Anesthesia and analgesia
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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
Comparative Study Clinical TrialNeostigmine reversal of vecuronium neuromuscular block and the influence of renal failure.
The duration of clinical relaxation induced by vecuronium and reversal by neostigmine was studied in 40 patients with renal failure (RF) and 40 patients with normal renal function (NL) under general anesthesia. Patients were premedicated with flunitrazepam, and anesthesia commenced with fentanyl 1-2 micrograms/kg, thiopental 5-8 mg/kg, and vecuronium 0.1 mg/kg. Anesthesia was maintained with 60% nitrous oxide in oxygen, isoflurane 0.3%-1.0% end-tidal concentration, and 1 microgram/kg fentanyl every 20-30 min. ⋯ Spontaneous recovery time, reversal time, and the time to recovery of TOF ratio to 0.7 were recorded. RF did not prolong the vecuronium neuromuscular blocking effect, reversal was achieved at the same rate in NL as in RF, and the duration of reversal of neuromuscular blocking effect of vecuronium was not influenced by the time of administration of neostigmine. Therefore, the neuromuscular blocking effect of a tracheal intubating dose of vecuronium can be reversed at the same rate in patients with end-stage RF as in patients with normal kidney function.
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Anesthesia and analgesia · Jan 1996
Clinical Trial Controlled Clinical TrialPositive pressure ventilation with the laryngeal mask airway in children.
We studied the safety of positive pressure ventilation (PPV) when using the size 2 laryngeal mask airway (LMA) in 46 ASA physical status I or II children (aged 38 +/- 21 mo) undergoing elective surgery. The LMA cuff was inflated in incremental steps to achieve a cuff leak pressure > or = 15 cm H2O. Abdominal circumference was measured before and after PPV in study patients, as well as in a control group managed with tracheal intubation. ⋯ Mild gastric distention often occurs. The risk of clinically significant gastric distention appears to be small, but it warrants close monitoring. We conclude that with certain precautions described in the text, the size 2 LMA provides a relatively safe airway for PPV in children.
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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 StudyFactors associated with excessive postoperative blood loss and hemostatic transfusion requirements: a multivariate analysis in cardiac surgical patients.
The purpose of this study was to prospectively evaluate whether heparin and protamine doses administered using a standardized protocol based on body weight and activated clotting time values are associated with either transfusion of hemostatic blood products (HBPs) or excessive postoperative bleeding. Analysis using 10 multiple logistic or linear regression models in 487 cardiac surgical patients included perioperative variables that may have an association with either transfusion of HBP and/or excessive postoperative chest tube drainage (CTD). ⋯ Preoperative use of warfarin or heparin was not associated with excessive blood loss of perioperative transfusion of HBPs. In contrast to previous studies using bovine heparin, data from the present study do not support the use of reduced doses of porcine heparin during CPB.