[Comparative analysis of antioxidant defense during on-pump and off-pump cardiac surgery].
OBJECTIVE
The transient myocardial ischemia that occurs during cardiac surgery leads to oxidative stress and the production of free radicals. The resulting damage can be reduced if cardiopulmonary bypass is avoided. We obtained indirect measures of the oxidative damage occurring during cardiac surgery by monitoring the glutathione system and we studied the influence of cardiopulmonary bypass.


METHODS
The study included 19 patients undergoing cardiac surgery. Cardiopulmonary bypass was used in 9 (47.4%). Blood samples were obtained from each patient at different times during and after surgery. Total, oxidized and reduced glutathione levels were measured, as was the activity of related enzymes (i.e., glutathione peroxidase, glutathione reductase, and glutathione transferase).


RESULTS
The total glutathione level decreased more in patients in whom cardiopulmonary bypass had been used. In addition, the oxidized glutathione level was reduced in these patients, which suggests that antioxidant defense was not fully effective. In contrast, the oxidized glutathione level tended to increase in patients in whom cardiopulmonary bypass had not been used. There was no significant difference in enzymatic activity between the two groups.


CONCLUSIONS
In this study, patients who underwent off-pump cardiac surgery had a better antioxidant profile. The implication could be that cardiac surgery without cardiopulmonary bypass has a less damaging effect on ischemic myocardium.
Castillo Caparrós
Antonio
A
Servicio de Anestesiología, Hospital Clínico-Universitario Virgen de la Victoria, Málaga, Spain.
Montijano Cabrera
Angela M
AM
Olalla Mercadé
Eduardo
E
Narbona Vergara
Ignacio
I
D000368:Aged; D000704:Analysis of Variance; D000975:Antioxidants; D006348:Cardiac Surgical Procedures; D002315:Cardiopulmonary Bypass; D005260:Female; D005609:Free Radicals; D005978:Glutathione / Q000097:blood; D005979:Glutathione Peroxidase / Q000097:blood; D005980:Glutathione Reductase / Q000097:blood; D005982:Glutathione Transferase / Q000097:blood; D006801:Humans; D008297:Male; D008875:Middle Aged; D018384:Oxidative Stress; D012307:Risk Factors
D000975:Antioxidants; D005609:Free Radicals; D005979:Glutathione Peroxidase; D005980:Glutathione Reductase; D005982:Glutathione Transferase; D005978:Glutathione