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Biomedical subjects

D J Allison

Publications and source records attributed to D J Allison.

At least 19 recordsLinked to original sources
PubMed2000

Benefits of music therapy as an adjunct to chest physiotherapy in infants and toddlers with cystic fibrosis.

Routine chest physiotherapy (CPT) is an important component of prophylactic therapy in children with cystic fibrosis (CF) and requires a significant commitment of time and energy. It is important, therefore, to establish CPT as a positive experience. In this study, we evaluated the effect of recorded music as an adjunct to CPT. Specifically, we compared the use of newly composed music, familiar music, and the family's usual routine on children's and parents' enjoyment of CPT and the parents' perception of time taken to complete CPT. Enjoyment and perception of time were evaluated via questionnaires designed specifically for this study. Participants were caregivers of one or more children with CF who were aged between 4(1/2) months and 24 months at the commencement of the clinical trial and required CPT on a daily basis. Participants were randomly allocated into control and treatment groups. Control group participants experienced two conditions consecutively: no audiotape (NT; control) and familiar music tape (FT; placebo control). Treatment group participants were given the treatment music tape (TT), which was composed and compiled by a music therapist. After baseline assessment, evaluation occurred at two 6-weekly intervals. Children's enjoyment increased significantly after use of the TT (+1. 25 units) compared to NT (-0.5 units; P = 0.03), as did parents' enjoyment (+1.0 vs. 0.0 units, P = 0.02). Children's enjoyment did not change significantly after use of the FT (+0.75 units) compared to NT (n.s.). Likewise, parents' enjoyment did not change significantly after use of the FT (+1.0 units, n.s.). There was no change in perception of time after use of the TT (-4.5 vs. +0.2 min, n.s.) or the FT (+3.3 min, n.s.). These results indicate that children's and parents' enjoyment of CPT significantly increased after the use of specifically composed and recorded music as an adjunct. We therefore recommend that recorded music, such as that provided in this study, be given to parents to use as an adjunct to CPT when their young children are diagnosed with CF, in order to assist the establishment of a positive routine.

Adult↗
PubMed1998

Three-dimensional spiral CT angiography in pancreatic surgical planning using non-tailored protocols: comparison with conventional angiography.

The aim of this study was to investigate three-dimensional spiral computed tomography (3DCT) as an adjunct to routine pancreatic CT scanning, with particular regard to the identification of surgically important hepatic arterial anomalies, correlated with conventional visceral angiography. 32 patients underwent spiral CT scans prior to pancreatic surgery using established protocols. Oral contrast medium was used throughout. 150 ml of intravenous contrast medium was given at 3 ml s-1 with a 24 s spiral CT sequence starting 35 s after the start of infusion. Two protocols were employed, both with a pitch of 1:3 mm table feed/collimation (n = 17) and 5 mm table feed/collimation (n = 15). Overlapping (1 mm minimum) axial reformats were reconstructed. 3DCT shaded-surface displays of the visceral arteries were assessed for visceral arterial anomalies. Visceral angiography (n = 23) was independently correlated. Satisfactory 3D angiograms were performed in all but one patient, in whom the coeliac axis was missed. (i) 3 mm protocol: 3DCT (n = 17) showed three anomalous right hepatic arteries (ARHA), one trifurcation anomaly and one splenic artery with an aortic origin. Angiography (n = 11) confirmed these findings, although one patient with an ARHA did not have angiography. A left gastric arterial supply to the left liver was not detected. (ii) 5 mm protocol: 3DCT (n = 15) showed two cases of ARHA. While confirming these findings, angiography (n = 12) showed a third case of ARHA, in which the coeliac and superior mesenteric artery had very close origins. A left gastric supply to the left liver was also missed. It is concluded that satisfactory 3DCT is possible without changing existing scanning protocols, although narrow sections are required for the confident assessment of right hepatic arterial anomalies, and any left hepatic supply via the left gastric artery was poorly assessed in this series.

Adolescent↗
PubMed1998

Meckel's diverticulum: angiographic findings in 16 patients.

OBJECTIVE: The purpose of this study was to assess the sensitivity of angiography in revealing the vitellointestinal artery or other arteriographic abnormalities in patients in whom surgery subsequently proved Meckel's diverticulum. MATERIALS AND METHODS: From the 36 patients who had undergone a Meckel's diverticulectomy between 1980 and 1997 at Hammersmith Hospital or a referring hospital, we selected 18 who had undergone preoperative angiography at our institution. Case notes and angiograms of these 18 patients were reviewed for the presence of a persistent vitellointestinal artery or other angiographic evidence of a Meckel's diverticulum. RESULTS: Angiograms of 16 of 18 patients were available for review. A striking male preponderance existed (male:female = 13:3). Mean age was 28 years (range, 12-65 years). In 11 (69%) of the 16 patients, a persistent vitellointestinal artery was seen that had been noted at the time of the study and reported before surgery for nine patients. Other angiographic abnormalities at the site of the Meckel's diverticulum were present in four patients and included a vascular blush, early venous return, and arterial irregularity. CONCLUSION: Angiography will show a persistent vitellointestinal artery in most individuals with a Meckel's diverticulum who present with chronic gastrointestinal bleeding. However, the recognition of a persistent vitellointestinal artery may be difficult because of overlying vessels, and superselective catheterization of distal ileal arteries may be necessary.

Adolescent↗
PubMed1998

Hot spot. Planning, design and construction is the right remedy for ED dangers.

Forget the TV show "ER." The real thing is much more dramatic--and dangerous. In fact, the emergency department poses the greatest security risk in hospitals. Some estimates show that about 60 percent of crime in hospitals occurs in EDs. That's why the department should be designed, constructed and furnished to minimize security risks. Careful, strategic site planning and design measures are especially important for the site areas adjacent to or serving the ED. Here are some special planning and design tactics that can improve your hospital's security.

Emergency Service, Hospital↗
PubMed1997

A multinational study of the factorial structure and other characteristics of the Dartmouth COOP Functional Health Assessment Charts/WONCA.

BACKGROUND: The 'Dartmouth COOP Functional Health Assessment Charts/WONCA' constitute a relatively new derived instrument for assessing health status that is specifically intended for use in primary care on a world-wide basis. It needs further validation in its special area of use. OBJECTIVES: Over a range of countries, social backgrounds and case mixes, our aim was (i) to examine the factorial structure of the instrument; (ii) to explore how well it was understood; (iii) to check its acceptability; and (iv) to assess the value of the pictures on the charts. METHODS: The charts themselves, accompanied by a short questionnaire about the charts, were administered to 1719 patients at eight varied types of treatment centre in Canada, Japan, Nepal and Spain. The responses to the instrument were subjected to standard factor analysis and a special Q-type principal components analysis. The responses to direct questions about the charts were compared with the answers to open-ended questions. RESULTS: Factor analysis suggested a shared factorial pattern for all sites, with the first two factors accounting for 88.5% of the variability in correlations between the charts across the sites. The individual questions were understood by most patients, but a substantial minority did not appear to grasp the underlying purpose of the instrument. The instrument was well accepted. The pictures were considered to be helpful by most respondents, especially those at the Nepal sites. The variability in the scores for the individual charts across sites was less than expected and not always in the expected direction. CONCLUSIONS: The COOP/WONCA system continues to show promise, but needs more validation.

Canada↗
PubMed1996

Glomerular filtration rate in relation to extracellular fluid volume: similarity between 99mTc-DTPA and inulin.

The rate constant (alpha2) of the terminal exponential of the technetium-99m diethylene triamine penta-acetic acid (DTPA) plasma clearance curve is close to the ratio of glomerular filtration rate (GFR) to extracellular fluid volume (ECV) and is therefore a convenient, already normalised, measure of filtration function. Since alpha2 depends on the distribution volume of the tracer, our aim was to compare alpha2 from inulin and 99mTc-DTPA and also to compare the equilibration kinetics of the two filtration markers. Fifty millilitres of 99mTc-DTPA (250MBq) and inulin (10%), mixed in the same syringe, were given by intravenous injection in 15 patients undergoing routine 99mTc-DTPA renography for a variety of clinical indications. Frequent antecubital venous blood samples were taken up to about 4h after injection to construct plasma clearance curves from which GFR, ECV and GFR/ECV (i.e. the reciprocal of mean transit time through the distribution volume) were calculated. 99mTc-DTPA/inulin concentration ratio curves were also constructed after normalisation to the ratio in the syringe. GFR given by the two markers correlated closely (DTPA=0.98.inulin-0.4ml/min; r=0.98). 99mTc-DTPA had the same distribution volume as inulin, had a similar transit time through it and gave the same value of alpha2 (r=0.98). GFR/ECV from 99mTc-DTPA accordingly correlated closely with GFR/ECV from inulin (DTPA=0.75.inulin+0.99 ml/min; r=0.95). Even though the distribution volumes and the times to equilibration (i.e. to reach the terminal exponential) were similar, the distribution volume of 99mTc-DTPA at about 10min after injection was, after subtraction of the plasma volume, about twice that of inulin. We confirm the validity of 99mTc-DTPA for measuring GFR. alpha2 is a convenient measure of GFR, can be based on the terminal exponential of inulin of 99mTc-DTPA curves and can be converted to GFR/ECV with an appropriate scaling factor. The kinetics or the two clearance curves with respect to anatomical correlates of the exponentials and the rates of diffusion throughout the respective distribution volumes requires further study.

Extracellular Space↗
PubMed1995

Default display arrangements of images on PACS monitors.

Our hospital is currently installing one of the largest non-military hospital-wide picture archiving and communications systems (PACS) in the world [1, 2]. We are designing default modes for the display of images on PACS workstation monitors so that these can be implemented in future software releases. In this article we present the considerations and reasoning influencing our decisions upon how best to arrange and present the images from the various radiological modalities for ease of soft copy reporting.

Barium Sulfate↗
PubMed1995

Technical note: a radiological education system--organization of an image library.

A successful radiological library and teaching system should be easy to compile, user-friendly, dynamic and flexible. Nowadays it must be amenable to incorporation into digitally-based communication systems such as personal computers (pc) and picture archiving and communication systems (PACS). This article describes the structural organization and capabilities of such a digital radiological education system, and demonstrates how it fulfils these aims.

Computers↗
PubMed1995

The use of xenon-133 for measurement of blood flow through systemic arteriovenous malformations before and after therapeutic embolization.

Embolization is increasingly used to treat systemic arteriovenous (AV) shunts although its success, as judged by either angiographic or clinical means, is difficult to quantify. The aim of the study was to quantify blood flow through AV shunts with 133Xe, which, because of its relatively long transit time through peripheral tissues, behaves like microspheres. Following arterial injection, 133Xe entering an AV shunt rapidly arrives in the lung and can be quantified with a scintillation probe. In 17 patients with systemic AV shunts, the reduction in shunt flow following therapeutic embolization was quantified in the angiography theatre by comparing the initial count rates in the lung, recorded by probe, following injection of identical quantities of 133Xe into a supplying artery before and after embolization. By comparing the lung counts with those given by an intravenous injection of 133Xe, the fraction of flow at the catheter tip entering the shunt was also quantified. Tissue perfusion in the vascular territory distal to the shunt was measured at the same time by recording the clearance of non-shunted 133Xe with a second probe over the extremity. Control injections of 133Xe were given in the contralateral limb in order to assess 133Xe transit in the absence of shunting and to compare tissue perfusion between the two sides. Shunt flow ranged from 40% to 100% (of that at the tip of the catheter) (n = 14), while the reduction in shunt flow following embolization ranged from 15% to 96% (n = 19). Tissue perfusion distal to the shunt and in the contralateral limb was about 5 ml 100 ml-1 min-1. Contrast medium had no consistent effect on tissue perfusion in either limb, or on shunt flow. There was no difference in peripheral perfusion between the abnormal and control sides, nor any significant difference in perfusion in the distal tissue on the abnormal side before and after embolization. There was, however, a consistent increase in the fraction of the injected 133Xe delivered to the distal tissue after embolization (median increase 93%, p < 0.001). The technique is relatively simple and merits further development as a means of continuous quantification of systemic AV shunt flow in the angiography theatre at the time of embolization.

Adult↗
PubMed1995

Pulmonary arteriovenous malformations: results of treatment with coil embolization in 53 patients.

OBJECTIVE: The purpose of this study was to determine the effects of percutaneous transcatheter coil embolization of pulmonary arteriovenous malformations on arterial oxygen saturation, pulmonary gas exchange, anatomic right-to-left shunt, and lung function and to assess the complications of the procedure. SUBJECTS AND METHODS: Fifty-three patients were included in the study: 42 (79%) had associated hereditary hemorrhagic telangiectasia. Nineteen (36%) had neurologic problems compatible with paradoxical embolization. During 102 separate embolization procedures, all malformations with feeding vessels > or = 3 mm in diameter were embolized with steel coils. Arterial oxygen saturation at rest and on exercise and the intrapulmonary right-to-left shunt fraction (99mTc-macroaggregate injection), forced expiratory volume in 1 sec, vital capacity, diffusing capacity for carbon monoxide, and transfer coefficient were measured before and after embolization. Complications of the procedure were recorded and investigated. RESULTS: Before treatment, all patients had hypoxemia in the supine posture (SaO2, 89 +/- 1% [standard error of the mean]), which fell a further 6% (absolute) on standing. Mean values for transfer coefficient and diffusing capacity for carbon monoxide were reduced, at 85 +/- 3% and 78 +/- 3% (predicted value), respectively. After embolization, the mean values for supine and erect SaO2 rose to 94 +/- 1% and 93 +/- 1%. Transfer coefficient increased by a mean of 5.4% of predicted value. The mean shunt fraction fell from 23 +/- 2% preembolization to 9 +/- 1% postembolization. In 102 procedures, there were 18 complications, 12 mild, two moderate, and four potentially serious (systemic coil embolization in two patients, cerebrovascular accident [transient], and myocardial puncture), but there were no lasting sequelae. CONCLUSION: Our results show that coil embolization is an effective and well-tolerated method for treatment of pulmonary arteriovenous malformations. Improvements in pulmonary gas exchange and lung function and a decrease in right-to-left shunting occurred after treatment. The procedure was well tolerated and had a low complication rate.

Adolescent↗
PubMed1995

Multidisciplinary approach to the management of head and neck arteriovenous malformations.

Arteriovenous malformations (AVM) of the head and neck are quite rare in contrast to low-flow vascular anomalies, but often present with significant haemorrhage or cosmetic defects. Treatment of these high-flow vascular anomalies is hazardous and has a predictably high incidence of recurrence if not managed correctly. Intervention is indicated for complications such as pain, haemorrhage, pressure symptoms, ischaemic ulceration and even congestive cardiac failure. A multidisciplinary team approach is required in the assessment and treatment of these lesions, and involves preoperative angiography with superselective embolisation, followed by resection of the lesion, ideally within 72 h. Recent advances in microsurgery and in therapeutic radiology have greatly improved the prognosis for patients with these malformations. We present a series of four patients who have undergone preoperative embolisation and subsequent surgical excision, with a mean follow-up of 28 months. The complication rate has remained low and there has been no re-expansion of the lesions to date.

Adolescent↗
PubMed1992

Transjugular and plugged liver biopsies.

When a liver biopsy is indicated the transabdominal approach using either a Menghini or Tru-Cut needle has been shown to be an extremely safe procedure with very low morbidity and mortality rates in patients with normal or only mildly disturbed coagulation. When the coagulation status is severely deranged, however, several methods of obtaining a liver biopsy have been devised to circumvent the increased risk of bleeding. The transjugular approach has been shown to be both successful and relatively safe. The less cumbersome technique of plugging the needle track after percutaneous transabdominal biopsy has been reported relatively recently. Although it is likely that the latter method will produce good biopsy samples in the majority of cases (and in this regard it may prove to be better than the transjugular route), considerably more experience is required before its true complication rate is known. In a hospital where large numbers of transjugular biopsies are performed by experienced radiologists and in which skilled pathologists are used to interpreting the histological appearances of small, crushed liver samples, there is no compelling reason to change to the plugged biopsy technique. The more difficult question is whether hospitals in which the radiological and histological skills necessary for consistent success with the transjugular approach are not available should adopt the plugged biopsy method. The answer to this question is probably in the affirmative, but will depend on the confidence and interventional experience of the local operator and on more detailed factual information concerning the safety of the plugged method. With regard to the latter point, the publication of a large controlled study on the safety and efficacy of plugged liver biopsy would be a valuable contribution to the world literature on the subject.

Biopsy, Needle↗
PubMed1992

Recurrent respiratory obstruction from a mediastinal bronchogenic cyst.

A large mediastinal bronchogenic cyst presented acutely with paroxysmal atrial fibrillation and severe airflow obstruction. The patient had experienced identical symptoms on two other occasions over the previous 24 years. These had been previously misdiagnosed as due to a mediastinal lymphoma. Percutaneous extrapleural aspiration successfully decompressed the cyst with substantial improvement in lung function. Recurrent swelling of the cyst occurred that could not be relieved surgically. After repeat aspiration percutaneous instillation of bleomycin and alcohol has been used to prevent further increase in the size of the cyst.

Adult↗