Brenton S Alexander

Learn More
BACKGROUND Cardiac output (CO) monitoring based on pulse contour analysis (Vigileo-FloTrac) has the potential to be used for goal-directed fluid therapy in the perioperative setting. However, factors such as vasopressor usage may impact Vigileo-FloTrac's reliability in tracking CO changes. We tested third-generation Vigileo-FloTrac system's ability to(More)
Blood pressure monitoring has come a long way from the initial observations made by Reverend Hales in the 18th century. There are none that deny the importance of monitoring perioperative blood pressure; however, the limited ability of the current prevalent technology (oscillometric blood pressure monitoring) to offer continuous blood pressure measurements(More)
STUDY OBJECTIVE To evaluate the validity of cardiac output (CO) measurements obtained using the Nexfin device in comparison to those obtained with the esophageal Doppler in steady-state conditions and after phenylephrine administration. DESIGN Prospective observational study. SETTING Operating room of a North American academic medical center. PATIENTS(More)
INTRODUCTION Dynamic predictors of fluid responsiveness have made automated management of fluid resuscitation more practical. We present initial simulation data for a novel closed-loop fluid-management algorithm (LIR, Learning Intravenous Resuscitator). METHODS The performance of the closed-loop algorithm was tested in three phases by using a patient(More)
The Nexfin device allows for non-invasive beat-to-beat blood pressure monitoring (BPNXF). Perioperative hypotension and hypertension have been shown to be associated with poor clinical outcomes. The goal of the present study was to assess the ability of this device to decrease the duration of significant intraoperative hypo- or hypertension compared to(More)
Several minimally-invasive technologies are available for cardiac output (CO) measurement in children, but the accuracy and precision of these devices have not yet been evaluated in a systematic review and meta-analysis. We conducted a comprehensive search of the medical literature in PubMed, Cochrane Library of Clinical Trials, Scopus, and Web of Science(More)
BACKGROUND Multiple studies have shown that cerebral tissue oxygen saturation (Sct(O(2))) is decreased after phenylephrine treatment. We hypothesized that the negative impact of phenylephrine administration on Sct(O(2)) is affected by arterial blood carbon dioxide partial pressure (Pa(CO(2))) because CO(2) is a powerful modulator of cerebrovascular tone. (More)
BACKGROUND How phenylephrine and ephedrine treatments affect global and regional haemodynamics is of major clinical relevance. Cerebral tissue oxygen saturation (Sct(O2) )-guided management may improve postoperative outcome. The physiological variables responsible for Sct(O2) changes induced by phenylephrine and ephedrine bolus treatment in anaesthetized(More)
Closed-loop (automated) controllers are encountered in all aspects of modern life in applications ranging from air-conditioning to spaceflight. Although these systems are virtually ubiquitous, they are infrequently used in anesthesiology because of the complexity of physiologic systems and the difficulty in obtaining reliable and valid feedback data from(More)
BACKGROUND The perioperative setting in the United States is noted for variable and fragmented care that increases the chance for errors and adverse outcomes as well as the overall cost of perioperative care. Recently, the American Society of Anesthesiologists put forward the Perioperative Surgical Home (PSH) concept as a potential solution to this problem.(More)