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
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 Agreement Between Radiologic and Clinical Measurements of Lumbar and Cervical Epidural Depths in Patients Undergoing Prone Interlaminar Epidural Steroid Injection.
Fluoroscopy-guided epidural steroid injection (ESI) commonly is performed to treat radicular pain yet can lead to adverse events if the needle is not advanced with precision. Accurate preoperative assessment of the distance from the skin to the epidural space holds the potential for reducing the risks of adverse effects from ESI. It was hypothesized that the distance from the skin to the epidural space as measured on preoperative magnetic resonance imaging (MRI) would agree with the distance traveled by a Tuohy needle to reach the epidural space during midline, interlaminar ESI. This study compared the final needle depth measurement at the point of loss of resistance (LOR) from cervical or lumbar ESI to the distance from the skin to the anterior and posterior borders of the epidural space on the associated cervical and lumbar preoperative MRI. ⋯ This study assessed the agreement between MRI-derived measurements of epidural depth and those determined clinically. MRI-derived measurements from the skin to the anterior border of the ligamentum flavum, which represents the most posterior aspect of the epidural space, revealed stronger agreement with LOR depths than did measurements to the dura or the most anterior aspect of the epidural space. These results require further analysis and refinement before supporting clinical application.
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Anesthesia and analgesia · May 2017
A High Preoperative Pain and Symptom Profile Predicts Worse Pain Outcomes for Children After Spine Fusion Surgery.
Preoperative pain predicts persistent pain after spine fusion, yet little is understood about the nature of that pain, related symptoms, and how these symptoms relate to postoperative pain outcomes. This prospective study examined children's baseline pain and symptom profiles and the association between a high symptom profile and postoperative outcomes. ⋯ A behavioral pain vulnerable profile was present preoperatively in 30% of children with idiopathic scoliosis and was independently associated with poorer and potentially long-lasting pain outcomes after spine fusion in this setting. This high symptom profile is similar to that described in children and adults with chronic and centralized pain disorders and was more prevalent in girls and those with long-standing pain. Further study is needed to elucidate the potential mechanisms behind our observations.
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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.