Epidural anesthesia may attenuate lipid peroxidation during aorto-femoral surgery.
OBJECTIVE
To determine the effect of epidural anesthesia (EP) on oxygenation of the chronically ischemic limb in patients undergoing aorto-femoral bypass grafting and to assess whether it produces an alteration of lipid peroxidation and antioxidant status following revascularization.


METHODS
In this prospective, randomized, single-blinded study 40 ASA II or III patients undergoing elective aorto-femoral bypass grafting were allocated to receive general anesthesia (group GA, n = 20), or epidural + GA (group EP, n = 20) during surgery. Femoral venous blood-gas status, activities of the protecting antioxidant enzymes superoxide dismutase (SOD), glutathione peroxidase (GSH-px), glutathione reductase (GSH-rd), glutathione (GSH) and thiobarbituric acid-reactive substances (TBARS) as a marker of lipid peroxidation were determined in blood samples taken from the femoral vein at different intervals before and after revascularization.


RESULTS
Before the induction of anesthesia in group EP, femoral venous PO(2) [mean (standard deviation), 95% confidence interval] increased after achieving an adequate level of blockade by EP extending to the dermatomal level of T6-8 [29.32 (4.6), 26.34-32.30 to 36.29 (4.6), 33.37-39.22 mmHg, P < 0.05]. Femoral venous PO(2) was similar in both groups thereafter. In the GA group a significant increase in erythrocyte TBARS was observed immediately after restoration of blood flow when compared with baseline values [221.32 (102), 148.35-294-29 to 337.26 (123) 248.99-425.53 nmol*g(-1) hemoglobin, P < 0.01] but not at any other moment. In the EP group TBARS did not increase throughout the study. Within group comparisons revealed no significant differences in GSH, GSH-px, GSH-rd and SOD.


CONCLUSIONS
In patients with atherosclerotic aorto-iliac occlusive disease EP may possibly attenuate lipid peroxidation following revascularization but has no effect on antioxidant enzyme activities.
Yüceyar
Lale
L
Department of Anesthesiology, Istanbul University Cerrahpasa Medical Faculty, Istanbul, Turkey. Lyuceyar@hotmail.com
Erolçay
Hülya
H
Konukoglu
Dildar
D
Bozkurt
A Kürsat
AK
Aykaç
Bora
B
D000368:Aged; D000767:Anesthesia, Epidural; D000768:Anesthesia, General; D000975:Antioxidants / Q000378:metabolism; D001157:Arterial Occlusive Diseases / Q000601:surgery*; D001161:Arteriosclerosis / Q000601:surgery*; D001784:Blood Gas Analysis; D004912:Erythrocytes / Q000201:enzymology / Q000378:metabolism; D005260:Female; D005268:Femoral Vein / Q000601:surgery*; D005979:Glutathione Peroxidase / Q000097:blood; D005980:Glutathione Reductase / Q000097:blood; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D015227:Lipid Peroxidation / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D015425:Myocardial Reperfusion; D009204:Myocardial Revascularization; D013482:Superoxide Dismutase / Q000097:blood; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism
D000975:Antioxidants; D017392:Thiobarbituric Acid Reactive Substances; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D005980:Glutathione Reductase