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Geoffrey Donnan

Publications and source records attributed to Geoffrey Donnan.

9 recordsLinked to original sources
PubMed2007

Stroke symptoms and the decision to call for an ambulance.

BACKGROUND AND PURPOSE: Few acute stroke patients are treated with alteplase, partly because of significant prehospital delays after symptom onset. The aim of this study was to determine among ambulance-transported stroke patients factors associated with stroke recognition and factors associated with a call for ambulance assistance within 1 hour from symptom onset. METHODS: For 6 months in 2004, all ambulance-transported stroke or transient ischemic attack patients arriving from a geographically defined region in Melbourne (Australia) to 1 of 3 hospital emergency departments were assessed. Tapes of the call for ambulance assistance were analyzed and the patient and the caller were interviewed. RESULTS: One hundred ninety-eight patients were included in the study. Stroke was reported as the problem in 44% of ambulance calls. Unprompted stroke recognition was independently associated with facial droop (P=0.015) and a history of stroke or transient ischemic attack (P<0.001). More than half of the calls for ambulance assistance were made within 1 hour from symptom onset and only 43% of these callers spontaneously identified the problem as "stroke." Factors independently associated with a call within 1 hour were: speech problems (P=0.009), caller family history of stroke (P=0.017), and the patient was not alone at symptom onset (P=0.018). CONCLUSIONS: Stroke was reported as the problem (unprompted) by <50% of callers. Fewer than half the calls were made within 1 hour from symptom onset. Interventions are needed to more strongly link stroke recognition to immediate action and increase the number of stroke patients eligible for acute treatment.

Aged↗
PubMed2006

Economic evaluation of Australian stroke services: a prospective, multicenter study comparing dedicated stroke units with other care modalities.

BACKGROUND AND PURPOSE: Level I evidence from randomized controlled trials demonstrates that the model of hospital care influences stroke outcomes; however, the economic evaluation of such is limited. An economic appraisal of 3 acute stroke care models was facilitated through the Stroke Care Outcomes: Providing Effective Services (SCOPES) study in Melbourne, Australia. The aim was to describe resource use up to 28 weeks poststroke for each model and examine the cost-effectiveness of stroke care units (SCUs). METHODS: A prospective, multicenter, cohort study design was used. Costs and outcomes of stroke patients receiving 100% treatment in 1 of 3 inpatient care models (SCUs, mobile service, conventional care) were compared. Health-sector resource use up to 28 weeks was measured in 1999. Outcomes were thorough adherence to a suite of important clinical processes and the number of severe inpatient complications. RESULTS: The sample comprised 395 participants (mean age 73 [SD 14], 77% first-ever strokes, males 53%). When compared with conventional care (n=84), costs for mobile service (n=209) were significantly higher (P=0.024), but borderline for SCU (n=102, P=0.08; 12,251 Australian dollars; 15,903 Australian dollars; 15,383 Australian dollars respectively). This was primarily explained by the greater use of specialist medical services. The incremental cost-effectiveness of SCUs over conventional care was 9867 Australian dollars per patient achieving thorough adherence to clinical processes and 16,372 Australian dollars per patient with severe complications avoided, based on costs to 28 weeks. CONCLUSIONS: Although acute SCU costs are generally higher, they are more cost-effective than either mobile service or conventional care.

Aged↗
PubMed2004

Association of outcome with early stroke treatment: pooled analysis of ATLANTIS, ECASS, and NINDS rt-PA stroke trials.

BACKGROUND: Quick administration of intravenous recombinant tissue plasminogen activator (rt-PA) after stroke improved outcomes in previous trials. We aimed to analyse combined data for individual patients to confirm the importance of rapid treatment. METHODS: We pooled common data elements from six randomised placebo-controlled trials of intravenous rt-PA. Using multivariable logistic regression we assessed the relation of the interval from stroke onset to start of treatment (OTT) on favourable 3-month outcome and on the occurrence of clinically relevant parenchymal haemorrhage. FINDINGS: Treatment was started within 360 min of onset of stroke in 2775 patients randomly allocated to rt-PA or placebo. Median age was 68 years, median baseline National Institute of Health Stroke Scale (NIHSS) 11, and median OTT 243 min. Odds of a favourable 3-month outcome increased as OTT decreased (p=0.005). Odds were 2.8 (95% CI 1.8-4.5) for 0-90 min, 1.6 (1.1-2.2) for 91-180 min, 1.4 (1.1-1.9) for 181-270 min, and 1.2 (0.9-1.5) for 271-360 min in favour of the rt-PA group. The hazard ratio for death adjusted for baseline NIHSS was not different from 1.0 for the 0-90, 91-180, and 181-270 min intervals; for 271-360 min it was 1.45 (1.02-2.07). Haemorrhage was seen in 82 (5.9%) rt-PA patients and 15 (1.1%) controls (p<0.0001). Haemorrhage was not associated with OTT but was with rt-PA treatment (p=0.0001) and age (p=0.0002). INTERPRETATION: The sooner that rt-PA is given to stroke patients, the greater the benefit, especially if started within 90 min. Our results suggest a potential benefit beyond 3 h, but this potential might come with some risks.

Aged↗
PubMed2004

Inactive and alone: physical activity within the first 14 days of acute stroke unit care.

BACKGROUND AND PURPOSE: One way that stroke units may improve outcome is by reducing complications of immobility through early mobilization; however, this intervention needs testing. The purpose of this study was to determine the physical activity patterns of stroke patients managed within acute stroke units as a first step in developing an early mobilization protocol. METHODS: We recruited 64 patients within 14 days after stroke from 5 metropolitan stroke units and observed them for 2 consecutive days at 10-minute intervals between the hours of 8 am and 5 pm. At each observation, we ascertained physical activity, location, and other person(s) present. Therapists recorded therapy details. RESULTS: The 58 patients who completed the study had a mean age of 71.3 years. Stroke severity ranged from mild (National Institutes of Health Stroke Scale score, 1) to severe (score, 27), and mean time after stroke at observation was 5.6 days (range, 0 to 13 days). Only 9 patients were restricted to bed. During the therapeutic day, patients spent >50% resting in bed, 28% sitting out of bed, and only 13% engaged in activities with the potential to prevent complications and improve recovery of mobility. Patients were alone >60% of the time. CONCLUSIONS: This is the first multicenter study of physical activity early after stroke. We believe the next step is to conduct a randomized controlled trial to evaluate the effect of increased levels of physical activity early after stroke compared with current standards of care.

Acute Disease↗
PubMed2004

Penumbral topography in human stroke: methodology and validation of the 'Penumbragram'.

The location as well as the volume of the ischemic penumbra in human stroke is likely to influence the outcome of therapeutic intervention but its spatial extent is poorly characterized. Based on the observation that infarct expansion progresses from the center to the periphery of the penumbra in animal stroke models, we describe a method of mapping the three-dimensional spatial extent of the penumbra relative to the infarct in a 'Penumbragram'. Central, peripheral and external zones of the final infarct were defined according to median voxel distance from the infarct center (IC) and were further subdivided by coronal, sagittal and axial planes through the IC. In 10 patients with hypoxic, viable (penumbral) tissue identified by (18)F-Fluoromisonidazole positron emission tomography within 48 h of stroke onset, 'Penumbragrams' displaying the percentage of penumbra in each region were generated using anatomically co-registered data sets. The correlation between penumbral percentage and time from stroke onset was negative in the central (P < 0.05) and peripheral (P > 0.05) zones of the infarct and positive in external zones (P < 0.05). The validity of infarct segmentation was assessed by factor analysis with no a priori grouping of regions. Negative and positive correlations of penumbra volume and time from stroke onset were observed in seven (five corresponding to central zone of the infarct) and four (all in external zone) infarct regions and were measured reliably (Cronbach's alpha 0.84 and 0.9, respectively). The 'Penumbragram' is a valid method for objectively mapping the spatial extent of the penumbra, which is applicable to other imaging modalities.

Aged↗
PubMed2003

The functional magnetic resonance imaging hemodynamic response to faces remains stable until the ninth decade.

The effects of aging on blood oxygen level dependent signal changes and the hemodynamic response (HDR) remain controversial. Using functional magnetic resonance (MR) imaging, we examined the HDR properties and activated voxel counts in striate and extrastriate cortex in 18 healthy elderly subjects in response to a simple visual paradigm. Subjects of equal number and gender were prospectively separated into groups from the seventh, eighth, and ninth decades. Activation data were compared with those of 6 healthy subjects aged 30-39 under the same conditions. We found no systematic difference in HDR amplitude, shape, or latency across these groups. However, increasing age over 60 was associated with a significant decline in activated voxel counts, relative to the young controls. The results are discussed in comparison with previously published studies and in the context of the effects of aging on MR signal change. While robust activation can be produced in the striate and extrastriate cortices until the end of the ninth decade, caution should be exercised when comparing data from subjects in different decades. As functional magnetic resonance imaging is increasingly being used to examine patients with stroke and dementia, these results emphasize the importance of careful selection and age matching of control subjects when comparing with a patient population affected by disease processes associated with aging.

Adult↗
PubMed2003

International Society of Hypertension (ISH): statement on blood pressure lowering and stroke prevention.

The ISH Statement on blood pressure lowering and stroke prevention was finalized after presentation and discussion at the World Health Organization and International Society of Hypertension (WHO-ISH) Meeting on Stroke and Blood Pressure, held in Melbourne Australia, 5-7 December 2002. The meeting was conducted under the auspice of the Austin Hospital Medical Research Foundation, Melbourne.

Anticoagulants↗
PubMed2003

Rationale for a trial of low-dose aspirin for the primary prevention of major adverse cardiovascular events and vascular dementia in the elderly: Aspirin in Reducing Events in the Elderly (ASPREE).

Low-dose aspirin (acetylsalicylic acid) therapy has been shown to reduce the risk of vascular events and there is increasing evidence of its potential to reduce the rate of cognitive decline in the elderly. Adverse effects including gastrointestinal and intracranial haemorrhage may offset these benefits. The balance of risks versus benefits of aspirin for the primary prevention of cardiovascular disease and vascular dementia has not been established in the elderly. There is clearly a need to conduct a study in family practice to investigate whether routine use of low-dose aspirin for the primary prevention of cardiovascular disease and vascular dementia in the elderly is beneficial or harmful. Aspirin in reducing events in the elderly (ASPREE) is a placebo-controlled trial of low-dose aspirin for the primary prevention of major adverse cardiovascular events and vascular dementia. It will follow 15,000 subjects aged 70 years or more for an average of 5 years. This sample size has a power of 87% to detect a 15% reduction in primary events in the aspirin group, with an anticipated combined primary event rate of 20 per 1000 patient years.

Aged↗