[Fatal hypoxemia following extracorporeal circulation for aortocoronary bypass. A case]

A lethal case of acute respiratory distress syndrome of the adult following extracorporeal circulation for aorto-coronary bypass is reported. This case illustrates the two mechanisms currently thought to be responsible for this pathology: (1) the passage of blood over the synthetic fibres of the cardiopulmonary bypass machine activates the complement, and the systemic inflammatory reaction that ensues accounts for the increased permeability of the alveolar capillary membrane; (2) the haemodilution inherent in extracorporeal circulation explains the hypoproteinaemia usually observed at the end of the procedure; the resulting fall in capillary osmotic pressure upsets the equilibrium of pressures in the capillary vessels.