Mechanism of the lack of a beneficial response to inotropic drugs in hemorrhagic shock

Abstract

Lanatoside C, glucagon, and isoproterenol, three inotropic agents were found to be ineffective in prolonging survival or in improving the over‐all circulatory status of dogs in hemorrhagic shock, despite their temporary effectiveness as inotropic agents. Lanatoside C constricted the splanchnic circulation leading to lysosomal disruption, release of cathepsin D, and production of a myocardial depressant factor (MDF). Glucagon dilated the splanchnic circulation only transiently but directly disrupted splanchnic lysosomes and thus MDF was produced. Isoproterenol dilated the peripheral vasculature to such an extent that circulatory collapse ensued. Other inotropic agents may be of value in the treatment of postoligemic shock, but potentially deleterious side effects must be considered when they are administered in circulatory shock.