Anesthesia and analgesia
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Anesthesia and analgesia · Dec 1997
Randomized Controlled Trial Comparative Study Clinical TrialPharmacokinetics and pharmacodynamics of propofol in a new solvent.
Pain on injection is the most commonly reported adverse event after propofol injection. In a randomized, cross-over study in two groups of 12 healthy male volunteers (24-42 yr), we compared the pharmacokinetics and pharmacodynamics of two new propofol formulations (1% and 2% concentrations) in a fat emulsion consisting of medium- and long-chain triglycerides with the standard propofol formulation. After a single intravenous bolus injection of 2 mg/kg, propofol blood levels were measured for 24 h and evaluated according to an open three-compartment model. The derived pharmacokinetic variables were not different among formulations. Additionally, electroencephalographic recordings of the onset and duration of hypnotic action were comparable with all formulations. After propofol 1% in the new formulation, fewer volunteers reported severe or moderate pain on injection (9%) than after the standard formulation (59%) (P < 0.05). We attribute this result to a lower concentration of free propofol in the aqueous phase of the new formulation. ⋯ Changing the composition of the carrier fat emulsion for propofol does not have an impact on the pharmacokinetics and efficacy of propofol, but it promises to provide better patient acceptance by lowering the incidence of moderate and severe pain on injection.
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Anesthesia and analgesia · Dec 1997
Pharmacokinetics and efficacy of long-term epidural ropivacaine infusion for postoperative analgesia.
The aim of this study was to evaluate the pharmacokinetics and efficacy of the new local anesthetic ropivacaine when used for epidural infusion for up to 72 h after major orthopedic surgery. Immediately after surgery, an epidural infusion of ropivacaine 2 mg/mL was begun at a rate of 6 mL/h in 11 patients. The infusion rate was then adjusted according to patient analgesic needs or side effects. Blood samples were taken during and after the infusion to determine total and unbound ropivacaine and alpha1-acid glycoprotein (AAG) concentrations. Patients were assessed regularly for sensory and motor block and pain using a visual analog scale (VAS) score (0-100 mm). Ten patients received 63-72 h of infusion. Total plasma concentrations of ropivacaine and binding protein (AAG) increased during the infusion such that free concentrations plateaued or began to fall over time. VAS values during mobilization were less than 40 mm in 93% of patients. The majority of patients had no measurable motor block once the surgical block had regressed. When epidural ropivacaine was titrated to achieve a stable sensory block, there was a low incidence of motor block, and free plasma ropivacaine levels were well below the toxic range. ⋯ The pharmacokinetics of continuous epidural infusions of ropivacaine are described in patients for up to 72 h postoperatively. Clinical efficacy and side effects are also reported. An understanding of the plasma concentrations obtained and modes of elimination during prolonged epidural infusion is important for safe, routine clinical use in postoperative analgesia.
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Anesthesia and analgesia · Dec 1997
Predicting and treating coagulopathies after cardiopulmonary bypass in children.
Coagulopathies in children after cardiopulmonary bypass (CPB) are complex. There are very limited data correlating coagulation tests with postoperative bleeding. We evaluated coagulation changes after CPB and after the administration of coagulation products to 75 children. Baseline coagulation tests were obtained and repeated after protamine administration, after transfusion of individual coagulation products, and on arrival in the intensive care unit (ICU). Regression analysis demonstrated no baseline coagulation test to predict postoperative chest tube drainage. Weight and duration of CPB were determined to be the only predictors of bleeding. Further analyses demonstrated that children <8 kg had more bleeding and required more coagulation products than children >8 kg. Postprotamine platelet count and fibrinogen level correlated independently with 24-h chest tube drainage in children <8 kg, whereas postprotamine platelet count and thrombelastographic values did so in patients weighing >8 kg. Platelet administration alone was found to restore effective hemostasis in many patients. With ongoing bleeding, cryoprecipitate improved coagulation parameters and limited blood loss. Fresh-frozen plasma administration after platelets worsened coagulation parameters and was associated with greater chest tube drainage and more coagulation product transfusions in the ICU. Objective data to guide post-CPB component therapy transfusion in children are suggested. ⋯ Children <8 kg can be expected to have more severe coagulopathies, require more coagulation product transfusions, and bleed more after cardiopulmonary bypass. Correlations between coagulation tests and postoperative chest tube drainage are defined. Platelets and, if necessary, cryoprecipitate optimally restore hemostasis. Fresh-frozen plasma offers no benefits in correcting postcardiopulmonary bypass coagulopathies in children.
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Anesthesia and analgesia · Dec 1997
Multi-institutional survey of graduates of pediatric anesthesia fellowship: assessment of training and current professional activities.
We surveyed all the graduates of four fellowship programs in pediatric anesthesia between 1985 and 1993 to assess their current professional activities, their evaluation of fellowship training, and their opinions on future directions of such training. One-hundred ninety-one (62%) of the graduates responded. Nearly all of the respondents had sought fellowship training for pediatric anesthesia and thought that the training was worthwhile. At the time of the survey, 40% worked in a children's hospital, 72% had university or affiliate positions, and 54% had a practice that was > 50% pediatric. Those with > or = 12 mo fellowship and/or board certification in pediatrics were the most likely to have a pediatric-dedicated practice. Seventy percent of the respondents thought that fellowship training should be for 12 mo, and the proportion of respondents who recommended inclusion of training in pain management and clinical research was greater than the number who had actually received such training. Fifty-eight percent of respondents supported restriction of fellowship positions in the future, but 83% did not support a mandatory 2-yr fellowship with research training. We conclude that fellowships in pediatric anesthesia seem to be successful in providing training that is not only satisfying to the trainees, but that is also followed by active involvement in the care of children and in the training of residents and fellows in anesthesia. Additional information should be gathered to assess the impact of this training on pediatric care, to formulate a standardized curriculum, and to justify support for such training in the future. ⋯ We surveyed graduates of four fellowship programs in pediatric anesthesia (1985-1993) to assess current professional activities, fellowship training, and future directions of such training. Fellowships in pediatric anesthesia seem to provide training that is satisfying to trainees and that is followed by active involvement in the care of children.