Showing papers by "Alan H. Morris published in 2003"

Effects of recruitment maneuvers in patients with acute lung injury and acute respiratory distress syndrome ventilated with high positive end-expiratory pressure.

Abstract: OBJECTIVE Positive end-expiratory pressure (PEEP) and recruitment maneuvers (RMs) may partially reverse atelectasis and reduce ventilation-associated lung injury. The purposes of this study were to assess a) magnitude and duration of RM effects on arterial oxygenation and on requirements for oxygenation support (Fio2/PEEP) in patients with acute lung injury and acute respiratory distress syndrome (ALI/ARDS) receiving ventilation with low tidal volumes and high levels of PEEP; and b) frequency of adverse respiratory and circulatory events attributable to RMs. DESIGN Prospective, randomized, crossover study. SETTING Thirty-four intensive care units at 19 hospitals. PATIENTS Seventy-two patients with early ALI/ARDS. Baseline PEEP and Fio2 were 13.8 +/- 3.0 cm H2O and 0.39 +/- 0.10, respectively (mean +/- sd). INTERVENTIONS We conducted RMs by applying continuous positive airway pressure of 35-40 cm H2O for 30 secs. We conducted sham RMs on alternate days. We monitored oxyhemoglobin saturation by pulse oximetry (SpO2), Fio2/PEEP, blood pressure, and heart rate for 8 hrs after RMs and sham RMs. We examined chest radiographs for barotrauma. MEASUREMENTS AND MAIN RESULTS Responses to RMs were variable. Greatest increments from baseline SpO2 within 10 mins after RMs were larger than after sham RMs (1.7 +/- 0.2 vs. 0.6 +/- 0.3 %, mean +/- SEM, p < .01). Systolic blood pressure decreased more +/- 1.1 mm Hg, p < .01). Changes in Fio2/PEEP requirements were not significantly different at any time after RMs vs. sham RMs. Barotrauma was apparent on first radiographs after one RM and one sham RM. CONCLUSIONS In ALI/ARDS patients receiving mechanical ventilation with low tidal volumes and high PEEP, short-term effects of RMs as conducted in this study are variable. Beneficial effects on gas exchange in responders appear to be of brief duration. More information is needed to determine the role of recruitment maneuvers in the management of ALI/ARDS.

Treatment algorithms and protocolized care

Abstract: Purpose of reviewExcess information in complex ICU environments exceeds human decision-making limits and likely contributes to unnecessary variation in clinical care, increasing the likelihood of clinical errors. I reviewed recent critical care clinical trials searching for information about the imp

Performance Analysis Integration in the Uintah Software Development Cycle

Abstract: The increasing complexity of high-performance computing environments and programming methodologies presents challenges for empirical performance evaluation. Evolving parallel and distributed systems require performance technology that can be flexibly configured to observe different events and associated performance data of interest. It must also be possible to integrate performance evaluation techniques with the programming paradigms and software engineering methods. This is particularly important for tracking performance on parallel software projects involving many code teams over many stages of development. This paper describes the integration of the TAU and XPARE tools in the Uintah Computational Framework (UCF). Discussed is the use of performance mapping techniques to associate low-level performance data to higher levels of abstraction in UCF and the use of performance regression testing to provide a historical portfolio of the evolution of application performance. A scalability study shows the benefits of integrating performance technology in building large-scale parallel applications.

Cognitive evaluation of the predictors of use of computerized protocols by clinicians.

Abstract: We describe a cognitive approach to evaluating the factors that motivate clinicians to use computerized protocols. Using Value-Expectancy theories we developed an open-ended interview to assess clinicians' beliefs and experiences about the use of computerized protocols. Using a qualitative methodology, 3 reviewers independently identified key concepts raised by 13 interviewees. These concepts were aggregated and independently sorted into 39 categories. Then final categories were chosen by consensus. Analysis of the concepts showed consistency across clinician specialties of physicians, nurses and respiratory therapists. Inter-rater reliability calculated using Cohen's Kappa was 0.474. Identified constructs from Value-Expectancy and Intrinsic Motivation theories were: Work Importance, Perception of Situation, Role Relevance, Beliefs regarding Control, Beliefs regarding Normative Expectations, Beliefs regarding Self-Efficacy, Attitude, Habit, Environmental Support and Pre-Behavior. This model will form the basis for an instrument to assess the beliefs and expectations of clinical use regarding the use of computerized protocols.

Responses to Review of Our CO Paper by Wilkinson, Tremblett and Major: August 22, 2003:

Abstract: D r. Jonathan Will~inson I~indly reviewed1 the recent publication, Hyperbatic oxygen for acute corbon monoxide poisoning,2 and a letter to the editorJ pointed out concerns about our conclusions. In his review, Dr Wilkinson raised concerns about selection bias, bias of the results due to an unequal distribution between treatment arms of patients with cerebellar dysfunction, a difference in the duration of carbon monoxide exposure duration between treatment groups, and an insignificant difference in cognitive sequelae rates at 12 months. However, Dr. Wilkinson recommended hyperbaric oxygen for acute carbon monoxide poisoning, \"if practical.\" The letter to the editor from Tremblett and Major raise issues about patients in the hyperbaric oxygen treatment group receiving longer duration oxygen than the controls and concerns about methodology of carboxyhemoglobin measurements. We offer our replies: