20 results on '"Horton, Stephen"'
Search Results
2. Anticoagulation strategies and difficulties in neonatal and paediatric extracorporeal membrane oxygenation (ECMO).
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Stocker, Christian F. and Horton, Stephen B.
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ANTICOAGULANTS , *CEREBRAL hemorrhage , *EXTRACORPOREAL membrane oxygenation , *HEMOSTASIS , *HEPARIN , *PATIENT monitoring , *CHILDREN - Abstract
Objective: The aim of this review is to highlight an emerging problem with anticoagulation-related complications in neonatal and paediatric ECMO, to explore for flaws in the currently recommended anticoagulation management responsible for these problems and to discuss possible strategies mitigating further escalation of the issue. Data Sources: Pertinent neonatal and paediatric literature on the topic of interest and international Extracorporeal Life Support Organisation (ELSO) registry data request. Conclusions: The international ELSO registry data reveals increasing rates of anticoagulation-related complications during neonatal and paediatric ECMO worldwide. The causes are multifactorial and the proposed solution to the problem is to match anticoagulation management to the pathophysiological complexity of haemostasis on ECMO. [ABSTRACT FROM AUTHOR]
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- 2016
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3. A NOTE ON THE CREDIT CRISIS, TIME AND SOCIAL ORDER.
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Horton, Stephen
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FOREIGN exchange , *FINANCIAL crises , *DEBT , *SOCIALIZATION , *PUBLIC sector - Abstract
The article analyzes the relationship between the exchange value of money and the future capital value of money in the context of the 2008/2009 global financial crisis. It argues that state's socialization of private debt has resulted in the internalization of the so-called negative time within the public sector. The author also explains that the future capital value of money is a central structuring principle that effects financial stability and interest rates.
- Published
- 2009
4. The use of extracorporeal life support in the treatment of influenza-associated myositis/rhabdomyolysis.
- Author
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Augustin, Simon L., Horton, Stephen, Thuys, Clarke, Bennett, Martin, Claessen, Catie, and Brizard, Christian
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FATIGUE (Physiology) , *HEADACHE , *MUSCLE diseases , *EDEMA , *EXTRACORPOREAL membrane oxygenation , *ACUTE kidney failure , *MYOGLOBINURIA - Abstract
A 13-year-old girl presented to the emergency department with fatigue, headaches and muscle stiffness after returning from a family camping trip. Within 24 h, she was transferred to ICU with general oedema and low saturations, where she had a cardio-respiratory arrest and was placed on veno-arterial extracorporeal membrane oxygenation (ECMO). The patient was successfully supported with ECMO for profound myocardial dysfunction and haemofiltration for rhabdomyolysis and acute renal failure. Patients who present with profound myocardial dysfunction and myoglobinuria as a consequence of viral infection can be successfully supported with ECMO. [ABSTRACT FROM AUTHOR]
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- 2006
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5. New technology increases perioperative haemoglobin levels for paediatric cardiopulmonary bypass: what is the benefit?
- Author
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Thuys, Clarke, Horton, Stephen, Bennett, Martin, and Augustin, Simon
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HEMOGLOBINS , *BLOOD proteins , *CARDIOPULMONARY bypass , *CARDIAC surgery , *ARTIFICIAL blood circulation , *PERFUSIONISTS , *OPERATING room technicians , *SURGERY - Abstract
Increasing perioperative haemoglobin level by reducing priming volume and maintaining a safe cardiopulmonary bypass (CPB) system is the aim of every perfusionist. In this study, we have compared the two membrane oxygenators and pump systems used for paediatric bypass at the Royal Children's Hospital on a regular basis since 1988. We looked at all patients who had the Cobe VPCML (Cobe Laboratories, Denver, CO, USA) and Terumo RX-05 (Terumo Corporation, Tokyo, Japan) oxygenators used for flows from 800 mL/min up to the maximum rated flow for the respective oxygenator from January 2002 until March 2004. The VPCML refers to using only the 0.4-m2 section of the oxygenator. The pump systems used were the Stöckert CAPS (Stöckert Instrumente GmbH, Munich, Germany) and Jostra HL 30 (Jostra AB, Lund, Sweden). Changing from the VPCML to the RX-05 resulted in a 37% reduction in priming volume. The introduction of the Jostra HL 30 with a custom-designed mast system reduced the priming volume by another 15%. This change in priming volume allowed a significant increase, from 6 to 34%, in the percentage of patients who received bloodless primes, and for those patients who received blood primes, an increase in haemoglobin (Hb) on bypass from 8.2 to 9.6 g/dL, on average. [ABSTRACT FROM AUTHOR]
- Published
- 2006
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6. The Gambler: (re)placing the desire of money.
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Horton, Stephen
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HUMAN geography , *HORSE racing , *DIALECTIC , *HISTORICAL materialism , *GAMBLING - Abstract
The Gambler conjures a world of myth: not as a fiction of human consciousness but as unconscious image-language. Its ambition is to write geography as material subject. In tracing the discourse written in the built environment the text ranges over the analyses of Marx and Freud and into the gestural worlds of Kafka and the blood sports of the ancient Colosseum. It discovers the myth of New Zealand horse racing, written in pictures in the local pub where virtual racing, abstracted from the living world, (dis)plays on the television screen. Here, finally, The Gambler comes to terms with loss. [ABSTRACT FROM AUTHOR]
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- 2005
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7. 180 Ma continental drainage divide in northeastern Australia: Role of passive margin tectonics.
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Nott, Jonathan and Horton, Stephen
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STRUCTURAL geology , *SEDIMENT analysis , *CONTINENTAL margins - Abstract
Examines the role of passive margin tectonics in determining continental drainage divide in northeastern Australia. Stratigraphy and sedimentology of Jurassic and Tertiary sediments within the Laura and Carpenteria basins; Account on the highlands evolution models adjacent to passive continental margins; Hypothesis on continental drainage divide denudation.
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- 2000
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8. Effect of Nitric Oxide via Cardiopulmonary Bypass on Ventilator-Free Days in Young Children Undergoing Congenital Heart Disease Surgery: The NITRIC Randomized Clinical Trial.
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Schlapbach, Luregn J., Gibbons, Kristen S., Horton, Stephen B., Johnson, Kerry, Long, Debbie A., Buckley, David H. F., Erickson, Simon, Festa, Marino, d'Udekem, Yves, Alphonso, Nelson, Winlaw, David S., Delzoppo, Carmel, van Loon, Kim, Jones, Mark, Young, Paul J., Butt, Warwick, Schibler, Andreas, and NITRIC Study Group, the Australian and New Zealand Intensive Care Society Clinical Trials Group (ANZICS CTG), and the ANZICS Paediatric Study Group (PSG)
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PREVENTION of heart diseases , *THERAPEUTIC use of nitric oxide , *CARDIAC surgery , *RESEARCH , *RESPIRATORY insufficiency , *SYNDROMES , *CONVALESCENCE , *RESEARCH methodology , *CONGENITAL heart disease , *EVALUATION research , *ARTIFICIAL respiration , *COMPARATIVE studies , *RANDOMIZED controlled trials , *BLIND experiment , *CARDIAC output , *CARDIOPULMONARY bypass , *RESPIRATION , *NITRIC oxide , *OXYGENATORS , *HEART diseases - Abstract
Importance: In children undergoing heart surgery, nitric oxide administered into the gas flow of the cardiopulmonary bypass oxygenator may reduce postoperative low cardiac output syndrome, leading to improved recovery and shorter duration of respiratory support. It remains uncertain whether nitric oxide administered into the cardiopulmonary bypass oxygenator improves ventilator-free days (days alive and free from mechanical ventilation).Objective: To determine the effect of nitric oxide applied into the cardiopulmonary bypass oxygenator vs standard care on ventilator-free days in children undergoing surgery for congenital heart disease.Design, Setting, and Participants: Double-blind, multicenter, randomized clinical trial in 6 pediatric cardiac surgical centers in Australia, New Zealand, and the Netherlands. A total of 1371 children younger than 2 years undergoing congenital heart surgery were randomized between July 2017 and April 2021, with 28-day follow-up of the last participant completed on May 24, 2021.Interventions: Patients were assigned to receive nitric oxide at 20 ppm delivered into the cardiopulmonary bypass oxygenator (n = 679) or standard care cardiopulmonary bypass without nitric oxide (n = 685).Main Outcomes and Measures: The primary end point was the number of ventilator-free days from commencement of bypass until day 28. There were 4 secondary end points including a composite of low cardiac output syndrome, extracorporeal life support, or death; length of stay in the intensive care unit; length of stay in the hospital; and postoperative troponin levels.Results: Among 1371 patients who were randomized (mean [SD] age, 21.2 [23.5] weeks; 587 girls [42.8%]), 1364 (99.5%) completed the trial. The number of ventilator-free days did not differ significantly between the nitric oxide and standard care groups, with a median of 26.6 days (IQR, 24.4 to 27.4) vs 26.4 days (IQR, 24.0 to 27.2), respectively, for an absolute difference of -0.01 days (95% CI, -0.25 to 0.22; P = .92). A total of 22.5% of the nitric oxide group and 20.9% of the standard care group developed low cardiac output syndrome within 48 hours, needed extracorporeal support within 48 hours, or died by day 28, for an adjusted odds ratio of 1.12 (95% CI, 0.85 to 1.47). Other secondary outcomes were not significantly different between the groups.Conclusions and Relevance: In children younger than 2 years undergoing cardiopulmonary bypass surgery for congenital heart disease, the use of nitric oxide via cardiopulmonary bypass did not significantly affect the number of ventilator-free days. These findings do not support the use of nitric oxide delivered into the cardiopulmonary bypass oxygenator during heart surgery.Trial Registration: anzctr.org.au Identifier: ACTRN12617000821392. [ABSTRACT FROM AUTHOR]- Published
- 2022
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9. Clinical assessment can be lifesaving: Salvage of catastrophic cerebral ischemia by conversion to central extracorporeal membrane oxygenation.
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Ivanov, Yaroslav, Buratto, Edward, Konstantinov, Igor E., Clifford, Michel, Brizard, Christian P., and Horton, Stephen
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EXTRACORPOREAL membrane oxygenation , *CIRCLE of Willis , *CATASTROPHIC illness , *PEDIATRICS , *CEREBRAL ischemia , *DISEASE risk factors - Abstract
Peripheral veno-artertial extracorporeal membrane oxygenation (VA-ECMO) is commonly used in the paediatric population for intractable respiratory and cardiac failure. One of the devastating complications of VA-ECMO is severe brain damage due to ischemia or haemorrhage. We describe a case of peripheral cervical VA-ECMO complicated by evolving right cerebral ischemia which was rescued with rapid conversion from peripheral to central VA-ECMO support. Notably, the patient had a complete circle of Willis. Following conversion, we observed complete resolution of neurological symptoms with full functional recovery. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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10. Dismal Outcomes of Second-Run Extracorporeal Life Support in the Paediatric Population.
- Author
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Soquet, Jerome, Chiletti, Roberto, Horton, Stephen, Konstantinov, Igor E., Brink, Johann, Brizard, Christian P., Butt, Warwick, and d'Udekem, Yves
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HOSPITAL admission & discharge , *CONGENITAL heart disease , *EXTRACORPOREAL membrane oxygenation , *CARDIAC surgery , *LENGTH of stay in hospitals , *LONGITUDINAL method , *DISCHARGE planning , *TREATMENT effectiveness , *RETROSPECTIVE studies , *HEART assist devices - Abstract
Background: In 2011 we reported unfavourable outcomes of second-run extracorporeal life support (ECLS) in children. We wanted to investigate whether this previous report affected our strategy and modified our long-term outcomes.Methods: Between 1988 and 2015, 31 patients underwent a second-run ECLS. Median age at the time of first support was 9days (0-16 years). Median length of support for the first and second runs were 4.7days (0.1-10) and 3.6days (0.5-8.7) respectively, with an interval of 1.8days (0.1-66) between supports.Results: There was an increasing trend in the number of patients undergoing second-run ECLS after our report: 21 patients between 1988 and mid-2010 (0.9 patients/year) and 10 between mid-2010 and 2015 (two patients/year) (p=0.06). However, among all the patients who underwent ECLS, the proportion of second-run ECLS was not different before and after 2010 (4% vs. 4.2% respectively, p=0.92). While 58% of patients (18/31) survived weaning of support, only 23% (7/31) survived to hospital discharge and 14% (5/31) were still alive after hospital discharge at a median of 6.5 years (1.2-11.6). The three patients who had positive long-term outcomes had the second-run ECLS instituted to allow for major cardiac operations.Conclusions: Compassionate use of second-run ECLS is difficult to refuse but one should be aware that its outcomes are dismal. In our centre, benefits seem to be limited to cases where the second-run ECLS allows for a major cardiac intervention. [ABSTRACT FROM AUTHOR]- Published
- 2019
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11. Extracorporeal cardiopulmonary resuscitation: another piece of the jigsaw.
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Horton, Stephen B and Penny, Daniel J
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CARDIOPULMONARY resuscitation , *EXTRACORPOREAL membrane oxygenation , *INTENSIVE care units , *PEDIATRICS , *MEDICAL equipment safety measures - Published
- 2005
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12. Spatio-temporal evolution of frequency-magnitude distribution and seismogenic index during initiation of induced seismicity at Guy-Greenbrier, Arkansas.
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Mousavi, S. Mostafa, Ogwari, Paul O., Horton, Stephen P., and Langston, Charles A.
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MAGNITUDE estimation , *INDUCED seismicity , *SPATIAL distribution (Quantum optics) , *PRESSURE - Abstract
In this study, we carry out detailed analyses of the spatio-temporal variations of seismic b -value during the onset of the potentially induced-earthquake sequence between Guy and Greenbrier, Arkansas, to investigate correlations with pore-pressure change. The range of b -values suggests that the seismicity in the Guy-Greenbrier area is mostly a result of the activation of pre-existing faults. The spatial distribution of b -value correlates with modeled pore-pressure changes. In the northern segment of the fault, b -value increases with depth due to large pore-pressure changes and opening of new fractures in the deeper part and stress relaxation in the shallower parts. Whereas, in the southern segment, the shallower part shows higher b- values due to higher pore-pressure fluctuations but the deeper part in the crystalline basement has low b -value due to higher confining stress. The correlation between the temporal variation of b -value and hypocentral depth explains a previously observed temporal drop of b -value. This suggests that temporal variations should be interpreted along with the spatial variations. Estimation of the seismogenic indices for the Guy-Greenbrier fault is provided. Our analysis suggests that monitoring changes in b -value and seismogenic indices during an injection period might be used to avoid the occurrence of significant events if injection volume is reduced at critical times. [ABSTRACT FROM AUTHOR]
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- 2017
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13. Nitric oxide administration during paediatric cardiopulmonary bypass: a randomised controlled trial.
- Author
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James, Christopher, Millar, Johnny, Horton, Stephen, Brizard, Christian, Molesworth, Charlotte, and Butt, Warwick
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CARDIOPULMONARY bypass , *THERAPEUTIC use of nitric oxide , *RANDOMIZED controlled trials , *ARTIFICIAL blood circulation , *PREVENTION of heart diseases , *REPERFUSION injury , *THERAPEUTICS , *SYSTEMIC inflammatory response syndrome , *AGE distribution , *CARDIAC output , *CHI-squared test , *COMPARATIVE studies , *RESEARCH methodology , *MEDICAL cooperation , *NITRIC oxide , *NONPARAMETRIC statistics , *RESEARCH , *EVALUATION research , *BLIND experiment , *PREVENTION ,CARDIAC surgery patients - Abstract
Purpose: Cardiopulmonary bypass induces an ischaemia-reperfusion injury and systemic inflammatory response, which contributes to low cardiac output syndrome following cardiac surgery. Exogenous nitric oxide during cardiopulmonary bypass has shown potential to ameliorate such injury. We undertook a large randomised controlled trial to investigate the clinical effects of administering nitric oxide to the cardiopulmonary bypass circuit in children.Methods: After written informed consent, children were randomised to receive 20 ppm nitric oxide to the gas inflow of the cardiopulmonary bypass oxygenator, or standard conduct of bypass.Results: 101 children received nitric oxide and developed low cardiac output syndrome less frequently (15 vs. 31 %, p = 0.007) than the 97 children who did not receive nitric oxide. This effect was most marked in children aged less than 6 weeks of age (20 vs. 52 %, p = 0.012) and in those aged 6 weeks to 2 years (6 vs. 24 %, p = 0.026), who also had significantly reduced ICU length of stay (43 vs. 84 h, p = 0.031). Low cardiac output syndrome was less frequent following more complex surgeries if nitric oxide was administered (17 vs. 48 %, p = 0.018). ECMO was used less often in the nitric oxide group (1 vs. 8 %, p = 0.014).Conclusions: Delivery of nitric oxide to the oxygenator gas flow during paediatric cardiopulmonary bypass reduced the incidence of low cardiac output syndrome by varying degrees, according to age group and surgery complexity.Clinical Trial Registration: ACTRN12615001376538. [ABSTRACT FROM AUTHOR]- Published
- 2016
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14. A New Madrid Seismic Zone Fault System Model From Relative Event Locations and Application of Optimal Anisotropic Dynamic Clustering.
- Author
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Zhang, Yixin, Fadugba, Oluwaseun, Powell, Christine, Horton, Stephen, and Langston, Charles A.
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EARTHQUAKE zones , *FAULT zones , *INFRASTRUCTURE (Economics) , *EARTHQUAKE magnitude , *SEISMIC event location , *PALEOSEISMOLOGY , *EARTHQUAKES - Abstract
A refined model of fault structure in the active New Madrid Seismic Zone (NMSZ) is presented based on relocated hypocenters and application of a statistical clustering method to determine fault planes. Over 200 earthquakes are recorded in the NMSZ every year, but the three‐dimensional (3‐D) fault structure is difficult to determine because the zone is covered by thick, Mississippi Embayment sediment. The distribution of earthquakes in the NMSZ indicates four major arms of seismicity, suggesting the presence of a northeast‐southwest trending strike‐slip fault system with a major northwest trending, contractional stepover fault. Relocation of 4,131 earthquakes using HypoDD resulted in major improvement in the depiction of fault structure in the NMSZ including three‐dimensional structural variations along the along the Reelfoot fault (RF) and a well‐defined intersection of the Axial and RFs. Optimal Anisotropic Dynamic Clustering analysis of the relocated hypocenters produced a fault model consisting of 12, well resolved planes. The RF is continuous along strike from the northern end to the Ridgely fault, located south of the intersection with the Axial fault (AF). The crosscutting Ridgely fault may serve as a barrier to rupture propagation along the entire fault. The strike‐slip arms of seismicity are well resolved and correspond to near vertical planes. Three planes are resolved in the southern part of the AF and are associated with the Osceola igneous complex. Plain Language Summary: A refined fault model is determined for the active New Madrid seismic zone using earthquakes that occurred from 2000 to 2019. The seismic zone is located in the central United States and poses a hazard to critical infrastructure and numerous population centers. The major faults are the Reelfoot thrust fault and the strike‐slip Axial fault (AF). The first step in constructing the improved fault model involved relocation of the earthquakes to decrease location error. The second step involved fitting planes to the relocated earthquakes under the assumption that the earthquakes cluster along fault segments. The resulting model provides a three‐dimensional representation of the fault structure. A major fault disrupts the southern portion of the Reelfoot fault, making it discontinuous. The northern part of the AF is very well defined. Earthquakes are more scattered along the southern part of the AF, but three fault planes are resolved that are located along the side of a major intrusion. The fault model can be used in studies involving possible rupture length and magnitude of large earthquakes. Key Points: New Madrid Seismic Zone hypocenters for the years 2000–2019 are relocated and have a median relative location error of 65 mPlanes are fit to the relocated hypocenters producing a detailed three‐dimensional model of fault structureThe Reelfoot fault is segmented by the Ridgely fault [ABSTRACT FROM AUTHOR]
- Published
- 2022
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15. Platelet Phenotype and Function Changes With Increasing Duration of Extracorporeal Membrane Oxygenation.
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Van Den Helm, Suelyn, Yaw, Hui Ping, Letunica, Natasha, Barton, Rebecca, Weaver, Asami, Newall, Fiona, Horton, Stephen B., Chiletti, Roberto, Johansen, Amy, Best, Derek, McKittrick, Joanne, Butt, Warwick, d'Udekem, Yves, MacLaren, Graeme, Linden, Matthew D., Ignjatovic, Vera, and Monagle, Paul
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EXTRACORPOREAL membrane oxygenation , *PHENOTYPIC plasticity , *THROMBIN receptors , *BLOOD platelets , *VON Willebrand factor - Abstract
Objectives: To investigate platelet pathophysiology associated with pediatric extracorporeal membrane oxygenation (ECMO).Design: Prospective observational study of neonatal and pediatric ECMO patients from September 1, 2016, to December 31, 2019.Setting: The PICU in a large tertiary referral pediatric ECMO center.Patients: Eighty-seven neonates and children (< 18 yr) supported by ECMO.Interventions: None.Measurements and Main Results: Arterial blood samples were collected on days 1, 2, and 5 of ECMO and were analyzed by whole blood flow cytometry. Corresponding clinical data for each patient was also recorded. A total of 87 patients were recruited (median age, 65 d; interquartile range [IQR], 7 d to 4 yr). The median duration of ECMO was 5 days (IQR, 3-8 d) with a median length of stay in PICU and hospital of 18 days (IQR, 10-29 d) and 35 days (IQR, 19-75 d), respectively. Forty-two patients (48%) had at least one major bleed according to a priori determined definitions, and 12 patients (14%) had at least one thrombotic event during ECMO. Platelet fibrinogen receptor expression decreased (median fluorescence intensity [MFI], 29,256 vs 26,544; p = 0.0005), while von Willebrand Factor expression increased (MFI: 7,620 vs 8,829; p = 0.0459) from day 2 to day 5 of ECMO. Platelet response to agonist, Thrombin Receptor Activator Peptide 6, also decreased from day 2 to day 5 of ECMO, as measured by binding with anti-P-selectin, PAC-1 (binds activated GPIIb/IIIa), and anti-CD63 monoclonal antibodies (P-selectin area under the curve [AUC]: 63.46 vs 42.82, respectively, p = 0.0022; PAC-1 AUC: 93.75 vs 74.46, p = 0.0191; CD63 AUC: 55.69 vs 41.76, p = 0.0020).Conclusions: The loss of platelet response over time may contribute to bleeding during ECMO. These novel insights may be useful in understanding mechanisms of bleeding in pediatric ECMO and monitoring platelet markers clinically could allow for prediction or early detection of bleeding and thrombosis. [ABSTRACT FROM AUTHOR]- Published
- 2022
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16. Hemostatic Response in Paediatric Patients Undergoing Cardiopulmonary Bypass Surgery.
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Ignjatovic, Vera, Than, Jenny, Summerhayes, Robyn, Newall, Fiona, Horton, Stephen, Cochrane, Andrew, and Monagle, Paul
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CARDIOPULMONARY bypass , *HEMOSTASIS , *PROTAMINES , *THROMBOSIS , *THROMBOPLASTIN , *PEDIATRIC cardiology - Abstract
This prospective, single-center cohort study aimed to evaluate the hemostatic response during and after Cardiopulmonary Bypass (CPB) surgery in a large cohort of children up to 6 years of age. Blood samples were drawn at eight time points: post-induction of anesthesia, pre-unfractionated heparin (UFH), post-UFH, post-initiation of bypass, pre-protamine, post-protamine, post-chest-closure, and 6 h post-chest-closure. As expected, all measures of the UFH effect increased significantly post-UFH bolus and decreased post-protamine administration. However, thrombin generation remained inhibited compared to baseline values despite the post-UFH reversal by protamine. We also demonstrate that residual UFH effect is not responsible for the ongoing inhibition of thrombin observed post-protamine administration. The significant increase in both free and total tissue factor pathway inhibitor levels during the CPB surgery might contribute to the persistent thrombin generation/endogenous thrombin potential inhibition post-protamine administration. This study makes a significant and novel contribution by investigating the physiological mechanisms behind the degree of thrombin inhibition by UFH and the residual levels of thrombin inhibition that continue despite protamine reversal and provides a new foundation for future interventional studies in the setting of paediatric CPB surgery. [ABSTRACT FROM AUTHOR]
- Published
- 2011
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17. Centrifugal pump inlet pressure site affects measurement.
- Author
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Augustin, Simon, Horton, Alison, Butt, Warwick, Bennett, Martin, and Horton, Stephen
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COMPUTER software , *CONFIDENCE intervals , *LIFE support systems in critical care , *T-test (Statistics) , *DATA analysis , *EQUIPMENT & supplies ,RESEARCH evaluation - Abstract
During extracorporeal life support (ECLS), blood is exposed to a myriad of unphysiological factors that can affect outcome. One aspect of this is the sub-atmospheric pressure generated by the ECLS pump and imparted to blood elements along the pump inlet line. This pressure can be measured on the inlet line close to the pump head by adding a connector, or at the venous cannula connection site. We compared the two measurement sites located at both points; between the venous cannula-inlet tubing and inlet tubing-pump, with a range of cannulae and flows. We also investigated the effects on inlet pressure from pump afterload and increasing inlet tubing length. [ABSTRACT FROM AUTHOR]
- Published
- 2010
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18. Monitoring Unfractionated Heparin (UFH) therapy: Which Anti Factor Xa assay is appropriate?
- Author
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Ignjatovic, Vera, Summerhayes, Robyn, Gan, Andrew, Than, Jenny, Chan, Anthony, Cochrane, Andrew, Bennett, Martin, Horton, Stephen, Shann, Frank, Lane, Geoff, Ross-Smith, Maree, and Monagle, Paul
- Subjects
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HEPARIN , *THERAPEUTICS , *MICROBIOLOGICAL assay , *THROMBOSIS - Abstract
Abstract: Introduction: Anti-Factor Xa (Anti-Xa) assays specifically determine the anticoagulant activity of UFH by measuring the ability of heparin-bound Antithrombin (AT) to inhibit a single enzyme, Factor Xa (FXa). Recent improvements in the automation, cost-effectiveness and accessibility of the assay to clinicians, have resulted in the Anti-Xa assay becoming a part of daily clinical practice in many institutions. Objectives: We hypothesized that different Anti-Xa assays have different applicability for use in clinical settings, depending on the amount of UFH administered. This was investigated in a tertiary paediatric institution. Materials and methods: Samples were collected from children receiving Low-dose of UFH of at least 10 IU/kg/h, with or without a previous bolus of up to 25 IU/kg/h, within the previous 6 h in the PICU and HDU. High-dose UFH population consisted of children undergoing Cardiac Catheterization (CC), who received a bolus of UFH of 100 IU/kg body weight, 30 min prior to sampling. Results and conclusions: The Anti-Xa activity for a given dose of UFH was found to vary significantly based on the Anti-Xa assay and the population being monitored. Our study suggests that the MODIFIED COMATIC Anti-Xa assay provides the best physiological measure of the UFH effect in children, as it does not introduce sources of error, such as exogenous AT, which may increase the measured ant Factor Xa activity, nor Dextran Sulphate which can displace plasma protein bound heparin and once again leading to falsely elevated assay results. Further studies that include assessment of clinical outcomes are required to confirm the applicability of use of this particular assay in monitoring UFH therapy. [Copyright &y& Elsevier]
- Published
- 2007
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19. Isovolumic Acceleration Reflects Changes in Isovolumic but not Ejection Intraventricular Pressure Gradients in a Lamb Model of Cardio-pulmonary Bypass
- Author
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Brooks, Paul, Namachivayam, Poongundran, Shekerdemian, Lara, Horton, Stephen, Cochrane, Andrew, Cheung, Michael, Penny, Daniel, and Smolich, Joseph
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- 2008
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20. Isovolumic Acceleration Reflects Changes in Isovolumic but not Ejection Intraventricular Pressure Gradients in a Lamb Model of Cardio-pulmonary Bypass
- Author
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Brooks, Paul, Namachivayam, Poongundran, Shekerdemian, Lara, Horton, Stephen, Cochrane, Andrew, Cheung, Michael, Penny, Daniel, and Smolich, Joseph
- Published
- 2008
- Full Text
- View/download PDF
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