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Biomedical subjects

N Johnson

Publications and source records attributed to N Johnson.

At least 91 records · Page 5Linked to original sources
PubMed2000

Ventricular tachycardia catheter ablation in arrhythmogenic right ventricular dysplasia: a 16-year experience.

Arrhythmogenic right ventricular dysplasia (ARVD) is a structural heart disease affecting young adults that leads to cardiac rhythm disorders including supraventricular and mostly ventricular arrhythmias. Sudden death may be the first presentation of the disease. Ablation techniques have been used for the treatment of ventricular tachycardia in cases resistant to drug therapy. Radiofrequency is appropriate as a first approach for ventricular tachycardia ablation in ARVD; however, its effectiveness is less than 40% at the first session. Fulguration is effective for ventricular tachy-cardia ablation and should be used in the same session after ineffective radiofrequency ablation. However, fulguration requires expertise, general anesthesia, and more than one session in half of all patients. Radiofrequency and fulguration plus other common forms of treatment including pacemakers and automatic implantable cardioverter defibrillators provides a clinical success rate of 81% to 93% in a series of 50 consecutive patients studied during 16 years. Earlier poor reputation of fulguration was the result of poorly understood technical problems concerning the physics and biophysics of the procedure under control with presently available methods. This in-depth study of a large population over a long time period demonstrates that fulguration should be rehabilitated.

Adolescent↗
PubMed2000

A comparison of complementary therapy use between breast cancer patients and patients with other primary tumor sites.

BACKGROUND: Interest in complementary therapies in the United States is rising. We sought to characterize the use of complementary therapies among our cancer patients in our community and analyze differences in use between patients with breast versus those with other primary tumor sites. METHODS: A survey of 1,935 randomly selected patients from the tumor registry was performed. A questionnaire was mailed to 935 breast cancer patients and 1,000 patients with other primary site diagnoses. RESULTS: There were 617 responses (288 breast, 329 other). Seventy-five patients (75%) reported use of a complementary modality. Top therapies used were nutrition (63%), massage (53%), and healing herbs (44%). The most common reason for use, immune modulation (73%), was similar in both groups. Therapy was used consistently by 84% of breast patients versus 66% of others (P = 0.003). CONCLUSION: A significant number of cancer patients are using complementary therapies. Breast cancer patients are far more likely to be consistent users compared with other tumor sites.

Adolescent↗
PubMed2000

Sentinel node biopsy and internal mammary lymphatic mapping in breast cancer.

BACKGROUND: Currently outer quadrant breast tumors are not felt to have significant drainage to the internal mammary nodal chain. We evaluated the incidence of internal mammary sentinel nodes (IMSN) found with lymphoscintigraphy for all breast quadrants. METHODS: Eighty women were prospectively studied by technitium-sulfur colloid injection, nuclear medicine imaging, and intraoperative gamma probe identification of sentinel nodes. IMSN detected were surgically removed. RESULTS: Ten of 80 ( 12%) patients had IMSN identified in addition to axillary sentinel nodes (AXSN). Four tumors were located medially, 6 (60%) were in the outer quadrants. Metastatic disease was present in 3 of 10 women. Patients with positive IMSN also had positive AXSN. CONCLUSIONS: Patients undergoing lymphatic mapping for the management of breast cancer should have radiolabelled tracer and gamma probe sentinel node identification regardless of tumor location in the breast.

Biopsy↗
PubMed2000

Towards a "good" death: end-of-life narratives constructed in an intensive care unit.

End-of-life decisions regarding the withdrawal and withholding of life supporting technology have become commonplace within intensive care units (ICUs). In this paper, we examine the dialogue between ICU team members and families regarding limitation of treatment as a therapeutic narrative--that is, as a story which frames therapeutic events as well as the critically ill patient's experience in a meaningful and psychologically comforting way for families and health care providers alike. The key themes of these end-of-life narratives are discussed, as well as the qualities that the stories share with other narratives of the same genre.

Attitude of Health Personnel↗
PubMed2000

Contamination of banked femoral head allograft: incidence, bacteriology and donor follow up.

BACKGROUND: Allograft donations are not uncommonly found to be contaminated. The issue of contaminated donations from live donors at the time of surgery, and the significance of this to the patient in terms of subsequent sepsis of the arthroplasty, were examined. METHODS: The donations of femoral heads to the Queensland Bone Bank over a 9-year period were reviewed, and the incidence and bacteriology of contamination were detailed. Clinical outcomes were determined for donors who had positive cultures at the time of retrieval and they were compared with those of culture-negative donors. RESULTS: Between March 1987 and February 1996, 232 femoral heads were donated to the Queensland Bone Bank. Four specimens were sent for culture with each femoral head (surface swab of femoral head, acetabular swab, bone biopsy and capsule). In 51 cases, one or more positive cultures were obtained (22% contamination rate). The majority of organisms cultured were Staphylococcus epidermidis. One hundred and seventy donations came from surgery performed at the Princess Alexandra Hospital, and 40 femoral heads were considered contaminated. Deep infection was recorded in one of the 40 cases with contaminated donations and three out of 130 non-contaminated donations had subsequent septic episodes. CONCLUSION: The contamination rate detailed in the present report is higher than in most series. This may be due to the fact that four bacteriological specimens are taken to assess contamination. Two of these specimens are tissue samples which yielded more positive results than did the two swabs. All other series take no more than two bacteriological specimens, which are usually bone swabs. These are shown to have a poor yield of positive cultures. Therefore there is a significant underestimation of contamination rates by other bone banks. This has implications for the recipients of bone from those banks, particularly when the allograft material is not secondarily sterilized. This is important given increasing allograft usage, and the increasing numbers of revision joint arthroplasty and impaction grafting procedures being performed. Sterilization of all bone by irradiation to 25 kGy is recommended.

Acetabulum↗
PubMed2000

Postgraduate courses in quality improvement: achievements and future directions.

Since 1996, the Centre for Clinical Epidemiology and Biostatistics at the University of Newcastle has offered courses in Quality Improvement in Health Care. The courses are offered at Graduate Certificate, Graduate Diploma and Masters levels, principally by distance learning. They offer training in research methods as well as the concepts and application of quality improvement. Feedback from students, many of whom are quality coordinators in Australian health care facilities, has been positive. Enrolments are taken mid-year as well as at the beginning of the academic year.

Australia↗
PubMed2000

Initial cleft size does not correlate with outcome in unilateral cleft lip and palate.

Clinical outcomes in children born with a cleft lip and palate (CLP) have been an area of interest for orthodontists for a number of years. Whilst tools for measurement of these outcomes are available, there is no widely accepted measure of initial cleft severity and no known quantitative indices. Therefore, the potential influence of initial severity remains unmeasured and largely ignored. The aim of this investigation was to determine the importance of initial cleft severity in determining patient outcome. The longitudinal records of 49 children born with a unilateral cleft lip and palate (UCLP), and treated in a single centre were examined. An index of initial cleft severity was developed that categorizes the cleft area as a percentage of the total palate area. The dental arch relationships of the same patients at 6 years of age were also determined. The nature of the association between these was investigated for agreement and correlation by calculation of weighted Kappa and Spearman's correlation coefficient, respectively. No evidence was found in this sample that the initial cleft area had any bearing on the quality of outcome at 6 years of age.

Adolescent↗
PubMed2000

Cause and clinical characteristics of rib fractures in infants.

OBJECTIVE: Rib fractures are uncommon in infancy and, when diagnosed, often raise the suspicion of child abuse. However, the prevalence of other causes of rib fractures has not been well defined. The purpose of this study was to determine the causes and clinical presentations of rib fractures in infants <12 months old. METHODS: Retrospectively, we identified all infants with rib fractures under 12 months old over a 3-year period using computerized databases at the Children's Hospital Medical Center in Cincinnati, Ohio and at the Children's Hospital, Winnipeg, Manitoba, Canada. Data extracted from the individual patient charts included: age, sex, chief complaint, number and location of rib fractures, associated injuries, birth history, history of cardiopulmonary resuscitation, and any evidence of bone dysplasia. After the chart review and a review of the radiographs by a pediatric radiologist, all fractures were determined to be attributable to one of the following causes: child abuse, birth injury, bone fragility, or accidental trauma. A determination of abuse was made when there were other injuries indicative of abuse, there was no clinical or radiographic evidence of bone fragility, there was a confession of abuse, when no reasonable history of trauma was provided, or when the history was not plausible to explain the rib fractures. Standard practice at these hospitals involves obtaining skeletal surveys on all children <2 years old when abuse is suspected. The child abuse team, which consists of physicians, nurses, and social workers, conducts these investigations and works closely with police in evaluating these children. RESULTS: Thirty-nine infants with rib fractures were identified. Thirty-two (82%) were caused by child abuse. Three (7. 7%) were attributable to accidental injuries, 1 (2.6%) was secondary to birth trauma, and 3 (7.7%) were attributable to bone fragility. All 3 infants with fractures from accidental injury had sustained notable trauma (a motor vehicle collision, a forceful direct blow, and a fall from a height). Of the 3 infants with fractures secondary to bone fragility, 1 infant had osteogenesis imperfecta, 1 infant had rickets, and 1 infant, who was born at 23 weeks' gestation, had fragile bones attributable to prematurity. CONCLUSIONS: Most rib fractures in infants are caused by child abuse. Although much less common, rib fractures can also occur after serious accidental injuries, birth trauma, or secondary to bone fragility. A thorough clinical and imaging evaluation is mandatory.

Birth Injuries↗
PubMed2000

Dentoalveolar relations in children born with a unilateral cleft lip and palate (UCLP) in Western Australia.

OBJECTIVE: Our objective was to evaluate complete unilateral cleft lip and palate repair outcome in the Cleft Unit in Perth, Western Australia, by assessment of dentoalveolar relationships. DESIGN: This is a retrospective study. SETTING: Our subjects were individuals under the care of the cleft team in Perth, Western Australia. PARTICIPANTS: All patients with unilateral cleft lip and palate and available 6-year casts who had been born since January 1, 1985, were identified from the cleft unit's database. The nature of the cleft was verified by examination of birth study models and photographs. A total of 54 such patients were identified. MAIN OUTCOME MEASURES: Main outcome measures were identified through dental arch relationship grading of study models using the 5 Year Old Study Model Index. RESULTS: Interexaminer and intraexaminer agreement kappa statistics revealed good to very good agreement using this index. The results indicate that the surgical outcome was graded as excellent, good, or fair for 77% of patients and poor or very poor for 23% of patients. CONCLUSIONS: The results of the Western Australia study compare favorably to the overall U.K. outcome (the Clinical Standards Advisory Group study) but unfavorably to the results of some European centers, such as Oslo.

Child↗
PubMed2000

The epidemic of Alzheimer's disease. How can we manage the costs?

Alzheimer's disease is one of several diseases of the elderly that has recently come into prominence for a number of reasons. First, its prevalence is set to increase as a result of the aging of Western populations. Secondly, the use of institutional care has fallen as a result of major policy changes in many countries, and this has caused a shift in the pattern of care for the elderly. Finally, the advent of innovative pharmacotherapy has caused third-party payers and clinicians to question the way in which this disease is best managed. International epidemiological data for Western populations point to a potentially considerable increase in the prevalence of the disease over the next 2 decades. Although the cost estimates of the disease vary widely among, or indeed, within different Western countries, they may be considerable. It is clear that innovative strategies, e.g. the use of respite care, sheltered housing and pharmacotherapy, might serve to limit the amount of time patients spend in institutional care. Even a small reduction in this form of care might be sufficient to offset the costs of treatment. What is lacking today are clear demonstrations as to how these new strategies might contribute to the overall management of this complex and multifactorial disease: this should be the joint focus of care providers and the pharmaceutical industry in the near future.

Aged↗
PubMed2000

[Electrocardiographic changes and rhythm problems in the diabetic].

Diabetes is a cause of serious myocardial disease related to an increased incidence of coronary artery disease, probably aggravated by cardiac autonomic neuropathy (CAN). In its incipient form, CAN hardly changes the sinus rhythm with an increase in nocturnal heart rate but without an appreciable effect on the indices of variability. In more advanced forms, "CAN+", there are not only changes in the heart rate variability but also in ventricular repolarisation. It is classical to underline the value of the corrected QT interval but this index has little real value. The "QT dispersion", comparing the duration of ventricular repolarisation on the surface leads, is no better a marker from the theoretical point of view. The dynamics of ventricular repolarisation on the other hand seem to be much more indicative of ventricular myocardial disease. They are studied by evaluating the QT-heart rate relationship and its increase distinguishes clearly CAN diabetics from CAN+ diabetics. In addition, in the latter subjects, diurnal physiological increase in the heart rate dependency of the QT interval (QT/RR slope) disappears or even inverse. It is probably this phenomenon which is responsible for the traditionally increased risk of ventricular arrhythmias and particularly sudden death in diabetics with autonomic neuropathy.

Action Potentials↗
PubMed1999

Life support in the intensive care unit: a qualitative investigation of technological purposes. Canadian Critical Care Trials Group.

BACKGROUND: The ability of many intensive care unit (ICU) technologies to prolong life has led to an outcomes-oriented approach to technology assessment, focusing on morbidity and mortality as clinically important end points. With advanced life support, however, the therapeutic goals sometimes shift from extending life to allowing life to end. The objective of this study was to understand the purposes for which advanced life support is withheld, provided, continued or withdrawn in the ICU. METHODS: In a 15-bed ICU in a university-affiliated hospital, the authors observed 25 rounds and 11 family meetings in which withdrawal or withholding of advanced life support was addressed. Semi-structured interviews were conducted with 7 intensivists, 5 consultants, 9 ICU nurses, the ICU nutritionist, the hospital ethicist and 3 pastoral services representatives, to discuss patients about whom life support decisions were made and to discuss life-support practices in general. Interview transcripts and field notes were analysed inductively to identify and corroborate emerging themes; data were coded following modified grounded theory techniques. Triangulation methods included corroboration among multiple sources of data, multidisciplinary team consensus, sharing of results with participants and theory triangulation. RESULTS: Although life-support technologies are traditionally deployed to treat morbidity and delay mortality in ICU patients, they are also used to orchestrate dying. Advanced life support can be withheld or withdrawn to help determine prognosis. The tempo of withdrawal influences the method and timing of death. Decisions to withhold, provide, continue or withdraw life support are socially negotiated to synchronize understanding and expectations among family members and clinicians. In discussions, one discrete life support technology is sometimes used as an archetype for the more general concept of technology. At other times, life-support technologies are discussed collectively to clarify the pursuit of appropriate goals of care. CONCLUSIONS: The orchestration of death involves process-oriented as well as outcome-oriented uses of technology. These uses should be considered in the assessment of life-support technologies and directives for their appropriate use in the ICU.

Attitude of Health Personnel↗
PubMed1999

Primary care. Don't leave me this way.

Primary care has an ageing workforce. A quarter of GP principals, half of single-handed doctors, and 44 percent of practice managers in this study were over 50. The data suggests that 166 extra staff will have to be recruited for each primary care group in the study area over the next five years. Individual practices and PCGs need to be made aware of the need for workforce planning. PCGs will have to address the issue of ensuring that practice staff have equity with those in other parts of the NHS.

Aged↗