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Biomedical subjects

R M Gardner

Publications and source records attributed to R M Gardner.

At least 19 recordsLinked to original sources

Familiarity and anticipation of negative life events as moderator variables in predicting illness.

A 10-month longitudinal study with 79 university students examined the role of positive and negative life experiences on the subsequent development of health problems. The Life Experiences Survey (LES; Sarason, Johnson & Siegel, 1978) was modified to measure the potential role of five moderating variables on illness. Students gave monthly reports of life events experienced, as well as health status, on the Seriousness of Illness Rating Scale (Wyler, Masuda & Holmes, 1968). Results indicated that both positive and negative life events were predictors of subsequent health problems. Negative life events that were familiar to the students and were unanticipated proved to be significant moderator variables; both factors were significant predictors of the number of health problems subsequently experienced.

Adaptation, Psychological

Computerized identification of patients at high risk for hospital-acquired infection.

Surveillance for hospital-acquired infections is required in U.S. hospitals, and statistical methods have been used to predict the risk of infection. We used the HELP (Health Evaluation through Logical Processing) Hospital Information System at LDS Hospital to develop computerized methods to identify and verify hospital-acquired infections. The criteria for hospital-acquired infection are standardized and based on the guidelines of the Study of the Efficacy of Nosocomial Infection Control and the Centers for Disease Control. The computer algorithms are automatically activated when key items of information, such as microbiology results, are reported. Computer surveillance identified more hospital-acquired infections than did traditional methods and has replaced manual surveillance in our 520-bed hospital. Data on verified hospital-acquired infections are electronically transferred to a microcomputer to facilitate outbreak investigation and the generation of reports on infection rates. Recently, we used the HELP system to employ statistical methods to automatically identify high-risk patients. Patient data from more than 6000 patients were used to develop a high-risk equation. Stepwise logistic regression identified 10 risk factors for nosocomial infection. The HELP system now uses this logistic-regression equation to monitor and determine the risk status for all hospitalized patients each day. The computer notifies infection control practitioners each morning of patients who are newly classified as being at high risk. Of 605 hospital-acquired infections during a 6-month period, 472 (78%) occurred in high-risk patients, and 380 (63%) were predicted before the onset of infection. Computerized regression equations to identify patients at risk of having hospital-acquired infections can help focus prevention efforts.

Cross Infection

Effect of estriol on the structure and organization of collagen in the lamina propria of the immature rat uterus.

Estradiol produces both hypertrophic and hyperplastic changes in the uterus, and these changes are associated with alterations in the structure of collagen in the lamina propria. Estriol induces only hypertrophic responses in the immature rat uterus; its effects on collagen structure were characterized in this study. Light micrographs of Masson's trichrome-stained sections revealed that the intensity of the collagen stain in the lamina propria of the rat uterus was profoundly reduced, relative to that in controls, 4 h after estriol (40 micrograms/kg) administration. These changes were not evident 24 h after estriol administration. In control uteri, transmission electron micrographs revealed that the collagen fibers surrounding stromal cells formed dense collections of bundles that were seen throughout the extracellular matrix, whereas in tissues exposed to estriol 4 h earlier, large regions of the extracellular spaces were devoid of collagen bundles. The 4-h changes in collagen were eliminated when animals were pretreated with actinomycin D (8 mg/kg) or cycloheximide (4 mg/kg). Dense collections of collagen bundles were present in tissues 24 h after estriol treatment, and their appearance was not altered by actinomycin D or cycloheximide treatment. Alterations in collagen 4 h after hormone administration appeared to be estrogen-specific since dexamethasone (600 micrograms/kg) and dihydrotestosterone (400 micrograms/kg) had no effect. These data provide evidence that the changes in collagen structure in the uterus are associated with events that function during the hypertrophic growth responses induced by estrogens.

Animals

The fast flush test measures the dynamic response of the entire blood pressure monitoring system.

The fast flush test (FT) is the only test that allows clinicians to determine in vivo the natural frequency (fn) and damping coefficient (zeta) of an invasive blood pressure monitoring system. The underlying assumption to the validity of the FT is that it activates the whole system including the distal catheter. We devised an in vitro model of a typical invasive blood pressure monitoring system to determine whether this assumption was true. The model consisted of a conventional transducer with a flush device attached to various lengths of connecting tubing (91.4, 182.9, and 274.3 cm) terminated by four different diameter catheters (5.1 cm 14 G, 16 G, 18 G, and 20 G). A microtipped transducer catheter was inserted into the distal catheter tubing system. A FT was performed and the fn and zeta were recorded from the conventional transducer and simultaneously from the microtipped transducer catheter. Similar studies were conducted using the ROSE damping device as well as with systems including 0.1 ml of air near the conventional transducer. These studies utilized 18- and 20-G catheters with each of the three lengths of connecting tubing. All measurements of fn and zeta at the proximal conventional transducer were identical to those measurements as recorded by the distal microtipped transducer catheter. We conclude that the FT activates the whole monitoring system and that fn and zeta are the same throughout the system including the distal catheter.

Blood Pressure Monitors

Evaluation of accuracy and reproducibility of peak flowmeters at 1,400 m.

Peak flow meters provide physicians and patients with objective measures about changes in pulmonary obstruction. We evaluated eight models of peak flowmeters and measured their accuracy and reproducibility with methods recently recommended by the National Asthma Education Program (NAEP). Waveforms from the American Thoracic Society's spirometer testing set were used to drive a computer-controlled syringe. Testing was done at Salt Lake City at an altitude 1,400 m. It appears that the original Wright peak flowmeter has been used as the "de facto" standard. We found that the original Wright peak flowmeter overestimated flows in its midrange; and, as a consequence, most of the other peak flowmeters also overestimated peak flows. The overestimation of peak flows may have been understated because of the 1,400-m altitude testing site. To the credit of the instrument manufacturers, we were pleasantly surprised with the quality, accuracy, and reproducibility of presently available peak flowmeters; however, as a result of our testing, we suspect that with little effort, manufacturers of peak flowmeters could improve the accuracy of their devices. Standardized testing methods and equipment should make the task of peak flowmeter design, manufacture, and testing even easier. We trust that manufacturers of peak flowmeters will respond appropriately and improve their instruments.

Adult

Integration of a stand-alone expert system with a hospital information system.

A stand-alone PC expert system for evaluating the appropriateness of inpatient admissions has been integrated with an existing hospital information system. The expert system supports preadmission screening for appropriateness of inpatient admissions. The HIS provides extensive clinical data in a coded electronic form, permitting high-level decision support. The integrated system was developed for a 20 week randomized clinical trial to evaluate the effects of preadmission screening on inappropriate inpatient admissions. Three factors of the integration are considered: programmatic integration of the expert system, seamless presentation of mixed platform applications, and integration of coded data from the stand-alone application into the HIS data structure.

Evaluation Studies as Topic

In vivo regulation of parathyroid hormone-related peptide messenger ribonucleic acid in the rat uterus by 17 beta-estradiol.

During pregnancy, elevated levels of PTH-related peptide (PTHrP) persist in the myometrium of the rat uterus. Near term, intrauterine occupancy is correlated with high levels of PTHrP messenger RNA in the gravid horn of the unilaterally pregnant uterus. In nongravid tissue from these same animals the presence of smaller yet significant elevations of PTHrP mRNA suggests that the PTHrP gene also may be regulated by humoral factor(s). To test this hypothesis, we assessed the action of 17 beta-estradiol (E2) on the expression of the PTHrP gene in the uterus of the ovariectomized rat. While low levels of PTHrP mRNA are detected in uteri from ovariectomized rats, a single dose of E2 (4, 40, or 400 micrograms/kg body weight) stimulated a 6- to 8-fold increase in the levels of PTHrP mRNA in the uterus at approximately 2 h after E2 treatment. This increase was transient with levels gradually declining to pretreatment (basal) levels within 24 h. Other steroid hormones tested, including dihydrotestosterone, dexamethasone, and progesterone, failed to stimulate this response. The increase of PTHrP mRNA accumulation required a dose greater than 0.4 micrograms/kg. The magnitude and duration of PTHrP mRNA accumulation were very similar when doses of 40 or 400 micrograms/kg were used. In addition, the stimulation of the PTHrP gene by E2 is neither age dependent nor specific to the rat and is, in part, under transcriptional control. Together, these data indicate that in vivo E2 regulates the levels of PTHrP mRNA in the rat uterus and support a role for E2 in the increased expression of PTHrP mRNA in early gestational tissue, as well as in the nongravid horn of the unilaterally pregnant uterus.

Aging

In vivo regulation of Zif268 messenger RNA expression by 17 beta-estradiol in the rat uterus.

Administration of 17 beta-estradiol (E2) induces a mitogenic response in the rat uterus. Previous studies have shown that this effect involves the transient activation of c-fos and c-myc expression, followed by significant increases in both DNA synthesis and cell proliferation. Zif268 is a zinc finger-containing, DNA-binding transcription factor that has been implicated in the regulation of cell growth and development and has been shown to be coregulated with c-fos in a number of systems. To determine whether Zif268 is also a target for estrogen regulation, we measured the effects of E2 on Zif268 mRNA expression in the uterus of the ovariectomized rat. In this report we demonstrate that although low levels of Zif268 mRNA expression are detectable in the uteri from ovariectomized control rats, treatment with E2 (4, 40, or 400 micrograms/kg BW) induces a rapid and transient 45- to 50-fold increase in the level of Zif268 mRNA 2 h after E2 treatment. The elevated levels of Zif268 mRNA returned to basal 6 h after hormone treatment. Lower doses of E2 (0.004, 0.04, and 0.4 micrograms/kg) had little or no effect on Zif268 mRNA expression, while higher doses of E2 (4-400 micrograms/kg) resulted in maximal increases in Zif268 expression. Dexamethasone, 5 alpha-dihydrotestosterone, and progesterone had no effect on uterine Zif268 mRNA expression, and the induction of Zif268 by E2 was abolished by pretreating the animals with the RNA synthesis inhibitor actinomycin-D. In addition, stimulation of Zif268 mRNA expression was observed with the short-acting estrogen estriol, suggesting that the response may be specific for estrogenic steroids.(ABSTRACT TRUNCATED AT 250 WORDS)

Actins

Body-size judgments and eye movements associated with looking at body regions in obese and normal weight subjects.

Eye movements of 20 male and 20 female obese and nonobese subjects were monitored during two body-size estimation tasks using a computer-based video technology. Analysis indicated no differences in body-size estimation between subjects using the staircase method. All subjects slightly underestimated body size; however, obese subjects were more sensitive than normal-weight subjects in detecting size distortion when a signal-detection task was employed. Eye-movement data indicated subjects looked longest at the chest, followed by waist, head, thighs, and calves/feet, in both the staircase and the signal-detection methods. Women viewed the waist region longer than men. On a signal-detection task subjects were better at detecting body-size distortion when viewing the body from the back than from front or profile.

Adolescent

Development of a computerized adverse drug event monitor.

Adverse events during drug therapy are receiving renewed attention. Some adverse drug events (ADEs) are identified only after the widespread clinical use of a drug. The Food and Drug Administration advocates post-marketing surveillance systems to provide early warnings of previously undetected ADEs. The identification of ADEs by U.S. hospitals is now required by the Joint Commission on Accreditation of Healthcare Organizations. We developed a series of computer programs and data files on the HELP System to help identify ADEs. The HELP System monitors laboratory test results, drug orders, and data entered through a computerized ADE reporting program. A nurse or pharmacist verifies computer alerts of possible ADEs. The computerized system identified 401 ADEs during the first year of use compared to 9 by voluntary reporting methods during the previous year (p less than 0.001). This paper describes the development and early use of the computerized ADE surveillance system.

Adverse Drug Reaction Reporting Systems

Assessing the effectiveness of a computerized blood order "consultation" system.

To optimize blood ordering and accurately assess transfusion practice, in 1987, an "on line" computerized, knowledge-based, blood order critiquing system was integrated into the HELP Hospital Information System (HIS) at LDS Hospital. Evaluations of the computerized ordering system demonstrated its benefits and limitations on transfusion practice. Based on this experience, a second generation blood ordering system using a consultation mode was developed. A pilot test of this blood order consultant system, using historical data in the HELP system's database, was performed. This pilot test demonstrated that the consultation system provided accurate recommendations for red blood cell (RBC) and platelet orders. Comparing the appropriateness of blood orders with the recommendations made by the director of the blood bank, the orders recommended by the computer "consultant" agreed 95.5% of the time. The computer consultation system also recommended fewer RBC units for transfusion. Preliminary results obtained using the consultant approach suggest that we may be able to simplify blood ordering practice and also reduce the number of units of blood products ordered. Based on these findings we are now preparing to compare the "critiquing" and "consultation" approaches using a clinical trial.

Artificial Intelligence

Real time data acquisition: experience with the Medical Information Bus (MIB).

Care of the acutely ill patient requires rapid acquisition, recording and communications of data. In the modern hospital it is not unusual for a patient to be connected to several monitoring and recording devices simultaneously. Each of these devices is typically made by a different manufacturer who may specialize in one sort of measurement, for example, pulse oximetry. Most of the modern monitoring and recording devices are micro-processor based and have communications capabilities. Unfortunately, there is no operable standard communications technology available from all devices. In addition different clinical staff (physicians, nurses, or respiratory therapists) may be responsible for collecting data. As a result there is a need to develop methods, standards, and strategies for timely and automatic collection of data from these monitoring and recording devices. We report on more than 5 years of clinical experience of automated ICU data collection using a prototype of the Medical Information Bus (MIB).

Computer Communication Networks

Clinical evaluation of computer-based respiratory care algorithms.

A collection of computer-based respiratory care algorithms were implemented as a prototype computer-based patient advice system (COMPAS) within the existing HELP hospital information system. Detailed medical logic recommended ventilator adjustments for 5 different modes of ventilation: assist/control (A/C), intermittent mandatory ventilation (IMV), continuous positive airway pressure (CPAP), pressure controlled inverted ratio ventilation (PC-IRV), and extracorporeal carbon dioxide removal (ECCO2R). Suggestions for adjusting the mode of ventilation, fraction of inspired oxygen (FiO2), positive end-expiratory pressure (PEEP), peak inspiratory pressure, and several other therapeutic measures related to the treatment of severe arterial hypoxemia in adult respiratory distress syndrome (ARDS) patients were automatically presented to the clinical staff via bedside computer terminals. COMPAS was clinically evaluated for 624 hours of patient care on the first 5 ARDS patients in a randomized clinical trial. The clinical staff carried out 84% (320/379) of the computerized therapy suggestions. In response to a questionnaire distributed to clinical users of the system, 86% judged the system to be potentially valuable. Through implementation of COMPAS, a computer-based ventilatory therapy advice system, we have laid the groundwork for standardization of ventilator management of arterial hypoxemia in critically ill ARDS patients.

Algorithms

Therapeutic antibiotic monitoring: surveillance using a computerized expert system.

STUDY OBJECTIVE: To develop and evaluate a computerized system to monitor therapeutic antibiotics in a hospital setting. MATERIAL AND METHODS: From November 1986 through October 1987, we prospectively monitored 1,632 hospitalized patients who had 2,157 microbiology specimens sent for culture and sensitivity testing. During the study period, computer algorithms were used to identify patients whose antibiotic therapy was inappropriate in relation to microbiology culture and sensitivity data. When inconsistencies occurred between antibiotic therapy and in vitro sensitivity data, computer algorithms generated therapeutic antibiotic monitor (TAM) alerts. A clinical pharmacist then notified the attending physician of the alert. RESULTS: Antibiotic therapy was identified by the computer as inappropriate in 696 instances (32%). After we eliminated false-positive alerts, 420 evaluable TAM alerts remained. Physicians responded to the TAM alerts by either changing or starting antimicrobial therapy in 125 cases (30%). Moreover, physicians were previously unaware of the relevant susceptibility test results in 49% of the alerts. CONCLUSION: Computer-assisted monitoring is an efficient and promising method to identify and correct errors in antimicrobial prescribing and to assure the appropriate use of therapeutic antibiotics.

Algorithms

Computer-critiqued blood ordering using the HELP system.

Recently the medical risk of blood transfusions has emphasized the need to improve the safe use of blood products. For the past 2 1/2 years at LDS Hospital we have used the HELP computer system to assist and critique ordering of blood products "on-line" by physicians and nurses. This report details the computer methods used to order blood products and to critique the appropriateness of those orders. Physicians personally enter the orders for more than 45% of the blood products using computer terminals, whereas 7% are from physician standing orders. Nurses enter the remaining orders from written orders (26%), verbal orders (14%), and phone orders (8%). There were 3396 blood orders for 1043 patients generated by 273 physicians during the fourth quarter of 1989. Each order is justified at the time it is entered by selecting from a menu of physician-approved criteria. The criteria are linked to supportive data in the data base, i.e., laboratory results and clinical data. The computer verified that 82% of these orders met criteria. Quality Assurance nurses verified the remaining 18%. Of these 18% only one in eight required manual chart review. After computer and Quality Assurance review, only eight (0.24%) of the orders were found to be true exceptions to established criteria. Physicians and nurses have accepted the computerized critiquing system. Through use of the computer we provide "on-line" critiquing and improve the use of scarce blood product resources.

Blood Banks