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
Intracranial Electrical Impedance Tomography: A Method of Continuous Monitoring in an Animal Model of Head Trauma.
Electrical impedance tomography (EIT) is a method that can render continuous graphical cross-sectional images of the brain's electrical properties. Because these properties can be altered by variations in water content, shifts in sodium concentration, bleeding, and mass deformation, EIT has promise as a sensitive instrument for head injury monitoring to improve early recognition of deterioration and to observe the benefits of therapeutic intervention. This study presents a swine model of head injury used to determine the detection capabilities of an inexpensive bedside EIT monitoring system with a novel intracranial pressure (ICP)/EIT electrode combination sensor on induced intraparenchymal mass effect, intraparenchymal hemorrhage, and cessation of brain blood flow. Conductivity difference images are shown in conjunction with ICP data, confirming the effects. ⋯ This study confirms that the bedside EIT system with ICP/EIT combination sensor can detect induced trauma. Such a technique may hold promise for further research in the monitoring and management of traumatically brain-injured individuals.
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Anesthesia and analgesia · Oct 2013
Maternal Sepsis Mortality and Morbidity During Hospitalization for Delivery: Temporal Trends and Independent Associations for Severe Sepsis.
Sepsis is currently the leading cause of direct maternal death in the United Kingdom. In this study, we aimed to determine frequency, temporal trends, and independent associations for severe sepsis during hospitalization for delivery in the United States. ⋯ Maternal severe sepsis and sepsis-related deaths are increasing in the United States. Severe sepsis often occurs in the absence of a recognized risk factor and underscores the need for developing systems of care that increase sensitivity for disease detection across the entire population. Physicians should enhance surveillance in patients with congestive heart failure, chronic liver disease, chronic renal disease, and systemic lupus erythematous and institute early treatment when signs of sepsis are emerging.
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Anesthesia and analgesia · Oct 2013
Sevoflurane End-Tidal to Effect-Site Equilibration in Women Determined by Response to Laryngeal Mask Airway Insertion.
End-tidal concentrations (CET) have been used to guide delivery of inhaled anesthetic drugs for many years. Effect-site concentrations (Ceff) are a frequently used guide to therapy with IV drugs and should also be of benefit with inhaled drugs, especially during periods of rapid change. For Ceff to be useful, the appropriate levels required for any given end point, and the delay between central compartment and effect, need to be defined. In this study, we explored these relationships for the effect of response to insertion of the classic laryngeal mask airway (cLMA) and compared the utility of CET and Ceff-guided cLMA insertion. ⋯ This study confirmed that real-time calculation and display of Ceff based on measured CET values are feasible. We determined the optimum t(1/2)ke0 for sevoflurane for the effect of cLMA insertion as 2.25 minutes, similar to that determined for loss of consciousness using the raw electroencephalogram. We also showed that Ceff is a more reliable (P < 0.05) guide to successful cLMA insertion than CET.
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Anesthesia and analgesia · Oct 2013
Rescheduling of Previously Cancelled Surgical Cases Does Not Increase Variability in Operating Room Workload When Cases Are Scheduled Based on Maximizing Efficiency of Use of Operating Room Time.
Conceptually, cancelling a case close to the scheduled day of surgery increases variability in operating room (OR) workload (i.e., total hours of scheduled cases plus turnovers), creating managerial problems. However, in our recent study of an OR scheduling office, cancellations (slightly) reduced variability in workload among days. If a relatively low incidence of cancellations does not cause increased variability in workload, this would be a useful finding when focusing strategic OR management initiatives. However, the previous study considered only the effect on the schedule for the day the cancelled case originally was scheduled to be performed, not the future date on which the case was performed. ⋯ Rescheduled cancelled cases did not increase variability in OR workload. This finding is useful combined with our recent finding that cancellation slightly reduces variability in OR workload on the date of cancellation. Cancellations should not be interpreted as a system failure that increases variability in surgical workload. We recommend that anesthesiologists aim to reduce cancellation rates if above benchmarked averages, but otherwise focus on more strategically beneficial initiatives. We recommend also that these results be considered if cancellation rates are used in assessing anesthesiology group performance.