Publications by authors named "John F Fraser"

Background: Bypass graft surgery is a key surgical intervention for ischemic heart disease (coronary bypass graft surgery) and critical limb ischemia (peripheral bypass graft surgery). Graft occlusion remains a significant clinical problem for both types. Further research into the pathobiological mechanisms of graft occlusion are needed in order to design targeted therapeutic strategies.

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This study aimed to describe the population pharmacokinetics of caspofungin in critically ill patients receiving extracorporeal membrane oxygenation (ECMO) and to identify dosing regimens with a high likelihood of achieving effective exposures. Serial blood samples were collected over a single-dosing interval during ECMO. Total plasma concentrations were measured by a validated chromatographic assay.

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Objective: This review aims to assess the incorporation of patient and family input into intensive care unit (ICU) design processes. It aims to highlight the importance of prioritising patient and family perspectives in ICU design to improve patient experiences and clinical outcomes.

Background: Traditionally, ICU design has focused on clinical efficiency at the expense of patient-centered needs, leading to heavily sedated patients and neglected holistic care delivery.

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  • - Open-lung ventilation during cardiopulmonary bypass (CPB) may help reduce postoperative lung damage in heart transplant patients, based on a study using sheep models to compare ventilatory strategies during surgery.
  • - The study found that the group receiving open-lung ventilation had significantly less lung damage and inflammatory cell infiltration compared to the group that received no ventilation (measured by histological scores).
  • - Despite showing benefits in lung protection, no significant differences were observed in overall hemodynamic stability between the two groups, indicating the need for more research to confirm these findings in clinical settings.
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Background: In this COVID-19 Critical Care Consortium (CCCC) sub-study, we qualified neurological complications associated with SARS-CoV2 infection.

Methods: The CCCC is an international, multicenter study. Eligible patients were COVID-19 patients admitted to intensive care units (ICU) across 23 centers between 1/7/2020 to 6/23/2022.

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  • Escherichia coli is a leading cause of bloodstream infections and sepsis, but existing animal models fail to replicate the complexities of these conditions, hindering the development of effective treatments.
  • Researchers aimed to create a more accurate large-animal model of septic shock using sheep, by infusing a specific strain of antibiotic-resistant E. coli and closely monitoring their health over 48 hours.
  • The study successfully induced septic shock in five sheep, showing consistent and reproducible results, including significant drops in blood pressure and increases in lactate levels following the bacterial infusion.
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  • The study analyzes sex differences in ICU outcomes for severe COVID-19 patients, focusing on mortality rates between males and females.
  • It includes data from 10,259 patients admitted to ICUs worldwide between January 2020 and June 2022, revealing that males had a higher hazard of death (HR=1.14) despite adjustment for complications.
  • Additionally, males exhibited more severe health issues, requiring greater interventions and showing higher risks for cardiac arrest and pulmonary embolism compared to females.
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  • Anemia is linked to an increased risk of cardiac arrest and stroke in COVID-19 patients, with a study analyzing the impact of hemoglobin levels at ICU admission on these outcomes.
  • The retrospective study reviewed data from over 6,900 ICU patients across 370 international sites, measuring the incidence of stroke or cardiac arrest within 30 days of admission, with anemia classified into normal, mild, moderate, and severe categories.
  • The results showed that as anemia severity increased, so did the risk of cardiac arrest or stroke, particularly noting that moderate/severe anemia raised the risk by 32% compared to those with normal hemoglobin levels.
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  • The study explored the effects of conservative versus liberal oxygen strategies on patients receiving venoarterial extracorporeal membrane oxygenation (VA-ECMO) in the ICU, aiming to find a balance between avoiding hyperoxia and preventing hypoxia.
  • A total of 300 patients were randomly assigned to either conservative (target SaO 92-96%) or liberal oxygen (target SaO 97-100%), but both groups showed similar outcomes in ICU-free days and mortality rates at days 28 and 60.
  • The conservative group had significantly more major protocol deviations compared to the liberal group, but overall, the two oxygen strategies did not differ in their impact on patient recovery in the ICU.
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Background: Packed red blood cell (pRBC) transfusion is a relatively safe and mainstay treatment commonly used in cardiac surgical patients. However, there is limited evidence on clinical effects of transfusing blood nearing end-of shelf life that has undergone biochemical changes during storage.

Objective: To investigate evidence of associations between morbidity/mortality and transfusion of blood near end of shelf-life (> 35 days) in cardiac surgical patients.

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  • The study investigates the survival outcomes of adult COVID-19 patients on venovenous extracorporeal membrane oxygenation (VV-ECMO) across different regions and timeframes, analyzing data from 1060 patients in 351 institutions worldwide between January 2020 and December 2021.
  • It found that the in-hospital mortality rate for the overall cohort was 47.12%, with notable differences in mortality trends among regions, especially a spike in deaths in North America and Europe during mid-2020, while Latin America maintained better survival rates for longer.
  • The results suggest that various factors, including the timing of ECMO initiation and patient demographics, contribute to mortality variances, emphasizing the need for improved patient selection
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  • Single-cell spatial analysis of proteins is crucial for gaining insights into biology, especially in cancer research.
  • The text outlines an automated protocol for multi-slide immunofluorescence staining and imaging of human head and neck cancer samples using PhenoCycler-Fusion 2.0 technology.
  • It includes detailed steps for tissue preparation, staining with immunophenotyping markers, and subsequent analysis procedures, with more specifics available in a referenced study by Jhaveri et al.
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  • Right ventricle (RV) failure is a common issue in cardiopulmonary diseases and accurately assessing RV function is critical for treatment, though it's challenging due to its complex anatomy and pathophysiology.
  • Traditional methods like TAPSE, RV S', and RV FAC have limitations, particularly load-dependency that complicates diagnosis during RV failure.
  • Newer echocardiographic techniques such as "strain," "RV-pulmonary arterial coupling," and "RV myocardial work" provide improved assessment by addressing load dependency, and this review explores these advancements and their implications.
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  • A study was conducted to compare stroke incidences and mortality rates in critically ill COVID-19 patients from low-and middle-income countries (LMICs) and high-income countries (HICs).
  • The results showed that stroke incidence was significantly higher in LMICs (35.7 per 1000 admitted-days) compared to HICs (17.6 per 1000 admitted-days), with patients from LMICs also facing higher mortality rates (43.6% vs. 29.2%).
  • The findings highlight the need for better stroke diagnosis and healthcare resource allocation in LMICs, as both higher income status and the presence of stroke are associated with increased risk of death
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  • ICU environment affects patient recovery, with issues like noise and poor lighting impacting outcomes and staff wellbeing.
  • The ICU of the Future project aims to improve bedspace design and assess its effects on health metrics through innovative co-designed spaces.
  • This two-year study will involve various assessments (environment, sleep, delirium, etc.) comparing upgraded beds to standard ones to gather data on patient outcomes and the economic impact of improved ICU settings.
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  • - This study investigates the correlation between a new echocardiographic parameter called Pressure-Strain Product (PSP) and established metrics like Left Ventricular Stroke Work Index (LVSWI) and Cardiac Power Index (CPI) in sheep experiencing cardiogenic shock under veno-arterial extracorporeal membrane oxygenation (V-A ECMO).
  • - Research involved nine Dorset-cross ewes undergoing induced cardiogenic shock, with simultaneous measurements of PSP, LVSWI, and CPI taken at multiple time points during a 24-hour observation period.
  • - Results indicate that PSPcirc (a variant of PSP) shows a significant correlation with LVSWI and CPI, suggesting its potential as a reliable, non-invasive
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Background: The commonest echocardiographic measurement, left ventricular ejection fraction, can not necessarily predict mortality of recipients following heart transplantation potentially due to afterload dependency. Afterload-independent left ventricular stroke work index (LVSWI) is alternatively recommended by the current guideline; however, pulmonary artery catheters are rarely inserted in organ donors in most jurisdictions. We propose a novel non-invasive echocardiographic parameter, Pressure-Strain Product (PSP), as a potential surrogate of catheter-based LVSWI.

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  • Impaired primary hemostasis and abnormal blood vessel growth (angiogenesis) contribute to gastrointestinal bleeding in patients using continuous-flow left ventricular assist devices (CF-LVADs) in a "two-hit hypothesis."
  • A study examined the effects of acute exercise on blood samples from 22 CF-LVAD patients, measuring changes in hemostatic and angiogenic biomarkers.
  • Results showed that acute exercise significantly increased platelet count and function, as well as various factors related to blood clotting and vessel growth, suggesting potential benefits for GI bleeding management in these patients.
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Introduction: Use of doxorubicin, an anthracycline chemotherapeutic agent has been associated with late-occurring cardiac toxicities. Detection of early-occurring cardiac effects of cancer chemotherapy is essential to prevent occurrence of adverse events including toxicity, myocardial dysfunction, and death.

Objective: To investigate the prevalence of elevated cardiac troponin T (cTnT) and associated factors of myocardial injury in children on doxorubicin cancer chemotherapy.

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  • ECMO is utilized as a critical therapy for COVID-19 patients suffering from severe ARDS, but bleeding and thrombotic complications are significant issues during treatment.
  • Data from a global study involving over 1,200 severe COVID-19 patients on ECMO indicates that 38% experienced coagulation issues, with 54% facing hemorrhagic complications and higher mortality rates among those with bleeding.
  • The study suggests that while coagulation disorders are common and serious in these patients, the associated mortality risk may be lower than earlier reports from single-nation studies.
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Transpulmonary pressure can be estimated using esophageal balloon (EB) catheters, which come in a variety of manufacturing configurations. We assessed the performance of novel polyurethane EB designs, Aspisafe NG and NG+, against existing alternatives. We created a biomechanical model of the chest cavity using a plastic chamber and an ex-vivo porcine esophagus.

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Limb ischaemia is a clinically relevant complication of venoarterial extracorporeal membrane oxygenation (VA ECMO) with femoral artery cannulation. No selective distal perfusion or other advanced techniques were used in the past to maintain adequate distal limb perfusion. A more recent trend is the shift from the reactive or emergency management to the pro-active or prophylactic placement of a distal perfusion cannula to avoid or reduce limb ischaemia-related complications.

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Background: ICU outcomes are continuing to improve. However, this has not been matched by similar improvements of the ICU bedspace environment, which can detrimentally impact on patient outcomes. Excessive sound and noise, especially, has been linked with adverse and potentially preventable patient outcomes and staff errors.

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