Totale antioxidative Kapazität bei am Herzen operierten Kindern

Oxidative stress results from the release of oxygen free radicals. The best known mechanisms which lead to the oxidative stress are ischemia- reperfusion injury and activation of neutrophile. Oxidative stress is one of the most important factors which induce inflammatory complications and tissue damage after CPB. There are an enzymatic and non-enzymatic defence mechanism against reactive oxygen free radicals which together create a total anti-oxidant capacity. Oxidative stress during operation cause consumption of antioxidants and tissue damage. Our study was aimed to determine plasma anti-oxidant capacity in children undergoing elective cardiac surgery with cardiopulmonary bypass (CPB). The role of the oxygenation with 100% O2 during CPB was investigated. The role of hypoxemia was investigated. The influence of ischemia-reperfusion injury and oxidative stress on clinical outcome was studied. 26 children (aged from 6 to 180 months) with cyanotic (n=6; Fallot) or non cyanotic cardiac defect (n=20; VSD, ASD, AV) were investigated. All patients were operated on under general anesthesia, receiving mechanical ventilation with pure oxygen, on hypothermic CPB with or without cardio - circulatory arrest. Total anti - oxidant capacity of plasma samples was assessed by the determination of the Trolox Equivalents Anti - Oxidant Capacity (TEAC) sequentially before, during and after cardiac surgery up to the 10th post-operative day. The a-tocopherol concentration im plasma was measured. The triglyceride concentration in plasma was measured to detect a dilution and to correct a-tocopherol values. TEAC was analysed with respect to operation stress variables such as duration of CPB, aortic clamping, cardiocirculatory arrest and clinical outcome such as hemodynamic variables, renal function, maximal glutamate oxaloacetate (GOT), oxygenation index, catecholamine dosis and duration of intensiv care unit. In all children TEAC values im plasma significantly decreased after induction of anesthesia with mechanical ventilation (p<0.001). We could exlude a dilution because the concentration of triglycerides at this timepoint remained unchanged. During CPB, there was no further decrease of TEAC, but a continuous increase up to the end of CPB. TEAC values after the protamin administration showed significant higher level than 10 minutes after the onset of the CPB(p<0.001). From the end of the CPB until the 10 th day postoperative the TEAC values stay without significant differences. Preoperativ TEAC values were in cyanotic and non cyanotic patients without significant difference. TEAC values were significant higher in cyanotic patients 4 and 24 hours postoperatively (p<0.001). The TEAC values 4 and 24 hours postoperatively correlated with dte duration of the aortic clamping (Spearman 0,4 (p<0,05 and 0,5 (p<0,005)). Postoperative TEAC values correlated negatively with mediane blood pressure and positively catecholamine therapy, liver enzymen, duration of ventilation and stay on unit intensiv care. We show that 1. general anesthesia with pure oxygen ventilation and not extracorporeal circulation with ischemia - reperfusion is related to a significant decrease of the total anti - oxidant capacity of children undergoing cardiac surgery. 2. The decrease of the total anti - oxidant capacity after the oxygenation is transient and TEAC values reach preoperative level on the first postoperative day. 3. The determination of total antioxidant capacity by trolox equivalents does not allow any statements about the influence of hypoxemia 4. TEAC values after the operation were higher in patients with most operation stress and worse clinical outcome variables, suggesting release of antioxidants from damaged tissues as a response to higher stress rather than higher regeneration of antioxidant capacity.

Grantor dc:publisher

Publikationsserver der RWTH Aachen University

Year dc:date

2003

Author dc:creator

• Sokalska, Magdalena

Contributors dc:contributor

• Seghaye, Marie-Christine

• info:eu-repo/classification/ddc/610
• Medizin
• antioxidative Kapazität
• TEAC
• extrakorporaler Kreislauf
• angeborene Herzfehler

Statement dc:rights

• info:eu-repo/semantics/openAccess

Language dc:language

ger

Identifier

https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-120845%22

OAI identifier oai:identifier

oai:publications.rwth-aachen.de:59027