Cooling Gradients and Formation of Gaseous Microemboli With Cardiopulmonary Bypass: An Echocardiographic Study

摘要: Abstract Background . Previous studies demonstrated gas emboli formation during rewarming from hypothermia on cardiopulmonary bypass when the temperature gradient exceeded a critical threshold. It also has been suggested that of arterial may occur cooling cooled oxygenated blood exiting heat exchanger is warmed mixture with patient's blood. The purpose this study was to determine under what circumstances would bypass. Methods Eight anesthetized mongrel dogs were placed using roller pump, membrane oxygenator, and line filter. For detection, we positioned transesophageal echocardiographic probe at aortic arch distal cannula Doppler probes common carotid artery line. Cooling gradients between normothermic perfusate 5°, 10°, 15°, 20°, 0°C (isothermal controls) investigated. In addition preestablished gradients, investigated effect rapid (maximal flow through water bath 4°C) after initiation Results Minimal detected 10°C or greater. incidence related directly magnitude ( p Conclusions greater be associated formation, but they limited clinical significance because no arch. During application cooling, observed.