Anesthesia and analgesia
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Anesthesia and analgesia · May 1987
Comparative StudyThe pattern of train-of-four fade after atracurium: influence of different priming doses.
This study was designed to investigate the effect of three different priming doses of atracurium--0.06, 0.07, and 0.08 mg/kg--followed 3 min later by the remainder of a 0.5 mg/kg dose on the relationship between the depression in the first twitch of the train-of-four (T1) and train-of-four (TOF) fade. This relationship was studied after the administration of the full dose of the relaxant in all groups. ⋯ Acceleration of the onset of neuromuscular blockade was, however, evident in all groups that received atracurium in divided doses. The implication is, therefore, that prejunctional activity may not contribute significantly to the acceleration of onset of neuromuscular blockade after administration of atracurium in divided doses, as described in this study.
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Anesthesia and analgesia · May 1987
Comparative StudyPrior carotid surgery does not affect the reliability of landmarks for location of the internal jugular vein.
Twenty-one volunteer subjects who had undergone prior carotid endarterectomy (CEA) agreed to an ultrasound study of the neck. The transducer was held as one would hold a cannulating needle and ultrasound images were obtained of the great vessels in the neck. Each of two cannulating techniques was simulated on each side of every patient's neck. ⋯ These data show that prior CEA does not affect the location of the IJV. Tissue alterations or adhesions may render actual IJV cannulation more difficult or risky. The data suggest but do not prove that prior CEA may not increase the incidence of CA puncture under clinical conditions.
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Anesthesia and analgesia · May 1987
Comparative StudyBupivacaine disposition in mother, fetus, and neonate after spinal anesthesia for cesarean section.
Uptake of bupivacaine from the subarachnoid space and its placental transfer were measured in six patients undergoing elective cesarean section. Maternal plasma levels (59 +/- 32 ng/ml) were only about 5% of those found in a comparable previous study of epidural anesthesia. Mean plasma umbilical venous bupivacaine levels (20.2 +/- 21 ng/ml) were 7% of those found after epidural anesthesia. ⋯ Neonatal urine had measurable levels of both bupivacaine and its inactive metabolite, 2,6-pipecolylxylidine (PPX), for at least 36 hr after delivery. The results demonstrate that bupivacaine crosses the placenta and reaches the fetus, but in very low amounts. This transplacental passage occurs despite injection of only small doses of a very highly protein bound drug into the subarachnoid space.
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Anesthesia and analgesia · May 1987
Comparative StudyPlasma concentrations of epidural bupivacaine in mother and newborn: 0.125% versus 0.375%.
Central venous plasma concentrations of bupivacaine were determined in two groups of 15 parturients each who were given epidural analgesia for labor and vaginal delivery. One group received 10 ml of 0.125% bupivacaine plus epinephrine 1:800,000, the other group received 7 ml of 0.375% bupivacaine plus epinephrine 1:800,000. Plasma concentrations of bupivacaine in the umbilical venous (UV) and the umbilical arterial (UA) blood of their babies were also determined. ⋯ The measured plasma concentrations speak in favor of the less concentrated solution of bupivacaine in epidural analgesia for obstetrics. Seven milliliters of bupivacaine 0.375% is suitable for epidural analgesia in obstetrics but a low concentration-low dose technique, using 10 ml of bupivacaine 0.125% plus epinephrine 1:800,000 is safer. It provides good analgesia with minimal or no motor block and is associated with low maternal and neonatal plasma concentrations of bupivacaine, well below toxic levels and, to our knowledge, lower than in any other study.