Anesthesia and analgesia
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Anesthesia and analgesia · Dec 2015
The Efficacy and Safety of the Novel Peripheral Analgesic Isovaline as an Adjuvant to Propofol for General Anesthesia and Conscious Sedation: A Proof-of-Principle Study in Mice.
The combination of propofol and an opioid analgesic is widely used for procedural sedation, as well as total IV anesthesia. However, opioids produce respiratory depression, a primary cause of death due to these agents. We recently reported on the antinociceptive actions of isovaline, a small nonbiogenic amino acid that does not readily cross the blood-brain barrier and acts on peripheral γ-aminobutyric acid type B receptors. Here, we explored the possibility that isovaline may be an effective and safe alternative to opioids as an adjunct to propofol for producing anesthesia. ⋯ The novel analgesic, isovaline, coadministered with propofol, produced general anesthesia and conscious sedation in mice. The margin of safety for propofol-isovaline was considerably higher than that for propofol-fentanyl. This study's results show that propofol-based sedation and general anesthesia can be effectively and safely produced by replacing the conventional opioid component with a brain-impermeant peripherally acting γ-aminobutyric acid type B receptor agonist. The results provide proof of the principle of combining a peripheral analgesic with a centrally acting hypnotic to produce general anesthesia. This principle suggests a novel approach to clinical general anesthesia and conscious sedation.
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Anesthesia and analgesia · Dec 2015
The Influence of Hypovolemia and Fluid Resuscitation During Hemorrhagic Shock on Apneic Oxygen Desaturation After Preoxygenation in a Swine Model.
Patients experiencing major bleeding often require both aggressive fluid resuscitation and rapid sequence tracheal intubation. The influence of hemorrhage-induced hypovolemia, and/or subsequent fluid resuscitation, on the time until critical oxygen desaturation is not well described. We studied the time to oxygen desaturation in a pig model of hemorrhage shock and colloid resuscitation. ⋯ In patients with acute hemorrhagic shock, a hypovolemic state increases the duration of apnea until critical oxygen desaturation. Clinicians should thus consider the relationship between fluid resuscitation and time to desaturation when performing tracheal intubation in such patients.
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Anesthesia and analgesia · Dec 2015
Randomized Controlled TrialThe Effect of Systemic Magnesium on Postsurgical Pain in Children Undergoing Tonsillectomies: A -Double-Blinded, Randomized, Placebo-Controlled Trial.
Tonsillectomy is a frequently performed surgical procedure in children; however, few multimodal analgesic strategies have been shown to improve postsurgical pain in this patient population. Systemic magnesium infusions have been shown to reliably improve postoperative pain in adults, but their effects in pediatric surgical patients remain to be determined. In the current investigation, our main objective was to evaluate the use of systemic magnesium to improve postoperative pain in pediatric patients undergoing tonsillectomy. We hypothesized that children who received systemic magnesium infusions would have less post-tonsillectomy pain than the children who received saline infusions. ⋯ Despite a large number of studies demonstrating the efficacy of systemic magnesium for preventing postsurgical pain in adults, we could not find evidence for a significant clinical benefit of systemic magnesium infusion in children undergoing tonsillectomies. Our findings reiterate the importance of validating multimodal analgesic strategies in children that have been demonstrated to be effective in the adult population.
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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.