ORCID Profile
0000-0002-1675-0522
Current Organisations
UnitingCare Health
,
Prince Charles Hospital
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Publisher: Elsevier BV
Date: 2015
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 12-2013
Publisher: Cold Spring Harbor Laboratory
Date: 02-06-2020
DOI: 10.1101/2020.05.29.20115253
Abstract: There is a paucity of data that can be used to guide the management of critically ill patients with coronavirus disease 2019 (COVID-19). Global collaboration offers the best chance of obtaining these data, at scale and in time. In the absence of effective therapies, insights derived from real-time observational data will be a crucial means of improving outcomes. In response to the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, a research and data-sharing collaborative has been assembled to harness the cumulative experience of intensive care units (ICUs) worldwide. The resulting observational study provides a platform to rapidly disseminate detailed data and insights. The COVID-19 Critical Care Consortium observational study is an international, multicenter, prospective, observational study of patients with confirmed or suspected SARSCoV-2 infection admitted to ICUs. This is an evolving, open-ended study that commenced on January 1 st , 2020 and currently includes more than 350 sites in over 48 countries. The study enrolls patients at the time of ICU admission and follows them to the time of death, hospital discharge, or 28 days post-ICU admission, whichever occurs last. All subjects, without age limit, requiring admission to an ICU for SARS-CoV-2 infection, confirmed by real-time polymerase chain reaction (PCR) and/or next-generation sequencing or with high clinical suspicion of the infection. Patients admitted to an ICU for any other reason are excluded. Key data, collected via an electronic case report form devised in collaboration with the ISARIC/SPRINT-SARI networks, include: patient demographic data and risk factors, clinical features, severity of illness and respiratory failure, need for non-invasive and/or mechanical ventilation and/or extracorporeal membrane COVID–19 CCC observational study protocol oxygenation (ECMO), and associated complications, as well as data on adjunctive therapies. Final outcomes of in-hospital death, discharge or continuing admissions at 28 days. This large-scale, observational study of COVID-19 in the critically ill will provide rapid international characterization. Open-ended accrual will increase the power to answer hypothesis-led questions over time. Several sub-studies have already been initiated, examining hemostasis, neurological, cardiac, and long-term outcomes.
Publisher: Springer Science and Business Media LLC
Date: 05-04-2014
Publisher: Elsevier BV
Date: 2019
Publisher: Wiley
Date: 12-2020
DOI: 10.1111/IMJ.15047
Publisher: AME Publishing Company
Date: 03-2017
Publisher: Wiley
Date: 26-11-2019
DOI: 10.1002/HBM.24874
Publisher: Elsevier BV
Date: 03-2012
DOI: 10.1016/J.HLC.2011.09.008
Abstract: Percutaneous intervention is becoming an increasingly recognised modality for the management of prosthetic paravalvar leaks (PVLs) with particular utility in severely symptomatic non-surgical candidates. To date, application of this intervention has predominantly involved closure of mitral valve PVLs. Consequently, current literature on its application to aortic PVLs is limited. This article describes what we believe to be the first percutaneous closure of an aortic prosthetic PVL in Australia.
Publisher: Wiley
Date: 10-2003
Publisher: Elsevier BV
Date: 03-2018
DOI: 10.1016/J.AHJ.2017.12.008
Abstract: Transcatheter aortic valve implantation (TAVI) is associated with a high incidence of cerebrovascular injury. As these injuries are thought to be primarily embolic, neuroprotection strategies have focused on embolic protection devices. However, the topographical distribution of cerebral emboli and how this impacts on the effectiveness of these devices have not been thoroughly assessed. Here, we evaluated the anatomical characteristics of magnetic resonance imaging (MRI)-defined cerebral ischemic lesions occurring secondary to TAVI to enhance our understanding of the distribution of cardioembolic phenomena. Forty patients undergoing transfemoral TAVI with an Edwards SAPIEN-XT valve under general anesthesia were enrolled prospectively in this observational study. Participants underwent brain MRI preprocedure, and 3 ± 1 days and 6 ± 1 months postprocedure. Mean ± SD participant age was 82 ± 7 years. Patients had an intermediate to high surgical risk, with a mean Society of Thoracic Surgeons score of 6.3 ± 3.5 and EuroSCORE of 18.1 ± 10.6. Post-TAVI, there were no clinically apparent cerebrovascular events, but MRI assessments identified 83 new lesions across 19 of 31 (61%) participants, with a median ± interquartile range number and volume of 1 ± 2.8 lesions and 20 ± 190 μL per patient. By volume, 80% of the infarcts were cortical, 90% in the posterior circulation and 81% in the right hemisphere. The distribution of lesions that we detected suggests that cortical gray matter, the posterior circulation, and the right hemisphere are all particularly vulnerable to perioperative cerebrovascular injury. This finding has implications for the use of intraoperative cerebral embolic protection devices, particularly those that leave the left subclavian and, therefore, left vertebral artery unprotected.
Publisher: Springer Science and Business Media LLC
Date: 21-11-2016
Publisher: Springer Science and Business Media LLC
Date: 28-11-2016
Publisher: Elsevier BV
Date: 2015
Publisher: Wiley
Date: 26-05-2016
Publisher: Wiley
Date: 20-07-2023
DOI: 10.1002/IJGO.14997
Abstract: To investigate associations between transfusion of blood products close to the end of shelf‐life and clinical outcomes in obstetric inpatients. Mortality and morbidity were compared in patients transfused exclusively with red blood cells (RBC) stored for less than 21 days (fresh) versus RBC stored for 35 days or longer (old), and platelets (PLT) stored for 3 days or fewer (fresh) versus 4 days or longer (old) in Queensland, Australia from 2007 to 2013. Multivariable models were used to examine associations between these groups of blood products and clinical end points. There were 3371 patients who received RBC and 280 patients who received PLT of the eligible storage durations. Patients transfused with old RBC received fewer transfusions (2.7 ± 1.8 vs. 2.3 ± 1.0 units P 0.001). However, a higher rate of single‐unit transfusions was also seen in those patients who exclusively received old RBC (252 [9.3%] vs. 92 [13.7%] P = 0.003). Comparison of fresh vs. old blood products revealed no differences in the quantities of transfused RBC (9.5 ± 5.9 vs. 9.1 ± 5.2 units P = 0.680) or PLT (1.5 ± 0.8 vs. 1.4 ± 1.1 units P = 0.301) as well as the length of hospital stay for RBC (3 [2–5] vs. 3 [2–5] days P = 0.124) or PLT (5 [4–8] vs. 6 [4–9] days P = 0.120). Transfusing exclusively older RBC or PLT was not associated with increased morbidity or mortality.
Publisher: Elsevier BV
Date: 09-2023
Publisher: BMJ
Date: 12-2020
DOI: 10.1136/BMJOPEN-2020-041417
Abstract: There is a paucity of data that can be used to guide the management of critically ill patients with COVID-19. In response, a research and data-sharing collaborative—The COVID-19 Critical Care Consortium—has been assembled to harness the cumulative experience of intensive care units (ICUs) worldwide. The resulting observational study provides a platform to rapidly disseminate detailed data and insights crucial to improving outcomes. This is an international, multicentre, observational study of patients with confirmed or suspected SARS-CoV-2 infection admitted to ICUs. This is an evolving, open-ended study that commenced on 1 January 2020 and currently includes sites in over 48 countries. The study enrols patients at the time of ICU admission and follows them to the time of death, hospital discharge or 28 days post-ICU admission, whichever occurs last. Key data, collected via an electronic case report form devised in collaboration with the International Severe Acute Respiratory and Emerging Infection Consortium/Short Period Incidence Study of Severe Acute Respiratory Illness networks, include: patient demographic data and risk factors, clinical features, severity of illness and respiratory failure, need for non-invasive and/or mechanical ventilation and/or extracorporeal membrane oxygenation and associated complications, as well as data on adjunctive therapies. Local principal investigators will ensure that the study adheres to all relevant national regulations, and that the necessary approvals are in place before a site may contribute data. In jurisdictions where a waiver of consent is deemed insufficient, prospective, representative or retrospective consent will be obtained, as appropriate. A web-based dashboard has been developed to provide relevant data and descriptive statistics to international collaborators in real-time. It is anticipated that, following study completion, all de-identified data will be made open access. ACTRN12620000421932 ( anzctr.org.au/ACTRN12620000421932.aspx ).
Publisher: Elsevier BV
Date: 10-2013
DOI: 10.1016/J.IJCARD.2013.07.117
Abstract: The efficacy of transcatheter aortic valve implantation (TAVI) in high surgical risk and inoperable patients with severe aortic stenosis (AS) is rapidly gaining credibility with an ever-expanding body of supporting evidence. The potential of TAVI to be a treatment option for a significant cohort of patients with aortic stenosis has fuelled a drive for the optimum device and resulted in exponential advances in the technology with a focus on adverse event minimization and procedural simplification. Consequently, a plethora of new transcatheter valve choices are now available for clinical study or in the pipeline. The evaluation of past, current and emerging devices allows for an appreciation of the design considerations involved in this process and an insight to the future direction of the technology.
Publisher: Springer Science and Business Media LLC
Date: 20-08-2019
Publisher: Oxford University Press (OUP)
Date: 02-2021
DOI: 10.1093/EURHEARTJ/EHAB002
Abstract: Silent brain infarcts (SBIs) are frequently identified after transcatheter aortic valve implantation (TAVI), when patients are screened with diffusion-weighted magnetic resonance imaging (DW-MRI). Outside the cardiac literature, SBIs have been correlated with progressive cognitive dysfunction however, their prognostic utility after TAVI remains uncertain. This study’s main goals were to explore (i) the incidence of and potential risk factors for SBI after TAVI and (ii) the effect of SBI on early post-procedural cognitive dysfunction (PCD). A systematic literature review was performed to identify all publications reporting SBI incidence, as detected by DW-MRI after TAVI. Silent brain infarct incidence, baseline characteristics, and the incidence of early PCD were evaluated via meta-analysis and meta-regression models. We identified 39 relevant studies encapsulating 2408 patients. Out of 2171 patients who underwent post-procedural DW-MRI, 1601 were found to have at least one new SBI (pooled effect size 0.76, 95% CI: 0.72–0.81). The incidence of reported stroke with focal neurological deficits was 3%. Meta-regression noted that diabetes, chronic renal disease, 3-Tesla MRI, and pre-dilation were associated with increased SBI risk. The prevalence of early PCD increased during follow-up, from 16% at 10.0 ± 6.3 days to 26% at 6.1 ± 1.7 months and meta-regression suggested an association between the mean number of new SBI and incidence of PCD. The use of cerebral embolic protection devices (CEPDs) appeared to decrease the volume of SBI, but not their overall incidence. Silent brain infarcts are common after TAVI and diabetes, kidney disease, and pre-dilation increase overall SBI risk. While higher numbers of new SBIs appear to adversely affect early neurocognitive outcomes, long-term follow-up studies remain necessary as TAVI expands to low-risk patient populations. The use of CEPD did not result in a significant decrease in the occurrence of SBI.
Publisher: CABI Publishing
Date: 06-01-2023
DOI: 10.1079/SEARCHRXIV.2023.00206
Abstract: Shock-induced endotheliopathy (SHINE), defined as a profound sympathoadrenal hyperactivation in shock states leading to endothelial activation, glycocalyx damage, and eventual compromise of end-organ perfusion, was first described in 2017. The aggressive resuscitation therapies utilised in treating shock states could potentially lead to further worsening endothelial activation and end-organ dysfunction.
Publisher: Elsevier BV
Date: 11-2017
DOI: 10.1016/J.ATHORACSUR.2017.04.053
Abstract: Transcatheter aortic valve replacement entails profound and unavoidable hemodynamic perturbations that may contribute to the neurological injury associated with the procedure. Thirty-one patients were monitored with cerebral oximetry as a surrogate marker of perfusion while undergoing transcatheter aortic valve replacement via a transfemoral approach under general anesthesia to detect intraoperative hypoperfusion insult. Serial neurologic, cognitive, and cerebral magnetic resonance imaging assessments were administered to objectively quantify perioperative neurologic injury and ascertain any association with significant cerebral oximetry disturbances. Cerebral oximetry reacted promptly to rapid ventricular pacing with significant cerebral desaturation, relative to baseline, of greater than 12% and greater than 20% in 12 of 31 (68%) and 9 of 31 (29%) patients, respectively or to an absolute measurement of less than 50% in 10 of 31 (33%) patients. Hyperemia occurred immediately following relief of aortic stenosis exceeding baseline by greater than 10% and greater than 20% in 14 of 31 (45%) and 5 of 31 (16%) patients. Postoperative cognitive dysfunction was evident in 3 of 31 (10%) patients and new magnetic resonance imaging-defined ischemic lesions were seen in 17 of 28 (61%) patients. No patient experienced clinically apparent stroke. Cerebral oximetry reacted promptly to rapid ventricular pacing with significant desaturation and hyperemia a common occurrence. However, no association between this intraoperative insult and objective neurologic injury was detected.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 11-2014
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 04-06-2013
DOI: 10.1161/CIRCULATIONAHA.112.001091
Abstract: Recent transcatheter aortic valve replacement studies have raised concerns about adverse cerebrovascular events. The etiopathology of the embolized material is currently unknown. A total of 40 patients underwent transcatheter aortic valve replacement with the use of a dual filter–based embolic protection device (Montage Dual Filter System, Claret Medical, Inc). Macroscopic material liberated during the transcatheter aortic valve replacement procedure was captured in the device filter baskets in 30 (75%) patients and sent for histopathologic analysis. The captured material varied in size from 0.15 to 4.0 mm. Amorphous calcified material (size, 0.55–1.8 mm) was identified in 5 patients (17%). In 8 patients (27%), the captured material (size, 0.25–4.0 mm) contained valve tissue composed of loose connective tissue (collagen and elastic fibers) with focal areas of myxoid stroma, with or without coverage by endothelial cells and intermixed with fibrin. In another 13 (43%) patients, collagenous tissue, which may represent elements of vessel wall and valvelike structures, was identified. In 9 patients (30%), thrombotic material was intermixed with neutrophils (size, 0.15–2.0 mm). Overall, thrombotic material was found in 52% of patients, and tissue fragments compatible with aortic valve leaflet or aortic wall origin were found in 52% (21/40) of patients. Embolic debris traveling to the brain was captured in 75% of transcatheter aortic valve replacement procedures where a filter-based embolic protection device was used. The debris consisted of fibrin, or amorphous calcium and connective tissue derived most likely from either the native aortic valve leaflets or aortic wall.
Publisher: Wiley
Date: 2007
DOI: 10.1002/JNR.21171
Abstract: The botulinum neurotoxins are the most dangerous toxins known (BoNTs serotypes A-G) and induce profound flaccid neuromuscular paralysis by blocking nerve-muscle communication. Poisoned motoneurons react by emitting a sprouting network known to establish novel functional synapses with the abutting muscle fiber. Understanding how our motoneurons are capable of bypassing such transmission blockade, thereby overcoming paralysis, by an astonishing display of plasticity is one of the research goals that have numerous therapeutic ramifications. This Mini-Review aims at giving a brief update on the recent discoveries regarding the molecular mechanism of botulinum toxins intoxication. Curing botulism still is a challenge once the toxin has found his way inside motoneurons. In view of the potential use of botulinum toxins as biological weapon, more research is needed to find efficient ways of curing this disease.
Publisher: SAGE Publications
Date: 2018
Publisher: BMJ
Date: 04-2021
DOI: 10.1136/OPENHRT-2020-001565
Abstract: Point of care viscoelastic measures with thromboelastography (TEG Haemonetics Corporation, Switzerland) and thromboelastometry (ROTEM, Tem Innovations GmbH, Germany) now supersede laboratory assays in the perioperative assessment and management of coagulation. To the best of our knowledge, this sophisticated coagulation assessment has not been performed to characterise thrombotic changes in the transcatheter aortic valve implantation (TAVI) setting, nor have the two latest iteration cartridge-based systems been directly compared in the elective perioperative period. Patients undergoing TAVI were prospectively recruited. S les (n=44) were obtained at four timepoints (postinduction of anaesthesia, postheparin (100 IU/kg), postprotamine (1 mg/100 IU heparin) and 6 hours postoperatively). Each s le was concurrently assessed with standard laboratory tests (prothrombin time/international normalised ratio, activated partial thromboplastin time, thrombin clotting time, platelet count and direct fibrinogen, ROTEMSigma and TEG6s). Clot strength showed a statistically significant increase postheparin/TAVI deployment. When considering the subgroup of s les taken following the administration heparin, the heparinase channel of the TEG6s did not yield clotting strength results in 55% of s les and clotting time exceeded the upper limit of normal in 70% of s les. It was retrospectively recognised that the arachidonic acid channel of the TEG6s Platelet Mapping Cartridge had been decommissioned prohibiting assessment of aspirin effect. This study demonstrated a small intraprocedural prothrombotic change of uncertain clinical importance during the transcatheter aortic valve procedure. Further comparison with percutaneous coronary intervention and aortic valve replacement cohorts are needed to assess the merits of current antithrombotic guidelines, which are extrapolated from the PCI setting. The heparin effect was more consistently quantified by ROTEM.
Publisher: Springer Science and Business Media LLC
Date: 09-07-2014
Publisher: Springer Science and Business Media LLC
Date: 26-07-2021
DOI: 10.1186/S12992-021-00731-2
Abstract: The initial research requirements in pandemics are predictable. But how is it possible to study a disease that is so quickly spreading and to rapidly use that research to inform control and treatment? In our view, a dilemma with such wide-reaching impact mandates multi-disciplinary collaborations on a global scale. International research collaboration is the only means to rapidly address these fundamental questions and potentially change the paradigm of data sharing for the benefit of patients throughout the world. International research collaboration presents significant benefits but also barriers that need to be surmounted, especially in low- and middle-income countries. Facilitating international cooperation, by building capacity in established collaborative platforms and in low- and middle-income countries, is imperative to efficiently answering the priority clinical research questions that can change the trajectory of a pandemic.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 28-01-2014
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 26-10-2016
Abstract: The application of transcatheter aortic valve implantation ( TAVI ) to intermediate‐risk patients is a controversial issue. Of concern, neurological injury in this group remains poorly defined. Among high‐risk and inoperable patients, subclinical injury is reported on average in 75% undergoing the procedure. Although this attendant risk may be acceptable in higher‐risk patients, it may not be so in those of lower risk. Forty patients undergoing TAVI with the Edwards SAPIEN ‐ XT ™ prosthesis were prospectively studied. Patients were of intermediate surgical risk, with a mean±standard deviation Society of Thoracic Surgeons score of 5.1±2.5% and a Euro SCORE II of 4.8±2.4% participant age was 82±7 years. Clinically apparent injury was assessed by serial National Institutes of Health Stroke Scale assessments, Montreal Cognitive Assessments (Mo CA ), and with the Confusion Assessment Method. These identified 1 (2.5%) minor stroke, 1 (2.5%) episode of postoperative delirium, and 2 patients (5%) with significant postoperative cognitive dysfunction. Subclinical neurological injury was assessed using brain magnetic resonance imaging, including diffusion‐weighted imaging ( DWI ) sequences preprocedure and at 3±1 days postprocedure. This identified 68 new DWI lesions present in 60% of participants, with a median±interquartile range of 1±3 lesions atient and volumes of infarction of 24±19 μL/lesion and 89±218 μL atient. DWI lesions were associated with a statistically significant reduction in early cognition (mean ΔMo CA −3.5±1.7) without effect on cognition, quality of life, or functional capacity at 6 months. Objectively measured subclinical neurological injuries remain a concern in intermediate‐risk patients undergoing TAVI and are likely to manifest with early neurocognitive changes. URL : www.anzctr.org.au . Australian & New Zealand Clinical Trials Registry: ACTRN 12613000083796.
Publisher: Elsevier BV
Date: 02-2019
DOI: 10.1016/J.AMJCARD.2018.10.022
Abstract: Magnetic resonance imaging (MRI) studies have consistently identified a high incidence of silent brain infarction (SBI) after cardiac intervention. The frequent occurrence, objective measurement and clinical sequelae of SBI have seen interest in their detection for both research and clinical purposes. However, MRI is expensive, time-consuming, unsafe in acutely-ill patients, and not always available, limiting its use as a routine screening tool. For this purpose, a blood biomarker of SBI would be the "Holy Grail." By performing targeted profiling of serologic biomarkers this study aimed to assess their potential as screening tools for perioperative SBI. This is a nested case-control study of 20 prospectively recruited patients undergoing transcatheter aortic valve implantation under general anesthesia. Clinical and diffusion-weighted MRI assessments were performed at baseline and on day 3 postprocedure to identify the presence (cases) or absence (controls) of new SBI. Blood was collected at baseline and 24, 48, and 72 hours postprocedure and analyzed for S100 calcium-binding protein B, neuron specific enolase (NSE), matrix metalloproteinase 9 (MMP 9), and glial fibrillary acidic protein. Best-fit polynomial curves using a smoothing model were generated for each biomarker and inferential testing at a predefined 24-hour postprocedure timepoint detected a significant difference for MMP 9 (72,435 SEM: 25,030 p = 0.027). Longitudinal regression revealed a statistically significant case-control difference for both NSE (mean: 10,747 SEM: 3,114) and MMP 9 (63,842 SEM: 16,173). In conclusion, NSE and MMP 9 are present in higher levels following SBI and warrant further investigation for their utility as screening tools.
Publisher: Elsevier BV
Date: 05-2017
DOI: 10.1093/BJA/AEX088
Abstract: Cognitive dysfunction is a poorly understood but potentially devastating complication of cardiac surgery. Clinically meaningful assessment of cognitive changes after surgery is problematic because of the absence of a means to obtain reproducible, objective, and quantitative measures of the neural disturbances that cause altered brain function. By using both structural and functional connectivity magnetic resonance imaging data to construct a map of the inter-regional connections within the brain, connectomics has the potential to increase the specificity and sensitivity of perioperative neurological assessment, permitting rational in idualized assessment and improvement of surgical techniques.
Location: Australia
Start Date: 2016
End Date: 2017
Funder: National Heart Foundation of Australia
View Funded ActivityStart Date: Start date not available
End Date: End date not available
Funder: Health Innovation, Investment and Research Office
View Funded ActivityStart Date: 2018
End Date: 2018
Funder: Cardiac Society of Australia and New Zealand
View Funded ActivityStart Date: 2015
End Date: 2017
Funder: National Heart Foundation of Australia
View Funded ActivityStart Date: 2006
End Date: 2006
Funder: QIMR Berghofer Medical Research Institute
View Funded ActivityStart Date: 2011
End Date: 2011
Funder: University of Queensland
View Funded ActivityStart Date: 2018
End Date: 2018
Funder: The Prince Charles Hospital
View Funded ActivityStart Date: 2017
End Date: 2017
Funder: Wesley Research Institute
View Funded ActivityStart Date: 2014
End Date: 2014
Funder: Medtronic
View Funded ActivityStart Date: 2016
End Date: 2016
Funder: National Heart Foundation of Australia
View Funded ActivityStart Date: 2017
End Date: 2017
Funder: Health Innovation, Investment and Research Office
View Funded ActivityStart Date: 2016
End Date: 2016
Funder: Royal Australasian College of Physicians
View Funded ActivityStart Date: 2015
End Date: 2016
Funder: Australian Society for Medical Research
View Funded ActivityStart Date: 2016
End Date: 2016
Funder: Australian Society of Anaesthetists
View Funded ActivityStart Date: 2015
End Date: 2015
Funder: The Australian & New Zealand Intensive Care Society
View Funded Activity