Anesthesia and analgesia
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Anesthesia and analgesia · Mar 2016
Observational StudyBlood Bupivacaine Concentrations After Transversus Abdominis Plane Block in Neonates: A Prospective Observational Study.
Untreated pain can have instant and prolonged consequences to behavioral and neurologic outcomes in neonates. Although the use of transversus abdominis plane (TAP) block to minimize postsurgical pain has been demonstrated in neonates, no data regarding the safety of this procedure are available for this patient population. For instance, it is unknown whether plasma levels of local anesthetics are safe in neonates after TAP blocks. The main objective of the current investigation was to evaluate plasma bupivacaine concentrations in neonates having an ultrasound-guided TAP block. ⋯ Our results suggest a low risk of local anesthetic toxicity in neonates after a TAP block. Future studies to determine the efficacy of the TAP block to minimize postsurgical pain in this patient population are warranted.
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Anesthesia and analgesia · Mar 2016
Observational StudyRisk Factors Involved in Central-to-Radial Arterial Pressure Gradient During Cardiac Surgery.
A central-to-radial arterial pressure gradient may occur after cardiopulmonary bypass (CPB), which, in some patients, may last for a prolonged time after CPB. Whenever there is a pressure gradient, the radial artery pressure measure may underestimate a more centrally measured systemic pressure, which may result in a misguided therapeutic strategy. It is clinically important to identify the risk factors that may predict the appearance of a central-to-radial pressure gradient, because more central sites of measurements might then be considered to monitor systemic arterial pressure in high-risk patients. The objective of this study was to assess preoperative and intraoperative risk factors for central-to-radial pressure gradient. ⋯ Central-to-radial gradients are common in cardiac surgery. The threshold for using a central site for blood pressure monitoring should be low in small, high-risk patients undergoing longer surgical interventions to avoid inappropriate administration of vasopressors and/or inotropic agents.
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Anesthesia and analgesia · Mar 2016
Observational StudyVariability of Automated Intraoperative ST Segment Values Predicts Postoperative Troponin Elevation.
Intraoperative electrocardiographic monitoring is considered a standard of care. However, there are no evidence-based algorithms for using intraoperative ST segment data to identify patients at high risk for adverse perioperative cardiac events. Therefore, we performed an exploratory study of statistical measures summarizing intraoperative ST segment values determine whether the variability of these measurements was associated with adverse postoperative events. We hypothesized that elevation, depression, and variability of ST segments captured in an anesthesia information management system are associated with postoperative serum troponin elevation. ⋯ Analysis of automated ST segment values obtained during anesthesia may be useful for improving the prediction of postoperative troponin elevation.
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Anesthesia and analgesia · Mar 2016
Human Lumbar Ligamentum Flavum Anatomy for Epidural Anesthesia: Reviewing a 3D MR-Based Interactive Model and Postmortem Samples.
The ligamentum flavum (LF) forms the anatomic basis for the loss-of-resistance technique essential to the performance of epidural anesthesia. However, the LF presents considerable interindividual variability, including the possibility of midline gaps, which may influence the performance of epidural anesthesia. We devise a method to reconstruct the anatomy of the digitally LF based on magnetic resonance images to clarify the exact limits and edges of LF and its different thickness, depending on the area examined, while avoiding destructive methods, as well as the dissection processes. ⋯ The major anatomical features of the LF were reproduced in the 3D model. Details of its structure and variations of thickness in successive sagittal and axial slides could be visualized. Gaps within LF previously studied in cadavers have been identified in our interactive 3D model, which may help to understand their nature, as well as possible implications for epidural techniques.
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When adding new markers to existing prediction models, it is necessary to evaluate the models to determine whether the additional markers are useful. The net reclassification improvement (NRI) has gained popularity in this role because of its simplicity, ease of estimation, and understandability. Although the NRI provides a single-number summary describing the improvement new markers bring to a model, it also has several potential disadvantages. ⋯ Also, overfitting, or otherwise misspecified training models, produce overly positive NRI results. Because of the unaccounted for uncertainty in the model coefficient estimation, investigators should rely on bootstrapped confidence intervals rather than on tests of significance. Keeping in mind the limitations and drawbacks, the NRI can be helpful when used correctly.