Anesthesia and analgesia
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Anesthesia and analgesia · Sep 2013
Computational analysis of the effects of reduced temperature on thrombin generation: the contributions of hypothermia to coagulopathy.
Hypothermia, which can result from tissue hypoperfusion, body exposure, and transfusion of cold resuscitation fluids, is a major factor contributing to coagulopathy of trauma and surgery. Despite considerable efforts, the mechanisms of hypothermia-induced blood coagulation impairment have not been fully understood. We introduce a kinetic modeling approach to investigate the effects of hypothermia on thrombin generation. ⋯ We developed a general computational strategy that can be used to simulate the effects of changing temperature on the kinetics of biochemical systems and applied this strategy to analyze the effects of hypothermia on thrombin generation. We found that thrombin generation can be noticeably impaired in subjects with different blood plasma composition even in moderate hypothermia. Our work provides mechanistic support to the notion that thrombin generation impairment may be a key factor in coagulopathy induced by hypothermia and complicated by blood plasma dilution.
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Anesthesia and analgesia · Sep 2013
Case cancellation rates measured by surgical service differ whether based on the number of cases or the number of minutes cancelled.
Surgical cancellation rates typically are reported as the number of cancelled cases divided by the number of scheduled cases. However, the total number of cancelled minutes also has financial impact on surgeons' productivity. Cancellation rates can instead be calculated based on the number of minutes of cancelled cases. Hospitals typically benchmark cancellation rates, since not all cancellations are preventable (e.g., those due to new onset of patient symptoms requiring further workup and treatment before surgery can safely proceed). If the mean estimated duration of cancelled cases were the same as that of scheduled cases, rates would be equivalent whether calculated using the number of cancellations or the minutes of cancellations. It is unknown whether there is a difference between these 2 methods. ⋯ Calculating cancellation rates using case counts can inaccurately represent their impact on surgeon's productivity compared with using minutes of cancelled cases. Comparing numeric cancellation rates between hospitals or services without checking for bias may lead to inappropriate conclusions. We recommend that hospitals evaluate their data for potential bias to determine whether cancellation rates need to be calculated using scheduled minutes of cases rather than numbers of cancellations.
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Anesthesia and analgesia · Sep 2013
Case ReportsCase report: quetiapine and refractory hypotension during general anesthesia in the operating room.
Quetiapine is an atypical antipsychotic with known α-adrenergic antagonism. We present a case of refractory hypotension that occurred after induction of general anesthesia in a patient being treated with quetiapine. ⋯ We observed that the hypotension was most responsive to vasopressin. We recommend further investigation regarding the interaction of quetiapine and general anesthesia.
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Anesthesia and analgesia · Sep 2013
Brief report: leaking esophageal probe may lead to false ventilator settings when guiding positive end-expiratory pressure by transpulmonary pressure.
Esophageal pressure (Pes) is a surrogate for intrapleural pressure. Measuring Pes during mechanical ventilation allows for positive end-expiratory pressure adjustments by transpulmonary pressure (PL), which has been shown to improve oxygenation and outcome in acute respiratory distress syndrome patients. In morbidly obese patients, we saw progressively increasing PL measurements, although airway pressure (Paw), intra-abdominal pressure, and patient position did not change. On further examination, we determined that the gradual increases of PL were artifacts caused by a leak in the pressure probes, which resulted in underestimation of Pes and overestimation of PL as derived from the equation Paw - Pes = PL.