The Journal of thoracic and cardiovascular surgery
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J. Thorac. Cardiovasc. Surg. · Jan 1993
Randomized Controlled Trial Clinical TrialSuccessful restoration of cell-mediated immune response after cardiopulmonary bypass by immunomodulation.
The objectives of this prospective randomized trial were to quantify immunosuppressive effects of cardiopulmonary bypass, to identify mechanisms responsible for postoperative immunosuppression, and to investigate the effects of immunomodulatory intervention on these mechanisms. Sixty patients were studied after cardiopulmonary bypass. Immunomodulatory therapy consisted of the cyclooxygenase inhibitor indomethacin, which blocks the downregulating agent prostaglandin E2, and thymopentin, which enhances T-lymphocytic activity. ⋯ As an in vivo correlate of the immunomechanistic alterations, patients demonstrated an impaired delayed-type hypersensitivity response to an antigen skin test battery. These changes in immunoreactivity could be successfully counteracted by the combined immunomodulatory regimen, whereas sole indomethacin treatment could only partially restore depressed host defense parameters. With this study we could demonstrate for the first time that human lymphocytic interleukin-2 synthesis, which represents the key event among forward regulatory immune mechanisms, can be protected via in vivo immunoaugmentatory therapy and that this therapy can successfully counteract immunosuppressive effects of cardiopulmonary bypass.
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Routine cultures of epicardial pacing wires removed 5 to 10 days postoperatively were obtained in 205 adults who underwent cardiac operations through median sternotomy. The study was conducted in a double-blind prospective fashion in which clinicians were unaware of culture results. With the exception of 10 out-of-town patients who were followed up only until the day of hospital discharge, the patients were followed for at least 6 weeks (195 patients) for evidence of poststernotomy wound infections. ⋯ In two of these four patients deep sternal infections developed. In the remaining 178 patients whose wire cultures were negative, no deep sternal infections developed. The fact that all clinically manifested deep sternal infections were associated with positive epicardial pacing wires cultures suggests that epicardial pacing wires cultures may be useful in the treatment of high-risk patients or of those in whom deep sternal infections are suspected.
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J. Thorac. Cardiovasc. Surg. · Jan 1993
Comparative StudyWarm versus cold blood cardioplegia--is there a difference?
This experimental study sought to compare the effectiveness of warm blood cardioplegia versus cold blood cardioplegia in protecting areas of ischemic myocardium during urgent coronary revascularization. In 40 adult pigs, the second and third diagonal vessels were occluded with snares for 90 minutes. ⋯ Hearts protected with antegrade warm blood cardioplegic solution had the lowest pH values in the area at risk (6.59 +/- 0.10 antegrade warm blood cardioplegia versus 6.80 +/- 0.10 retrograde warm blood cardioplegia versus 6.72 +/- 0.18 antegrade cold blood cardioplegia versus 6.85 +/- 0.15 antegrade/retrograde cold blood cardioplegia and the highest area of necrosis (42% +/- 3% antegrade warm blood cardioplegia versus 26% +/- 2% [p < 0.05 from antegrade warm blood cardioplegia] retrograde warm blood cardioplegia versus 31% +/- 2% [p < 0.05 from antegrade warm blood cardioplegia] antegrade cold blood cardioplegia versus 21% +/- 2% [p < 0.05 from antegrade warm blood cardioplegia] antegrade/retrograde cold blood cardioplegia). We conclude that in the presence of an acute coronary occlusion with ischemic myocardium, warm blood cardioplegic solution should be given in a continuous retrograde fashion and does not result in myocardial protection superior to the protection that can be achieved with antegrade/retrograde cold blood cardioplegic solution.
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J. Thorac. Cardiovasc. Surg. · Jan 1993
Impaired endothelium-dependent coronary microvascular relaxation after cold potassium cardioplegia and reperfusion.
Myocardial dysfunction after cardiac operations might be influenced by altered myocardial perfusion in the postoperative period. To investigate possible alterations in vascular reactivity, in vitro coronary microvascular responses were examined after ischemic cardioplegia with use of a porcine model of cardiopulmonary bypass. Since myocardial perfusion is primarily regulated by arteries less than 200 microns in diameter, these vascular segments were examined. ⋯ After 1 hour of ischemic cardioplegia without reperfusion, endothelium-dependent relaxation was only slightly affected. Transmission electron microscopy showed minimal endothelial damage after ischemic cardioplegia and reperfusion. These findings have important implications regarding coronary spasm and cardiac dysfunction after cardiac operations.