Anesthesiology
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Randomized Controlled Trial Multicenter Study
Period-dependent Associations between Hypotension during and for Four Days after Noncardiac Surgery and a Composite of Myocardial Infarction and Death: A Substudy of the POISE-2 Trial.
The relative contributions of intraoperative and postoperative hypotension to perioperative morbidity remain unclear. We determined the association between hypotension and a composite of 30-day myocardial infarction and death over three periods: (1) intraoperative, (2) remaining day of surgery, and (3) during the initial four postoperative days. ⋯ Clinically important hypotension-a potentially modifiable exposure-was significantly associated with a composite of myocardial infarction and death during each of three perioperative periods, even after adjustment for previous hypotension.
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Neurosteroids like alphaxalone are potent anxiolytics, anticonvulsants, amnestics, and sedative-hypnotics, with effects linked to enhancement of γ-aminobutyric acid type A (GABAA) receptor gating in the central nervous system. Data locating neurosteroid binding sites on synaptic αβγ GABAA receptors are sparse and inconsistent. Some evidence points to outer transmembrane β-α interfacial pockets, near sites that bind the anesthetics etomidate and propofol. Other evidence suggests that steroids bind more intracellularly in β-α interfaces. ⋯ Alphaxalone binds in transmembrane β-α pockets of synaptic GABAA receptors that are adjacent and intracellular to sites for the potent anesthetics etomidate and propofol.
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Defining the Intrinsic Cardiac Risks of Operations to Improve Preoperative Cardiac Risk Assessments.
Current preoperative cardiac risk stratification practices group operations into broad categories, which might inadequately consider the intrinsic cardiac risks of individual operations. We sought to define the intrinsic cardiac risks of individual operations and to demonstrate how grouping operations might lead to imprecise estimates of perioperative cardiac risk. ⋯ A continuum of intrinsic cardiac risk exists among operations. Grouping operations into broad categories inadequately accounts for the intrinsic cardiac risk of individual operations.