The Annals of Thoracic Surgery, Vol 57, 956-959, Copyright © 1994 by The Society of Thoracic Surgeons
ATP reduces blood loss produced by heparin in cardiopulmonary bypass operations
HV Garcia Jr, E Buffolo, HB Nader and CP Dietrich
Disciplina de Cirurgia Cardiovascular, Escola Paulista de Medicina, Sao Paulo, Brazil.
It was previously shown that topical application of heparin produces
enhanced bleeding from small vessels and capillaries. Adenosine
triphosphate at low concentrations is able to dislodge heparin bound to a
receptor, counteracting its antihemostatic activity. These results led us
to measure the amounts of heparin remaining in the blood after protamine
neutralization of the patients subjected to cardiopulmonary bypass
operation and to test the topical application of the nucleotide. Adenosine
triphosphate at a concentration of 10(-4) mol/L significantly reduces the
blood volume (p < 0.005) oozed from the thoracic cavity of the patients
(mean, 288 +/- 188 mL) when compared with controls (mean, 564 +/- 288 mL).
Adenosine triphosphate at 5 x 10(-5) mol/L reduces the blood loss to a mean
of 370 +/- 155 mL in the patients tested (p < 0.08). About 10% of
heparin of low molecular weight (< or = 6.0 Kda), which is also found in
the oozed blood, is not neutralized by protamine. We suggest that the
excessive blood loss of the patients is probably produced by low molecular
weight heparins in the commercial preparations that are not neutralized by
protamine.
