Anesthesia and analgesia
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Anesthesia and analgesia · Jan 1996
Randomized Controlled Trial Comparative Study Clinical TrialThe acute and residual effects of subanesthetic concentrations of isoflurane/nitrous oxide combinations on cognitive and psychomotor performance in healthy volunteers.
A blind, randomized, cross-over trial was conducted to determine the degree of psychomotor/cognitive impairment and the recovery profile produced by combinations of subanesthetic concentrations of isoflurane and nitrous oxide in healthy volunteers. In the experiment, subjects (n = 10) inhaled 100% oxygen-placebo, 30% nitrous oxide in oxygen, and 0.2% and 0.4% isoflurane in oxygen, alone, and in combination with 30% nitrous oxide, in different sessions. ⋯ The time course of recovery was extremely rapid, with subjects returning to control-level functioning 5 min after cessation of the drug inhalation. The drug combination of isoflurane and nitrous oxide appears to be a promising candidate for conscious sedation procedures, although its analgesic and mood-altering effects need to be studied more systematically.
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Anesthesia and analgesia · Jan 1996
Multicenter Study Clinical TrialA pilot study of the effects of a perflubron emulsion, AF 0104, on mixed venous oxygen tension in anesthetized surgical patients.
A pilot study of a perfluorochemical (PFC) emulsion was undertaken to determine whether administration of a perflubron emulsion could result in measurable changes in mixed venous oxygen tension. Seven adult surgical patients received a 0.9-g PFC/kg intravenous dose of perflubron emulsion after acute normovolemic hemodilution (ANH). Hemodynamic and oxygen transport data were collected before and after ANH, immediately after PFC infusion, and at approximate 15-min intervals throughout the surgical period. ⋯ As surgery progressed, the hemoglobin concentration decreased with ongoing blood loss while PVO2 values remained at or above predosing levels. Peak perflubron blood levels were 0.8 g/dL immediately postinfusion, and approximately 0.3 g/dL at 1 h. This pilot study demonstrates that administration of perflubron emulsion results in measurable changes in mixed venous oxygen tension during intraoperative ANH.
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Anesthesia and analgesia · Jan 1996
Randomized Controlled Trial Comparative Study Clinical TrialRenal and hepatic function in surgical patients after low-flow sevoflurane or isoflurane anesthesia.
The safety of low-flow sevoflurane anesthesia, which produces higher concentrations of toxic compounds, has been questioned. One hundred surgical patients received sevoflurane or isoflurane anesthesia at a total flow rate of 1 L/min. End-tidal CO2 concentrations and inspired and end-tidal anesthetic concentrations were monitored during anesthesia. ⋯ In both groups, total bilirubin, direct bilirubin, aspartate aminotransferase, and alanine aminotransferase were increased postoperatively. There was no difference between groups. Low concentrations of Compound A were present in low-flow sevoflurane anesthesia, but no significant differences in clinical laboratory values were observed between low-flow sevoflurane and isoflurane anesthesia.
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Anesthesia and analgesia · Jan 1996
Comparative StudyDoes age or pseudocholinesterase activity predict mivacurium infusion rate in children?
Previous studies have suggested that the mivacurium infusion rate to maintain target twitch depression is greater in children than in adults, and that there is only a limited relationship between pseudocholinesterase activity and mivacurium infusion rate in children. We therefore examined whether mivacurium infusion rates are larger in children than in adults, and whether pseudocholinesterase activity influences mivacurium infusion rate in children. In 20 children aged 1-9 yr, mechanical twitch response to ulnar nerve train-of-four stimulation was measured; concurrent data were obtained in 14 adults aged 18-58 yr. ⋯ For children, IR50 (r2 = 0.22, P = 0.038) but not IR90 (r2 = 0.11 P = 0.21) was related to pseudocholinesterase activity. Infusion rates were approximately twice as large in children as in adults. We confirm that mivacurium infusion rates are larger in children than in adults and demonstrate a relationship between pseudocholinesterase activity and infusion rates.
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Anesthesia and analgesia · Jan 1996
Comparative StudyCoronary perfusion pressure during cardiopulmonary resuscitation after spinal anesthesia in dogs.
Cardiac arrest during spinal anesthesia is a rare event, but when it does happen cardiopulmonary resuscitation (CPR) is often ineffectual. This study examines the effect of spinal anesthesia on coronary perfusion pressure (CPP) during CPR and the subsequent response of CPP to epinephrine administration. Twenty mongrel dogs were anesthetized, and randomly assigned to a spinal injection with either 0.5 mg/kg bupivacaine or with an equivalent volume of normal saline. ⋯ Epinephrine is effective in increasing CPP during CPR above the critical threshold. These data suggest that if cardiac arrest occurs during spinal anesthesia, epinephrine should be given in doses of 0.01-0.02 mg/kg IV initially and then increasing to 0.1 mg/kg IV. When this does not work, and ineffective CPR is suspected, alternative resuscitative measures should be considered.