Anesthesiology
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Observational Study
Postoperative Hypotension after Noncardiac Surgery and the Association with Myocardial Injury.
Intraoperative hypotension has been associated with postoperative morbidity and early mortality. Postoperative hypotension, however, has been less studied. This study examines postoperative hypotension, hypothesizing that both the degree of hypotension severity and longer durations would be associated with myocardial injury. ⋯ In this study, postoperative hypotension was common and was independently associated with myocardial injury.
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Review Case Reports
Determining Associations and Estimating Effects with Regression Models in Clinical Anesthesia.
There are an increasing number of "big data" studies in anesthesia that seek to answer clinical questions by observing the care and outcomes of many patients across a variety of care settings. This Readers' Toolbox will explain how to estimate the influence of patient factors on clinical outcome, addressing bias and confounding. One approach to limit the influence of confounding is to perform a clinical trial. ⋯ Logistic regression is used when the outcome is binary (e.g., intracranial hemorrhage: yes or no), by modeling the natural log for the odds of an outcome. Because outcomes are influenced by many factors, we commonly use multivariable logistic regression to estimate the unique influence of each factor. From this tutorial, one should acquire a clearer understanding of how to perform and assess multivariable logistic regression.
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Isoflurane Exposure in Juvenile Caenorhabditis elegans Causes Persistent Changes in Neuron Dynamics.
Animal studies demonstrate that anesthetic exposure during neurodevelopment can lead to persistent behavioral impairment. The changes in neuronal function underlying these effects are incompletely understood. Caenorhabditis elegans is well suited for functional imaging of postanesthetic effects on neuronal activity. This study aimed to examine such effects within the neurocircuitry underlying C. elegans locomotion. ⋯ Altered locomotive behavior and activity dynamics indicate a persistent effect on interneuron dynamics and circuit function in C. elegansafter developmental exposure to isoflurane. These effects are modulated by a loss of daf-16 or mTOR activity, consistent with a pathologic activation of stress-response pathways.
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Recent cryo-electron microscopic imaging studies have shown that in addition to binding to the classical extracellular benzodiazepine binding site of the α1β3γ2L γ-aminobutyric acid type A (GABAA) receptor, diazepam also binds to etomidate binding sites located in the transmembrane receptor domain. Because such binding is characterized by low modulatory efficacy, the authors hypothesized that diazepam would act in vitro and in vivo as a competitive etomidate antagonist. ⋯ At micromolar concentrations and in the presence of flumazenil to inhibit allosteric modulation via the classical benzodiazepine binding site of the GABAA receptor, diazepam acts as an in vitro and in vivo competitive etomidate antagonist.
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Sevoflurane anesthesia induces Tau phosphorylation and cognitive impairment in neonatal but not in adult mice. This study tested the hypothesis that differences in brain Tau amounts and in the activity of mitochondria-adenosine triphosphate (ATP)-Nuak1-Tau cascade between the neonatal and adult mice contribute to the age-dependent effects of sevoflurane on cognitive function. ⋯ Higher brain Tau concentrations and lower brain mitochondrial metabolism in neonatal compared with adult mice contribute to developmental stage-dependent cognitive dysfunction after sevoflurane anesthesia.