Anesthesia and analgesia
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Anesthesia and analgesia · Aug 2002
The technical aspects of epidural steroid injections: a national survey.
Although epidural steroid injections (ESIs) are a common treatment for chronic pain conditions, it is not clear whether there is consensus on their technical aspects. The current literature suggests that variations in technical aspects may affect ESI outcomes. The goal of the survey was to help establish a standard frame of reference for the performance of ESIs. We analyzed survey results from 68 academic anesthesia programs and 28 private practices in the United States. The main finding in this survey is that there is no clear-cut consensus as to the ideal method to perform ESI. There is a wide variation among individual practices in almost every technical aspect of ESI. Private practices use significantly more fluoroscopy than academic centers. The large difference was found in the cervical region where 73% of private practices and only 39% of academic institutions polled perform the ESIs with fluoroscopic guidance (P = 0.005). A similar discrepancy was found in approaches to the epidural space after laminectomy where 61% of private practices, but only 15% of academic centers, use the transforaminal approach. The study results indicate that there is no consensus, and that there is a wide variation in current practices. ⋯ A national survey of practices performing epidural steroid injections was conducted. The purpose was to establish whether consensus exists on technical aspects of this procedure. The study results indicate that there is no consensus, and that there is a wide variation in current practices.
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Anesthesia and analgesia · Aug 2002
Case ReportsFalsely increased bispectral index values in a series of patients undergoing cardiac surgery using forced-air-warming therapy of the head.
Falsely increased bispectral index (BIS) values of >70 occur during forced-warm-air therapy in patients undergoing cardiac surgery. When forced-warm-air therapy for the head is used (as in ultra-fast-tracking cardiac patients), BIS interpretation needs careful examination. Falsely increased BIS values can easily be recognized when the warm-air flow is stopped. Within 2-3 min, BIS returns to a much lower, "true" value.
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Anesthesia and analgesia · Aug 2002
Case ReportsTreatment of persistent tachycardia with dexmedetomidine during off-pump cardiac surgery.
After unsuccessful treatment of intraoperative tachycardia with esmolol during off-pump revascularization, heart rate was successfully reduced with a bolus and infusion of dexmedetomidine.
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Anesthesia and analgesia · Aug 2002
A second-generation blood substitute (perflubron emulsion) increases the blood solubility of modern volatile anesthetics in vitro.
Perfluorocarbon-based emulsions increase the blood solubility of isoflurane, enflurane, and halothane, with a maximal effect reported for the less soluble isoflurane. Current volatile anesthetics are less soluble and may be more affected by this phenomenon. Perflubron (Oxygent(TM)) is a perfluorocarbon-based emulsion in late-stage clinical testing in surgical patients for use as a temporary oxygen carrier. We tested the hypothesis that perflubron increases the solubility of isoflurane, sevoflurane, and desflurane, as reflected by their blood/gas partition coefficient (lambda(Bl:g)). Fresh whole-blood samples were drawn from eight volunteers and mixed with perflubron to obtain concentrations of 1.2%, 1.8%, and 3.6% by volume (equivalent to in vivo doses of 1.8 to 5.4 g/kg, which represent up to twice the intended clinical dose range). By using the double-extraction method, we demonstrated increased lambda(Bl:g) for isoflurane, sevoflurane, and desflurane. However, the solubility in blood does not really change, because volatile anesthetics are actually partitioning into perflubron. Increasing the amount of emulsion in the blood consequently increases the amount of gas carried, as reflected by the measured linear correlation between the lambda(Bl:g) values of all three volatile anesthetics and perflubron doses. Even though the increase ranges from 0.9 (desflurane) to 2.6 (sevoflurane) times the normal value, the apparent lack of clinical implications in current trials with perflubron may trigger further in vivo experiments. ⋯ Perflubron increases the in vitro solubility of volatile anesthetics when present in the blood at clinically relevant concentrations. Volatile anesthetics actually partition into the emulsion, but the solubility in the blood does not change. Further studies are needed to assess whether perflubron will affect the pharmacokinetics of volatile anesthetics in vivo.
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Anesthesia and analgesia · Aug 2002
The construction of learning curves for basic skills in anesthetic procedures: an application for the cumulative sum method.
This study aimed at constructing learning curves for basic procedural skills in anesthesiology using the cumulative sum method. We recorded 1234 peripheral venous cannulations, 895 orotracheal intubations, 688 spinals, and 344 epidurals performed by residents during the first 10 mo of training. Learning curves for each procedure were constructed by using the cusum method. The number of procedures performed until attainment of acceptable failure rates was calculated. All residents mastered peripheral venous cannulation after 79 +/- 47 procedures. Four of 7 residents attained acceptable failure rates at orotracheal intubation after 43 +/- 33 proce- dures. Seven of 11 residents attained acceptable failure rates at spinal anesthesia after 36 +/- 20 procedures. At epidural anesthesia, 5 of 11 residents attained acceptable failure rates after 21 +/- 11 procedures. The cusum method is a useful tool for objectively measuring performance during the learning phase of basic procedures. The wide interindividual variability in the number of procedures required to be performed before attaining acceptable failure rates suggests that performance should be followed on an individual basis. ⋯ Learning curves for peripheral venous cannulation, tracheal intubation, and spinal and epidural anesthesia were constructed using the cumulative sum (cusum) method. There was a wide variability in the number of procedures performed until attainment of acceptable failure rates. The cusum method may improve our means of evaluating residents' technical skills.