Anesthesia and analgesia
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Anesthesia and analgesia · Mar 2018
Review Comparative StudyStatistical Significance Versus Clinical Importance of Observed Effect Sizes: What Do P Values and Confidence Intervals Really Represent?
Effect size measures are used to quantify treatment effects or associations between variables. Such measures, of which >70 have been described in the literature, include unstandardized and standardized differences in means, risk differences, risk ratios, odds ratios, or correlations. While null hypothesis significance testing is the predominant approach to statistical inference on effect sizes, results of such tests are often misinterpreted, provide no information on the magnitude of the estimate, and tell us nothing about the clinically importance of an effect. ⋯ This tutorial reviews different effect size measures and describes how confidence intervals can be used to address not only the statistical significance but also the clinical significance of the observed effect or association. Moreover, we discuss what P values actually represent, and how they provide supplemental information about the significant versus nonsignificant dichotomy. This tutorial intentionally focuses on an intuitive explanation of concepts and interpretation of results, rather than on the underlying mathematical theory or concepts.
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Anesthesia and analgesia · Mar 2018
Clinical Trial Observational StudyMicroparticle Release During Normal Cesarean Delivery.
Coagulation increases during pregnancy and peaks during parturition. We hypothesized that an increase in microparticle (MP) levels in plasma occurs around the time of placental separation and subsides over several hours. We performed a prospective observational pilot study to investigate plasma MP levels in healthy parturients immediately before and after cesarean delivery. ⋯ Samples underwent flow cytometry and staining to determine MP levels. Placental-derived MPs were further characterized for the presence of procoagulant proteins. Placental-derived MPs increased immediately after delivery before returning to baseline in healthy parturients.
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Anesthesia and analgesia · Mar 2018
Comparative StudyYears Versus Days Between Successive Surgeries, After an Initial Outpatient Procedure, for the Median Patient Versus the Median Surgeon in the State of Iowa.
Previously, we studied the relative importance of different institutional interventions that the largest hospital in Iowa could take to grow the anesthesia department's outpatient surgical care. Most (>50%) patients having elective surgery had not previously had surgery at the hospital. Patient perioperative experience was unimportant for influencing total anesthesia workload and numbers of patients. More important was the availability of surgical clinic appointments within several days. These results would be generalizable if the median time from surgery to a patient's next surgical procedure was large (eg, >2 years), among all hospitals in Iowa with outpatient surgery, and without regard to the hospital where the next procedure was performed. ⋯ The median time to the next surgery was >2 years for patients versus 1 day for surgeons. Thus, although patients' experiences are an important attribute of quality of care, surgeons' experiences are orders of magnitude more important from the vantage point of marketing and growth of an anesthesia practice.
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Anesthesia and analgesia · Mar 2018
Patients Undergoing Cesarean Delivery After Exposure to Oxytocin During Labor Require Higher Postpartum Oxytocin Doses.
Experts recommend postpartum oxytocin to prevent uterine atony and hemorrhage, but oxytocin may be associated with dose-dependent adverse effects, and the correct dose of postpartum oxytocin has yet to be determined. The effective dose in 90% of patients (ED90) of oxytocin after cesarean delivery may be higher in patients exposed to oxytocin during labor compared to patients unexposed. We therefore undertook this study to compare postpartum oxytocin requirements in patients exposed to oxytocin prior to cesarean delivery versus those not exposed, when all were treated according to a specific institutional protocol. ⋯ Reported increases in the ED90 of postpartum oxytocin after oxytocin exposure during labor appear to be clinically significant. We have therefore altered our institutional protocol so that women preexposed to oxytocin routinely receive higher initial postpartum oxytocin infusion rates.
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Anesthesia and analgesia · Mar 2018
Photoplethysmography and Heart Rate Variability for the Diagnosis of Preeclampsia.
The goal of this study was to determine a set of timing, shape, and statistical features available through noninvasive monitoring of maternal electrocardiogram and photoplethysmography that identifies preeclamptic patients. ⋯ Vascular parameters, as assessed noninvasively by photoplethysmography and heart rate variability, may have a role in screening women suspected of having preeclampsia, particularly in areas with limited resources.