Anesthesia and analgesia
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Anesthesia and analgesia · Jan 2018
ReviewThe Technology of Processed Electroencephalogram Monitoring Devices for Assessment of Depth of Anesthesia.
Commercial brain function monitors for depth of anesthesia have been available for more than 2 decades; there are currently more than 10 devices on the market. Advances in this field are evidenced by updated versions of existing monitors, development of new monitors, and increasing research unveiling the mechanisms of anesthesia on the brain. Electroencephalography signal processing forms an integral part of the technology supporting the brain function monitors for derivation of a depth-of-anesthesia index. ⋯ This review will highlight the general design principles of these devices and the crucial stages in electroencephalography signal processing and classification, with a focus on the key mathematical techniques used in algorithm development for final derivation of the index representing anesthetic state. We will briefly discuss the advantages and limitations of this technology in the clinical setting as a tool in our repertoire used for optimizing individualized patient care. Also included is a table describing 10 available commercial depth-of-anesthesia monitors.
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Anesthesia and analgesia · Jan 2018
Review Case ReportsAnesthetic Management of Narcolepsy Patients During Surgery: A Systematic Review.
Narcolepsy is a rare sleep disorder characterized by excessive daytime sleepiness, sleep paralysis, and/or hypnagogic/hypnopompic hallucinations, and in some cases cataplexy. The response to anesthetic medications and possible interactions in narcolepsy patients is unclear in the perioperative period. In this systematic review, we aim to evaluate the current evidence on the perioperative outcomes and anesthetic considerations in narcolepsy patients. ⋯ We found a paucity of prospective clinical trials in this patient population, as most of the studies were case reports or observational studies. Continuation of preoperative medications, depth of anesthesia monitoring, use of multimodal analgesia with short-acting agents and regional anesthesia techniques were associated with favorable outcomes. Obstetric patients may be at greater risk for worsening narcolepsy symptoms, possibly related to a reduction or discontinuation of medications. For neurosurgical procedures involving the hypothalamus or third and fourth ventricle, postoperative considerations should include monitoring for symptoms of narcolepsy. Future studies are needed to better define perioperative risks associated with anesthesia and surgery in this population of patients.
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Anesthesia and analgesia · Jan 2018
Study Design Rigor in Animal-Experimental Research Published in Anesthesia Journals.
Lack of reproducibility of preclinical studies has been identified as an impediment for translation of basic mechanistic research into effective clinical therapies. Indeed, the National Institutes of Health has revised its grant application process to require more rigorous study design, including sample size calculations, blinding procedures, and randomization steps. We hypothesized that the reporting of such metrics of study design rigor has increased over time for animal-experimental research published in anesthesia journals. ⋯ Our hypothesis that reported metrics of rigor in animal-experimental studies in anesthesia journals have increased during the past decade was confirmed. More consistent reporting, or explicit justification for absence, of sample size calculations, blinding techniques, and randomization procedures could better enable readers to evaluate potential sources of bias in animal-experimental research manuscripts. Future studies should assess whether such steps lead to improved translation of animal-experimental anesthesia research into successful clinical trials.
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Anesthesia and analgesia · Jan 2018
Randomized Controlled Trial Multicenter Study Comparative StudyRespiratory System Mechanics During Low Versus High Positive End-Expiratory Pressure in Open Abdominal Surgery: A Substudy of PROVHILO Randomized Controlled Trial.
In the 2014 PROtective Ventilation using HIgh versus LOw positive end-expiratory pressure (PROVHILO) trial, intraoperative low tidal volume ventilation with high positive end-expiratory pressure (PEEP = 12 cm H2O) and lung recruitment maneuvers did not decrease postoperative pulmonary complications when compared to low PEEP (0-2 cm H2O) approach without recruitment breaths. However, effects of intraoperative PEEP on lung compliance remain poorly understood. We hypothesized that higher PEEP leads to a dominance of intratidal overdistension, whereas lower PEEP results in intratidal recruitment/derecruitment (R/D). To test our hypothesis, we used the volume-dependent elastance index %E2, a respiratory parameter that allows for noninvasive and radiation-free assessment of dominant overdistension and intratidal R/D. We compared the incidence of intratidal R/D, linear expansion, and overdistension by means of %E2 in a subset of the PROVHILO cohort. ⋯ During mechanical ventilation with protective tidal volumes in patients undergoing open abdominal surgery, lung recruitment followed by PEEP of 12 cm H2O decreased the incidence of intratidal R/D and did not worsen overdistension, when compared to PEEP ≤2 cm H2O.