Anesthesia and analgesia
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Anesthesia and analgesia · Oct 1993
Multicenter Study Clinical TrialEffects on recovery when isoflurane is used to supplement propofol-nitrous oxide anesthesia.
During propofol-nitrous oxide (N2O) anesthesia, volatile anesthetics are frequently administered to treat signs of inadequate anesthesia and to decrease the possibility of intraoperative awareness. Because the clinical effects of this combination have not been examined rigorously, we used data from the 1989-90 Phase IV clinical trial with propofol to evaluate recovery from propofol-N2O anesthesia with and without supplementation with isoflurane. In this study involving 15,806 patients at 1722 institutions, propofol was administered for induction and maintenance of anesthesia with N2O for procedures lasting less than 60 min. ⋯ Adjunctive use of isoflurane prolonged the time to awakening and to becoming oriented, but discharge times were similar for the two groups. The incidence of postoperative nausea, vomiting, recall, and excitement did not differ between the two groups. We conclude that the addition of isoflurane to a propofol-N2O anesthetic does not alter recovery from anesthesia.
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Anesthesia and analgesia · Oct 1993
ReviewCocaine abuse in the parturient and effects on the fetus and neonate.
The growing use of cocaine among pregnant women and women of childbearing age has become an issue of great concern to physicians. Cocaine abuse among parturients is associated with multi-target organ involvement, including the cardiovascular, respiratory, neurologic, and hematologic systems. ⋯ Although a history of premature rupture of membranes, smoking, alcohol use, syphilis serology, and use of other illicit drugs suggests cocaine abuse, the single most important predictor is the absence of prenatal care. The intraoperative anesthetic management should take into consideration the different effects of cocaine on the mother, the fetus, and the neonate.
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Anesthesia and analgesia · Oct 1993
Comparative StudyComparison of bedside coagulation monitoring tests with standard laboratory tests in patients after cardiac surgery.
We compared portable bedside tests of whole blood coagulation with standard laboratory plasma coagulation tests to assess the accuracy and precision of the bedside tests in a clinical setting (postcardiac surgery). The Ciba Corning 512 Coagulation Monitor (Ciba Corning Diagnostics Corp., Medfield, MA) and the Hemochron 801 (International Technidyne Corp., Edison, NJ) were tested. One hundred forty-one patients who underwent cardiac surgery requiring cardiopulmonary bypass were evaluated upon arrival in the intensive care unit. ⋯ The difference between Hemochron TT and Hemochron HNTT correlated weakly, but significantly, with laboratory aPTT ratio (r = 0.52, P < 0.001). The slope of the regression line indicated that a TT-HNTT difference > 30 s correlated with an aPTT > 1.5 x control. We conclude that, in the postoperative cardiac surgical patient, PT was both accurate and precise in two commercially available tests, but aPTT was not.(ABSTRACT TRUNCATED AT 250 WORDS)
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Anesthesia and analgesia · Oct 1993
Nitrous oxide decreases solubility of isoflurane and halothane in blood.
This study investigated the effects of carrier gases on the solubility of isoflurane or halothane in blood. The blood/gas partition coefficients (lambda blood/gas) of 1 minimum alveolar anesthetic concentration of isoflurane or halothane in 100% oxygen, 30% oxygen with 70% nitrous oxide, 100% nitrous oxide or air were measured at 37 degrees C, with blood from four donors. ⋯ The values of isoflurane or halothane in 100% nitrous oxide (1.29 +/- 0.03; 2.25 +/- 0.08) and in a gas mixture of 30% oxygen and 70% nitrous oxide (1.33 +/- 0.04; 2.29 +/- 0.05) were lower (P < 0.05) than those obtained with 100% oxygen (1.40 +/- 0.03; 2.37 +/- 0.04). We conclude that nitrous oxide decreases the lambda blood/gas of isoflurane or halothane, and that this change of solubility, although small, increases the uptake rate of halothane or isoflurane.
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Anesthesia and analgesia · Oct 1993
The direction dependence of thermoregulatory vasoconstriction during isoflurane/epidural anesthesia in humans.
We tested the hypothesis that once thermoregulatory vasoconstriction is triggered at a given core temperature during isoflurane anesthesia, redilation starts at a substantially higher core temperature. To avoid direct perception of cutaneous cooling and warming, we used epidural anesthesia and limited our thermal manipulations to the blocked area. Seven volunteers were anesthetized with isoflurane/epidural anesthesia (approximately T9 dermatomal level). ⋯ The difference between the two thresholds defined the direction-dependent hysteresis. Vasoconstriction occurred at 35.2 +/- 0.6 degrees C and vasodilation at 36.2 +/- 0.5 degrees C (P < 0.01, paired t-test); consequently, the hysteresis was 1.0 +/- 0.6 degrees C. The observed hysteresis suggests that thermoregulatory responses during combined isoflurane/epidural anesthesia are not determined simply by instantaneous thermal input to central controllers, but may also depend on the direction of core temperature change.