The Journal of thoracic and cardiovascular surgery
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J. Thorac. Cardiovasc. Surg. · Oct 1993
Comparative StudyRecovery of cerebral blood flow and energy state in piglets after hypothermic circulatory arrest versus recovery after low-flow bypass.
A miniature piglet model that replicates clinical hypothermic (14 degrees C nasopharyngeal) circulatory arrest and low-flow (50 ml/kg per minute) bypass was used to study carotid blood flow with electromagnetic flow probe, cerebral blood flow by microsphere injection, cerebral metabolic rate by arteriovenous oxygen and glucose extractions, lactate production by cerebral arteriovenous difference, and cerebral edema. Data from five animals that underwent circulatory arrest and five animals that underwent low-flow bypass (aged 28.8 +/- 0.4 [mean +/- standard error of the mean] days) were analyzed. The duration of circulatory arrest and low-flow bypass was 1 hour. ⋯ After 3 hours of normothermic reperfusion, phosphocreatine and adenosine triphosphate recovered to 98.6% +/- 9.0% and 90.1% +/- 13.5% of baseline, respectively, and pH was 7.087 +/- 0.051, similar to baseline (7.1755 +/- 0.041). In the low-flow bypass group, the disparity between the depressed level of cerebral oxygen consumption and normal high-energy phosphate levels may reflect incomplete cerebral rewarming or decreased energy consumption. In the circulatory arrest group, the parallel recovery of oxygen consumption and high-energy phosphates eventually achieving baseline levels suggests that the degree of hypothermia used provides adequate protection for acute cerebral recovery after 1 hour of circulatory arrest.(ABSTRACT TRUNCATED AT 400 WORDS)
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J. Thorac. Cardiovasc. Surg. · Oct 1993
Contracture of the newborn myocardium after prolonged prearrest cooling.
Profound hypothermic circulatory arrest is frequently used to facilitate the surgical repair of congenital heart defects in neonates. Deep hypothermia is achieved by a period of core systemic cooling during cardiopulmonary bypass before cardioplegic arrest. There have been conflicting reports with respect to the consequence of perfusing a nonarrested newborn heart under hypothermic conditions. ⋯ These results suggest that prolonged cold perfusion of the nonarrested newborn heart impairs functional recovery and is therefore detrimental. When followed by a period of ischemic arrest, it further potentiates the myocardial injury and induces severe contracture. This preceding adverse effect of prolonged myocardial cold perfusion before cardiac arrest may, in part, explain the suboptimal protective effect of cardioplegia in neonates.
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Talc was used intrapleurally for the creation of pleural adhesions in 360 patients. The indications for use were malignant pleural effusion in 169 patients, benign effusions in 41, recurrent pneumothorax in 122, empyema in 19, and chylothorax in 9. Of 336 patients available for follow-up, excellent results (complete pleurodesis) were achieved in 284 patients (84.5%), fair results in 28 (8.3%), and poor results (no adhesions) in 24 (7.2%). ⋯ Talc is the most effective and least expensive agent for creation of pleural adhesions. Its use is simple and easily tolerated by the patients. Because of the carcinogenic effect of asbestos, purified talc that is free of asbestos fibers must be used.