Anesthesiology
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Permissive hypercapnia is a ventilatory strategy aimed at avoiding lung volutrauma in patients with severe acute respiratory distress syndrome (ARDS). Expiratory washout (EWO) is a modality of tracheal gas insufflation that enhances carbon dioxide removal during mechanical ventilation by reducing dead space. The goal of this prospective study was to determine the efficacy of EWO in reducing the partial pressure of carbon dioxide (PaCO2) in patients with severe ARDS treated using permissive hypercapnia. ⋯ Expiratory washout is an effective and easy-to-use ventilatory modality to reduce PaCO2 and increase pH during permissive hypercapnia. However, it significantly increases airway pressures and lung volume through expiratory flow limitation, reexposing some patients to a risk of lung volutrauma if the extrinsic positive end-expiratory pressure is not substantially reduced.
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Electronic anesthesia record keeping (EARK) systems increasingly are used in the operating room, but studies have only recently begun to investigate their effect on anesthesia task performance. Teak analysis, workload assessment, and vigilance assessment techniques were used to study senior residents providing anesthesia for coronary artery bypass graft (CABG) procedures. The impact on anesthesia residents' workload of the routine use of transesophageal echocardiography (TEE) also was examined. ⋯ This study provides an objective description of the task distribution and workload during the administration of anesthesia for cardiac surgery. Under the conditions of this study. EARK use modestly decreased the time spent record keeping during the postintubation prebypass period. However, there was no effect of EARK either on vigilance or several measures of workload. TEE use was associated with increased workload and possibly decreased vigilance.
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In 1981, with support from the American Society of Anesthesiologists and the American College of Obstetricians and Gynecologists, anesthesia and obstetric providers were surveyed to identify the personnel and methods used to provide obstetric anesthesia in the United States. The survey was expanded and repeated in 1992 with support from the same organizations. ⋯ Compared with 1981, analgesia is more often used by parturients during labor, and general anesthesia is used less often in patients having cesarean section deliveries. In the smallest hospitals, regional analgesia for labor is still unavailable to many parturients, and more than one half of anesthetics for cesarean section are provided by nurse anesthetists without medical direction by an anesthesiologist. Obstetricians are less likely to personally provide epidural analgesia for their patients. Anesthesia personnel are less involved in newborn resuscitation.
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Comparative Study
Assessment of the potency and intrinsic activity of systemic versus intrathecal opioids in rats.
One measure of an opioid's efficacy is its ability to retain its analgesic effect as the intensity of a noxious stimulus is increased. A few studies have assessed the ability of either spinal or systemic opioids to produce analgesia using low- and high-intensity stimulation. There are little data available to show whether there are differences in efficacy between systemic and intrathecal opioid administration. The purpose of this study was to assess the relative efficacy of several clinically useful opioids systemically and spinally and to determine whether intrathecal administration resulted in greater efficacy than systemic administration. ⋯ As intensity of noxious stimulation is increased, the more potent opioid agonists, administered systemically, produce antinociception with lesser increases in dose compared with lower potency drugs such as meperidine or morphine. When given spinally all opioid agonists tested, including morphine and meperidine, demonstrated good efficacy, as measured by their ability to provide antinociception for high versus low intensity stimulation.