A LTHOUGH the meaning of the term "shock" is controversial,1 there is general agreement that the cardinal manifestation of both experimental and clinical shock states is a deficiency of blood flow.2-5 The lowered systemic arterial pressure observed clinically often is treated with vasopressor drugs, but their use has been discouraged 6 because of concern that a further reduction in systemic blood flow might result. A variety of therapeutic agents has been recommended to increase blood flow in shock, including vasodilators,7 ganglionic block agents,8 adrenergic blocking agents,9 isoproterenol10 and corticosteroids.11
Dextran has been widely used in the emergency treatment of shock associated with blood loss,12 but it has not been routinely employed in hypotensive patients without a history or signs of blood volume depletion. The ten patients studied in the present report became acutely hypotensive without obvious blood loss. Right atrial pressures were not significantly elevated, indicating the absence of overt right