The Annals of thoracic surgery
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Randomized Controlled Trial Comparative Study Clinical Trial
Effect of pulsatile flow during cardiopulmonary bypass on thyroid hormone metabolism.
Changes in thyroid hormone levels during and after cardiopulmonary bypass (CPB) are well documented. However, little is known about the effects of pulsatile flow during CPB on thyroid hormone metabolism. To examine the effect of flow pattern, a prospective study was carried out using 30 patients undergoing coronary artery bypass grafting. ⋯ However, levels of T3 and free T3 during and after CPB showed a significant difference between the two groups, with a smaller decrease in patients in whom pulsatile flow was used during bypass (p < 0.05). Thyroxine, and thyroid-stimulating hormone free T4 values showed no difference between the two groups at any sampling time. These data provide support for the use of pulsatile flow during CPB to establish a more physiologic state and maintain better thyroid hormone metabolism.
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Comparative Study
Pediatric and adult thoracic trauma: age-related impact on presentation and outcome.
To assess the impact of age on presentation and outcome, 2,415 cases involving blunt and penetrating thoracic trauma over an 8-year period were reviewed retrospectively from a single level I trauma center. Of the 2,073 patients alive on arrival, 79 were 12 years of age or less (children), 137 were 13 to 17 years of age (adolescent), 1,742 were 18 to 59 years of age (adults), and 115 were 60 years of age or more (elderly). Chi-square analysis was performed relative to presentation (blunt versus penetrating), need for thoracotomy, and hospital mortality. Although blunt thoracic trauma comprised 64/79 of children (81%) and 90/115 of the elderly (78%), penetrating thoracic trauma was more common for adolescents 79/137 (58%) and adults 1013/1742 (58%) (p < 0.05). There was no significant difference in need for thoracotomy among the four age groups after blunt thoracic trauma. For penetrating trauma, however, there was a significantly higher incidence of thoracotomy in children as compared with the other three age groups (p < 0.05). ⋯ (1) Blunt injuries comprised a greater proportion of thoracic trauma in children and the elderly. (2) In this series, children with penetrating thoracic trauma underwent thoracotomy more frequently. (3) Hospital mortality appeared to be increased for the elderly. (4) Analyses of pediatric thoracic trauma must separate children from adolescent age groups.
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Comparative Study
Determination of organ blood flows during retrograde inferior vena caval perfusion.
Cerebral, renal, and hepatic blood flows and oxygen metabolism were measured in 8 mongrel dogs undergoing hypothermic (20 degrees C) retrograde perfusion via the inferior vena cava (IVC) and compared with cardiopulmonary bypass and retrograde superior vena caval perfusion. Inferior vena caval perfusion was performed with aortic drainage and clamping of the superior vena cava at an IVC pressure of 20 or 30 mm Hg. Cerebral, renal, and hepatic blood flows at 30 mm Hg of IVC pressure were 7.5 +/- 3.8, 8.1 +/- 3.1, and 15.3 +/- 5.5 mL.min-1.100 g-1, respectively, as determined by the hydrogen clearance method. ⋯ However, high IVC pressure was associated with high portal venous pressure, which may produce ascites. Regional blood flow during retrograde IVC perfusion was measured by the colored microsphere method in another 8 normothermic dogs. Inferior vena caval perfusion at 30 mm Hg supplied adequate blood flow to the liver (15.44 +/- 12.1 mL.min-1 x 100 g-1) and kidneys (6.35 +/- 2.0 mL.min-1 x 100 g-1).(ABSTRACT TRUNCATED AT 250 WORDS)
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Brain protection during cardiopulmonary bypass and hypothermic circulatory arrest is incomplete. Activation of blood protease cascades may contribute to cellular injury under these conditions. To test this hypothesis, effects of the protease inhibitor aprotinin on recovery of brain energy metabolism after hypothermic circulatory arrest were studied in the piglet. ⋯ The response to endothelium-independent vasodilation (nitroglycerin) was the same in both groups. Carotid blood flow tended to be greater at 20 minutes of reperfusion and less during 45 to 80 minutes after reperfusion in the aprotinin-treated animals. Brain water content postoperatively was 0.8077 in the aprotinin group and 0.8122 in control animals (p = 0.06).(ABSTRACT TRUNCATED AT 250 WORDS)