Oxidative stress : natural history and modulation In surgery and trauma patients
Date
2004-07-14
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
ORCID
Type
Degree Level
Doctoral
Abstract
Oxidative stress has been associated with many disease conditions in adults and neonates based on clinical and post mortem studies. Trauma is the commonest cause of oxidative stress. However a gap in knowledge of the natural history of oxidative stress in humans was identified as most studies have been post mortem or in animals. The aim of this research is to understand treat and oxidative stress in trauma and surgical patients. The study involved three components including: the development and evaluation of the novel oxistress assay; study of clinical trauma and oxidative stress; and clinical trial of alanyl-glutamine supplementation following major surgery. The novel oxistress assay was used on urine samples in the normal population to determine reference values and subsequently on hospital patients to determine sensitivity and specificity. The study of clinical trauma and oxidative stress evaluated plasma antioxidants (FRAP assay), red cell glutathione (Asensi’s method), plasma and urine protein carbonyl (Levine’s method) and total oxidants in plasma and urine (oxistress assay) over 7 day period following trauma. The clinical trial was a double blind study of 69 major surgery patients evaluating biochemical and clinical parameters over 7 day period in comparison with pre-operative status. The novel oxistress assay proves to be a sensitive and accurate bedside diagnostic tool for oxidative stress. It can also be used in the laboratory setting. Oxidative stress is associated with increased trauma severity resulting in antioxidant depletion, strong oxidant production and protein degradation. The presence of pre-morbid medical factors also increased oxidative stress in trauma patients. Oral alanyl-glutamine supplementation (0.3 g/kg) increased plasma glutamine and antioxidant levels while decreasing urine oxidant levels. It significantly reduced hospital stay in non-cancer and higher disease complexity patients. The intervention also reduced the resource intensity weighting (RIW) score. Oxidative stress is a clinical problem in surgery and trauma patients that can now be easily diagnosed at the bedside using the novel oxistress assay. Treatment with alanyl-glutamine is effective in reducing oxidative stress and improving clinical outcome. It is highly recommended probably at a higher dose in order to achieve optimal results.
Description
Keywords
Oxistress Assay, Enteral Alanyl-glutamine supplementation, Post-surgery, Free radicals, Antioxidants, Trauma, Oxidative Stress
Citation
Degree
Doctor of Philosophy (Ph.D.)
Department
Surgery
Program
Surgery