Anesthesia and analgesia
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Anesthesia and analgesia · Oct 2013
The Association Between Preoperative Anemia and 30-Day Mortality and Morbidity in Noncardiac Surgical Patients.
Anemia has been associated with increased postoperative morbidity and mortality. We used the American College of Surgeons National Surgical Quality Improvement Program database to retrospectively assess the relationship between preoperative anemia and 30-day postoperative mortality and morbidity in noncardiac surgical patients, careful to distinguish confounding variables from mediator variables. ⋯ Preoperative anemia appears to be associated with baseline diseases that markedly increase mortality. Anemia per se is a rather weak independent predictor of postoperative mortality. Our analysis also illustrates how analyzing large variable-rich registries challenges investigators to discriminate between confounding variables and mediator variables, i.e., factors that might be considered as "causal pathways" for the effect of the exposure or intervention on outcome.
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Anesthesia and analgesia · Oct 2013
Propofol Shares the Binding Site with Isoflurane and Sevoflurane on Leukocyte Function-Associated Antigen-1.
We previously demonstrated that propofol interacted with the leukocyte adhesion molecule leukocyte function-associated antigen-1 (LFA-1) and inhibited the production of interleukin-2 via LFA-1 in a dependent manner. However, the binding site(s) of propofol on LFA-1 remains unknown. ⋯ We demonstrated that propofol bound to the lovastatin site in LFA-1. Previously we showed that the volatile anesthetics isoflurane and sevoflurane bound to this site. Taken together, the lovastatin site is an example of the common binding sites for anesthetics currently used clinically.
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Anesthesia and analgesia · Oct 2013
Direct Pulse Oximetry Within the Esophagus, on the Surface of Abdominal Viscera, and on Free Flaps.
Pulse oximetry is a noninvasive photometric technique that provides information about arterial blood oxygen saturation (SpO2) and heart rate and has widespread clinical applications. This is accomplished via peripheral pulse oximetry probes mainly attached to the finger, toe, or earlobe. The direct application of pulse oximetry to an organ, such as the esophagus, liver, bowel, stomach or free flap, might provide an indication of how well perfused an organ or a free flap is. Also, the placement of a pulse oximetry probe at a more central site, such as the esophagus, might be more reliable at a time when conventional peripheral pulse oximetry fails. ⋯ The technological developments and the measurements presented in this work pave the way to a new era of pulse oximetry where direct and continuous monitoring of blood oxygen saturation of internal organs and tissues (esophagus, bowel, liver, stomach, free flaps) could be possible.
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Anesthesia and analgesia · Oct 2013
The Association of Preoperative Statin Use and Acute Kidney Injury After Noncardiac Surgery.
Our objective was to examine the association between preoperative statin therapy and the incidence of postoperative acute kidney injury (AKI) in patients undergoing elective noncardiac surgery. ⋯ Our data did not support the hypothesis that preoperative statin therapy in doses routinely used to treat hypercholesterolemia is associated with a change in the incidence of AKI, postoperative dialysis, or hospital mortality in patients undergoing noncardiac surgery.
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Anesthesia and analgesia · Oct 2013
Simulation of the Kinetics of Neuromuscular Block: Implications for Speed of Onset.
The onset time for paralysis varies 3-fold among nondepolarizing muscle relaxants. Possible explanations include: (a) pharmacokinetic differences among drugs and (b) buffering of drug molecules by acetylcholine receptors as they diffuse into the neuromuscular junction. Although some pharmacokinetic models consider buffered diffusion, these models do not account for either the high density of receptors or synapse geometry. Here, I used computer simulations to calculate the kinetics of buffered diffusion. The goal was to determine the conditions under which buffered diffusion could account for differences in onset time among nondepolarizing muscle relaxants. ⋯ Monte Carlo simulation provides a biophysically appropriate way to incorporate buffered diffusion into pharmacokinetic modeling. The simulations indicated that buffered diffusion could account for differences in onset time among drugs. However, a better understanding of the geometry of the human neuromuscular junction is needed before the magnitude of the effect of buffered diffusion can be quantified.