Anesthesia and analgesia
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Anesthesia and analgesia · Mar 2009
An evaluation of a novel software tool for detecting changes in physiological monitoring.
We have developed a software tool (iAssist) to assist clinicians as they monitor the physiological data that guide their actions during anesthesia. The system tracks the statistical properties of multiple dynamic physiological processes and identifies new trend patterns. We report our initial evaluation of this tool (in pseudo real-time) and compare the detection of trend changes to a post hoc visual review of the full trend. We suggest a combination of criteria by which to evaluate the performance of monitoring devices that aim to enhance trend detection. ⋯ The algorithms perform favorably compared with a visual inspection of the complete trend. Further research is needed to identify when and how to draw the clinician's attention to these changes.
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Anesthesia and analgesia · Mar 2009
Lidocaine injection into the rat dorsal root ganglion causes neuroinflammation.
Injury of a spinal nerve or dorsal root ganglion (DRG) during selective spinal nerve blocks is a potentially serious complication that has not been adequately investigated. Our hypothesis was that local anesthetic injection into these structures may result in an inflammatory response and hyperalgesia. ⋯ Lidocaine injection into the DRG may produce hyperalgesia, possibly due to activation of resident satellite glial cells. In a clinical setting, local anesthetic injection into the DRG should be avoided during selective spinal nerve blocks.
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In addition to inhibiting the excitation conduction process in peripheral nerves, local anesthetics (LAs) cause toxic effects on the central nervous system, cardiovascular system, neuromuscular junction, and cell metabolism. Different postoperative neurological complications are ascribed to the cytotoxicity of LAs, but the underlying mechanisms remain unclear. Because the clinical concentrations of LAs far exceed their EC(50) for inhibiting ion channel activity, ion channel block alone might not be sufficient to explain LA-induced cell death. However, it may contribute to cell death in combination with other actions. In this study, we compared the cytotoxicity of six frequently used LAs and will discuss the possible mechanism(s) underlying their toxicity. ⋯ LAs can cause rapid cell death, which is primarily due to necrosis. Lidocaine and bupivacaine can trigger apoptosis with either increased time of exposure or increased concentration. These effects might be related to postoperative neurologic injury. Lidocaine, linked to the highest incidence of transient neurological symptoms, was not the most toxic LA, whereas bupivacaine, a drug causing a very low incidence of transient neurological symptoms, was the most toxic LA in our cell model. This suggests that cytotoxicity-induced nerve injury might have different mechanisms for different LAs and different target(s) other than neurons.
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Anesthesia and analgesia · Mar 2009
An absorbable local anesthetic matrix provides several days of functional sciatic nerve blockade.
Functional blockade of peripheral nerves is the primary objective of local anesthesia, and it is often desirable to have a persistent blockade, sustained throughout and beyond a surgical procedure. Current local anesthetics give effective analgesia for <8-12 h after a single bolus injection. We report on an implantable, controlled-release drug delivery system intended for use in bone and consisting of a Food and Drug Administration-approved matrix containing lidocaine that is capable of local delivery for several days. ⋯ Xybrex is an absorbable, controlled-release drug delivery system that provides several days of analgesia for rat peripheral nerves without apparent significant local neurotoxicity or systemic toxicity.
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Anesthesia and analgesia · Mar 2009
Real-time assessment of perioperative behaviors and prediction of perioperative outcomes.
New onset maladaptive behaviors, such as temper tantrums, nightmares, bed-wetting, attention-seeking, and fear of being alone are common in children after outpatient surgery. Preoperative anxiety, fear and distress behaviors of children predict postoperative maladaptive behaviors as well as emergence delirium. Parental anxiety has also been found to influence children's preoperative anxiety. Currently, there is no real-time and feasible tool to effectively measure perioperative behaviors of children and parents. We developed a simple and real-time scale, the Perioperative Adult Child Behavioral Interaction Scale (PACBIS) to assess perioperative child and parent behaviors that might predict postoperative problematic behavior and emergence excitement. ⋯ The PACBIS is the first real-time scoring instrument that evaluates children's and parents' perioperative behavior. The specific behaviors identified by the PACBIS might provide targets for interventions to improve perioperative experiences and postoperative outcomes.