The Journal of thoracic and cardiovascular surgery
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J. Thorac. Cardiovasc. Surg. · Apr 1993
Cardiac-derived thromboxane A2. An initiating mediator of reperfusion injury?
After crystalloid cardioplegic arrest, cardiac-derived thromboxane A2 may be an important initiating mediator of no-reflow and hemodynamic deterioration during reperfusion because of its potent vasoactive properties. Although previous studies have already documented the increased release of cardiac thromboxane A2 after ischemia, none have studied the effects of cardiac thromboxane A2 on hemodynamics. We therefore tested the ability of cardiac thromboxane A2 to mediate deterioration of coronary flow and functional recovery during reperfusion after global ischemia. ⋯ In relation to the group with cardioplegic solution alone, postischemic aortic flow, coronary flow, cardiac output, and stroke work were all significantly greater (p < 0.05) in the group with the receptor antagonist (aortic flow: 49.5 +/- 2.4 versus 29.4 +/- 3.3 ml/min; coronary flow; 12.4 +/- 1.2 versus 8.5 +/- 1.3 ml/min; cardiac output, 62.0 +/- 2.8 versus 38.0 +/- 4.4 ml/min; stroke work, 12.6 +/- 0.8 versus 7.1 +/- 0.8 cm H2O.ml). Overall, postischemic coronary effluent thromboxane B2 levels were greater than preischemic values (105.6 +/- 12.4 versus 69.6 +/- 9.8, p < 0.05) and treatment with the receptor antagonist did not significantly affect postischemic thromboxane B2 levels (92.0 +/- 7.3 versus 82.3 +/- 15.5, p = not significant). Neither ischemia nor treatment with the receptor antagonist significantly affected heart rate.(ABSTRACT TRUNCATED AT 400 WORDS)
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J. Thorac. Cardiovasc. Surg. · Apr 1993
Comparative StudyHemostatic activation during cardiopulmonary bypass with different aprotinin dosages in pediatric patients having cardiac operations.
The effect of high-dose aprotinin treatment on hemostatic activation during cardiopulmonary bypass in pediatric patients having cardiac operations was investigated. Sixty patients weighing less than 10 kg undergoing cardiac operations for different types of congenital heart diseases were studied: 20 patients were treated with aprotinin 2 x 15,000 KIU/kg, 20 patients with 2 x 30,000 KIU/kg, and 20 patients without aprotinin treatment served as the control group. Different split products of fibrinogen and/or fibrin and the fibrinolytic activity on fibrin plates were measured to assess fibrinolytic activation. ⋯ These observations suggest an attenuation of hemostatic activation during cardiopulmonary bypass with less plasmin formation and, because of inhibition of contact activation, less thrombin generation with aprotinin treatment. Thus the thrombotic-thrombolytic equilibrium is kept more balanced after cardiopulmonary bypass. High-dose aprotinin treatment is recommended for pediatric patients undergoing cardiac operations.
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J. Thorac. Cardiovasc. Surg. · Apr 1993
Randomized Controlled Trial Comparative Study Clinical TrialComparison of two aprotinin dosage regimens in pediatric patients having cardiac operations. Influence on platelet function and blood loss.
Only a few studies have reported on the effects of aprotinin in pediatric cardiac surgery, and the correct dose is controversial. In a prospective, randomized study, three groups of children weighing less than 20 kg were investigated. In group 1 (n = 14): aprotinin 20,000 U/kg was given after induction of anesthesia, 20,000 U/kg was added to the prime, and another 20,000 U/kg was given every hour of cardiopulmonary bypass (low-dose regimen). ⋯ Blood loss was similar for all three groups and added up to approximately 28 ml/kg until the first postoperative day. The use of packed red cells was also comparable for the three groups, whereas the use of fresh frozen plasma was highest in group 1 (1680 ml until the first postoperative day). We conclude from this study that aprotinin did not improve platelet function and did nor reduce blood loss or the need for homologous blood transfusion in pediatric cardiac surgery, regardless of whether a low-dose or a high-dose regimen was used.
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J. Thorac. Cardiovasc. Surg. · Apr 1993
Randomized Controlled Trial Comparative Study Clinical TrialComparison of insufflated talc under thoracoscopic guidance with standard tetracycline and bleomycin pleurodesis for control of malignant pleural effusions.
The standard palliation of malignant pleural effusions involves tube thoracostomy drainage with chemical pleurodesis. The insufflation of intrapleural talc under thoracoscopic guidance (n = 39) was evaluated against documented controls that consisted of patients (n = 85) who participated in a randomized study with tube thoracostomy drainage followed by either bleomycin or tetracycline sclerosis. Under local anesthesia, which was supplemented by intravenous sedation, patients in the talc group underwent complete pleural fluid evacuation. ⋯ The tetracycline group had successful pleurodesis in only 33% at 30 days and 47% at 90 days (p < 0.001 and p < 0.001 versus the talc group). There were only two patients in the talc group in whom pleurodesis was not successful, and both were subsequently found to have extraluminal compression of the right lower lobe bronchus, which prevented lung reexpansion. These data demonstrate that the insufflation of talc into the pleural cavity under thoracoscopic guidance is a safe and efficacious procedure in the control of malignant pleural effusions.
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J. Thorac. Cardiovasc. Surg. · Apr 1993
Acute isovolemic hemodilution and blood transfusion. Effects on regional function and metabolism in myocardium with compromised coronary blood flow.
The use of isovolemic hemodilution to prevent adverse side effects of homologous blood transfusions has increased. The lowest level of hemoglobin that can be tolerated without regional myocardial dysfunction, however, had not been precisely defined for left ventricular myocardium with compromised coronary blood flow. This level was determined in our study in 19 dogs with critical stenosis of the left anterior descending coronary artery during graded isovolemic hemodilution. ⋯ At a mean level of hemoglobin of 6.0 +/- 0.4 gm/dl, marked contractile dysfunction developed in the left anterior descending region: Systolic shortening decreased from 24.2% +/- 2.1% to 17.9% +/- 1.9% (p < 0.01); postsystolic shortening increased from 4.0% +/- 3.0% to 12.2% +/- 3.8% (p < 0.01); and in the left anterior descending region, oxygen consumption decreased. The increase of arterial level of hemoglobin by only 1.9 +/- 0.2 gm/dl restored contractile function in the left anterior descending region, regional oxygen consumption, and oxygen extraction across the left anterior descending region. Moderate isovolemic hemodilution is relatively well tolerated in left ventricular myocardium with compromised coronary blood flow, and hemodilution regional contractile dysfunction induced by hemodilution is reversible by minimal blood transfusion.