Anesthesia and analgesia
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Anesthesia and analgesia · May 2017
Posttransfusion Increase of Hematocrit per se Does Not Improve Circulatory Oxygen Delivery due to Increased Blood Viscosity.
Blood transfusion is used to treat acute anemia with the goal of increasing blood oxygen-carrying capacity as determined by hematocrit (Hct) and oxygen delivery (DO2). However, increasing Hct also increases blood viscosity, which may thus lower DO2 if the arterial circulation is a rigid hydraulic system as the resistance to blood flow will increase. The net effect of transfusion on DO2 in this system can be analyzed by using the relationship between Hct and systemic blood viscosity of circulating blood at the posttransfusion Hct to calculate DO2 and comparing this value with pretransfusion DO2. We hypothesized that increasing Hct would increase DO2 and tested our hypothesis by mathematically modeling DO2 in the circulation. ⋯ After accounting for the effect of increasing blood viscosity on blood flow owing to increasing Hct, we found in a mathematical simulation of DO2 that transfusion of up to 3 units of PRBCs does not increase DO2, unless anemia is the result of an Hct deficit greater than 60%. Observations that transfusions occasionally result in clinical improvement suggest that other mechanisms possibly related to increased blood viscosity may compensate for the absence of increase in DO2.
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Anesthesia and analgesia · May 2017
Prophylactic Plasma Transfusion Is Not Associated With Decreased Red Blood Cell Requirements in Critically Ill Patients.
Critically ill patients frequently receive plasma transfusion under the assumptions that abnormal coagulation test results confer increased risk of bleeding and that plasma transfusion will decrease this risk. However, the effect of prophylactic plasma transfusion remains poorly understood. The objective of this study was to determine the relationship between prophylactic plasma transfusion and bleeding complications in critically ill patients. ⋯ Prophylactic administration of plasma in the critically ill was not associated with improved clinical outcomes. Further investigation examining the utility of plasma transfusion in this population is warranted.
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Anesthesia and analgesia · May 2017
Development of a Pediatric Risk Assessment Score to Predict Perioperative Mortality in Children Undergoing Noncardiac Surgery.
Although there have been numerous attempts to predict perioperative mortality in adults, an objective model to predict mortality in children has not been developed. In this study, we aimed to develop a Pediatric Risk Assessment (PRAm) score to predict perioperative mortality in children undergoing noncardiac surgery. ⋯ In this study, we developed a simplified PRAm tool (PRAm score) as a predictor of perioperative mortality in children undergoing noncardiac surgery. The PRAm score has excellent accuracy. In patients assigned American Society of Anesthesiologists physical status classification ≥4, there is wide variability in objectively obtained PRAm scores.
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Anesthesia and analgesia · May 2017
Assessing the Impact of the Anesthesia Medication Template on Medication Errors During Anesthesia: A Prospective Study.
Medication errors continue to be a significant source of patient harm in the operating room with few concrete countermeasures. The organization and identification of medication syringes may have an impact on the commission of medication errors in anesthesia, so a team of physicians and designers at the University of Washington created the Anesthesia Medication Template (AMT) to define a formal way of organizing the anesthesia workspace. The purpose of this study is to assess the ability of the AMT to reduce perioperative medication errors by anesthesia providers. ⋯ Standardizing medication organization with the AMT is an intuitive, low-cost strategy with the potential to improve patient safety through reducing medication errors by anesthesia providers.
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Anesthesia and analgesia · May 2017
Comparative StudyComputational and In Vitro Experimental Investigation of Intrathecal Drug Distribution: Parametric Study of the Effect of Injection Volume, Cerebrospinal Fluid Pulsatility, and Drug Uptake.
Intrathecal drug delivery is an attractive option to circumvent the blood-brain barrier for pain management through its increased efficacy of pain relief, reduction in adverse side effects, and cost-effectiveness. Unfortunately, there are limited guidelines for physicians to choose infusion or drug pump settings to administer therapeutic doses to specific regions of the spine or the brain. Although empiric trialing of intrathecal drugs is critical to determine the sustained side effects, currently there is no inexpensive in vitro method to guide the selection of spinal drug delivery parameters. The goal of this study is to demonstrate current computational capabilities to predict drug biodistribution while varying 3 parameters: (1) infusion settings, (2) drug chemistry, and (3) subject-specific anatomy and cerebrospinal fluid dynamics. We will discuss strategies to systematically optimize these 3 parameters to administer drug molecules to targeted tissue locations in the central nervous system. ⋯ We present potential guidelines considering drug-specific kinetics of tissue uptake, which determine the speed of drug dispersion and influence tissue targeting. However, there are limitations to this analysis in that the parameters were obtained from an idealized healthy patient in a supine position. The proposed methodology could assist physicians to select clinical infusion parameters for their patients and provide guidance to optimize treatment algorithms. In silico optimization of intrathecal drug delivery therapies presents the first steps toward a possible care paradigm in the future that is specific to personalized patient anatomy and diseases.