[Experimental studies on amniotic fluid embolism].
The circulatory state of the so-called experimental amniotic fluid embolism (AFE) was studied in 39 dogs. The repeated infusion of a large quantity of human amniotic fluid had not produced the symptoms of AFE. But the infusion of human meconium-stained amniotic fluid, meconium suspension, its supernatant or boiled meconium suspension, or canine bile had produced the various typical shock symptoms of AFE. In these cases the shock effects were especially strong in the infusion of meconium suspension and the meconium-stained amniotic fluid. In these shock symptoms, arterial pressure decreased quickly after the infusion. When sudden death was fortunately avoided, right ventricular pressure increased and increases in pulmonary arterial pressure and pulmonary vascular resistance were indicated. In most cases cardiac output decreased. Central venous pressure increased suddenly before death. These experiments suggested that the pulmonary vasoconstriction was produced by the chemical factors in the amniotic fluid and by vasoactive substances released from the embolized lung. It also seemed that this pulmonary vasoconstriction rather than mechanical obstruction of pulmonary arterioles was probably the major cause of the shock symptoms of AFE.
D000818:Animals; D001794:Blood Pressure; D002496:Central Venous Pressure; D004285:Dogs; D004619:Embolism, Amniotic Fluid / Q000150:complications / Q000503:physiopathology*; D005260:Female; D011247:Pregnancy; D011651:Pulmonary Artery / Q000503:physiopathology; D012769:Shock / Q000209:etiology; D014655:Vascular Resistance; D014661:Vasoconstriction