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Biomedical subjects

B J Baker

Publications and source records attributed to B J Baker.

64 records · Page 4Linked to original sources
PubMed1983

Echocardiographic detection of right ventricular hypertrophy.

M-mode echocardiographic right ventricular wall thickness (RVW) and diastolic right ventricular internal diameter (RVID), when above the accepted normal range (RVW less than or equal to 5 mm, RVID less than or equal to 26 mm), are frequently used clinically to predict the presence of right ventricular hypertrophy. RVID was compared to anatomic right ventricular mass (RVM) in 27 patients and to RVW in 13 patients to determine their accuracy for predicting right ventricular hypertrophy (RVM greater than 65 gm). When increased, both measurements were specific for right ventricular hypertrophy. The specificity for RVW above 5 mm was 100% and for RVID greater than 26 mm was 79%. Neither was a sensitive indicator of hypertrophy. Only 36% of those with anatomic right ventricular hypertrophy had an echocardiographically dilated ventricle, and 67% had a thickened free wall. Neither measurement proved to be an accurate predictor of RVM, with a correlation for RVW of 0.56 and for diastolic RVID of 0.19.

Cardiomegaly↗
PubMed1983

Left atrial abnormality as an electrocardiographic criterion for the diagnosis of left ventricular hypertrophy in the presence of right bundle branch block.

Left atrial (LA) abnormality determined from precordial lead V1 was assessed by 2 observers as a criterion of left ventricular (LV) hypertrophy in the presence of right bundle branch block (BBB) in 23 patients. The presence of LV hypertrophy was confirmed from a postmortem cardiac partition technique and defined at 2 levels of confidence: probable and definite hypertrophy. Observers reliably differentiated between the hypertrophied and normal-sized ventricle in the presence of right BBB by using LA abnormality as an electrocardiographic criterion. When defined as definite hypertrophy, observer 1 correctly identified LV hypertrophy in 78% of the cases and observer 2 in 67% of the cases. False-positive results were present in 21% of cases by observer 1 and 14% by observer 2. Comparable results were achieved when a definition of probable hypertrophy was used. Observer performance of recognition of LA abnormality in this study was satisfactory with 91% agreement between observers. Our results are comparable and in some instances superior to conventional criteria commonly recommended to diagnose LV hypertrophy on the electrocardiogram without right BBB.

Aged↗
PubMed1983

Physiologic effects of oral bronchodilators during rest and exercise in chronic obstructive pulmonary disease.

At rest and during exercise, noninvasive studies of cardiopulmonary physiology in patients with chronic obstructive pulmonary disease (COPD) were carried out to determine the objective benefits of commonly used oral bronchodilator drugs in 15 stable patients without cardiovascular disease or reversible obstruction of airflow. Theophylline, terbutaline, a combination of theophylline and terbutaline, and placebo were given for ten days each in a randomly sequenced double-blind protocol for outpatients. Spirometric values, the ratio of physiologic dead space to tidal volume (VDp/VT), and the alveolar-arterial oxygen pressure difference (P[A-a]O2) were studied at rest on each regimen. During steady-state exercise the changes in VDp/VT and P(A-a)O2, as well as the ventilatory equivalent for oxygen and oxygen pulse, were measured. When compared with placebo, no significant change was noted in the previously mentioned measurements with any regimen, with the exception of a small improvement in the forced expiratory volume in one second, which was significant for all regimens. These findings suggest that commonly used oral bronchodilator drugs in usual doses may have small effects on airflow even in "irreversible" COPD but that the objective effect of these agents on gas exchange during rest and exercise is not significant.

Administration, Oral↗
PubMed1976

The Roy adaptation model. Using the adaptation model in a practitioner curriculum.

We believe that nurse practitioner role mastery should occur through supplementation of former roles, beginning early and continuing throughout the entire educational process, rather than through realignment to a new role. The educational process should therefore enable the student to identify with and build upon her role as a nurse, rather than abandoning it and adapting to a new quasi-role. If role mastery is to occur by gradual assimilation rather than by abrupt change, a nursing model is needed on which both preparation for and practice in the role can be based. The adaptation model provides the necessary framework to give direction to practitioner education; offers a relevant way of viewing the older adult in relation to his environment; and delineates guidelines for nurse practitioner action.

Adaptation, Physiological↗
PubMedDate not supplied

Organizing and documenting lactation support of NICU families.

A documentation tool designed for use by lactation consultants in the neonatal intensive-care unit provides an efficient and complete method for recording the progress of the mother and infant. It incorporates the research base into interventions that begin during the early postpartum period and continue through the preterm infant's hospital stay. The system for using this tool helps consultants in giving comprehensive and timely lactation support.

Breast Feeding↗
PubMedDate not supplied

Nursing staff attitudes toward the geriatric nurse practitioner student.

This study investigated nursing staff attitudes toward the geriatric nurse practitioner as an agent of change in a long-term care facility, based on two University of Miami GNP students' practicum in a county nursing home. Nursing personnel were surveyed before and after the practicum to measure their acceptance of the GNP. While nursing staff initially held a wait-and-see attitude, posttest ratings were favorable. Recommendations for improving quality of care in the setting were made by student participants, and a six-month follow-up revealed that a number of changes had been implemented.

Aged↗
PubMedDate not supplied

Digitalis-sensitive Na+, K+-ATPase: lack of a direct catecholamine-mediated stimulation in bovine myocardial tissue.

It has been documented that biogenic amines can stimulate Na+, K+-ATPase from various tissue preparations. However, it is unclear whether or not this stimulation occurs in myocardial tissues. We have evaluated possible catecholamine stimulation of purified Na+, K+- ATPase preparations utilizing a bovine ventricular microsomal preparation. We have studied the dose response of the enzyme to ouabain and digitoxigenin in the presence and absence of propranolol and norepinephrine. Our results indicate that propranolol increases the sensitivity of Na+, K+-ATPase to inhibition by digitalis, and that stimulation of Na+, K+-ATPase in bovine myocardium is not mediated via an adrenergic mechanism. In addition, our results indicate that in myocardial tissue, both stereoisomers of propranolol produce a direct nonspecific membrane effect which can modify Na+, K+-ATPase activity.

Animals↗