Canadian Journal of Anesthesia, Vol 22, 50-60, Copyright © 1975 by Canadian Anesthesiologists' Society

Use of Aspirin in Haemorrhagic Shock

¹ Departments of Anaesthesia and Haematology, St. Michael's Hospital and University of Toronto, Toronto, Ontario, Canada

Haemorrhagic shock was induced in two similar groups of dogs for two hours. One group received aspirin before shock and the other group served as a control. When blood was retransfused the PVR which was markedly elevated during shock returned to pre-shock value in the aspirin group but was elevated 100 per cent in the control group, despite correction of acidosis. Aspirin reduces collagen-induced platelet aggregation and thereby inhibits the formation of platelet micro-emboli without affecting the coagulation factors. This effect of aspirin is thought to be responsible for the lowering of the elevated PVR to pre-shock values in the aspirin group following retransfusion. Recause of the metabolic acidosis associated with the shock state, concurrent administration of sodium bicarbonate is recommended when retransfusing shocked patients with blood. A clinical trial of aspirin inearly treatment of shocked patients as well as for prophylaxis in high risk situations is justified.