Blood pressure effects of thyrotropin-releasing hormone and epinephrine in anaphylactic shock

To compare the effects of a single dose of thyrotropin-releasing hormone (TRH), epinephrine, and control (normal saline) on mean arterial pressure (MAP) and survival over a one-hour observation period, we carried out a randomized, blinded study using a rabbit model of anaphylaxis. Epinephrine resulted in an increased MAP over normal saline and TRH at one minute after treatment (P less than .001). TRH resulted in an increased MAP over normal saline at two minutes (P less than .017) and over epinephrine at four minutes (P less than .011) after treatment. No differences in MAP were detected beyond four minutes after treatment. There was no difference in survival between treated and control animals (alpha less than .168). Although no difference in survival existed, TRH had a slower onset, but more sustained effect on MAP than did epinephrine and normal saline.