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Biomedical subjects

R C Ellison

Publications and source records attributed to R C Ellison.

At least 91 records · Page 5Linked to original sources
PubMed1987

Perinatal events and necrotizing enterocolitis in premature infants.

Among 2123 premature infants monitored during a large multicenter study of patent ductus arteriosus, necrotizing enterocolitis (NEC) was diagnosed in 121 (5.7%) of these infants. Rates ranged from 13.5% among infants with a birth-weight (BW) of 500 to 749 g to 2.9% among infants whose BW was between 1500 and 1750 g. The presence of a hemodynamically significant patent ductus arteriosus did not alter the incidence of NEC. Of a large number of perinatal events and conditions considered, only BW and maternal toxemia were found to be associated with the rate of NEC, both relating inversely. Thus, these data do not support a relationship between NEC and a variety of perinatal factors previously postulated as potential determinants of the disorder.

Birth Weight↗
PubMed1987

Clinicians' appraisal of sonography.

The perceived efficacy of sonography in making diagnostic and management decisions in clinical practice was determined through a questionnaire survey of physicians who had recently referred patients to a university radiology department. Of 2,178 questionnaires sent, 1,611 were returned (74%). Sensitivity and specificity of sonography, corrected for verification bias, were 72% and 84%. Referring physicians considered the studies to be of value in arriving at the final diagnosis and in the clinical management of patients in approximately two-thirds of the cases. Results were considered of no value and misleading in 4% of the cases. Sonography was more accurate and was reported to be valuable by approximately 10% more physicians when a specific indication for an examination could be identified rather than when indications were vague and when sonographic findings were abnormal rather than normal (P less than .005). In general, sonography was of equal value to both specialists and nonspecialists. The results of this study suggest that sonography is, and is perceived by clinicians to be, an accurate and valuable clinical diagnostic modality.

Attitude of Health Personnel↗
PubMed1987

Sources of sodium, potassium, and energy in the diets of adolescents.

Analysis of food diaries of 200 students in two boarding high schools indicated that 30% of their average daily sodium intake was contributed by bakery foods and ready-to-eat cereals. The next most important source of sodium (24%) was a category made up of food adjuncts, snack-type foods, soups, and beverages. The largest proportion of sodium in most foods had been added during food manufacture or preparation. Salt added at the table contributed less than 1% of the sodium in the diets of the teenagers. All students did not eat foods from all categories on their day of recording; 70% or more ate bakery products, dairy foods, food adjuncts, and meat, fish, poultry, and eggs. Changes in recipe formulations can decrease sodium content for a variety of bakery products, cereals, mixed dishes, snack-type foods, soups, and processed meats. It is therefore possible to make large reductions in dietary sodium without disturbing other nutrient values.

Adolescent↗
PubMed1986

Perinatal risk assessment for patent ductus arteriosus in premature infants.

Data from 2107 inborn premature infants monitored for hemodynamically significant patent ductus arteriosus were used to develop means for clinically assessing at birth the risk of developing patent ductus arteriosus during the first 30 days of life. The overall 30-day incidence rates in birth weight categories 500 to 999, 1000 to 1499 g, and 1500 to 1750 g were 41, 17, and 7%, respectively. At-birth risk estimates obtainable from the derived multivariate functions ranged from 0 to 78% for the 500 to 999 and 1000- to 1499-g categories, and from 0 to 20% for the 1500- to 1750-g category. The derived risk functions provide for enhanced selectivity in the application of measures for the prevention of patent ductus arteriosus.

Adolescent↗
PubMed1986

Electrocardiogram of the premature infant at 1 year of age.

ECGs were examined from 461 premature infants at 1 year of age. Data from those without a history of bronchopulmonary dysplasia were generally similar to published norms for healthy 1-year old infants. History and persistence of residual lung disease were reflected in the ECG by a high prevalence of findings suggestive of right ventricular hypertrophy. Clinically significant patent ductus arteriosus during the neonatal period did not influence the 1-year ECG findings. The data expand the published experience with follow-up ECGs from premature infants and suggest that the ECG may be a useful tool in follow-up of chronic residual lung disease in this population.

Bronchopulmonary Dysplasia↗
PubMed1985

Uses of the case-control and cohort epidemiological approaches in pediatric practice and research.

Increasing reliance is being placed on the use of quantitative epidemiological methods in the conduct and evaluation of pediatric research. The basic design features of two common types of observational studies, the case-control study and the cohort study, are reviewed. Advantages and disadvantages of these two study designs are discussed with emphasis on aspects such as the selection of comparison groups, avoiding selection and recall bias, gathering exposure information, controlling for potentially confounding factors, and methods of analysis. Appreciation of the salient features of these study design approaches should aid the clinician/researcher in the conduct of research endeavors as well as in critically reviewing the medical literature.

Adolescent↗
PubMed1985

Risk factors for retrolental fibroplasia: experience with 3,025 premature infants. National Collaborative Study on Patent Ductus Arteriosus in Premature Infants.

The rate of retrolental fibroplasia in relation to prenatal and neonatal characteristics was explored on the basis of a cohort of 3,025 neonates with birth weight less than 1,750 g. The overall rate of retrolental fibroplasia of any degree at hospital discharge was 11%, varying from 43% for those with birth weight between 500 and 749 g to 3% for those in the 1,500- to 1,750-g category. Among the potential determinants, the main interest was in nonhyperoxic characteristics, conditional on measures of prematurity and oxygen supplementation. Maternal diabetes and antihistamine use during the last 2 weeks of pregnancy were associated with significantly higher rates of retrolental fibroplasia, whereas toxemia was associated with lower rates. Frequent apneic spells, bronchopulmonary dysplasia, and sepsis in the neonate were also associated with significantly higher rates. On the other hand, the data indicate no independent role of low Apgar score, intraventricular hemorrhage, exchange transfusion, patent ductus arteriosus, or certain other characteristics previously postulated as risk factors.

Anemia↗
PubMed1985

Dietary sodium reduction among students: feasibility and acceptance.

Modifications in the preparation of food served in a boarding high school during a 5-week period were successful in decreasing the sodium content of a variety of food products by an average of 51%. Such food was, in general, well accepted. The ratings of specific reduced-sodium food products equaled those of similar products containing "usual" amounts of sodium. Food diaries kept by students gave estimates of total sodium intake comparable with those measured by laboratory analysis of 24-hour food collections. Food diaries collected from an average of 70 volunteers per week indicated that during the reduced-sodium period, the total sodium intake of students, including that from dining hall food, snack food, and food consumed outside the school, decreased from 136 mEq (3 gm sodium, 8 gm salt) to 88 mEq (2 gm sodium, 5 gm salt), a reduction of 35% (p less than .0001). The impact of salt added at the table was very small; the choice and the quantity of foods consumed were the main determinants of sodium intake. The results indicate that foods can be prepared with appreciably less sodium and still be highly acceptable to young people.

Adolescent↗
PubMed1984

Clinical course to 1 year of age in premature infants with patent ductus arteriosus: results of a multicenter randomized trial of indomethacin.

Reported are 1-year follow-up results of a randomized clinical trial comparing three strategies of managing clinically significant patent ductus arteriosus at the time of diagnosis in premature infants: (1) immediate administration of a three-dose course of intravenously administered indomethacin in addition to usual medical therapy (fluid restriction and use of diuretics or digitalis or both), with surgery as a backup measure, (2) usual medical therapy alone initially, with indomethacin as the first and surgery as the final backup measure, and (3) usual medical therapy alone initially, with surgery alone as backup. Of primary concern were the relative merits of these three managements strategies in the terms of the long-term occurrence of a wide range of health problems. Although at the time of neonatal hospitalization there was a significant excess of bleeding episodes in infants receiving indomethacin as part of initial treatment, and a significantly higher rate of retrolental fibroplasia in the those given usual medical therapy with surgery as backup, there were no statistically significant differences at 1 year of age related to these intermediate outcomes. In other regards, too, the treatment strategies appeared interchangeable in terms of the 1-year outcome.

Bronchopulmonary Dysplasia↗
PubMed1984

A device for the automatic measurement of blood pressure in epidemiologic studies.

An automatic blood pressure apparatus was devised for use in an epidemiological study that required self-administered measurements of blood pressure for up to 200 students each week over a school year. A Dinamap device was used to determine systolic and diastolic blood pressures by the oscillometric method. An Apple II Plus computer with one disc drive was used for control of the device and storage of data. Two such apparatuses were assembled and used to make more than 6,000 recordings of blood pressure over a six-month period. Except for some initial problems with a computer component, the apparatuses performed well; successful blood pressure recordings were obtained 99% of the time. Use of the automatic devices proved to be very acceptable to students. It is concluded that the use of such devices offers a reasonable means for obtaining accurate measurements of blood pressure and may be applicable for many epidemiologic studies.

Blood Pressure Determination↗
PubMed1984

Surgical closure of patent ductus arteriosus in 268 preterm infants.

Over a 2 year period ending in April, 1981, 268 premature infants with birth weight below 1,750 gm underwent operation for a "hemodynamically significant" patent ductus arteriosus. Operations were performed in 13 centers participating in a collaborative study, which was primarily designed to evaluate the role of indomethacin in the management of patent ductus arteriosus. No patient died during the operations, which were done at a median age of 10 days. Eight infants (3%) died within 36 hours after operation. In only one was the death directly attributable to the operative procedure. Hospital mortality (23%) and postoperative morbidity, which included bronchopulmonary dysplasia, pneumothorax, and sepsis, were unrelated to birth weight, age at operation, and degree of preexisting pulmonary disease or preoperative treatment of the infant with indomethacin. Results indicate that surgical ligation is a safe and effective procedure for treating patent ductus arteriosus with large left-to-right shunting in small premature infants.

Clinical Trials as Topic↗
PubMed1983

Overall prognosis as the primary criterion of outcome in a clinical trial.

In a randomized trial on premature infants, with follow-up to 1 year of age only, the goal is to identify which one among the compared strategies of intervention affords the best outcome throughout life. This requires the assessment of lifetime prognosis at the end of follow-up as the primary criterion of outcome. Moreover, with the treatments potentially influencing a variety of organ systems, it is necessary to combine their separate prospects into an overall prognosis as a basis for identifying the preferable mode of intervention. The development of the scheme of rating overall prognosis posed considerable challenges, in theory as well as in application.

Clinical Trials as Topic↗
PubMed1983

Effects of indomethacin in premature infants with patent ductus arteriosus: results of a national collaborative study.

Among 3559 newborn infants with birth weight less than 1750 gm, 421 developing a hemodynamically significant patent ductus arteriosus were entered into a randomized trial to evaluate the role of indomethacin in the management of PDA. Indomethacin given concurrently with usual medical therapy at the time of diagnosis resulted in ductal closure in 79%, versus 35% with placebo (P less than 0.001). Indomethacin as backup to usual medical treatment resulted in similar closure rates. To assess overall effects through hospital discharge, three management strategies were compared. Although mortality did not differ significantly, infants given indomethacin only if usual therapy failed (strategy 2) had a lower incidence of bleeding than those to whom indomethacin was given with initial medical therapy (strategy 1) and lower rates of pneumothorax and retrolental fibroplasia than those to whom no indomethacin was administered, with surgery the only backup to medical therapy (strategy 3). Thus the administration of indomethacin only when medical treatment fails appears to be the preferable approach for the management of symptomatic PDA in premature infants.

Clinical Trials as Topic↗
PubMed1983

Evaluation of the preterm infant for patent ductus arteriosus.

As a first step in a multicenter, collaborative project to study the role of indomethacin in the management of patent ductus arteriosus in premature infants, a diagnostic scheme was developed, on an a priori basis, by a consensus of the participating neonatologists and pediatric cardiologists. The scheme, which utilizes clinical and noninvasive findings, was designed to detect infants with a "hemodynamically significant" patent ductus arteriosus (PDA). Among 1,689 infants with birth weight less than 1,750 g who were monitored during the first year of the study, 342 (20.2%) met the criteria for PDA. Rates were higher for smaller infants (42% with birth weight less than 1,000 g) than for larger infants (7% with birth weight 1,500 to 1,750 g). Although study protocol did not require a direct procedure to confirm the diagnosis of PDA, a marked decrease in the presence of most criteria was noted following surgical ligation of the ductus. Although the echocardiographic criterion (ratio of left atrium to aorta [LA/Ao] greater than or equal to 1.15) proved to have a low specificity for PDA, the data suggest that the overall scheme led to a very low rate of false-positive diagnosis. Following the application of the scheme for 1 year at 13 clinical centers, it has been shown to be a highly acceptable means of detecting infants with PDA.

Clinical Trials as Topic↗
PubMed1983

Echocardiographic characteristics of premature infants with patient ductus arteriosus.

As part of a multicenter collaborative study, M-mode echocardiograms were obtained shortly after birth on 3,559 premature infants with birth weight less than or equal to 1,750 g. Of these infants, 1,496 did not develop a cardiac murmur or other signs of a "hemodynamically significant" patent ductus arteriosus (PDA). Echocardiographic parameters from this "normal" group were compared with results obtained from 415 infants in whom PDA was diagnosed on the basis of clinical findings alone, irrespective of the echocardiogram (PDA group). The best discrimination between the two groups, when considering a single parameter, was provided by a left atrial to aortic root ratio (LA/AO) of 1.40, a left ventricular to aortic root ratio (LV/AO) of 2.10, or a left ventricular systolic time interval ratio (LPEP/LVET) of 0.27. Multivariate analysis demonstrated that better separation between the two groups occurred when the left atrial to aortic root ratio and the left ventricular systolic time interval ratio were considered jointly. Because of a large degree of overlap of all echocardiographic variables between the normal group and the group with PDA, the echocardiogram alone was not a good indicator of PDA. However, when used in conjunction with a priori estimates of the probability of PDA (based, for example, on birth weight and degree of respiratory disease), use of echocardiographic data was found to improve the detection of hemodynamically significant patent ductus arteriosus in premature infants.

Age Factors↗
PubMed1982

Blood pressure and haemodynamics in teenagers.

It has been suggested that a hyperkinetic circulatory state, with high cardiac output, causes high blood pressure in childhood and, secondarily, in adulthood. We studied blood pressure and cardiac output in 319 subjects aged 15 to 19. Blood pressure was measured with an automated device; cardiac output was estimated by M-mode echocardiography and indexed by body surface area. The distribution of cardiac output was stratified using quartiles. Mean arterial pressure was virtually constant over these strata, with boys and girls showing essentially the same pattern. Linear regression of mean arterial pressure on cardiac output yielded a coefficient which was not significantly different from zero. A history of high blood pressure in the parents was positively associated with mean arterial pressure, but unrelated to cardiac output, in the offspring. This evidence does not support the hypothesis that the hyperkinetic circulatory state causes high blood pressure in childhood; rather, raised blood pressure in adolescents appears to relate to increased peripheral vascular resistance. Therefore, our findings lend support to the view that change in blood pressure over time is caused by a gradual increase in peripheral resistance beginning early in life.

Adolescent↗
PubMed1982

Pediatric aspects of essential hypertension.

Severe hypertension is rarely seen in children, but there is increasing evidence that childhood may be an appropriate time to consider measures for the prevention of hypertension later in life. The normal range for blood pressure in children and the significance of an "elevated" blood pressure are discussed. Evidence is reviewed which indicates that heredity obesity, and sodium intake are important determinants of blood pressure. There is a role for the nutritionist in the management and the possible prevention of essential hypertension.

Child↗