• To investigate the best method of administration of blood potassium cardioplegia, 19 dogs were studied while undergoing 120 minutes each of aortic crossclamping (myocardial temperature, < 15 °C). Group 1 (six dogs) underwent a single 120-minute period of aortic crossclamping with the heart protected by multiple reinjections (1,000 mL every 30 minutes) of blood potassium cardioplegia solution (potassium chloride, 30 mEq/L; pH, 8; temperature, < 15 °C). Group 2 (six dogs) underwent four separate 30-minute periods of aortic crossclamping, but allowing hearts to beat in a nonworking state for 20 minutes at 35 °C between each arrest interval. Hearts in group 3 (seven dogs) were initially arrested as described above, following which a continuous infusion (75 mL/min; KCl, 10 mEq/L) of blood potassium cardioplegia solution was maintained throughout the arrest period. Measurements of myocardial metabolism, ventricular function, regional blood flow, and ultrastructure were carried out before arrest and 30 minutes after final unclamping. Analysis of the data revealed no significant benefit of one method over another, with the exception that adenosine triphosphate level was least preserved with intermittent unclamping and reperfusion. Because continuous perfusion techniques are more cumbersome than multidose reinjection, and intermittent aortic crossclamping lengthens total cardiopulmonary bypass time, we favor the simplest approach, multidose reinjection during a single uninterrupted period of aortic crossclamping.
(Arch Surg 1981;116:1509-1516)
Catinella FP, Cunningham JN, Srungaram RK, Nathan IM, Knopp EA, Paone G, Baumann FG, Adams PX, Spencer FC. Blood Potassium Cardioplegia AdministrationComparison of Myocardial Protection Offered by Three Techniques. Arch Surg. 1981;116(12):1509-1516. doi:10.1001/archsurg.1981.01380240003001