Hematological changes in long-term perfusion.

Abstract

Hematological changes were measured in 14 dogs during partial heart-lung bypass procedures of 10 hr duration with an extracorporeal flow approximating 40% of the cardiac output. The changes occurring during the 1st hr of perfusion were identical to those previously reported for short periods of total heart-lung bypass, namely, thrombocytopenia and leukopenia. Later on, however, compensatory mechanisms were manifested by the appearance of a leukocytosis with a shift to the left, a leveling off of thrombocyte counts, and the appearance of nucleated red cells in the peripheral blood. Bone marrow studies revealed stimulation of myeloid tissues. These compensatory responses observed during perfusion were similar to changes which have been described as typical of the postperfusion period after shorter durations of extracorporeal circulation. The trauma inflicted on erythrocytes during extracorporeal blood handling became evident after perfusion as a marked anemia and an increased mechanical fragility of the red cells. Submitted on September 22, 1961