Articles: function.
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Anesthesia and analgesia · Feb 2014
The Importance of Subjective Facial Appearance on the Ability of Anesthesiologists to Predict Difficult Intubation.
Previously we demonstrated that a computer algorithm based on bedside airway examinations and facial photographs accurately classified easy and difficult airways. The extent of the ability of anesthesiologists to perform the same task is unknown. We hypothesized that providing photographs would add to the predictive ability of anesthesiologists over that achieved when provided only with the Mallampati (MP) score and the thyromental distance (TMD). We further hypothesized that human observers would implicitly bias their predictions toward more sensitive determination of difficult airways, rather than more specific determination of easy airways. ⋯ Anesthesiologists can derive useful information from facial appearance that enhances the prediction of a difficult airway over that achieved when presented with MP and TMD data alone. Anesthesiologists implicitly bias their predictions toward detection of difficult airways, compared with the true incidence of difficult airways, at the expense of accuracy and specificity. This behavior may be rational for cognitive tasks in which the costs of failure are strongly asymmetric.
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Because of a lack of contemporary data regarding seizures after cardiac surgery, we undertook a retrospective analysis of prospectively collected data from 11 529 patients in whom cardiopulmonary bypass was used from January 2004 to December 2010. A convulsive seizure was defined as a transient episode of disturbed brain function characterised by abnormal involuntary motor movements. Multivariate regression analysis was performed to identify independent predictors of postoperative seizures. ⋯ Mean (IQR [range]) length of stay in the intensive care unit was 115 (49-228 [32-481]) h in patients with convulsive seizures compared with 26 (22-69 [14-1080]) h in patients without seizures (p < 0.001). Convulsive seizures are a serious postoperative complication after cardiac surgery. As tranexamic acid is the only modifiable factor, its administration, particularly in doses exceeding 80 mg.kg(-1), should be weighed against the risk of postoperative seizures.
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Acta Anaesthesiol Scand · Feb 2014
ReviewPopulation pharmacometrics in support of analgesics studies.
Population pharmacometric modeling is used to explain both population trends as well as the sources and magnitude of variability in pharmacokinetic and pharmacodynamics data; the later, in part, by taking into account patient characteristics such as weight, age, renal function and genetics. The approach is best known for its ability to analyze sparse data, i.e. when only a few measurements have been collected from each subject, but other benefits include its flexibility and the potential to construct more detailed models than those used in the traditional individual curve fitting approach. ⋯ In addition, the use of these models to design and optimize future studies is discussed. In this context, finding the best design factors, such as the sampling times or the dose, for future studies within pre-defined criteria using a previously constructed population pharmacokinetic model can help researchers acquire clinically meaningful data without wasting resources and unnecessarily exposing vulnerable patient groups to study drugs and additional blood sampling.
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Anesthesia and analgesia · Feb 2014
Stationary versus agitated storage of whole blood during acute normovolemic hemodilution.
Acute normovolemic hemodilution is an intraoperative technique to reduce the number of red blood cells lost in shed blood during surgery. Standard guidelines for storage of platelets recommend constant gentle agitation to maintain gas exchange for the metabolically active platelets. The collected whole blood (WB) for acute normovolemic hemodilution remains stationary for as long as 8 hours before reinfusion. We hypothesized that gentle agitation of WB throughout storage would improve the coagulation properties of the WB at the time of reinfusion. ⋯ Given the small sample size, there is no statistical evidence on which to reject the null hypothesis of there being no difference in the changes from the baseline between coagulation function as measured by TEG® between WB that is either agitated or kept stationary for 8 hours. These findings need to be confirmed in a larger study.
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Review Historical Article
Clinical applications of targeted temperature management.
Targeted temperature management (TTM) has been investigated experimentally and used clinically for over 100 years. The initial rationale for the clinical application of TTM, historically referred to as therapeutic hypothermia, was to decrease the metabolic rate, allowing the injured brain time to heal. Subsequent research demonstrated the temperature dependence of diverse cellular mechanisms including endothelial dysfunction, production of reactive oxygen species, and apoptosis. ⋯ Additionally, TTM has been demonstrated to improve outcomes for neonatal patients with anoxic brain injury secondary to hypoxic ischemic encephalopathy. Trials are currently under way, or have yielded conflicting results in, examining the utility of TTM for the treatment of ischemic stroke, traumatic brain injury, and acute myocardial infarction. In this review, we place TTM in historic context, discuss the pathophysiologic rationale for its use, review the general concept of a TTM protocol for the management of brain injury, address some of the common side effects encountered when lowering human body temperature, and examine the data for its use in diverse disease conditions with in-depth examination of TTM for postarrest care and pediatric applications.