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Biomedical subjects

C McCarthy

Publications and source records attributed to C McCarthy.

At least 19 recordsLinked to original sources
PubMed2006

Developments in and experience of kilovoltage X-ray cone beam image-guided radiotherapy.

This paper offers a realistic review of kilovoltage X-ray cone beam tomography integrated with the treatment machine for image-guided radiotherapy in the light of experience taking a commercial system from prototype development into clinical use. It shows that key practicalities cannot be ignored, in particular the regular characterization of mechanical flex during gantry rotation, the mapping of defects in flat panel image transducers and their response to X-ray exposure. The number of X-ray projections and the doses required for clinically useful cone beam reconstruction at different therapy sites are considered in the context of imaging that is fit for purpose. Three roles for cone beam tomography in radiotherapy are identified: patient setup in three dimensions (3D), where even low dose cone beam tissue detail is superior to megavoltage imaging; disease targeting where, despite wide field scatter and slow scanning, it is possible to generate images that are suitable for tumour delineation even at challenging sites; adaptive treatment planning, where calibrated cone beam images have been shown to provide sufficient target detail to support "plan of the day" selection and have the potential for planning with bulk corrections. With frequent use in mind, the need to limit patient dose during setup, yet maximize much needed image quality in the target zone, is considered. Finally, it is noted that the development of cone beam tomography for radiotherapy is far from complete, with X-ray source, image transducer, reconstruction algorithms and techniques for image profile collection still being researched.

Humans↗
PubMed2005

An assessment of clinically optimal gold marker length and diameter for pelvic radiotherapy verification using an amorphous silicon flat panel electronic portal imaging device.

Verification of target organ position is essential for the accurate delivery of conformal radiotherapy. Megavoltage electronic portal imaging with flat panel amorphous silicon detectors delivers high quality images that can be used for verification of bony landmark position. Gold markers implanted into the target organ can be visualized and used as a surrogate of actual organ position. On-line compensation for marker displacement, by adjusting patient position, can reduce geometric errors associated with radiation delivery. This study assesses the optimal marker length and diameter to be used with an amorphous silicon (a-Si) flat panel detector and electronic portal images (EPIs), prior to implementation of a clinical programme of gold marker insertion in prostate cancer patients. Seven marker sizes varying from 3 mm to 8 mm in length and 0.8 mm to 1.1 mm in diameter were investigated in a group of patients undergoing pelvic radiotherapy using an 8 MV Elekta SL20 linear accelerator. Markers were placed on the skin entry and exit sites of the treatment beam and EPIs in both lateral and anterior pelvic views were acquired. Three observers independently assessed visibility success and failure using a subjective scoring system. Markers less than 5 mm in length or 0.9 mm in diameter were poorly visualized (<70% visualization success in lateral EPIs). The marker measuring 0.9 mm x 5 mm appears to be clinically optimal in pelvic radiotherapy patients (80% visualization success in lateral EPIs) and will be used for actual organ implantation.

Electronics, Medical↗
PubMed2004

Evidence-based recommendations for the role of exercise in the management of osteoarthritis of the hip or knee--the MOVE consensus.

OBJECTIVES: Exercise is an effective and commonly prescribed intervention for lower limb osteoarthritis (OA). Many unanswered questions remain, however, concerning the practical delivery of exercise therapy. We have produced evidence-based recommendations to guide health-care practitioners. METHODS: A multidisciplinary guideline development group was formed from representatives of professional bodies to which OA is of relevance and other interested parties. Each participant contributed up to 10 propositions describing key clinical points regarding exercise therapy for OA of the hip or knee. Ten final recommendations were agreed by the Delphi technique. The research evidence for each was determined. A literature search was undertaken in the Medline, PubMed, EMBASE, PEDro, CINAHL and Cochrane databases. The methodological quality of each retrieved publication was assessed. Outcome data were abstracted and effect sizes calculated. The evidence for each recommendation was assessed and expert consensus highlighted by the allocation of two categories: (1) strength of evidence and (2) strength of recommendation. RESULTS: The first round of the Delphi process produced 123 propositions. This was reduced to 10 after four rounds. These related to aerobic and strengthening exercise, group versus home exercise, adherence, contraindications and predictors of response. The literature search identified 910 articles; 57 intervention trials relating to knee OA, 9 to hip OA and 73 to adherence. The evidence to support each proposition is presented. CONCLUSION: These are the first recommendations for exercise in hip and knee OA to clearly differentiate research evidence and expert opinion. Gaps in the literature are identified and issues requiring further study highlighted.

Contraindications↗
PubMed2004

Recent advances in detrusor muscle function.

Contractile activation of detrusor smooth muscle is initiated by the release of transmitters from motor nerves. Acetylcholine is a ubiquitous transmitter, as also is adenosine triphosphate (ATP) in many animal bladders and in people from several patient groups with pathological bladder function. In recent years there has been progress in explaining several cellular mechanisms that link transmitter release to contraction and these will be considered. The lifetime of ATP in the neuromuscular junction is finite and broken down ultimately to adenosine, which can exert modulatory control of contractile activation. Adenosine depresses nerve-mediated contractions and two sites of action have been proposed: an action on the motor nerves via A receptors to depress further transmitter release and a less well-defined depressant effect on the detrusor muscle. The Ca2+ ions that activate the contractile proteins are derived from intracellular stores, which releases their content via IP receptor activation and Ca2+-induced Ca2+ release. Filling of the stores in the rest interval is mediated via transmembrane flux of Ca2+through Ca2+ channels. Activation of the channels is regulated by the level of the intracellular [Ca2+], via activation and inactivation of Ca2+-sensitive K channels. Thus, Ca2+ store filling is regulated by intracellular [Ca2+] via a negative feedback process. The presence and physiological function of spontaneous contractions in detrusor remain contentious and little is known about their origin. One possibility is that they originate from random Ca2+ sparks, i.e. localized transient increases of [Ca2+] that may eventually progress to generate a cellular Ca2+ transient. Observations by confocal microscopy have revealed the presence of such sparks, especially near the cell membrane, and thus provide a cellular basis for spontaneous contractions. Finally, the questions arises as to whether detrusor smooth muscle is a functional syncitium. The demonstration of small gap junctions by electron microscopy and the demonstration of the gap junction protein connexin45 indicate that the muscle mass may indeed be functionally connected. The implications regarding the spread of excitation are discussed.

Animals↗
PubMed2004

Experience of domestic violence by women attending an inner city accident and emergency department.

OBJECTIVES: To identify the prevalence of domestic violence (DV) (defined as physical abuse perpetrated by intimate partners) in women attending an inner city accident and emergency department and to elicit women's response about being asked routinely about domestic violence in this setting. METHODS: 22 nursing shifts were purposefully sampled to be representative of day, night, and weekends. A questionnaire was administered to 198 consenting women who were not intoxicated, confused, or critically ill. RESULTS: The prevalence of acute trauma in women attributable to DV was 1% (95%CI 0.14 to 3.6), the prevalence of lifetime physical abuse was 34.8% (95%CI 28.2 to 41.5), of past year physical abuse was 6.1% (95%CI 3.2 to 10.3), and of lifetime life threatening physical abuse was 10.6% (95%CI 6.3 to 14.9). Seventy six per cent of women felt comfortable about being asked about DV and 60.5% of women felt that they should always or usually be asked about DV in this setting. CONCLUSION: This cross sectional survey adds to the body of knowledge showing that the prevalence of DV in women attending an accident and emergency department is high. Most women were in favour of being asked, and disclosure was associated with discomfort in few women. This sensitive area of history taking and referral could be undertaken by health professionals using a supportive approach.

Adolescent↗
PubMed2002

Management of suspected cervical spine injuries--the paediatric perspective.

Paediatric cervical spine immobilisation and management is one of the most difficult tasks to master in the paediatric trauma population. The Royal Children's Hospital--Melbourne has admitted 54 patients with diagnosed cervical spine injuries since January 1999. The management of such patients admitted to acute care facilities with suspected cervical spine injuries is inconsistent and at times sub-optimal. Management controversies centre around, application of cervical collars, clearance of the c-spine, patient movement and general care principles. In an endeavour to address these issues, the Royal Children's Hospital Trauma Service, in conjunction with the Emergency Department developed cervical spine guidelines. Teams consulted in the formulation of these guidelines included, Emergency Department, Intensive Care Unit, Orthopaedics, Neurosurgery, Radiology and General Surgery. These guidelines were developed as a clinical tool to guide management and standardise the approach of care for these patients. Specifically, the guidelines address: immobilisation of the paediatric cervical spine; radiology; clearing the cervical spine of injury; suspected or proven cervical spine injury; guidelines for times to fitting Philadelphia collar; ongoing care.

Accidents↗
PubMed2001

An audit of the application of care aims across the south west Thames region.

Care aims are a means of defining the purpose of intervention of health care. The Malcomess care aims model uses these labels to guide the planning, delivery and outcome measurement of care. Within speech and language therapy (SLT) this involves the use of one of seven labels which clarify and make explicit the purpose of each episode of care undertaken with a client. This relatively simple application has been shown to change the way SLTs work, clarifying expectations of many who use the service. In the South West Thames Region, a project was put in place for SLTs which included undertaking training, audit and support. The outcome of the audit showed that care aims had been adopted across the region in a sufficiently flexible way to meet local needs and offered therapists the tools to reflect on the types of interventions provided to clients.

England↗
PubMed2001

Power Doppler ultrasound assessment of rheumatoid hand synovitis.

OBJECTIVE: To evaluate power Doppler ultrasound (PD) as a technique in assessing response to treatment with steroids in rheumatoid hand synovitis. METHODS: Twelve patients with rheumatoid hand synovitis were assessed before and after treatment with steroids. Variables used to assess synovitis activity in each patient included patient visual analog scale (VAS) score for pain, physician assessment score (PAS), erythrocyte sedimentation rate (ESR), and PD of the metacarpophalangeal joints. RESULTS: Nine female and 3 male patients were studied; mean age was 53.3+/-6.5 yrs and mean disease duration 6.5+/-4.5 yrs. All patients had a good clinical response to steroid treatment and there was a significant improvement in the synovitis activity assessments. Wilcoxon signed-rank test using the exact method was applied to the change in disease activity variables. For PD signal, p < 0.002; VAS, p < 0.0016; ESR, p < 0.031; PAS, p < 0.008. CONCLUSION: PD quantifies synovitis and may be a useful adjunct to disease assessment and the response to treatment in RA.

Adult↗
PubMed2000

Selective ET(A) antagonists. 5. Discovery and structure-activity relationships of phenoxyphenylacetic acid derivatives.

The fifth paper in this series describes the culmination of our investigations into the development of a potent and selective ET(A) receptor antagonist for the treatment of diseases mediated by ET-1. Receptor site mapping of several ET(A) antagonists prepared previously identified a common cationic binding site which prompted synthesis of phenoxyphenylacetic acid derivative 13a, which showed good in vitro activity (IC(50) 59 nM, rat aortic ET(A)). Optimization of 13a led to the identification of 27b, which exhibited an IC(50) of 4 nM. Although this did not translate into the expected in vivo potency, a compound of comparable in vitro activity, 27a (RPR118031A), showed a far better pharmacokinetic profile and in vivo potency (75 micromol/kg) and was duly proposed and accepted as a development candidate.

Administration, Oral↗
PubMed2000

Pain in young children attending an accident and emergency department.

OBJECTIVES: To assess pain in young children presenting to an accident and emergency (A&E) department. To evaluate the use of the toddler-preschooler postoperative pain scale (TPPPS) and the use of analgesia in these children. METHODS: 100 children aged 1-5 years presenting to an A&E department were assessed for pain. Pain assessments were carried out using a modified form of the TPPPS; a visual analogue scale by parents and a numerical scale by nursing staff. RESULTS: The majority of children were assessed as having pain: 60 by the TPPPS, 58 by the nurses and 63 by parents. Only 30 children, however, received analgesia. Children with the highest pain scores as assessed by nursing staff or using the TPPPS all received analgesia. CONCLUSIONS: The pain scale appears suitable for use in young children in A&E departments. The subsequent management of pain in young children could be improved.

Child, Preschool↗
PubMed2000

History of 7,093 patients with lower urinary tract symptoms related to benign prostatic hyperplasia treated with alfuzosin in general practice up to 3 years.

OBJECTIVES: As we have previously published 4 articles reporting the treatment of 7,093 clinical benign prostatic hyperplasia (BPH) patients treated with alfuzosin in a 3-month open-labelled study which was subsequently extended to 12, 24, and 36 months, the objective of this article is to provide additional data on dropouts, acute urinary retention (AUR), progression to surgery, and safety under the natural conditions of general practice, paying special attention to the predictive factors. METHODS: 7,093 patients were initially enrolled by 1,812 centers for up to 3 months. Subsequently 1,508, 1,325, and 812 general practitioners agreed to extend the study up to 12, 24, and 36 months, respectively, which corresponds to 4 patient populations. RESULTS: The baseline symptom profile of patients who completed the study was identical to that of patients who dropped out (because the center resigned or during treatment). In the 4 patient populations, the percentage of patients per month who dropped out, experienced adverse effects, AUR and surgery were 0. 6-1.6, 0.1-0.5, 0.01-0.03, and 0.1-0.3%, respectively. The classes of symptom severity were not predictive for dropouts: 3.5, 12.6, 20, and 14.3% of the severe patients dropped out during treatment versus 4.2, 13.7, 22.9, and 14.0% of the moderate patients who dropped out up to 3, 12, 24, and 36 months, respectively. Safety was satisfactory regarding the number of adverse events and blood pressure measurement. No retrograde ejaculation was reported. CONCLUSION: Under the natural conditions of general practice the reasons for dropping out were not correlated with symptom severity.

Adrenergic alpha-Antagonists↗
PubMed2000

Computer needs assessment based on nursing tasks.

The purpose of this paper was to validate the Nurse Task Computer Use (NTCU) scale as a measure of the impact of computer use on tasks performed by nurses. It was expected that evaluation of a computer system by tasks is a better measure of nursing satisfaction. We used four strategies to accomplish validation. Initially, we used taxonomy of nursing interventions developed by Susan Grobe as a basis for identifying tasks. Next, using factor analysis, the results of the NTCU was compared to two validated user satisfaction scales. The third validation strategy consisted of comparing responses to the survey with interview findings for similarity, additional responses, and reoccurring patterns. Finally, findings from the results of the NTCU were compared to the Computers in Medical Care values survey. Results generally supported the validity and reliability of this instrument.

Attitude of Health Personnel↗
PubMed2000

Assessing the implementation process.

A Computerized Patient Record System (CPRS) has many benefits and could improve health care outcomes. Reaping these benefits, however, is dependent on successful implementation of a provider order entry system. The literature supports substantial evidence that even systems that are usable, effective and reliable have not been adopted by the intended users. A successful implementation may be substantially a function of the degree to which the processes of care have changed to adapt to the new system. To ensure successful implementation we suggest monitoring the implementation process itself. The purpose of this paper is to report the methodology we developed for assessing how successfully a provider order entry system is being implemented. We adopt a model of diffusion of information technology developed by Fichman (1994) and expanded by Ash (1997). In this model, diffusion is characterized be three categories, "breadth" (infusion) and "depth" (diffusion) and "quality" (appropriateness of use). In this paper we discuss the typology of diffusion and describe specific measures designed to measure infusion and diffusion of a hospital information system.

Diffusion of Innovation↗