Newborns and small infants require special procedures of extracorporeal circulation for open heart surgery, which must be based on their specific physiological and metabolic patterns, as well as on the response to deviations of their homeostasis. The authors reviewed the protocols of cardiopulmonary bypass utilized during 100 procedures with total circulatory arrest and discuss some mechanisms by which the blood components may be damaged or injured during perfusion. Mechanical injury of solid blood components and plasma proteins are discussed; the activation of certain plasmatic systems as the coagulation, fibrinolytic and complement by the Hageman factor, which can produce a generalized inflammatory reaction is also identified; deviations of acid-base balance by excessive lactic acid production may impair enzymatic and cellular functions which can cause injury of a metabolic nature. Thermal injury may also be produced by overheating blood during rewarming if the dynamic nature of heat exchangers function is not adequately monitored. The conclusion is that neonatal perfusion represents a continuing exercise of attention to detail and must be performed with a profound respect to their specific physiology, metabolism and response to injury.
extracorporeal circulation