Anesthesia and analgesia
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Anesthesia and analgesia · Dec 2015
Review Meta AnalysisSystematic Reviews of Anesthesiologic Interventions Reported as Statistically Significant: Problems with Power, Precision, and Type 1 Error Protection.
The GRADE Working Group assessment of the quality of evidence is being used increasingly to inform clinical decisions and guidelines. The assessment involves explicit consideration of all sources of uncertainty. One of these sources is imprecision or random error. Many published meta-analyses are underpowered and likely to be updated in the future. When data are sparse and there are repeated updates, the risk of random error is increased. Trial Sequential Analysis (TSA) is one of several methodologies that estimates this increased risk (and decreased precision) in meta-analyses. With nominally statistically significant meta-analyses of anesthesiologic interventions, we used TSA to estimate power and imprecision in the context of sparse data and repeated updates. ⋯ Most nominally statistically significant meta-analyses of anesthesiologic interventions are underpowered, and many do not maintain their risk of type 1 error <5% if TSA monitoring boundaries are applied. Consideration of the effect of sparse data and repeated updates is needed when assessing the imprecision of meta-analyses of anesthesiologic interventions.
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Anesthesia and analgesia · Dec 2015
Meta AnalysisThe Analgesic Efficacy of Ultrasound-Guided Transversus Abdominis Plane Block in Adult Patients: A Meta-Analysis.
Previous meta-analyses of the transversus abdominis plane (TAP) block have examined a maximum of 12 articles, including fewer than 650 participants, and have not examined the effect of ultrasound-guided techniques specifically. Recently, many trials that use ultrasound approaches to TAP block have been published, which report conflicting analgesic results. This meta-analysis aims to evaluate the analgesic efficacy of ultrasound-guided TAP blocks exclusively for all types of abdominal surgeries in adult patients. ⋯ Ultrasound-guided TAP block provides marginal postoperative analgesic efficacy after abdominal laparotomy or laparoscopy and cesarean delivery. However, it does not provide additional analgesic effect in patients who also received spinal anesthesia containing a long-acting opioid. The minimal analgesic efficacy is independent of the timing of injection, the approach adopted, or the presence of postoperative multimodal analgesia. Because of heterogeneity of the results, these findings should be interpreted with caution.
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Anesthesia and analgesia · Dec 2015
Meta AnalysisPreoperative Acute Normovolemic Hemodilution for Minimizing Allogeneic Blood Transfusion: A Meta-Analysis.
Previous studies have evaluated the efficacy of preoperative acute normovolemic hemodilution (PANH) in reducing the need for allogeneic blood transfusion. However, the results to date have been controversial. In this study, we sought to reassess the efficacy and safety of PANH based on newly emerging evidence. ⋯ Although these results suggest that PANH is effective in reducing allogeneic blood transfusion, we identified significant heterogeneity and publication bias, which raises concerns about the true efficacy of PANH.