THE CLINICAL use of generalized hypothermia in cardiopulmonary by-pass described by Sealy and associates has proved to be a valuable modality.1 The decrease in metabolic requirements contributes to a safer by-pass. Controlled myocardial hypothermia in conjunction with systemic hypothermia may be desirable during aortic valvular operations. This is usually accomplished with two heat exchangers; one in the systemic arterial circuit and another in the coronary perfusion circuit. An alternative method using a single heat exchanger eliminates unnecessary equipment and preparation.
The circuit required for controlled myocardial and generalized hypothermia with one heat exchanger is diagrammed in the Figure. A line detouring the heat exchanger is placed so that oxygenated blood may either flow completely through the heat exchanger or may be partially detoured from the heat exchanger. Blood for coronary perfusion is taken from the systemic arterial line distal to the heat exchanger but proximal to the detour
LUI AHF, STETSON RM. Single Heat ExchangerUse for Controlled Myocardial and Generalized Hypothermia. Arch Surg. 1966;93(5):838. doi:10.1001/archsurg.1966.01330050142022