Anesthesia and analgesia
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Anesthesia and analgesia · Jun 1997
Cerebral hemoglobin and optical pathlength influence near-infrared spectroscopy measurement of cerebral oxygen saturation.
Near-infrared spectroscopy (NIRS) is a noninvasive optical technique to monitor cerebral oxygen saturation at the bedside. Despite its applicability, NIRS has had limited clinical use because of concerns about accuracy, noted by intersubject variability in slope and intercept of the line between NIRS- and weighted-average arterial-cerebrovenous saturation (SMO2). This study evaluated transcranial optical pathlength and cerebral hemoglobin concentration as sources for this intersubject variability. ⋯ By adjusting the NIRS algorithm with the cerebral hemoglobin measurements, slope and intercept remained unchanged by hemodilution. These data indicate that intersubject variability in NIRS originates, in part, from biologic variations in transcranial optical pathlength and cerebral hemoglobin concentration. Instruments to account for these factors may improve NIRS cerebral oxygen saturation measurements.
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Anesthesia and analgesia · May 1997
Randomized Controlled Trial Multicenter Study Clinical TrialDose-ranging study in younger adult and elderly patients of ORG 9487, a new, rapid-onset, short-duration muscle relaxant.
The purpose of this multicenter, randomized, assessorblind placebo-controlled study was to determine which of five doses of the new, rapid-onset neuromuscular relaxant, ORG 9487, provided both good to excellent tracheal intubating conditions 60 s after administration and a clinical duration of action < 20 min in 120 younger (aged 18-64 yr) and 61 elderly (aged 65-85 yr) adult patients. Anesthesia was induced with fentanyl (2-5 micrograms/kg) and thiopental (3-6 mg/kg) and maintained with N2O/O2 and a propofol infusion (50-300 micrograms.kg-1.min-1). Neuromuscular train-of-four (TOF) monitoring by electromyography (Datex Relaxograph) commenced immediately after anesthetic induction and was followed, within 30 s, by one of five doses of ORG 9487 (0.5, 1.0, 1.5, 2.0, 2.5 mg/kg) or a placebo. ⋯ Good to excellent intubating conditions at 60 s were present in most younger adult (52 of 60) and elderly (26 of 31) patients administered doses > or = 1.5 mg/kg. Mean clinical durations < 20 min were observed in adult patients at doses up to 2.0 mg/kg and in geriatric patients up to 1.5 mg/kg. Thus, doses of 1.5-2.0 mg/kg ORG 9487 enabled both rapid tracheal intubation and a short clinical duration of action in adult and elderly patients.
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Anesthesia and analgesia · May 1997
Randomized Controlled Trial Comparative Study Clinical TrialThiopental-rocuronium versus ketamine-rocuronium for rapid-sequence intubation in parturients undergoing cesarean section.
We investigated the neuromuscular effects and conditions of tracheal intubation after administration of rocuronium in 40 parturients undergoing elective cesarean section. After preoxygenation, anesthesia was induced in 20 patients by thiopental 4 mg/kg and, in the other 20 patients, by ketamine 1.5 mg/kg. Rocuronium 0.6 mg/kg was then administered, and neuromuscular transmission was assessed using electromyographic response to train-of-four stimulation of the ulnar nerve at the wrist every 10 s. ⋯ Neither the time to 50% NMB nor the onset time were significantly different between the two groups. Tracheal intubation at 50% NMB was easily performed in all patients in the ketamine-rocuronium group but was difficult in 75% of the thiopental-rocuronium group. We concluded that ketamine 1.5 mg/kg followed by rocuronium 0.6 mg/kg may be suitable for rapid-sequence induction of anesthesia in parturients undergoing cesarean section.
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Anesthesia and analgesia · May 1997
Randomized Controlled Trial Clinical TrialThe efficacy of tranexamic acid versus placebo in decreasing blood loss in pediatric patients undergoing repeat cardiac surgery.
The antifibrinolytic drug, tranexamic acid, decreases blood loss in adult patients undergoing cardiac surgery. However, its efficacy has not been extensively studied in children. Using a prospective, randomized, double-blind study design, we examined 41 children undergoing repeat sternotomy for repair of congenital heart defects. ⋯ Children who were treated with tranexamic acid had 24% less total blood loss (26 +/- 7 vs 34 +/- 17 mL/kg) compared with children who received placebo (univariate analysis P = 0.03 and multivariate analysis P < 0.01). Additionally, the total transfusion requirements, total donor unit exposure, and financial cost of blood components were less in the tranexamic acid group. In conclusion, tranexamic acid can reduce perioperative blood loss in children undergoing repeat cardiac surgery.