Anesthesia and analgesia
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Anesthesia and analgesia · Oct 2011
Randomized Controlled Trial Comparative StudyProgrammed intermittent epidural bolus versus continuous epidural infusion for labor analgesia: the effects on maternal motor function and labor outcome. A randomized double-blind study in nulliparous women.
Programmed intermittent epidural anesthetic bolus (PIEB) technique may result in reduced total local anesthetic consumption, fewer manual boluses, and greater patient satisfaction compared with continuous epidural infusion (CEI). In this randomized, double-blind study, we compared the incidence of motor block and labor outcome in women who received PIEB or CEI for maintenance of labor analgesia. The primary outcome variable was maternal motor function and the secondary outcome was mode of delivery. ⋯ Maintenance of epidural analgesia with PIEB compared with CEI resulted in a lower incidence of maternal motor block and instrumental vaginal delivery.
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Anesthesia and analgesia · Oct 2011
ReviewAn introduction to multilevel modeling for anesthesiologists.
In population-based research, subjects are frequently in clusters with shared features or demographic characteristics, such as age range, neighborhood, who they have for a physician, and common comorbidities. Classification into clusters also applies at broader levels. Physicians are classified by physician group or by practice site; hospitals can be characterized by size, location, or demographics. ⋯ Data from nested structures may be interdependent because of similarities among subjects in a cluster, while nesting at multiple levels makes it difficult to know whether findings should be applied to the individual or to the larger group. Statistical tools, known variously as hierarchical linear modeling, multilevel modeling, mixed linear modeling, and other terms, have been developed in the education and social science fields to deal effectively with these issues. Our goal in this article is to review the implications of hierarchical, nested data organization and to provide a step-by-step tutorial of how multilevel modeling could be applied to a problem in anesthesia research using current, commercially available software.
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Anesthesia and analgesia · Oct 2011
Randomized Controlled TrialReversal of clopidogrel-induced bleeding with rFVIIa in healthy subjects: a randomized, placebo-controlled, double-blind, exploratory study.
Clopidogrel (Plavix®) therapy, although effective for minimizing risk of thrombotic events, is also associated with potential bleeding risk. Recombinant activated FVII (rFVIIa, NovoSeven®) induces hemostasis in hemophilia patients with inhibitors (alloantibodies) and has been proposed as potential treatment for mitigating clopidogrel therapy-mediated bleeding. ⋯ In this clinical study, rFVIIa (10 and 20 μg/kg) reversed the effect of clopidogrel on blood loss.
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Anesthesia and analgesia · Oct 2011
The limitations of near-infrared spectroscopy to assess cerebrovascular reactivity: the role of slow frequency oscillations.
A total hemoglobin reactivity index (THx) derived from near-infrared spectroscopy (NIRS) has recently been introduced to assess cerebrovascular reactivity noninvasively. Analogously to the pressure reactivity index (PRx), THx is calculated as correlation coefficient with arterial blood pressure (ABP). However, the reliability of THx in the injured brain is uncertain. Although slow oscillations have been described in NIRS signals, their significance for assessment of autoregulation remains unclear. In the current study, we investigated the role of slow oscillations of total hemoglobin for NIRS-based cerebrovascular reactivity monitoring. ⋯ Our results suggest that the NIRS-based cerebrovascular reactivity index THx can be used as a noninvasive substitute for PRx, but only during phases with sufficient slow wave power in the input signal. Furthermore, a good agreement between the THx measures on both sides seems to be a prerequisite for comparison of a global (PRx) versus the more local (THx) index. Nevertheless, noninvasive assessment of cerebrovascular reactivity may be desirable in patients without ICP monitoring and help to guide ABP management in these patients.
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Anesthesia and analgesia · Oct 2011
Pharmacokinetics and tissue penetration of cefoxitin in obesity: implications for risk of surgical site infection.
Obesity is a significant risk factor for surgical site infections (SSIs), for poorly understood reasons. SSIs are a major cause of morbidity, prolonged hospitalization, and increased health care cost. Drug disposition in general is frequently altered in the obese. Preoperative antibiotic administration, achieving adequate tissue concentrations at the time of incision, is an essential strategy to prevent SSIs. Nonetheless, there is little information regarding antibiotic concentrations in obese surgical patients. This investigation tested the hypothesis that the prophylactic antibiotic cefoxitin may have delayed and/or diminished tissue penetration in the obese. ⋯ Obese surgical patients have impaired tissue penetration of the prophylactic antibiotic cefoxitin, and inadequate tissue concentrations despite increased clinical dose (2 g). Inadequate tissue antibiotic concentrations may be a factor in the increased risk of SSIs in obese surgical patients. Additional studies are needed to define doses achieving adequate tissue concentrations.