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Sergei S. Brukhonenko designed and constructed one of the earliest heart-lung machines. He was the first to experimentally perform a total body perfusion with the heart of the animal isolated from the circulation. His work paved the way to the first experimental operations on heart valves. Although Brukhoneko's pioneering contributions have not received the recognition they deserve, his work represents an important landmark in cardiac surgery.

An analysis of 541 patients having total body perfusion under hypothermia (30°–33°C) showed that the use of pulsatile as against constant flow perfusion was not associated with a reduction in bicarbonate requirement, though the use of a vasodilator was. The implications of this are discussed.

A survey of the present status of extracorporeal circulation in open heart surgery revealed that the pump oxygenator has been widely accepted around the world, and various kinds of heart disease, especially congenital, have been cured surgically with a reasonable degree of safety. The film-type oxygenator, either disc or screen, is the one most commonly used. High flow rate, nearly equivalent to cardiac output in the normal circulation, is considered advantageous in total body perfusion. The combination of hypothermia with the pump oxygenator is still a debatable issue.

As considerable and widespread interest in open cardiac surgery has developed, many papers have appeared describing the various techniques and results with use of extracorporeal circulatory systems. However, the important aspects of pre and postoperative care of the open heart patients have received much less attention. This omission is indeed significant for given a group of cardiac patients with a good total body perfusion and a good surgical repair of their cardiac lesions, the difference between a very low operative risk and a higher mortality is often made by the attention given to details of management in the immediate pre and postoperative intervals. Therefore, it may be of value to others to examine suggestions based on experiences gained at the University of Minnesota Hospitals during the past five years in which period more than 700 open cardiac operations were performed.

The technic of total body perfusion with a pump oxygenator system has been used to extend pressure flow studies to the circulation as a whole. The effect of alterations in vasomotor tone on both total peripheral resistance and pressure flow relationships has been investigated by surgical ablation of the central nervous system or administration of vasoactive drugs. Certain aspects of the results obtained are discussed in relation to the concept of critical closing pressures.

SUMMARY Blood which is spilled into the pericardial cavity is rapidly hemolyzed. The return of this blood to the pump oxygenator is the major source of free plasma hemoglobin in total body perfusion.

A disposable blood oxygenator with built-in temperature controlling element is described. It is made with a semirigid housing of a clear polycarbonate plastic (Lexan). Within the housing is a bubble oxygenating system incorporating within its reservoir a canister providing 270 square inches of temperature exchanging surface.

SUMMARY 1.The effect of total body perfusion on digitalis tolerance was studied clinically in 84 infants and children undergoing open heart surgery and experimentally in eight mongrel dogs subjected to total body perfusion. 2.The clinical studies consisted of comparison of immediate postperfusion electrocardiograms to preperfusion electrocardiograms. There was no statistically significant difference between the incidence of postperfusion electrocardiographic arrhythmias in patients who had been digitalized prior to perfusion and in patients who had not received digitalis. Additionally there was no correlation between the incidence of postperfusion arrhythmias and the degree of the preperfusion electrocardiographic evidence of digitalis effect. 3.Studies of the effect of perfusion on digitalis tolerance in the dog were performed both for digitalis administered prior to perfusion ("tissue fixed") and for digitalis administered following perfusion. Perfusion was associated with no significant change in sensitivity to "tissue fixed" digitalis; however, all of the animals tested showed a decreased tolerance to digitalis administered one hour following perfusion. Decreased tolerance to digitalis persisted at four hours in 80 per cent of animals and at seven hours in 40 per cent of animals. 4.The application of this information to the administration of digitalis to patients undergoing open heart surgery is discussed.

SUMMARY In eight out of eleven patients investigated, the arterial carbon dioxide tension was higher in the period immediately after total cardiopulmonary bypass than before, although the minute volume delivered from the ventilator was unchanged. It was concluded that the increased carbon dioxide tension was due to an increase in physiological deadspace. Possible causes are discussed.