Digital radiography of subtle pulmonary abnormalities: an ROC study of the effect of pixel size on observer performance

Forty conventional radiographs with examples of mild interstitial infiltrates and subtle pneumothoraces and 40 normal studies of the chest were selected and digitized, with pixel sizes of 1.0, 0.5, 0.2, and 0.1 mm. Observer performance tests were carried out using receiver operating characteristic analysis. Conventional radiographs and digitized images were compared. The results indicate that, in such cases, diagnostic accuracy increases significantly as the pixel size is reduced, at least to the 0.1-mm level. We conclude that, for digital systems using screen-film or similar image receptors, use of a pixel size substantially larger than 0.1 mm may result in some loss of diagnostic accuracy.     

Evaluation of a peer assessment approach for enhancing the organizational capacity of state injury prevention programs.

To conduct a formative and pilot impact evaluation of the State Technical Assessment Team (STAT) program, a visitation-based (visitatie) peer assessment program designed to enhance the organizational capacity of state health department injury prevention programs. The formative evaluation was based on observational, record review, and key informant interview data collected during the implementation of the first 7 STAT visits. Pilot impact data were derived from semi-structured interviews with state injury prevention personnel one year after the visit. Formative evaluation identified 6 significant implementation problems in the first visits that were addressed by the program planners, resulting in improvements to the STAT assessment protocol. Impact evaluation revealed that after one year, the 7 state injury prevention programs had acted on 81% of the recommendations received during their STAT visits. All programs reported gains in visibility and credibility within the state health department and increased collaboration and cooperation with other units and agencies. Other significant program advancements were also reported. Specific program standards and review procedures are important to the success of peer assessment programs such as STAT. Early impact evaluation suggests that peer assessment protocols using the visitatie model can lead to gains in organizational capacity.     

Advanced practice nurses in emergency care settings: A demographic profile.

INTRODUCTION: Very little is known about clinical nurse specialists and nurse practitioners (advance practice nurses [APNs]) who practice in emergency care settings. The Advanced Practice Committee of the ENA sought to determine a profile of these individuals. METHODS: Surveys were distributed to all registrants at 2 ENA conferences and posted on the ENA Web site. This survey asked 17 questions concerning the demographic characteristics of the APN respondents (eg, education, experience, certification, state recognition, and practice area). The survey was completed by 166 APNs. RESULTS: APNs had considerable experience as ED registered nurses before becoming an APN. They obtained their APN education at the master's degree or post-master's degree level. State recognition was required for 89.2% of the APNs. The majority of APNs (61.4%) obtained their certification through the American Nurses Credentialing Center. Nurse practitioners were predominantly family nurse practitioners (43%), and clinical nurse specialists were either critical care clinical nurse specialists (8.9%) or had other certifications (5.9%). APNs provided services in both the main emergency department and the fast track (45.7%) and were relatively new to their role as an APN. DISCUSSION: Consistent with current educational and certification requirements, the vast majority of APNs held a master's degree. Although relatively new to their role as APNs in emergency care, they were nonetheless very experienced as ED registered nurses. The majority of APNs were certified, even though that is not required for practice in all states. Continued research is needed to identify the most effective utilization of APNs, document their contributions to patient care outcomes, and develop strategies to meet their educational and practice needs.     

Evaluation of asymptomatic subjects with low forced expiratory ratios (FEV1/VC).

BACKGROUND--Heightened bronchial hyperreactivity is frequently associated with airflow limitation, atopy, or cigarette smoking. The purpose of this study was to evaluate healthy subjects with significantly low values of forced expiratory volume in one second/vital capacity % (FEV1/VC%) by measuring their airway response to exercise and methacholine challenge, compared with a control group with normal spirometric values. METHODS--Eighty four healthy subjects with significantly low flow rates (group A, FEV1/VC% < 2 SD% predicted) were evaluated and compared with 37 subjects with normal flow rates (group B). Static lung volumes, spirometric tests, exercise, and methacholine challenges were performed. RESULTS--Lung volumes were normal for both groups. Mean FEV1/VC% was 69% for group A and 82% for the control group. Salbutamol improved baseline FEV1 in eight subjects in group A (mean 15%), while methacholine induced a drop in FEV1 in 12 subjects. The dose-response curve to methacholine reached a plateau in all the responders. None of the subjects in the control group improved their baseline FEV1/VC% to salbutamol, but three showed bronchial hyperreactivity similar to those in group A. CONCLUSIONS--Bronchial hyperreactivity does not occur more often in asymptomatic subjects with mildly low FEV1/VC% so these subjects do not require special investigations for airway disease.     

Atypical hemolytic uremic syndrome in human immunodeficiency virus-1-infected children

We describe the clinical and pathological findings of the hemolytic uremic syndrome (HUS) in two children with human immunodeficiency virus (HIV) infection. Both patients presented with microangiopathic hemolytic anemia, thrombocytopenia, and subsequently developed renal failure. The diagnosis of HUS was confirmed by renal histopathology in both patients. None of these children presented with bloody diarrhea, evidence of circulating antibody response to Escherichia coli O157 lipopolysaccharide, or other known risk factors for HUS, except for the presence of HIV infection. Each patient was treated with intravenous plasma infusion and renal replacement therapy. Their clinical course was characterized by non-oliguria and lack of significant hypertension throughout the acute phase of the disease. Despite these favorable clinical parameters, both patients developed end-stage renal failure. The etiology of this atypical HUS characterized by poor renal survival remains unknown and the role of HIV infection in its pathogenesis, although possible, is unclear. Received March 5, 1996; received in revised form and accepted October 15, 1996     

Strength, endurance, and stability of the tongue and hand in Parkinson disease.

Weakness and fatigue in the orofacial system often are presumed to contribute to the dysarthria associated with neuromotor disorders, although previous research findings are equivocal. In this study, tongue strength, endurance, and stability during a sustained submaximal effort were assessed in 16 persons with mild to severe Parkinson disease (PD) and a perceptible speech disorder. The same measures were taken from one hand for comparison. Only tongue endurance was found to be significantly lower in these participants than in neurologically normal control participants matched for sex, age, weight, and height. Analyses of data from a larger sample comprising the present and retrospective data revealed lower-than-normal tongue strength and endurance in participants with PD. No significant correlations were found between tongue strength and endurance, interpause speech rate, articulatory precision, and overall speech defectiveness for the present and previously studied participants with PD, bringing into question the influence of modest degrees of tongue weakness and fatigue on perceptible speech deficits.