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Biomedical subjects

L S Chan

Publications and source records attributed to L S Chan.

157 records · Page 9Linked to original sources
PubMedDate not supplied

A prospective evaluation of bacteremic patients with chronic liver disease.

We prospectively studied 51 consecutive bacteremic patients with chronic liver disease in order to evaluate their clinical presentation and to assess the relationship of various clinical parameters to mortality. Forty-two patients had alcoholic liver disease and 40 were in Class C, by the Pugh modification of Child's criteria. Soft tissue infections were the most common source of bacteremia, followed by pneumonia, spontaneous bacterial peritonitis and urinary tract infection. Gram positive organisms were isolated in 69% of cases, and Gram negative ones in 31%. In nine patients, no source of bacteremia was detected. Leukocytosis occurred in 59% of patients and bandemia in only 41%. Although appropriate antibiotic therapy was begun in all cases on admission, 17 patients (33%) died in the hospital. Of 38 clinical parameters evaluated, multivariate analysis revealed that the three variables contributing the most independent information toward predicting in-hospital mortality were the absence of a history of fever, an elevated serum creatinine and marked leukocytosis. Improved understanding of the pathophysiologic relationship between these parameters and patient outcome may enable us to improve the therapy of bacteremic patients with chronic liver disease.

Chronic Disease↗
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Analysing antibody response based on data obtained from serial dilution methods.

We identify several problem areas in statistical analyses of data obtained from serial dilution methods in serology. We provide the mathematical backgrounds of the key elements involved in this field of study and discuss the statistical considerations. The problem areas include the use of the geometric mean as an expression of the average of a set of observations, the use of fold increase to measure antibody response, and the statistical analysis of the change in antibody response with respect to other variables, such as age and pre-titer levels.

Adult↗
PubMedDate not supplied

Utility of B-type natriuretic peptide in differentiating congestive heart failure from lung disease in pediatric patients with respiratory distress.

Plasma B-type natriuretic peptide (BNP) has been reported to be helpful in differentiating cardiac from pulmonary etiologies of dyspnea in adults. We investigated whether BNP concentration could be applied similarly in children with respiratory distress. BNP levels were measured using a rapid immunoassay in 49 infants and children presenting with acute respiratory distress. The patient's history, symptoms, physical exam, chest x-ray, and an echocardiogram were used to identify patients with congestive heart failure (CHF) from noncardiac causes of respiratory distress. Results are reported as mean+/-SD. Patients with CHF (n = 23) had BNP levels of 693.0+/-501.6 pg/ml, significantly higher than those of the group of patients with lung disease (n = 26), whose BNP was 45.2+/-64.0 pg/ml (p < 0.001). There was no significant difference in age between the two groups (29.7+/-59.3 vs 13.1+/-22.6 months; p = 0.12). A BNP level of 40 pg/ml was 84% accurate in differentiating CHF from pulmonary disease. Fifteen of 23 CHF patients had ventricular volume overload from left-to-right shunting congenital heart defects and 8/23 had left ventricular systolic dysfunction. Age-adjusted comparison of the two subgroups of CHF patients revealed that children with left ventricular systolic dysfunction had significantly higher mean BNP levels than those with left-to-right shunts (1181+/-487 vs 433+/-471 pg/ml, p = 0.0074). We conclude that BNP level is of value in differentiating cardiac from pulmonary causes of respiratory distress in children.

Age Factors↗
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Evaluation of statistical packages for suitability for use by clinical investigators in medicine.

With the increased availability of personal computers and statistical software packages, it is inevitable that there will be increasing attempts by clinical investigators to perform data management and statistical analysis. Reviews of statistical packages are abundant in computer and statistical journals. However the majority of them were not written for clinical investigators in medicine. This paper presents an analytic approach to evaluate the suitability of statistical packages for use by clinical investigators for data-management and preliminary statistical-analysis purposes. The evaluation scheme addresses five areas of concern: availability of data-management features; availability of basic statistical-analysis features; ease of use; documentation; and quality of programs. Among six statistical packages reviewed by this process, CRISP is recommended as the most suitable package for clinical investigators to use for data-management and preliminary statistical-analysis purposes.

Evaluation Studies as Topic↗
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Reactions to booster pneumococcal vaccination in patients with sickle cell disease.

Repeat (booster) pneumococcal vaccination was administered to 32 patients with sickle cell disease in a double blind, placebo-controlled crossover study as early as 2.3 years after initial immunization. A significantly greater proportion of patients reported local pain, swelling or redness after booster, as compared to that after placebo (P less than 0.001), and pneumococcal antibody titer before vaccination was the predominant predictive variable for the development of fever, local pain and swelling after booster. A comparison of reaction rates following primary or booster immunization showed no significant differences in the frequency of reported symptoms except for muscle pain which occurred less frequently after booster (P less than 0.005). The concern for adverse reactions after repeat pneumococcal vaccination should not be an obstacle to the pursuit of further studies on the efficacy of pneumococcal vaccine and booster responses.

Adolescent↗
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Maternal and child mortality along the U.S.-Mexico border.

This paper examines the maternal mortality and the age-specific mortality rates for the under 25 year olds in six border regions on the U.S. side of the U.S.-Mexico border and compares them with those of adjoining regions in Mexico. On the U.S. side of the border, the improvement in the general mortality status of maternal and child health from 1970 to 1980 was equal to or better than that of the nation as a whole. Despite this improvement, in 1980 five of the six border regions showed higher mortality rates due to external causes for the 1-4 age-group. On the Mexican side, maternal and child mortality was lower in the border region than in other parts of Mexico but much higher than in the United States. The 1-4 year olds in Mexico had the highest mortality rates among the three age-groups over 1 year of age.

Age Factors↗
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California's use of health statistics in child health planning.

The California Health Plan for Children, 1979, compiled by the Committee on Health Planning of California, District IX of the American Academy of Pediatrics, is an extensive report on health problems unique to the children of California. Since its publication, many local and state health agencies have been using it as a guide and source of data in their planning efforts for child and youth health. The creation of the plan demonstrated a successful working relationship between health care practitioners and biostatisticians, the acceptance by health professionals of the use of health statistics in planning, the different uses of health statistics in formulating recommendations, and an approach to organizing and summarizing large bodies of data. Nevertheless, our experience indicates that although collection systems for data on population, mortality, natality, morbidity, and health services statistics abound, their use in community health planning for subpopulations is still limited by problems in the definition, validity, and completeness of the data elements. The establishment of an individualized data system for the entire population, to be developed, coordinated, and controlled by one central agency, could be a significant step toward solving these long-standing problems in our data systems.

Adolescent↗
PubMedDate not supplied

A study of the quality of prescriptions issued in a busy pediatric emergency room.

An analysis of 2,213 prescriptions written by physicians in a busy, urban pediatric emergency room revealed that only 110 or 5 percent had no errors or omissions of specifications. The quality of the prescriptions was evaluated according to the standards of acceptable prescribing for the following specifications: quantity, dosage, time interval between doses or specific hours to be given, and specific instructions. The hospital pharmacists, also under pressure, generally failed to monitor the prescriptions adequately--either they did not rectify the physicians' errors or at times they made incorrect changes. To improve the quality of prescriptions issued under pressure in an emergency room, several courses of action are recommended: Pharmacology departments of medical schools should place more emphasis on teaching students the art of writing explicit, comprehensible prescriptions. The physician and pharmacist should work as a team in the interest of providing patients with accurate and detailed prescriptions; or both the physician and the pharmacist should delegate the composition of prescriptions to an automated computer system, thereby reducing human error in writing and monitoring prescriptions and allowing both professionals more time for direct contact with patients.

Child↗
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Regionalization of infant transports: the southern California experience and its implications. I: Referral pattern.

The development and implementation of neonatal intensive care services have been essential components of perinatal regionalization during the past two decades. The transport of critically ill infants to regional neonatal intensive care units has played an important role in improving neonatal outcome. This article presents a profile of Southern California's 10-year infant transport experience (1979 through 1988) in terms of the following indicators: transport volume, cross-county referrals, distance travelled, referral pattern, and birth weight pattern. Findings point to the necessity of focusing attention on several critical issues confronting Southern California's neonatal services in the 1990s. They include adequacy of tertiary or intermediate bed capacity in neonatal intensive care units; appropriateness of existing infant referral practices; impact of maternal-fetal transports; availability of financing resources; and overall differences in morbidity and mortality rates between transported and nontransported infants in subpopulations.

Birth Weight↗
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Very low birth weight infants and their families during the first year of life: comparisons of psychosocial outcomes based on after-care services.

OBJECTIVE: To evaluate psychosocial outcomes in families of very low birth weight infants during the first year postdischarge. STUDY DESIGN: This was a prospective investigation of family functioning in families of 81 very low birth weight infants discharged from two tertiary care neonatal intensive care units in Los Angeles, CA. Infants were assigned to four groups receiving a variety of after-care services in their homes. Analyses of variance and t-tests were used to examine differences in outcomes, including parental involvement with infant, maternal depression, and family adaptation and cohesion over time. RESULTS: During the first year following discharge, there were no differences between after-care groups in levels of maternal depression as measured by the Center for Epidemiologic Studies Depression Scale or family cohesion and adaptability as measured by the Family Adaptability and Cohesion Evaluation Scales II. Significant between-group differences were seen on measures of home environment at both 6 and 12 months and self-reports of satisfaction with parenting at 6 months. CONCLUSION: Results of this study indicate that types of after-care services do not change basic maternal or family characteristics. However, long-term home-visiting services appear to impact the way mothers interact with their high-risk infants. Furthermore, such services seem to influence a mother's perception of satisfaction with her role.

Adult↗
PubMedDate not supplied

Very low birth weight infants and their families during the first year of life: comparisons of medical outcomes based on after care services.

OBJECTIVE: To evaluate factors contributing to optimal medical outcomes during the first year following discharge of very low birth weight infants from tertiary neonatal intensive care units. STUDY DESIGN: This was a prospective investigation of the health and development of 81 very low birth weight infants following discharge from two tertiary neonatal intensive care units in Los Angeles. Infants were assigned to four groups receiving a variety of after care services in their homes. Analyses of variance were computed to examine differences between groups for a variety of outcomes. RESULTS: No statistically significant differences were seen between after care groups on use of hospital emergency rooms (ER) rehospitalization rates, or child abuse and neglect. Highest overall rates of optimal outcomes were seen in the group receiving the highest intensity of after care services. Those groups receiving long-term home visiting services had significantly higher rates of up-to-date immunizations. CONCLUSION: There was no significant impact on infant mortality and morbidity of early discharge, regardless of the system of after care used. However, those infants who received the highest level of after care services had the most optimal health outcomes and were most likely to be receiving well-baby care. It is likely that the comprehensive, clinic-based system of health care available to all study infants was a significant factor in low rates of morbidity.

Aftercare↗