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Biomedical subjects

T Simpson

Publications and source records attributed to T Simpson.

At least 37 records · Page 2Linked to original sources
PubMed1998

Repeatability and comparability of automated keratometry: the Nikon NRK-8000, the Nidek KM-800 and the Bausch and Lomb keratometer.

This study assessed the repeatability of the Nikon NRK-8000, the Nidek KM-800 and the Bausch and Lomb keratometer. In addition, the comparability of the Nikon NRK-8000 and the Nidek KM-800 are evaluated relative to the Bausch and Lomb keratometer. Measurements were taken with all three techniques on two separate occasions with a test-retest separation of at least 24 hr. The right eyes of 30 normal subjects were used. Repeatability and comparability statistics and plots were generated using matrix representations of dioptric power. The Nidek KM-800 coefficient of repeatability values were found to be 0.345, 0.187, and 0.321 in the vertical, torsional, and horizontal meridians while the Nikon NRK-8000 values were 0.346, 0.232, and 0.276 respectively.

Adult↗
PubMed1997

Repeatability and accuracy of automated refraction: a comparison of the Nikon NRK-8000, the Nidek AR-1000, and subjective refraction.

This study assessed the repeatability of the Nikon NRK-8000, the Nidek AR-1000, and subjective refraction. In addition, the accuracy of the Nikon and the Nidek were evaluated in comparison to subjective refraction. Measurements were taken with all 3 techniques on 2 separate occasions with a test-retest separation of at least 24 h. The right eyes of 30 normal subjects were used. Repeatability and accuracy statistics and plots were generated using matrix representations of dioptric power. Subjective refraction was the most repeatable method, with the coefficient of repeatability (COR) found to be 0.611, 0.224, and 0.490 in the vertical, torsional, and horizontal meridians. The autorefractors' COR was found to range from 0.712 to 0.826 for the vertical and horizontal meridians, whereas the torsional meridian ranged from 0.224 to 0.319.

Adult↗
PubMed1997

A patient questionnaire approach to estimating the prevalence of dry eye symptoms in patients presenting to optometric practices across Canada.

OBJECTIVE: To collect questionnaire data from patients in a large clinical population that would allow for an estimate of the prevalence of self-reported symptoms of dry eyes. METHODS: A 13-point questionnaire (The Canada Dry Eye Epidemiology Study, CANDEES) was mailed to all optometric practices in Canada in October 1994, with the request that it be completed by 30 successive nonselected patients. RESULTS: Four hundred fifty sets of questionnaires (total, 13,517) were analyzed (a 15.7% return rate) from patients aged from < 10 years to > 80 years; 55% were in the 21- to 50-year age group; 60.7% were female; and 24.3% were contact lens wearers. A total of 28.7% reported dry eye symptoms, of whom 24.2% reported concurrent dry mouth, 24.5% had worse symptoms in the morning, 30.3% reported concurrent lid problems, and 35.7% reported a history of allergies. Of the 3716 patients reporting symptoms, 62 (1.6%) were in the "severe" category and 290 (7.8%) were in the "constant but moderate" category. Contact lens wear, concurrent allergies, dry mouth, lid problems, or use of medications increased the chance of a patient reporting dry eye symptoms. CONCLUSIONS: The prevalence of patients reporting any level of symptoms of dry eyes was approximately 1 in 4; severe symptoms were reported by 1 in 225 patients.

Adolescent↗
PubMed1997

Baccalaureate nurse educators' and critical care nurse managers' perceptions of clinical competencies necessary for new graduate baccalaureate critical care nurses.

BACKGROUND: Although nurse educators and nurse managers have disagreed about which clinical competencies are necessary for new graduates to begin working in critical care, the competencies are in need of revision and reassessment. OBJECTIVES: To validate a list of beginning-level competencies and to compare baccalaureate nurse educators' and critical care nurse manager's current perceptions of beginning clinical competencies for new baccalaureate graduates in critical care settings. METHODS: An expert panel of nurses from across the United States critiqued a questionnaire about which clinical competencies were considered relevant to critical care nursing practice. The revised questionnaire, containing 105 clinical competencies, was mailed to a randomly selected sample across the United States. Forty-one baccalaureate nurse educators and 41 critical care nurse managers completed the mail survey questionnaire (94% response rate) by rating the necessity ("essential," "desired," or "not required") of the clinical competencies for new baccalaureate nurses. RESULTS: A high degree of agreement was generally seen between nurse educators and nurse managers on the necessity ratings of the 105 competencies. The majority of nurse educators and nurse managers rated 81 of the 105 competencies as either "essential" or "desirable." Only five competencies showed considerable disagreement between nurse educators and nurse managers, and none of these competencies were rated "essential" by more than a few raters in either group. CONCLUSIONS: The agreement between nurse educators and nurse managers supports a competency list for baccalaureate nursing curricula and hospital inservice programs to integrate new graduates into critical care.

Clinical Competence↗
PubMed1996

Relationships among sleep dimensions and factors that impair sleep after cardiac surgery.

Factors associated with the attempted length, disturbance, effectiveness, and nap supplementation of sleep were analyzed in 97 patients recovering from cardiac surgery a few days before hospital discharge. Patients rated sleep for the prior night and factors that impaired their sleep after transfer from the critical care unit. The group averaged little sleep, with moderate disturbance and effectiveness and low nap supplementation. The disturbance, effectiveness, and attempted length of sleep were associated with an inability to perform their usual routine before sleep, inability to get comfortable, pain, noises, procedural care, and an unfamiliar bed. Patients encounter difficulties with sleep, even near discharge from the hospital. Interventions should be tested to mitigate specific factors that affect selected dimensions of sleep.

Adult↗
PubMed1996

Functional MRI of lateral occipitotemporal cortex during pursuit and motion perception.

We performed functional imaging with a conventional 1.5-T magnetic resonance scanner in 9 normal subjects. We used a gradient-echo technique to examine changes in signal between periods when subjects viewed a stationary black-and-white grating, a moving grating, and when they followed a moving spot. We located image pixels with significant differences between the viewing conditions. In 7 subjects, these occurred in the lateral occipitotemporal cortex, a region previously identified as a putative human homologue of the motion-sensitive middle temporal area (MT, or V5) of monkeys. Signal intensity was greater during pursuit of the moving dot than during viewing of the moving grating with the eyes still, despite the fact that the moving grating generated more retinal image motion. In contrast, signal intensity in striate cortex was least during pursuit of the moving dot. These findings suggest that the lateral occipitotemporal cortex has extraretinal signals during pursuit. Such signals may include attentional input, corollary eye movement information, or even a pursuit command. Extraretinal signals suggest that the lateral occipitotemporal cortex may contain a human homologue not only of MT but also of other components of the monkey V5 complex, such as the medial superior temporal area.

Adult↗
PubMed1996

Optical blur and the perception of global coherent motion in random dot cinematograms.

We evaluated the effect of +3.25 dioptres of optical blur on the discrimination of motion direction in random dot cinematograms. Dot displacement between frames varied from 2.1 to 63' of visual angle while the temporal interval was held constant. Optical blur worsened discrimination in three normal subjects at displacements below 16', but improved discrimination at displacements of 21' or more. In a second experiment, two subjects viewed equivalent velocity stimuli constructed with different combinations of temporal interval and spatial displacement. Results showed that the effect of blur was specific to displacement and not velocity. Furthermore, varying the dot density of the display showed that the effect of blur correlated with dot displacement and not the probability of dot mismatches. Since optical blur attenuates high spatial frequencies, this suggests that high spatial frequencies are important for motion perception when dot displacements are less than 16' to 21', but reduce motion perception at larger dot displacements. The use of random dot cinematograms in populations must take into account stimulus displacement and optical causes of reduced spatial acuity.

Contrast Sensitivity↗
PubMed1996

Role of endogenous renin-angiotensin system in c-fos activation and PKC-epsilon translocation in adult rat hearts.

Myocardial stretch and the renin-angiotensin system have been implicated in the development of cardiac hypertrophy through the activation of specific target genes. However, the relative importance of these putative hypertrophic stimuli has not been established in vivo. We used an isolated isovolumic heart preparation in which coronary perfusion pressure (CPP), left ventricular end-diastolic pressure, and pharmacological therapy can be independently manipulated to study this relationship. High CPP (140 cmH2O), which increased coronary flow (8.99 vs. 17.6 ml/min) and left ventricular systolic pressure (50 vs. 91 mmHg), increased steady state c-fos mRNA expression 2.3-fold (all P < 0.01 vs. low CPP). In contrast, increased left ventricular end-diastolic pressure (25 mmHg) and/or infusion of angiotensin II in the absence of increased CPP was not associated with an increase in c-fos mRNA expression. The change in c-fos gene expression seen with increased CPP was largely reversed by treatment with an angiotensin type 1 (AT1) receptor blocker. Hearts perfused at high CPP demonstrated increased translocation/activation of protein kinase C-epsilon relative to controls. None of the hearts studied were ischemic during perfusion. Thus, in the perfused adult rat heart, dynamic, but not static, stretch activates the early response gene, c-fos, and may involve the endogenous reninangiotensin system and protein kinase C.

Angiotensin II↗
PubMed1996

Patients' perceptions of environmental factors that disturb sleep after cardiac surgery.

BACKGROUND: Effective management of sleep disturbances after cardiac surgery requires insight into patients perceptions of which factors disturb sleep in the intensive care unit and after transfer from the intensive care unit. OBJECTIVE: To describe patients perceptions of environmental factors that disturbed sleep after cardiac surgery. SAMPLE: A convenience sample of 102 patients was surveyed in a 300-bed, acute-care teaching hospital. METHOD: Patients were interviewed several days before discharge from the hospital and rated the extent to which specific factors disturbed their sleep while in the intensive care unit and after transfer. RESULTS: The group mean for the extent of disturbance scores, averaged across all 35 environmental factors studied, was low during and after stay in the intensive care unit. However, selected items such as pain, and inability to get comfortable and perform a familiar nighttime routine, were moderately disturbing to many patients across phases of recovery. Patients varied widely in the number of factors, ranging from 0 to 33 factors, that disturbed sleep at least to some extent. Patients added factors that were not included in the original monitoring instrument. CONCLUSIONS: Patients attribute disturbed sleep to specific factors after cardiac surgery. The number of factors that disturb sleep varies among patients. Nurses can modify many of the factors that disturb sleep to promote an environment that will facilitate improved sleep, thereby enhancing the acute phase of recovery from cardiac surgery.

Aged↗
PubMed1996

Individual factors that influence sleep after cardiac surgery.

BACKGROUND: Up to 50% of patients who undergo cardiac surgery report problems with sleep after cardiac surgery. Knowledge about which individual factors are associated with sleep problems after cardiac surgery would help nurses identify patients who are at greater risk for sleep problems during hospitalization. OBJECTIVE: To compare patients perceptions of sleep before and during hospitalization for cardiac surgery and identify and analyze individual factors in relation to patients perceptions of sleep. METHOD: A sample of 102 patients who underwent elective or emergent cardiac surgery were studied at a 300-bed teaching hospital in the northwestern United States. A few days before their anticipated discharge from the hospital, consenting patients completed questions about their sleep before hospitalization and the night before their interview. RESULTS: Patients reported that they slept fewer hours in the hospital than at home. No differences were found in patients perceived depth and sufficiency of sleep, or refreshment before and after surgery. Patients who slept poorly at home did not report any worse sleep after surgery than patients who slept well at home. Women's perceptions about the sufficiency, refreshment, and quality of sleep were consistent before and after surgery, but no relationships were found among men's ratings. The length of sleep at home was positively related to the length of sleep after surgery in older patients. CONCLUSIONS: Sleep length is related to patients perceptions of sleep after cardiac surgery. Gender and age are also related to qualitative aspects of sleep before and after surgery and can be instrumental in an individualized assessment of sleep patterns anticipated after cardiac surgery.

Adult↗
PubMed1996

Implementation and evaluation of a liberalized visiting policy.

BACKGROUND: Visiting policies have been liberalized in ICUs, but the process and outcome of policy modifications have not been well described. OBJECTIVES: To describe the process by which nurses in one critical care unit modified visiting from a restricted to a liberalized (i.e., modified open) policy, and to evaluate the nurses' perceptions about visiting before and after the policy was liberalized. METHODS: A group of ICU/coronary care unit nurses met to discuss changes in their unit's visiting policy. Before the change was initiated, nurses (N = 36) in the unit were informally surveyed regarding their perceptions and attitudes about visiting. After a 3-month trial of liberalized visiting, in which visiting hours were increased at the discretion of the nursing staff, nurses (N = 32) were surveyed using a questionnaire about their beliefs, attitudes, level of satisfaction, and perceptions of their actual visiting policy. RESULTS: Nurses confirmed that the visiting policy had become liberalized, and they believed that liberalized visiting had positive effects on patients' emotional well-being. Nurses had more positive attitudes about the effects of liberalized visiting on families than on patients and unit function. Most nurses were satisfied with liberalized visiting. However, attitudes differed about how liberalized visiting affected patients' physiological responses or the unit function. CONCLUSIONS: Effective implementation of liberalized visiting depends on assessment of the following: nurses' beliefs, attitudes, and satisfaction about a change toward a more open visiting policy; staff involvement in determining the policy; and nurse manager and clinical nurse specialist support.

Attitude of Health Personnel↗
PubMed1996

Advancing nursing practice: acute care nurse practitioners meet challenges at and beyond the health care horizon.

Preparation of advanced practice nurses (APNs) with acute care skills relevant to today's health care environment is a challenge faced by nurse educators, care providers, professional organizations, and regulatory agencies. The acute care nurse practitioner (ACNP) is prepared to provide multidimensional, risk-appropriate management of medically vulnerable patients with serious illness in a variety of settings. ACNPs conduct comprehensive health assessments, order and interpret diagnostic tests, diagnose and manage health problems and disease-related symptoms, prescribe and evaluate drugs and treatments, and coordinate care during setting transitions. Working independently and collaboratively the ACNP enhances access to care and quality of care for patients and families through cost-effective, outcome-oriented practice. This article describes health care market factors fostering ACNP practice, ACNP practice domain, the University of Washington ACNP program, and collaborative contributions from educators, care providers, professional organizations, and regulatory groups needed to implement the role.

Acute Disease↗
PubMed1995

Multiple sclerosis can cause visual processing deficits specific to texture-defined form.

We performed the following tests in 25 patients with multiple sclerosis (MS) and 25 age-matched control subjects: recognition of texture-defined (TD) letters; recognition of motion-defined (MD) letters; and recognition of luminance-defined (LD) letters of 96% and 11% contrasts. Six patients with normal visual acuity were abnormal on recognizing TD letters, of whom one gave normal results on all other tests. Eleven patients were abnormal on MD letter recognition, of whom four gave normal results on all other tests. Visual acuity for letters of 11% contrast were abnormally low in seven patients, of whom two gave normal results on all other tests. We conclude that the neural mechanisms underlying recognition of TD, MD, and low-contrast LD letters in subjects with normal visual acuity are sufficiently different that they can be differentially damaged by MS. Therefore, TD, MD, and LD letter tests provide complementary information. We suggest that the detection of TD letters can be disrupted by demyelination of long-range horizontal connections between orientation-tuned neurons in the striate cortex.

Adult↗
PubMed1993

Unreliability of platelet glucose-6-phosphatase for the diagnosis of glycogen storage disease type Ia.

The diagnosis of glycogen storage disease type Ia currently uses enzyme analysis of liver tissue. This requires liver biopsy in the at-risk neonate or fetus. Conflicting reports have appeared in the literature on the use of peripheral platelet glucose-6-phosphatase activity for the diagnosis of this disorder. We have applied a sensitive radiometric assay system to the measurement of glucose-6-phosphatase activity in peripheral platelets. Two families with affected members were analysed, revealing no differences in glucose-6-phosphatase activity as compared with control values. Platelet measurement of glucose-6-phosphatase does not appear to be useful for the diagnosis of glycogen storage disease type Ia.

Blood Platelets↗
PubMed1993

Visit preferences of middle-aged vs older critically ill patients.

OBJECTIVE: To differentiate between middle-aged and older adults' visiting preferences in critical care settings. DESIGN: Patients' preferences for visiting, perceptions of illness severity and extent of fatigue associated with visiting and an objective measurement of illness severity while in critical care were surveyed within 3 days after transfer from the critical care unit. SETTING: Interviews occurred on the transitional care units with patients who transferred from either the coronary care or surgical intensive care units in a large Northeast teaching hospital. PATIENTS: Fifty-three middle-aged (35 through 65 years) and 46 older (over 65 years) patients were surveyed (N = 99). RESULTS: Both middle-aged and older patients consistently wanted to limit the number of visitors to two or three persons per visit. Compared with middle-aged patients, a greater proportion of older patients preferred to limit visits to once a day and wanted the visit length to be unlimited. A greater proportion of older coronary care unit patients preferred to limit visits to two times a day than older surgical unit patients. CONCLUSIONS: Middle-aged and older patients differed in their preferences for visits, with sufficient variation in responses to warrant tailoring visits to the unique preferences of patients based on age and clinical setting.

Adult↗
PubMed1992

Surgical treatment of ductal carcinoma in situ of the breast. 10- to 20-year follow-up.

Between 1967 and 1977, 36 patients received treatment at the Virginia Mason Medical Center in Seattle, Wash, for ductal carcinoma in situ of the breast. Twenty-five patients had modified radical mastectomies, 10 had radical mastectomies, and one had a simple mastectomy. Twenty-seven patients have been followed up for at least 10 years and are without known recurrence (mean follow-up, 17.7 years; range, 8 to 24 years), eight patients died without known recurrence (mean follow-up, 10.6 years; range, 6 to 14 years), and one patient with a prior contralateral mastectomy for infiltrating cancer of the breast had a recurrence in the scalene nodes on the side of the infiltrating cancer and died of metastatic cancer. No patients with ductal carcinoma in situ had local recurrences in the ipsilateral breast or chest wall, and no patients developed cancers in the contralateral breast; one patient had axillary metastasis. Twenty-eight (78%) of 36 patients had multicentric ductal carcinoma in situ in their mastectomy specimens. Twenty-three (88%) of 26 patients with comedocarcinoma-type ductal carcinoma in situ had multicentric lesions. Conversely, patients with low-grade nuclear papillary ductal carcinoma in situ did not have multicentric lesions. Five (14%) of 36 patients had incidental microinvasion discovered in the mastectomy specimens; all had comedocarcinoma. In summary, our study of patients with ductal carcinoma in situ revealed that (1) mastectomy provided excellent local and systemic control; (2) cancer in the contralateral breast was infrequent; (3) axillary metastasis was rare; and (4) histologic features of tumors markedly affected the frequency of multicentricity and chance for microinvasion.

Breast Neoplasms↗