Hemodynamic changes following corticosteroid and naloxone infusion in dogs subjected to hypovolemic shock without resuscitation

B-endorphin, which is released concomitantly with ACTH from the pituitary during stress, may also alter cardiac performance in hemorrhagic shock. In this study of 36 dogs subjected to hemorrhagic shock without resuscitation, we demonstrate the interaction of high doses of dexamethasone (DEX) or methylprednisolone (M) and opiate receptor blockade with naloxone (NAL). NAL, when given alone, resulted in the most hemodynamic improvement and the longest survival time while those animals receiving DEX or M, even in combination with NAL, did not do as well. These data suggest that corticosteroids block the NAL effect following hemorrhagic shock.