Browsing by Author "Hill, Lauren"

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    Corticotropin-releasing factor and acute post-operative gut function in truamatic abdominal injury and elective abdominal surgery
    (2009) Hill, Lauren; Kidson, Sue
    Shocked trauma patients in the Intensive Care Unit undergo a powerful, neuro-endocrine stress response driven by cytokine release and the hypothalamic-pituitary-adrenal axis. The response is activated under stress by corticotropin-releasing factor (CRF), the well-known 41 amino acid peptide neuro-hormone. Evidence from animal and human studies suggests that peripheral CRF is present in the gastrointestinal tract and associated with inflammatory changes. Critically ill patients frequently display somewhat unexplained gastrointestinal dysfunction including delayed gastric emptying, ileus and increased bowel permeability. The aim of the study was to investigate the role of CRF in critically ill adults with traumatic abdominal injury compared with elective surgical patients, and describe any association of CRF levels with alterations in acute post-operative gastrointestinal function. Eight patients with haemorrhagic shock following penetrating abdominal injury and seventeen patients undergoing elective surgery for hepato-biliary disease were studied for serial plasma and intestinal tissue CRF levels using radio-immunoassay. A RT-PCR technique was used to detect mRNA for CRF in intestinal tissue. Light microscopy was used to determine the quantity and distribution of mast cells in intestinal tissue. Post-operative gastric emptying was assessed using the paracetamol absorption test and intestinal permeability by measuring urinary lactulose:mannitol ratios following a bolus of these sugars. The study was approved by University of Cape Town Human Research Ethics Committee. Informed consent (retrospectively in the case of the trauma patients), was obtained from all subjects.
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    Vitamin C status, oxidative stress, hyperglycaemia and endothelial function in critically ill patients with septic shock : an observational study
    (2014) Katundu, Kondwani; Hill, Lauren; Davids, Lester
    Septic shock is associated with oxidative stress, reduced levels of plasma vitamin C and stress hyperglycaemia – all factors that may influence endothelial, and therefore, organ function. Vitamin C is an important antioxidant in human plasma; and it has been implicated in maintaining normal endothelial function during oxidative stress. The vitamin C status of critically ill patients in South African ICUs has not been well investigated; neither has the relationship between vitamin C status, oxidative stress, hyperglycaemia and endothelial function been studied in this patient group. In a prospective, cross-sectional study investigating these factors in critically ill patients with septic shock on inotropic support, serial blood samples from 25 patients were taken at days zero and one, following inotrope initiation, and on day seven after inotrope cessation. These samples were analysed for plasma vitamin C, thiobarbituric acid-reactive substances (TBARS) - as a biomarker of oxidative stress - and soluble vascular cell adhesion molecule-1 (sVCAM-1), and E-selectin, as markers of endothelial dysfunction. The plasma glucose to vitamin C ratios were also calculated. Daily clinical measures in the patients included Sequential Organ Failure Assessment (SOFA) score, mean arterial blood pressure, blood glucose, fluid balance and inotropic support. The clinical outcomes were recorded.