Anesthesia and analgesia
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Anesthesia and analgesia · Jan 2016
Observational StudyAn Observational Study of Cerebral Blood Flow Velocity During Hypotensive Epidural Anesthesia.
Hypotensive epidural anesthesia (HEA), as practiced at our institution, uses sympathetic blockade to achieve mean arterial blood pressure (MAP) of ≤50 mm Hg while administering epinephrine by infusion to support the circulation. HEA has not been associated with gross adverse effects on neurologic outcome or cognitive function in the postoperative period, suggesting adequate cerebral blood flow (CBF). However, the use of MAPs well below the commonly accepted lower limit of CBF autoregulation suggests that CBF should be significantly reduced below normal levels. To examine these conflicting hypotheses, we performed a prospective investigation of the effects of HEA on CBF velocity (CBFV), an accepted index of cerebral perfusion. ⋯ Both hypotheses proved partially correct. CBFV was sometimes well maintained during HEA, despite MAPs well below the commonly accepted lower limit of autoregulation. However, there was considerable interindividual heterogeneity with 23% of subjects having CBFV reductions >20% (99% lower confidence limit: 9%), with some reductions approaching the threshold for ischemic injury. The present data do not allow us to determine whether hypotension would be similarly tolerated in other circumstances.
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Anesthesia and analgesia · Jan 2016
ReviewEfficacy Outcome Measures for Procedural Sedation Clinical Trials in Adults: An ACTTION Systematic Review.
Successful procedural sedation represents a spectrum of patient- and clinician-related goals. The absence of a gold-standard measure of the efficacy of procedural sedation has led to a variety of outcomes being used in clinical trials, with the consequent lack of consistency among measures, making comparisons among trials and meta-analyses challenging. We evaluated which existing measures have undergone psychometric analysis in a procedural sedation setting and whether the validity of any of these measures support their use across the range of procedures for which sedation is indicated. ⋯ Certain scales, for example, those requiring motor stimulation, are unsuitable to evaluate sedation for procedures where movement is prohibited (e.g., magnetic resonance imaging scans). Further work is required to evaluate existing measures for procedures for which they were not developed. Depending on the outcomes of these efforts, it might ultimately be necessary to consider measures of sedation efficacy to be procedure specific.
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Target-controlled infusions (TCIs) have been used in research and clinical practice for >2 decades. Nonapproved TCI software systems have been used during the conduct of almost 600 peer-reviewed published studies involving large numbers of patients. The first-generation pumps were first approved in 1996, and since then an estimated 25,000 units have been sold and used. ⋯ Research software is also readily integrated into data management modules. Although TCI is a part of established practice around the world, TCI devices have not received regulatory approval in the United States. In the United States, TCI administration of propofol and opioids for sedation and anesthesia is only possible using research software in IRB-approved research studies.