PLASMA-TRANSAMINASE LEVELS IN CARDIAC SURGERY WITH EXTRACORPOREAL CIRCULATION

The biochemical consequences of cardiopulmonary bypass surgery in children

The changes in serum enzyme activities after successful and uncomplicated cardiopulmonary bypass (CPB) surgery in children are described. After maximum serum enzyme activities were attained, they thereafter declined steadily without any secondary peaks of activity, to be at or near normal activities by the seventh day after surgery. The possible sources and mechanisms of enzyme leakage from tissues after CPB are discussed. The concentration of some physiologically important constituents were determined in pump prime fluids and in the common circulation on bypass. The consequences of haemodilution on small children were undesirably reduced concentrations of magnesium, calcium and albumin, and this state persisted for some days after the end of bypass. Some possible implications of such unphysiological pump primes are discussed. We suggest that ASp AT, Ala AT, CK-MB, magnesium, calcium and urea should be routinely monitored for the first four days after surgery.

Serum enzyme changes after major lung surgery--with and without halothane

The postoperative changes in serum aspartate aminotransferase (SGOT), serum alanine aminotransferase (SGPT), and lactate dehydrogenase (LDH) levels after major lung operations were studied in patients some of whom received halothane and some of whom did not. There were no differences between the two groups of cases. It seemed possible that the rises in SGOT and LDH which occurred quite frequently were an indication that tissue autolysis was occurring in the body.

Changes in serum enzyme levels accompanying cardiac surgery with extracorporeal circulation

Serum lactic dehydrogenase, alpha-hydroxy-butyrate dehydrogenase, iso-citric dehydrogenase, and glutamic oxaloacetic transaminase activities were measured daily for two weeks postoperatively in the serum of 22 patients undergoing cardiac surgery with extracorporeal circulation.The length of perfusion was found to be a major factor affecting the extent of increased post-operative enzyme activities. Significantly higher levels were demonstrated in patients perfused for over one hour compared with those perfused for under one hour. Hepatocellular damage, age, and type of operation were not considered to be major factors in determining the extent of this increased activity.A considerable increase in enzyme activity was found to occur during perfusion when the dilution introduced by mixing the patient's circulation with the priming fluid of the heart-lung machine was taken into account. This dilution, when accounted for, increased the observed enzyme activity by 30 to 50%.