Anesthesia and analgesia
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Anesthesia and analgesia · Jun 2013
The hemodynamic management of 5177 neurosurgical and orthopedic patients who underwent surgery in the sitting or "beach chair" position without incidence of adverse neurologic events.
A small number of highly publicized case reports describe ischemic brain or spinal cord injury after surgery in the sitting ("beach chair") position. The incidence of such catastrophic outcomes remains unknown, as does the relationship between arterial blood pressure management and injury, because few hemodynamic details were included with those 4 cases. To add quantitative data to the discussion of anesthesia in the sitting position, we examined the detailed hemodynamics of a large number of patients managed at our institution who sustained no similar catastrophic outcomes. ⋯ This study provides a descriptive summary of intraoperative blood pressure changes, measured either invasively or noninvasively, and referenced to either head or heart level, but never lower than heart level, in patients under general anesthesia in the sitting position who sustained no catastrophic outcomes.
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Anesthesia and analgesia · Jun 2013
Editorial CommentA beach chair, comfortably positioned atop an iceberg.
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Anesthesia and analgesia · Jun 2013
Carboetomidate: an analog of etomidate that interacts weakly with 11β-hydroxylase.
Carboetomidate is a pyrrole etomidate analog that is 3 orders of magnitude less potent an inhibitor of in vitro cortisol synthesis than etomidate (an imidazole) and does not inhibit in vivo steroid production. Although carboetomidate's reduced functional effect on steroid synthesis is thought to reflect lower binding affinity to 11β-hydroxylase, differential binding to this enzyme has never been experimentally demonstrated. In the current study, we tested the hypothesis that carboetomidate and etomidate bind with differential affinity to 11β-hydroxylase by comparing their abilities to inhibit photoaffinity labeling of purified enzyme by a photoactivatable etomidate analog and to modify the enzyme's absorption spectrum in a way that is indicative of ligand binding. In addition, we made a preliminary exploration of the manner in which etomidate and carboetomidate might differentially interact with this site using spectroscopic methods as well as molecular modeling techniques to better understand the structural basis for their selectivity. ⋯ Carboetomidate's reduced ability to suppress in vitro and in vivo steroid synthesis as compared with etomidate reflects its lower binding affinity to 11β-hydroxylase and may be attributed to carboetomidate's inability to form a coordination bond with the heme iron located at the enzyme's active site.
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Anesthesia and analgesia · Jun 2013
Technical communication: inhaled anesthetic agent-vaporizer mismatch: management in settings with limited resources: don't try this at home.
Agent-specific vaporizers minimize opportunities for error and evidence our specialty's commitment to patient safety as a general principle. End-tidal anesthetic gas concentration monitoring is a useful adjunct whenever inhaled anesthetics are used in operating rooms. Due to their expense and required maintenance, end-tidal anesthetic gas monitors are not commonly used in developing nations. ⋯ Mismatching of inhaled agent and vaporizer is a dangerous practice and should not be performed unless it is absolutely necessary. Such situations may arise in remote locations where neither end-tidal anesthetic gas monitoring nor vaporizer-specific agent is available. We hope our article provides guidance in such situations.
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Anesthesia and analgesia · Jun 2013
Increased red blood cell transfusions are associated with worsening outcomes in pediatric heart transplant patients.
Red blood cell (RBC) transfusions are associated with increased morbidity. Children receiving heart transplants constitute a unique group of patients due to their risk factors. Although previous studies in nontransplant patients have focused primarily on the effects of postoperative blood transfusions, a significant exposure to blood occurs during the intraoperative period, and a larger percentage of heart transplant patients require intraoperative blood transfusions when compared with general cardiac surgery patients. We investigated the relationship between clinical outcomes and the amount of blood transfused both during and after heart transplantation. We hypothesized that larger amounts of RBC transfusions are associated with worsening clinical outcomes in pediatric heart transplant patients. ⋯ The majority of pediatric patients undergoing orthotropic heart transplantation receive RBC transfusions, with the largest amount transfused in the operating room. Escalating amounts of RBC transfusions are independently associated with increased length of intensive care unit stay, inotrope scores, and major adverse events. Since heart allografts are a limited resource, improvement in the blood transfusion and conservation practices can enhance clinical outcomes in pediatric heart transplant patients.