Comparative evaluation of two hypothermic treatments in cardiac surgery: a statistical decision theory approach

Blood cardioplegia can be administered both in anterograde and retrograde fashions. In an effort to better define the clinical performance of the combined anterograde/retrograde cardioplegia, this work compares the results yielded by this method with those obtained with the classic asanguineous crystalloid cardioplegia by analyzing their effects on a set of physiological variables monitored in patients. A set of 96 adult patients monitored in the intensive care unit (ICU) after hypothermic cardiopulmonary bypass for coronary or valvular disease was studied. In 55 patients the crystalloid cardioplegia technique was used as hypothermic treatment, while in the other patients the antero/retrograde blood cardioplegic technique was adopted. The statistical analysis developed can be divided into two phases. The first analyzes the separability of the two classes and their evolution in time. The second phase deals with the problem of identifying the single variable and/or the variable subset with the greatest separation power. The results confirm the role of the antero/retrograde blood cardioplegia in myocardium protection