The influence of heparin and isoprenaline on the changes produced by pulmonary embolism

The haemodynamic and respiratory changes occurring acutely after pulmonary embolism induced in dogs were documented, and the effect of heparin and isoprenaline on the emboli and on the changes induced were also studied. Heparin led to a greater reduction in embolus weight compared to control animals, but in the short time interval of this study it did not lead to improvement, in the respiratory or haemodynamic parameters. Isoprenaline led to increased pulmonary artery flow and a reversal of changes in lung compliance. It is concluded that both these agents should be instituted as soon as possible following pulmonary embolism.