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Pathophysiology of cardiopulmonary bypass

1989; Springer Science+Business Media; Volume: 36; Issue: S1 Linguagem: Inglês

10.1007/bf03005326

1496-8975

John M. Murkin,

Cardiac and Coronary Surgery Techniques

Since its development by Dr. John Gibbon and its clinical introduction in 1953, cardiopulmonary bypass (CPB) has seen widespread application as a circulatory support modality, enabling complex surgery of the heart and great vessels to be performed successfully.Various factors inherent in its use can, however, produce organ system dysfunction in the perioperative period.Systemic heparinization, acute haemodilution, core cooling, activation of various blood cascades, generation of microgaseous and blood element emboli, bypass of the pulmonary circulation, and alterations in perfusion pressure characteristics i.e., nonpulsatility, comprise some of the key elements attending CPB and having the potential to influence organ system functioning.While survival is no longer in question after routine CPB, subtle signs of organ system dysfunction can be detected postoperatively in many otherwise apparently intact patients.This is most evident in the CNS, as transient neurological dysfunction has been observed in over 60 per cent of patients.L2 Although persistent neurological deficits are relatively uncommon (0.5-1.5 per cent),l'2 there is evidence that patients suffering transient postoperative neurological dysfunction may exhibit subtle neurobehavioural deterioration at five-year follow-up.3The following discussion will describe some of the physiological responses to CPB, particularly as they relate to the CNS, and examine the rationale for current techniques and management during this procedure.