[Liquid shifts in the lung under fenoterol and verapamil. Experimental study on the origin of pulmonary oedema under tocolysis. III (author's transl)].

The question of the causal relationship between tocolysis and pulmonary edema has been unresolved up till now. Eight mongrel dogs were given infusions of Fenoterol (0.06 mcg/kg/min) and later of Fenoterol (0.06 mcg/kg/min) and Verapamil (2 mcg/kg/min). In the case of infusion of Fenoterol alone measurements by the thermo-dye-technique showed massive shifts of lung fluids from the intravascular to the extravascular space corresponding to interstitial edema. The addition of Verapamil induced no further changes. The intrapulmonary haemodynamical overload by increased cardiac output and pulmonary arterial pressure which we measured after infusion of Fenoterol must be regarded as the main cause of the shifts in fluid volumes. They seem to be amplyfied by central nervous-, metabolic- and localized toxical effects of the betamimetic drug. A direct cardiac cause as well as serious changes in electrolytes and colloidosmotic pressure could be excluded.