% nitrous oxide. Forty-six unpremedicated children had anesthesia induced by immediate 8% sevoflurane (high sevoflurane [HS]; circuit primed with 70% N2O and 8% sevoflurane before application of the face mask), gradual sevoflurane (GS; primed with 70% N2O with increments of sevoflurane), and gradual halothane (HAL; 70% N2O with incremental halothane). Blind video recordings were made, and each child's distress was rated prior to mask application, during mask application, and every 10 s thereafter using a behavioral rating scale. ⋯ Times to eye closure were also significantly different (P < 0.001): HS 37 +/- 10 s (range 15-56); GS 70 +/- 18 s (range 35-114); HAL 81 +/- 34 s (range 55-140). Distress scale scores showed more rapid decrement with HS than with GS or HAL. We conclude that 1) immediate 8% sevoflurane/N2O results in a significantly faster induction than GS or HAL;2) in children, HS in N2O will not result in a single-breath induction under the conditions of this study; 3) in this small group, HS was extremely well tolerated in ASA class I and II patients.
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Anesthesia and analgesia · Aug 1997
Randomized Controlled Trial Comparative Study Clinical TrialThe arterial blood propofol concentration preventing movement in 50% of healthy women after skin incision.
To target appropriate drug concentrations and to facilitate comparisons between drugs, the potency of propofol must be firmly established. We therefore determined the arterial blood propofol concentration preventing movement in 50% of patients after skin incision and the ability of arterial blood pressure and heart rate to predict movement after incision. Fifteen healthy women scheduled for breast surgery were randomly assigned to computer-targeted propofol blood concentrations. ⋯ The MABP50 and MABP95 values were 63 +/- 4 mm Hg and 43 mm Hg, respectively. Heart rate did not differ significantly in patients who moved and who did not move. Propofol blood concentrations required to prevent movement in most patients resulted in significant arterial hypotension.
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Anesthesia and analgesia · Aug 1997
Clinical Trial Controlled Clinical TrialThe effect of dopamine on hepatic blood flow in patients undergoing epidural anesthesia.
We studied the effect of dopamine on hepatic blood flow during epidural anesthesia with the infusion of hydroxyethyl starch (HES). Hepatic blood flow was measured noninvasively via indocyanine green (ICG) clearance (indices: K [ICG disappearance rate] and R15 [15-min ICG retention rate]). Group C (n = 7) received no epidural anesthesia, Group E (n = 14) received epidural anesthesia, and Group E + D (n = 7) received a dopamine infusion (5 microg x kg(-1) x min(-1)) during epidural anesthesia. ⋯ In Groups C and E + D, K decreased and R15 increased slightly, but not significantly. K was smaller and R15 greater in Group E than in Group C (P < 0.05). We conclude that hepatic blood flow is decreased by epidural anesthesia, despite normotension maintained by continuous infusion of HES, but that this decrease in flow is reversed by the addition of a dopamine infusion.
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Anesthesia and analgesia · Aug 1997
epsilon-Aminocaproic acid plasma levels during cardiopulmonary bypass.
epsilon-Aminocaproic acid (EACA) concentrations achieved during cardiopulmonary bypass (CPB) have not been previously reported. It is unknown whether plasma concentrations reported to inhibit fibrinolysis in vitro (130 microg/mL) are achieved or whether differences in these levels relate to variability in postoperative bleeding. EACA (total intraoperative dose 270 mg/kg) was administered to 27 patients undergoing cardiac reoperation. ⋯ Twenty-four-hour postoperative thoracic drainage and allogeneic red blood cell transfusions were not associated with plasma levels at any time. Although plasma EACA concentrations greater than 130 microg/mL were consistently achieved, we observed a marked variability (more than sixfold) in plasma concentrations and bleeding outcomes despite the use of a weight-based dosing regimen. This variability in drug levels appears to have little relevance to bleeding outcomes, possibly since mean plasma levels exceeded 130 microg/mL during CPB, and nearly all patients (26 of 27) achieved that target level.
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Anesthesia and analgesia · Aug 1997
Comparative StudyLaser Doppler skin blood flow and sympathetic nervous responses to surgical incision during halothane and isoflurane anesthesia.
The aim of the present study was to evaluate whether a sudden decrease in skin blood flow measured using a laser Doppler velocimeter reflects sympathetic nervous response to surgical skin incision during halothane (n = 17) and isoflurane (n = 16) anesthesia in 33 ASA physical status I or II patients scheduled for laparotomy. Plasma norepinephrine concentrations in the responding patients who showed a sudden decrease in the skin blood flow after surgical incision increased significantly and continued to increase 1-10 min after skin incision under halothane and isoflurane anesthesia. Although plasma norepinephrine concentrations in the nonresponders did not increase after surgical incision with halothane, the concentrations increased significantly at 1 min, but not at 3 and 10 min, after skin incision with isoflurane. ⋯ Plasma epinephrine concentration increased during skin incision, but the concentrations did not differ between the patients with and without a sudden decrease in skin blood flow. Increases in systolic blood pressure and rate-pressure product on skin incision were also significantly more in patients with skin blood flow response compared with those without the response. The magnitude of changes in plasma norepinephrine concentration and hemodynamic variables with skin incision was greater with isoflurane than with halothane at the same minimum alveolar anesthetic concentration level.