Biomedical subjects

Mark T O'Connell

Publications and source records attributed to Mark T O'Connell.

6 recordsLinked to original sources

PubMed2005

Effect of cerebral perfusion pressure augmentation on regional oxygenation and metabolism after head injury.

OBJECTIVE: In this study we have used O positron emission tomography, brain tissue oxygen monitoring, and cerebral microdialysis to assess the effects of cerebral perfusion pressure augmentation on regional physiology and metabolism in the setting of traumatic brain injury. DESIGN: Prospective interventional study. SETTING: Neurosciences critical care unit of a university hospital. PATIENTS: Eleven acutely head-injured patients requiring norepinephrine to maintain cerebral perfusion pressure. INTERVENTIONS: Using positron emission tomography, we have quantified the response to an increase in cerebral perfusion pressure in a region of interest around a brain tissue oxygen sensor (Neurotrend) and microdialysis catheter. Oxygen extraction fraction and cerebral blood flow were measured with positron emission tomography at a cerebral perfusion pressure of approximately 70 mm Hg and approximately 90 mm Hg using norepinephrine to control cerebral perfusion pressure. All other aspects of physiology were kept stable. MEASUREMENTS AND MAIN RESULTS: Cerebral perfusion pressure augmentation resulted in a significant increase in brain tissue oxygen (17 +/- 8 vs. 22 +/- 8 mm Hg; 2.2 +/- 1.0 vs. 2.9 +/- 1.0 kPa, p < .001) and cerebral blood flow (27.5 +/- 5.1 vs. 29.7 +/- 6.0 mL/100 mL/min, p < .05) and a significant decrease in oxygen extraction fraction (33.4 +/- 5.9 vs. 30.3 +/- 4.6 %, p < .05). There were no significant changes in any of the microdialysis variables (glucose, lactate, pyruvate, lactate/pyruvate ratio, glycerol). There was a significant linear relationship between brain tissue oxygen and oxygen extraction fraction (r = .21, p < .05); the brain tissue oxygen value associated with an oxygen extraction fraction of 40% (the mean value for oxygen extraction fraction in normal controls) was 14 mm Hg (1.8 kPa). The cerebral perfusion pressure intervention resulted in a greater percentage increase in brain tissue oxygen than the percentage decrease in oxygen extraction fraction; this suggests that the oxygen gradients between the vascular and tissue compartments were reduced by the cerebral perfusion pressure intervention. CONCLUSIONS: Cerebral perfusion pressure augmentation significantly increased levels of brain tissue oxygen and significantly reduced regional oxygen extraction fraction. However, these changes did not translate into predictable changes in regional chemistry. Our results suggest that the ischemic level of brain tissue oxygen may lie at a level below 14 mm Hg (1.8 kPa); however, the data do not allow us to be more specific.

Adolescent↗

PubMed2004

Undergraduate medical education for the 21st century: leadership and teamwork.

BACKGROUND: The health care delivery system is experiencing enormous flux. The knowledge and skills sets required of today's physicians include expertise in competency areas that have not been included in the traditional medical curricula. The Undergraduate Medical Education for the 21st Century (UME-21) project was designed to develop innovative curricula that addressed the training necessary for medical students to gain skills required to provide high-quality, accessible, and affordable care in the modern health care environment. One of the nine UME-21 content areas, leadership and teamwork, has historically received relatively little attention in medical education. METHODS: Each school participating in the UME-21 project submitted a final report that provided information for this descriptive summary of curricular innovations for teaching the concepts of leadership and teamwork to medical students. A classification lexicon for the curricular content and experiences in this content area was derived from these UME-21 project reports. Each school evaluated its curricular innovations independently using a variety of methods, largely descriptive and qualitative in nature. RESULTS: Eight UME-21 schools developed curricula addressing the content area of leadership and teamwork. The majority of these curricula used the clinical care teams in the clinical rotations to demonstrate the principles and importance of leadership and teamwork. Three of the schools implemented didactic sessions and workshops to explicitly address leadership and teamwork. One school used the gross anatomy dissection teams as the "laboratory" for demonstrating this content material. The evaluations of these curricular efforts showed them to be positively regarded by the medical students. Outcomes of measurable changes in competency in this area of expertise were not evaluated. CONCLUSIONS: There is little past experience in teaching leadership and teamwork in medical school. The UME-21 project supported the design and implementation of several curricular innovations in this content area, which were well received by learners. These eight leadership and teamwork curricula are described, a lexicon outlining the specific content that was addressed in this content area is presented, and lessons learned are included in this report. Further efforts to demonstrate the mastery of new skills in this important content area, based on curricula such as these, are needed.

Clinical Clerkship↗

PubMed2004

Teaching quality measurement and improvement, cost-effectiveness, and patient satisfaction in undergraduate medical education: the UME-21 experience.

BACKGROUND: The health care system in the United States is changing at an ever-increasing rate. Recent reports by the Institute of Medicine raising concerns regarding rates of medical errors and suggesting the need for reengineering of the health care delivery system have focused attention on the need for quality measurement and improvement. METHODS: We abstracted data from final written reports submitted by 18 Undergraduate Medical Education for the 21st Century (UME-21) schools, as well as other materials available from participating UME-21 schools. Specific curricular innovations developed and implemented were identified. Additionally, senior medical students' responses to the annual Graduation Questionnaire administered by the Association of American Medical Colleges (AAMC) were available for analysis. The change from 1999 to 2001 in the proportion of seniors rating instruction in quality assurance as adequate was compared among four groups of UME-21 schools and the other 107 US medical schools. RESULTS: Eleven of the 18 schools specifically addressed the content areas of quality measurement and improvement, including utilization management (27% of schools), cost-effectiveness (45% of schools), use of clinical practice guidelines (73% of schools), and patient satisfaction assessment (45% of schools). Each school developed unique approaches and educational materials pertinent to the content area. Overall, the percentage of seniors rating the relative amount of instructional time devoted to quality assurance in medicine by their school's curriculum as adequate or better rose from 49% to 66% between 1999 and 2001 at the 11 UME-21 schools that introduced initiatives in quality improvement into their curricula. This change was significantly higher than the pattern at other US medical schools between 1999 and 2001, at which seniors' ratings rose only from 43% to 56%. CONCLUSIONS: Curriculum development and implementation addressing quality improvement in medical practice accelerate improvement of students' perception that their education has adequately addressed this subject area. This article summarizes some of the experiences, curricular approaches, successes, failures, and lessons learned in quality improvement by schools participating in the UME-21 project.

Cost-Benefit Analysis↗

PubMed2004

Practicing effectively in today's health system: teaching systems-based care.

BACKGROUND AND OBJECTIVES: The Institute of Medicine and the new Accreditation Council for Graduate Medical Education General Essentials have focused attention on the Undergraduate Medical Education for the 21st Century (UME-21) core content area of systems-based care. Through teaching systems-based care, medical students can learn how physicians effectively deliver and coordinate care within the health system. While medical students can be introduced to the organization, financing, and delivery of the health care system through lectures, the principles and practice of systems-based care must be reinforced through structured learning experiences during the clinical (ie, third and fourth) years. The purpose of this article is to define the undergraduate clinical content and experiences in systems-based care offered by the eight UME-21 partner schools. METHODS: The eight partner UME-21 schools exposed third- and fourth-year medical students to a variety of clinical experiences outside the traditional teaching hospital in such settings as physician offices, skilled nursing facilities, the patient's home, hospice, and public health departments. They also taught systems-based care skills such as care coordination, performance assessment, and quality improvement. RESULTS: Based on surveys of graduating students, the UME-21 programs were successful in exposing students to the aforementioned topics, though there was variability among schools. DISCUSSION: The experiences of the UME-21 schools in teaching about systems-based care, as discussed in this paper, may be useful to those involved in medical school curricula planning.

Clinical Clerkship↗

PubMed2004

A curriculum in systems-based care: experiential learning changes in student knowledge and attitudes.

BACKGROUND: To provide efficient, quality patient care, physicians must have a fundamental understanding of how the health care delivery system functions and how to appropriately use the various components of this system. As part of the Undergraduate Medical Education for the 21st Century (UME-21) initiative, the University of Miami in partnership with AvMed Health Plans, a nonprofit managed care organization (MCO) developed a longitudinal educational program that prepares all students for medical practice in emerging systems of care. METHODS: The program, which spans the 4-year undergraduate curriculum, incorporates didactic sessions and practical experiences to teach about the clinical, managerial, financial, and ethical aspects of systems-based care. During the third year of medical school, students visit the administrative offices of AvMed Health Plans for a day-long series of presentation-discussions and experiential tours through the various administrative departments. There, they experience first-hand all facets of a systems-based approach to care using evidence-based practice guidelines, utilization review, quality measurement and improvement, and chronic disease management. RESULTS: An attitudinal survey, constructed to evaluate general attitudes toward managing care and MCOs, was administered to students at the beginning of their first, second, and third year and immediately before and after their visit to AvMed during their third year. Using factor analysis, there were no significant differences in students' attitudes at the beginning of the first, second, or third year nor immediately before the seminar day at the MCO. However, the day-long seminar at AvMed did have a favorable effect on attitudes toward systems of care and MCOs in general. In addition, students performed well on post-evaluation knowledge assessments addressing fundamental concepts of systems of care and the function of an MCO in managing the care of its members. The visit to the MCOs (AvMed) offices and the day-long curriculum was replicated at another medical school, with similar effects on students' attitudes. CONCLUSIONS: Medical students have neutral-to-negative opinions of systems of care and MCOs. Early educational experiences such as classroom lectures and panels that address managing care issues have minimal effect on these opinions. However, bringing medical students to an MCO's administrative offices, seeing first-hand how systems of care operate, and having an open dialogue with physician administrators does effect a positive change in medical student opinions of a system in which care is managed. In addition, medical students can gain new knowledge about effective systems-based practice.

Clinical Clerkship↗

PubMed2002

Correlation between cerebral blood flow, substrate delivery, and metabolism in head injury: a combined microdialysis and triple oxygen positron emission tomography study.

Microdialysis continuously monitors the chemistry of a small focal volume of the cerebral extracellular space. Conversely, positron emission tomography (PET) establishes metabolism of the whole brain, but only for the duration of the scan. The objective of this study was to apply both techniques to head-injured patients simultaneously to assess the relation between microdialysis (glucose, lactate, lactate/pyruvate [L/P] ratio, and glutamate) and PET (cerebral blood flow [CBF], cerebral blood volume, oxygen extraction fraction (OEF), and cerebral metabolic rate of oxygen) parameters. Microdialysis catheters were inserted into the frontal cerebral cortex and adipose tissue of the anterior abdominal wall of 17 severely head-injured patients. Microdialysis was performed during PET scans, with regions of interest defined by the location of the microdialysis catheter membrane. An intervention (hyperventilation) was performed in 13 patients. The results showed that combining PET and microdialysis to monitor metabolism in ventilated patients is feasible and safe, although logistically complex. There was a significant relation between the L/P ratio and the OEF (Spearman r = 0.69, P = 0.002). There was no significant relation between CBF and the microdialysis parameters. Moderate short-term hyperventilation appeared to be tolerated in terms of brain chemistry, although no areas were sampled by microdialysis where the OEF exceeded 70%. Hyperventilation causing a reduction of the arterial carbon dioxide tension by 0.9 kPa resulted in a significant elevation of the OEF, in association with a reduction in glucose, but no significant elevation in the L/P ratio or glutamate.

Adolescent↗